/* 英文参考 Cheers：Inter 正文、Anton 标题、Oswald 辅助标签。 */
@font-face {
  font-family: "Milo Inter";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("../fonts/reference/inter.be270d07ceaf.woff2") format("woff2");
}
@font-face {
  font-family: "Milo Anton";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("../fonts/reference/anton.3fcbc1c015d9.woff2") format("woff2");
}
@font-face {
  font-family: "Milo Oswald";
  font-style: normal;
  font-weight: 200 700;
  font-display: swap;
  src: url("../fonts/reference/oswald.b02999f59aec.woff2") format("woff2");
}
/* 中文字体为 Noto SC 本地子集，授权见 static/fonts/chinese/OFL-*.txt。 */
@font-face {
  font-family: "Milo Sans SC";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("../fonts/chinese/sans-preview.7343f84a0701.woff2") format("woff2");
}
/* 旧字体文件保留作为历史资产，当前仅使用上面的参考字体和中文黑体。 */
/* 美研所前端原型：主题变量与页面结构，独立于业务模板。 */
:root {
  --display: var(--sans);
  --condensed: var(--sans);
  --content-width: 1200px;
  --card-radius: 14px;
  --card-shadow: 0 4px 20px #233a2007;
  --paper: #f5f3ed;
  --surface: #fffdf8;
  --ink: #172d24;
  --muted: #657268;
  --green: #16664f;
  --on-green: #fffdf8;
  --line: #d8ddd3;
  --soft: #e5ebe0;
  --yellow: #e5c785;
  --peach: #eadace;
  --shadow: 0 22px 55px #233a2010;
  --serif: var(--display);
  --sans:
    "Milo Inter", "Milo Sans SC", ui-sans-serif, -apple-system,
    BlinkMacSystemFont, "Segoe UI", sans-serif;
  color-scheme: light;
}
:root[data-theme="dark"] {
  --paper: #17211d;
  --surface: #202d26;
  --ink: #ecede4;
  --muted: #adb9ae;
  --green: #afd3a6;
  --on-green: #17261d;
  --line: #3b4d40;
  --soft: #2c3c30;
  --yellow: #bda265;
  --peach: #775a4b;
  --shadow: 0 22px 55px #0002;
  color-scheme: dark;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 15px/1.8 var(--sans);
  -webkit-font-smoothing: antialiased;
}
button,
input,
select {
  font: inherit;
}
button,
a,
input,
select {
  -webkit-tap-highlight-color: transparent;
}
button,
a {
  touch-action: manipulation;
}
button {
  cursor: pointer;
}
a {
  color: inherit;
  text-decoration: none;
}
button {
  color: inherit;
}
button:disabled {
  cursor: default;
  opacity: 0.65;
}
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--green);
  outline-offset: 5px;
}
::selection {
  background: var(--green);
  color: var(--on-green);
}
img,
svg {
  max-width: 100%;
}
h1,
h2,
h3,
h4,
p {
  margin: 0;
}
h1,
h2,
h3 {
  font-weight: 500;
}
h1,
h2 {
  font-family: var(--serif);
  line-height: 1.3;
  letter-spacing: -0.04em;
}
h1 {
  font-size: clamp(38px, 4.6vw, 66px);
}
h2 {
  font-size: clamp(29px, 3vw, 42px);
}
h3 {
  font-size: 21px;
  line-height: 1.5;
}
p + p {
  margin-top: 16px;
}
small {
  font-size: 12px;
}
.muted {
  color: var(--muted);
}
.serif {
  font-family: var(--serif);
}
.wrap {
  width: min(var(--content-width), calc(100% - 96px));
  margin: auto;
}
.narrow {
  max-width: 760px;
  margin: auto;
}
.section {
  padding: 88px 0;
}
.divider {
  border-top: 1px solid var(--line);
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 24px;
}
.eyebrow:before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
}
.tag {
  display: inline-block;
  font-size: 12px;
  padding: 3px 10px;
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--muted);
}
.tag.free {
  background: var(--soft);
  border-color: transparent;
  color: var(--green);
}
.tag-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  min-height: 48px;
  padding: 10px 23px;
  background: var(--green);
  color: var(--on-green);
  border: 1px solid var(--green);
  border-radius: 5px;
  font-size: 14px;
  line-height: 1.5;
  transition:
    transform 0.18s,
    background 0.18s;
  text-align: center;
}
.btn:hover {
  transform: translateY(-2px);
}
.btn.secondary {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}
.btn.small {
  min-height: 40px;
  padding: 8px 16px;
  font-size: 13px;
}
.btn.block {
  display: flex;
  width: 100%;
}
.text-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid var(--line);
  padding: 4px 0;
  font-size: 14px;
}
.text-link:hover {
  border-color: var(--green);
  color: var(--green);
}
.actions {
  display: flex;
  align-items: center;
  gap: 22px;
  flex-wrap: wrap;
  margin-top: 30px;
}
.icon {
  width: 19px;
  height: 19px;
  flex: none;
  vertical-align: middle;
}
.skip {
  position: fixed;
  top: 10px;
  transform: translateY(-180%);
  opacity: 0;
  pointer-events: none;
  left: 20px;
  z-index: 100;
  background: var(--surface);
  padding: 12px;
}
.skip:focus {
  transform: none;
  opacity: 1;
  pointer-events: auto;
}
.header {
  border-bottom: 1px solid var(--line);
  position: relative;
  z-index: 20;
  background: var(--paper);
}
.header-inner {
  height: 88px;
  display: flex;
  align-items: center;
  gap: 46px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
}
.brand-mark {
  width: 35px;
  height: 37px;
  display: grid;
  place-items: center;
  border: 1.5px solid var(--ink);
  border-radius: 1px 1px 13px 1px;
  font: 23px var(--serif);
  position: relative;
}
.brand-mark:after {
  content: "";
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--green);
  right: 5px;
  top: 5px;
}
.brand strong {
  font-size: 17px;
  letter-spacing: 0.025em;
  font-weight: 600;
}
.brand small {
  display: block;
  font-size: 9px;
  line-height: 1.3;
  letter-spacing: 0.12em;
  color: var(--muted);
}
.nav {
  display: flex;
  gap: 27px;
  align-items: center;
  font-size: 14px;
}
.nav a {
  padding: 10px 0;
  position: relative;
}
.nav a[aria-current="page"]:after {
  content: "";
  height: 2px;
  background: var(--green);
  position: absolute;
  bottom: 1px;
  left: 0;
  right: 0;
}
.nav a:hover {
  color: var(--green);
}
.header-tools {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 16px;
}
.plain {
  border: 0;
  background: none;
  padding: 8px;
  font-size: 13px;
}
.language {
  white-space: nowrap;
}
.language span {
  opacity: 0.4;
  padding: 0 4px;
}
.theme-picker {
  position: relative;
}
.theme-picker > summary {
  display: flex;
  list-style: none;
  cursor: pointer;
  padding: 8px;
}
.theme-picker > summary::-webkit-details-marker {
  display: none;
}
.theme-menu {
  position: absolute;
  top: 43px;
  right: 0;
  width: 174px;
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 6px;
  border-radius: 7px;
  box-shadow: var(--shadow);
  z-index: 30;
}
.theme-menu button {
  display: flex;
  gap: 10px;
  width: 100%;
  border: 0;
  background: none;
  text-align: left;
  padding: 9px 11px;
  border-radius: 3px;
}
.theme-menu button[aria-pressed="true"],
.theme-menu button:hover {
  background: var(--soft);
}
.menu-toggle {
  display: none;
}
.mobile-nav {
  display: none;
}
.hero {
  display: grid;
  grid-template-columns: 1.12fr 1fr;
  gap: 72px;
  align-items: center;
  padding: 83px 0 70px;
}
.hero-copy > p {
  color: var(--muted);
  font-size: 16px;
  max-width: 470px;
  margin-top: 24px;
  line-height: 1.95;
}
.hero .hero-note {
  font-size: 12px;
  margin-top: 20px;
}
.hero h1 {
  line-height: 1.38;
}
.hero-art {
  position: relative;
  min-height: 435px;
  padding: 30px 22px 25px;
  display: flex;
  align-items: center;
}
.art-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 30px 30px;
  opacity: 0.38;
  mask-image: radial-gradient(ellipse, #000 30%, transparent 72%);
}
.research-sheet {
  width: 100%;
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 30px 31px 27px;
  border-radius: 4px;
  transform: rotate(-3deg);
}
.research-sheet:before {
  content: "";
  position: absolute;
  width: 66px;
  height: 24px;
  background: var(--yellow);
  opacity: 0.8;
  top: -10px;
  left: 40%;
  transform: rotate(5deg);
}
.sheet-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--line);
  padding-bottom: 15px;
  font-size: 11px;
  color: var(--muted);
}
.research-sheet h3 {
  font-family: var(--serif);
  font-size: 29px;
  line-height: 1.5;
  margin: 21px 0 6px;
}
.sheet-sub {
  font-size: 12px;
  color: var(--muted);
}
.question-row {
  display: flex;
  gap: 13px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
  align-items: center;
  font-size: 13px;
}
.question-row .num {
  font-family: var(--serif);
  font-size: 22px;
  color: var(--green);
}
.question-row span:last-child {
  margin-left: auto;
  color: var(--muted);
  font-size: 11px;
}
.sheet-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 19px;
  color: var(--green);
  font-size: 12px;
}
.circle-arrow {
  width: 35px;
  height: 35px;
  border: 1px solid var(--line);
  border-radius: 50%;
  display: grid;
  place-items: center;
}
.annotation {
  position: absolute;
  bottom: 4px;
  right: 0;
  background: var(--green);
  color: var(--on-green);
  font-family: var(--serif);
  font-size: 18px;
  padding: 14px 24px;
  transform: rotate(3deg);
  border-radius: 2px;
}
.under-hero {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 24px 0;
  gap: 25px;
}
.under-hero > div {
  display: flex;
  align-items: center;
  gap: 15px;
  font-size: 13px;
}
.under-hero svg {
  color: var(--green);
}
.under-hero small {
  display: block;
  color: var(--muted);
}
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 25px;
  margin-bottom: 36px;
}
.section-head p {
  color: var(--muted);
  margin-top: 12px;
  font-size: 14px;
}
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 27px;
}
.course-card {
  min-width: 0;
}
.course-art {
  height: 242px;
  position: relative;
  overflow: hidden;
  background: var(--soft);
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
}
.course-art.ochre {
  background: var(--yellow);
  color: #253729;
}
.course-art.rose {
  background: var(--peach);
  color: var(--ink);
}
.book {
  width: 148px;
  height: 184px;
  background: #275941;
  color: #f6f1df;
  transform: rotate(-9deg);
  border-radius: 2px 6px 6px 2px;
  padding: 19px 17px 20px 27px;
  box-shadow: 10px 13px 0 #0000000a;
  border-left: 5px solid #143f2d;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.3s;
}
.book:after {
  content: "";
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  border-left: 1px solid #ffffff20;
}
.book strong {
  font: 26px/1.25 var(--serif);
}
.book small {
  font-size: 9px;
}
.course-card:hover .book {
  transform: rotate(-4deg) translateY(-5px);
}
.book-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  width: 130px;
  transform: rotate(9deg);
}
.book-grid span {
  height: 62px;
  border: 1px solid currentColor;
  display: grid;
  place-items: center;
  font: 24px var(--serif);
  background: #fff6;
  border-radius: 3px;
}
.rings {
  position: relative;
  width: 170px;
  height: 170px;
  border: 1px solid currentColor;
  border-radius: 50%;
}
.rings:before,
.rings:after {
  content: "";
  position: absolute;
  inset: 22px;
  border: 1px solid currentColor;
  border-radius: 50%;
}
.rings:after {
  inset: 48px;
}
.rings span {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font: 32px var(--serif);
}
.art-corner {
  position: absolute;
  left: 18px;
  top: 16px;
  font-size: 11px;
  opacity: 0.7;
}
.art-foot {
  position: absolute;
  bottom: 15px;
  right: 18px;
  font-size: 10px;
  opacity: 0.7;
}
.course-card h3 {
  margin: 11px 0 9px;
  font-size: 20px;
}
.course-card p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.9;
}
.card-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 21px;
  padding-top: 15px;
  border-top: 1px solid var(--line);
  font-size: 12px;
}
.feature-band {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  background: var(--green);
  color: var(--on-green);
  border-radius: 6px;
  margin-top: 12px;
  overflow: hidden;
}
.feature-copy {
  padding: 53px 45px;
}
.feature-copy p {
  opacity: 0.8;
  margin-top: 20px;
  font-size: 14px;
  max-width: 380px;
}
.feature-copy .text-link {
  border-color: currentColor;
  margin-top: 25px;
}
.feature-steps {
  padding: 34px 42px;
  border-left: 1px solid #ffffff25;
}
.step {
  display: flex;
  align-items: start;
  gap: 24px;
  padding: 20px 0;
}
.step + .step {
  border-top: 1px solid #ffffff25;
}
.step b {
  font: 29px var(--serif);
  opacity: 0.55;
}
.step h3 {
  font-size: 17px;
}
.step p {
  font-size: 12px;
  opacity: 0.75;
  margin-top: 5px;
}
.notes-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 55px;
}
.note-feature {
  background: var(--soft);
  padding: 35px;
  min-height: 330px;
  display: flex;
  flex-direction: column;
  align-items: start;
  border-radius: 5px;
}
.note-feature h3 {
  font-family: var(--serif);
  font-size: 29px;
  margin: 22px 0 15px;
}
.note-feature > p {
  font-size: 14px;
  color: var(--muted);
}
.note-feature .note-meta {
  margin-top: auto;
  padding-top: 28px;
}
.note-meta {
  font-size: 12px;
  color: var(--muted);
  display: flex;
  gap: 18px;
  align-items: center;
}
.note-list article {
  padding: 23px 0;
  border-bottom: 1px solid var(--line);
}
.note-list article:first-child {
  padding-top: 0;
}
.note-list h3 {
  font-size: 18px;
  margin: 10px 0;
}
.note-list p {
  font-size: 13px;
  color: var(--muted);
}
.about-strip {
  display: grid;
  grid-template-columns: 150px 1fr auto;
  gap: 35px;
  align-items: center;
  padding: 48px 0;
  border-top: 1px solid var(--line);
}
.milo-seal {
  width: 120px;
  height: 120px;
  border: 1px solid var(--green);
  border-radius: 50%;
  display: grid;
  place-items: center;
  position: relative;
  color: var(--green);
}
.milo-seal:before {
  content: "";
  position: absolute;
  inset: 7px;
  border: 1px solid var(--line);
  border-radius: 50%;
}
.milo-seal strong {
  font: 42px var(--serif);
  font-weight: 400;
}
.about-strip p {
  max-width: 570px;
  color: var(--muted);
  font-size: 14px;
  margin-top: 13px;
}
.footer {
  border-top: 1px solid var(--line);
  padding: 48px 0 58px;
  margin-top: 40px;
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 35px;
}
.footer-top p {
  color: var(--muted);
  font-size: 12px;
  margin-top: 12px;
}
.footer-nav {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  font-size: 13px;
}
.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-top: 35px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  color: var(--muted);
  font-size: 11px;
}
.preview-label {
  display: flex;
  align-items: center;
  gap: 8px;
}
.preview-label:before {
  content: "";
  width: 5px;
  height: 5px;
  background: var(--green);
  border-radius: 50%;
}
.page-head {
  padding: 65px 0 42px;
}
.page-head p {
  color: var(--muted);
  max-width: 620px;
  margin-top: 20px;
}
.breadcrumbs {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 28px;
}
.breadcrumbs a:hover {
  color: var(--green);
}
.tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 25px 0 35px;
}
.tabs button {
  border: 1px solid var(--line);
  background: transparent;
  border-radius: 30px;
  padding: 8px 20px;
  font-size: 13px;
}
.tabs button[aria-pressed="true"] {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.notice {
  padding: 13px 17px;
  background: var(--soft);
  border-left: 2px solid var(--green);
  font-size: 12px;
  color: var(--muted);
  margin: 24px 0;
  line-height: 1.8;
}
.course-detail {
  display: grid;
  grid-template-columns: 1.45fr 0.8fr;
  gap: 80px;
  align-items: start;
}
.course-detail h1 {
  font-size: 48px;
}
.course-detail > div > p {
  margin-top: 25px;
  color: var(--muted);
}
.detail-aside {
  position: sticky;
  top: 25px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 22px;
}
.detail-aside .course-art {
  height: 230px;
  margin-bottom: 20px;
}
.detail-aside p {
  font-size: 13px;
  color: var(--muted);
  margin: 16px 0;
}
.content-section {
  margin-top: 45px;
}
.content-section h2 {
  font-size: 27px;
  margin-bottom: 20px;
}
.outcomes {
  list-style: none;
  margin: 0;
  padding: 0;
}
.outcomes li {
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
  display: flex;
  gap: 14px;
  font-size: 14px;
}
.outcomes .icon {
  color: var(--green);
  margin-top: 3px;
}
.lesson-row {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}
.lesson-row span:first-child {
  font: 22px var(--serif);
  color: var(--muted);
}
.lesson-row .tag {
  margin-left: auto;
  white-space: nowrap;
}
.lesson-row:hover {
  color: var(--green);
}
.faq {
  max-width: 760px;
  margin: 50px auto;
}
.faq > h2 {
  margin-bottom: 22px;
}
.faq details {
  border-bottom: 1px solid var(--line);
  padding: 19px 0;
}
.faq summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 15px;
}
.faq summary:after {
  content: "+";
  font-size: 20px;
  color: var(--muted);
}
.faq details[open] summary:after {
  content: "−";
}
.faq p {
  color: var(--muted);
  font-size: 14px;
  margin-top: 16px;
}
.lesson-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 50px;
  padding: 45px 0;
}
.lesson-sidebar {
  position: sticky;
  top: 25px;
  align-self: start;
}
.lesson-sidebar h3 {
  font-size: 17px;
  margin: 17px 0 25px;
}
.lesson-sidebar a {
  display: flex;
  gap: 12px;
  padding: 15px 12px;
  font-size: 12px;
  border-radius: 4px;
  margin: 4px 0;
}
.lesson-sidebar a.active {
  background: var(--soft);
  color: var(--green);
}
.lesson-main h1 {
  font-size: 36px;
}
.lesson-main > p {
  color: var(--muted);
  margin: 17px 0 25px;
}
.lesson-media {
  min-height: 300px;
  background: var(--soft);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  text-align: center;
  padding: 35px;
  border-radius: 5px;
  position: relative;
  gap: 17px;
}
.lesson-media h2 {
  font-size: 32px;
}
.lesson-media small {
  position: absolute;
  bottom: 16px;
  left: 20px;
  color: var(--muted);
}
.play-button {
  display: grid;
  place-items: center;
  width: 62px;
  height: 62px;
  border-radius: 50%;
  background: var(--green);
  border: 0;
  color: var(--on-green);
}
.lesson-body {
  margin-top: 36px;
}
.lesson-body h2 {
  font-size: 26px;
  margin: 30px 0 15px;
}
.lesson-body p {
  font-size: 15px;
  color: var(--muted);
}
.exercise {
  padding: 27px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 5px;
  margin: 25px 0;
}
.exercise blockquote {
  font-family: var(--serif);
  font-size: 23px;
  margin: 18px 0 23px;
}
.choice {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px 16px;
  border: 1px solid var(--line);
  background: transparent;
  border-radius: 4px;
  margin-top: 9px;
  font-size: 14px;
}
.choice:hover,
.choice[aria-pressed="true"] {
  border-color: var(--green);
  background: var(--soft);
}
.feedback {
  padding: 18px;
  background: var(--soft);
  margin-top: 20px;
  font-size: 14px;
}
.article-head {
  max-width: 820px;
  padding: 65px 0 32px;
  margin: auto;
}
.article-head h1 {
  font-size: 48px;
  margin: 25px 0;
}
.article-layout {
  display: grid;
  grid-template-columns: 160px 1fr 120px;
  gap: 40px;
  margin-bottom: 60px;
}
.article-body {
  font-size: 16px;
  line-height: 2.1;
}
.article-body p {
  margin: 20px 0;
  color: var(--muted);
}
.article-body h2 {
  font-size: 28px;
  margin: 38px 0 18px;
}
.article-body blockquote {
  margin: 35px 0;
  padding: 15px 25px;
  border-left: 2px solid var(--green);
  font: 27px/1.6 var(--serif);
  background: var(--soft);
}
.article-toc {
  position: sticky;
  top: 25px;
  align-self: start;
  font-size: 12px;
  color: var(--muted);
  padding-top: 22px;
}
.article-toc a {
  display: block;
  margin: 12px 0;
}
.article-actions {
  padding-top: 22px;
}
.tool-hero {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 70px;
  padding: 75px 0;
  align-items: center;
}
.tool-hero p {
  color: var(--muted);
  margin-top: 24px;
}
.tool-art {
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  padding: 28px;
}
.tool-art h3 {
  font-family: var(--serif);
  font-size: 30px;
  margin: 20px 0;
}
.tool-tree {
  border-left: 1px solid var(--line);
  margin: 20px 0 0 10px;
}
.tool-tree div {
  padding: 13px 0 13px 23px;
  font-size: 14px;
  position: relative;
}
.tool-tree div:before {
  content: "";
  width: 13px;
  border-top: 1px solid var(--line);
  position: absolute;
  left: 0;
  top: 27px;
}
.tool-tree small {
  display: block;
  color: var(--muted);
}
.info-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}
.info-columns h3 {
  margin-bottom: 15px;
  font-size: 19px;
}
.info-columns p {
  color: var(--muted);
  font-size: 14px;
}
.about-hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
  padding: 75px 0;
}
.about-hero p {
  color: var(--muted);
  margin-top: 24px;
}
.letter {
  padding: 45px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px;
  transform: rotate(2deg);
  box-shadow: var(--shadow);
}
.letter p {
  color: var(--ink);
  font: 21px/1.9 var(--serif);
  margin-top: 22px;
}
.letter-sign {
  text-align: right;
  margin-top: 25px;
  font: 32px var(--serif);
  color: var(--green);
}
.social-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0 35px;
}
.social-list > div {
  padding: 19px 0;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 16px;
}
.social-list small {
  color: var(--muted);
}
.pricing-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 35px;
  max-width: 920px;
  margin: 10px auto 50px;
}
.price-card {
  border: 1px solid var(--line);
  padding: 36px;
  background: var(--surface);
  border-radius: 6px;
}
.price-card.featured {
  border: 1px solid var(--green);
  position: relative;
}
.price-card h2 {
  font-size: 29px;
}
.price-card > p {
  color: var(--muted);
  font-size: 14px;
  margin: 15px 0;
}
.price {
  font-family: var(--serif);
  font-size: 38px;
  margin: 26px 0 20px;
}
.price small {
  font: 13px var(--sans);
  color: var(--muted);
}
.price-card ul {
  list-style: none;
  padding: 0;
  margin: 25px 0;
}
.price-card li {
  display: flex;
  gap: 13px;
  font-size: 14px;
  padding: 8px 0;
}
.price-card li svg {
  color: var(--green);
  margin-top: 3px;
}
.auth-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  max-width: 950px;
  margin: 65px auto;
  gap: 90px;
  align-items: center;
}
.auth-story h2 {
  font-size: 42px;
}
.auth-story p {
  margin-top: 25px;
  color: var(--muted);
}
.form-card {
  padding: 33px;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 6px;
}
.form-card h1 {
  font: 29px var(--serif);
  margin-bottom: 8px;
}
.field {
  margin: 21px 0;
}
.field label {
  display: block;
  font-size: 13px;
  margin-bottom: 8px;
}
.field input,
.field select {
  width: 100%;
  padding: 12px 13px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--ink);
  min-height: 47px;
}
.field small {
  display: block;
  color: var(--muted);
  margin-top: 7px;
}
.form-error {
  color: var(--ink);
  background: var(--soft);
  border-left: 3px solid var(--green);
  padding: 12px;
  font-size: 13px;
  margin: 15px 0;
}
.form-foot {
  font-size: 13px;
  text-align: center;
  margin-top: 22px;
  color: var(--muted);
}
.account-layout {
  display: grid;
  grid-template-columns: 190px 1fr;
  gap: 65px;
  padding: 55px 0;
}
.account-nav a {
  display: flex;
  gap: 12px;
  padding: 11px 14px;
  border-radius: 4px;
  font-size: 13px;
  margin: 5px 0;
}
.account-nav a.active {
  background: var(--soft);
}
.account-nav .brand {
  margin-bottom: 30px;
}
.account-main h1 {
  font-size: 38px;
}
.account-main > p {
  margin-top: 13px;
  color: var(--muted);
}
.continue-card {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 25px;
  border-radius: 6px;
  margin: 30px 0;
}
.continue-card .course-art {
  height: 170px;
  margin: 0;
}
.continue-card .book {
  transform: rotate(-7deg) scale(0.7);
}
.continue-card h3 {
  margin: 12px 0;
}
.progress {
  height: 4px;
  background: var(--line);
  border-radius: 2px;
  margin: 18px 0 9px;
  overflow: hidden;
}
.progress span {
  display: block;
  height: 100%;
  background: var(--green);
}
.account-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 25px;
}
.panel {
  border: 1px solid var(--line);
  padding: 25px;
  border-radius: var(--card-radius);
  background: var(--surface);
}
.panel h3 {
  font-size: 18px;
  margin-bottom: 14px;
}
.panel p {
  font-size: 13px;
  color: var(--muted);
}
.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}
.setting-row p {
  font-size: 13px;
  color: var(--muted);
  margin-top: 5px;
}
.setting-row select {
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface);
  color: var(--ink);
  max-width: 190px;
}
.switch {
  border: 0;
  background: var(--line);
  border-radius: 30px;
  width: 47px;
  height: 27px;
  padding: 3px;
  display: flex;
  flex: none;
}
.switch:before {
  content: "";
  width: 21px;
  height: 21px;
  background: var(--surface);
  border-radius: 50%;
  transition: transform 0.2s;
}
.switch[aria-checked="true"] {
  background: var(--green);
}
.switch[aria-checked="true"]:before {
  transform: translateX(20px);
}
.status-panel {
  max-width: 650px;
  margin: 65px auto;
  text-align: center;
  padding: 40px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 7px;
}
.status-symbol {
  width: 66px;
  height: 66px;
  background: var(--soft);
  border-radius: 50%;
  margin: 0 auto 25px;
  display: grid;
  place-items: center;
  color: var(--green);
}
.status-symbol svg {
  width: 30px;
  height: 30px;
}
.status-panel h1 {
  font-size: 35px;
}
.status-panel p {
  margin-top: 22px;
  color: var(--muted);
}
.status-panel .actions {
  justify-content: center;
}
.status-controls {
  margin: 0 auto 35px;
  max-width: 650px;
  text-align: center;
}
.status-controls label {
  font-size: 12px;
  color: var(--muted);
  margin-right: 12px;
}
.status-controls select {
  padding: 7px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 3px;
  color: var(--ink);
}
.empty {
  padding: 35px 0;
  text-align: center;
  color: var(--muted);
}
.legal h2 {
  font-size: 25px;
  margin: 35px 0 15px;
}
.legal p {
  color: var(--muted);
}
.legal {
  max-width: 740px;
  margin: 60px auto;
}
.legal h1 {
  font-size: 42px;
}
.legal .eyebrow {
  margin-top: 20px;
}
#toast {
  position: fixed;
  bottom: 25px;
  left: 50%;
  transform: translate(-50%, 20px);
  background: var(--ink);
  color: var(--paper);
  padding: 12px 22px;
  border-radius: 5px;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 0.2s,
    transform 0.2s;
  max-width: calc(100vw - 30px);
  z-index: 100;
}
#toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}
.checkline {
  display: flex;
  align-items: start;
  gap: 10px;
  font-size: 12px;
  color: var(--muted);
  margin: 20px 0;
}
.checkline input {
  margin-top: 5px;
  accent-color: var(--green);
}
.session-chip {
  font-size: 11px;
  background: var(--soft);
  color: var(--green);
  padding: 5px 9px;
  border-radius: 4px;
}
.lesson-end {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  padding-top: 25px;
  margin-top: 35px;
  border-top: 1px solid var(--line);
}
@media (min-width: 1450px) {
  .hero {
    padding: 100px 0 85px;
    gap: 100px;
  }
  .hero-art {
    min-height: 455px;
  }
}
@media (max-width: 1100px) {
  .wrap {
    width: calc(100% - 60px);
  }
  .header-inner {
    gap: 28px;
  }
  .nav {
    gap: 20px;
  }
  .header-tools {
    gap: 8px;
  }
  .hero {
    gap: 35px;
  }
  .hero h1 {
    font-size: 48px;
  }
  .hero-art {
    padding: 24px 10px;
  }
  .research-sheet {
    padding: 25px 23px;
  }
  .course-detail {
    gap: 40px;
  }
  .article-layout {
    grid-template-columns: 140px 1fr;
  }
  .article-actions {
    grid-column: 2;
  }
  .auth-layout {
    gap: 40px;
  }
  .account-layout {
    gap: 35px;
  }
  .feature-copy {
    padding: 40px 30px;
  }
  .feature-steps {
    padding: 25px;
  }
  .about-hero {
    gap: 40px;
  }
  .nav a {
    font-size: 13px;
  }
}
@media (max-width: 850px) {
  .nav,
  .header-tools > .login-link {
    display: none;
  }
  .menu-toggle {
    display: block;
  }
  .header-inner {
    height: 74px;
  }
  .header-tools {
    gap: 10px;
  }
  .mobile-nav.open {
    display: grid;
    grid-template-columns: 1fr 1fr;
    padding: 15px 0 25px;
    gap: 10px;
  }
  .mobile-nav a {
    padding: 10px 12px;
    font-size: 14px;
    border-bottom: 1px solid var(--line);
  }
  .hero {
    gap: 15px;
    padding: 55px 0;
  }
  .hero h1 {
    font-size: 42px;
  }
  .hero-copy > p {
    font-size: 14px;
  }
  .hero-art {
    min-height: 390px;
  }
  .research-sheet h3 {
    font-size: 23px;
  }
  .question-row {
    font-size: 11px;
    gap: 8px;
  }
  .question-row span:last-child {
    display: none;
  }
  .annotation {
    font-size: 15px;
  }
  .under-hero {
    gap: 15px;
  }
  .under-hero > div {
    font-size: 12px;
    gap: 9px;
  }
  .course-grid {
    gap: 18px;
  }
  .course-art {
    height: 205px;
  }
  .course-card h3 {
    font-size: 18px;
  }
  .feature-band {
    grid-template-columns: 1fr 1fr;
  }
  .notes-grid {
    gap: 30px;
  }
  .about-strip {
    grid-template-columns: 110px 1fr;
    gap: 20px;
  }
  .about-strip > .text-link {
    grid-column: 2;
    justify-self: start;
  }
  .milo-seal {
    width: 100px;
    height: 100px;
  }
  .course-detail {
    grid-template-columns: 1fr 300px;
    gap: 30px;
  }
  .course-detail h1 {
    font-size: 37px;
  }
  .lesson-layout {
    grid-template-columns: 180px 1fr;
    gap: 25px;
  }
  .tool-hero {
    gap: 35px;
  }
  .account-layout {
    grid-template-columns: 150px 1fr;
    gap: 25px;
  }
  .continue-card {
    grid-template-columns: 110px 1fr;
    gap: 20px;
  }
  .account-grid {
    grid-template-columns: 1fr;
  }
  .auth-layout {
    gap: 35px;
  }
  .auth-story h2 {
    font-size: 35px;
  }
  .header .brand small {
    display: none;
  }
  .pricing-layout {
    gap: 20px;
  }
}
@media (max-width: 620px) {
  .wrap {
    width: calc(100% - 40px);
  }
  .section {
    padding: 55px 0;
  }
  .brand strong {
    font-size: 15px;
  }
  .brand-mark {
    width: 30px;
    height: 32px;
    font-size: 21px;
  }
  .header-tools {
    gap: 4px;
  }
  .header-inner {
    gap: 10px;
    height: 72px;
  }
  .language {
    padding: 8px 4px;
    font-size: 12px;
  }
  .hero {
    grid-template-columns: 1fr;
    padding: 45px 0 35px;
    gap: 25px;
  }
  .hero h1 {
    font-size: 43px;
    line-height: 1.4;
    letter-spacing: -0.055em;
  }
  .hero-copy > p {
    font-size: 14px;
    max-width: none;
    margin-top: 20px;
  }
  .hero .eyebrow {
    margin-bottom: 20px;
  }
  .hero .actions {
    gap: 19px;
    margin-top: 24px;
  }
  .hero-art {
    min-height: 390px;
    padding: 22px 19px;
  }
  .research-sheet {
    padding: 25px 26px;
  }
  .research-sheet h3 {
    font-size: 29px;
  }
  .question-row {
    font-size: 12px;
  }
  .question-row span:last-child {
    display: block;
  }
  .annotation {
    right: 5px;
    font-size: 16px;
  }
  .under-hero {
    grid-template-columns: 1fr;
    padding: 8px 0;
    gap: 0;
  }
  .under-hero > div {
    padding: 14px 0;
    font-size: 13px;
  }
  .under-hero > div + div {
    border-top: 1px solid var(--line);
  }
  .under-hero small {
    display: inline;
    margin-left: 10px;
  }
  .section-head {
    align-items: start;
    gap: 20px;
  }
  .section-head h2 {
    font-size: 30px;
  }
  .section-head > .text-link {
    font-size: 12px;
    white-space: nowrap;
    margin-top: 7px;
  }
  .course-grid {
    grid-template-columns: 1fr;
    gap: 35px;
  }
  .course-art {
    height: 255px;
  }
  .course-card h3 {
    font-size: 22px;
  }
  .course-card p {
    font-size: 14px;
  }
  .course-card .card-bottom {
    margin-top: 17px;
  }
  .feature-band {
    grid-template-columns: 1fr;
  }
  .feature-copy {
    padding: 32px 25px;
  }
  .feature-steps {
    border-left: 0;
    border-top: 1px solid #ffffff25;
    padding: 15px 25px;
  }
  .feature-copy h2 {
    font-size: 31px;
  }
  .notes-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .note-feature {
    padding: 27px;
    min-height: 300px;
  }
  .note-feature h3 {
    font-size: 27px;
  }
  .about-strip {
    grid-template-columns: 1fr;
    padding: 35px 0;
    gap: 23px;
  }
  .about-strip > .text-link {
    grid-column: auto;
  }
  .about-strip h2 {
    font-size: 29px;
  }
  .footer {
    padding: 35px 0;
    margin-top: 20px;
  }
  .footer-top,
  .footer-bottom {
    flex-direction: column;
    gap: 23px;
  }
  .footer-nav {
    gap: 16px;
    font-size: 12px;
  }
  .page-head {
    padding: 43px 0 28px;
  }
  .page-head h1 {
    font-size: 38px;
  }
  .page-head p {
    font-size: 14px;
  }
  .tabs {
    gap: 7px;
    margin: 20px 0 28px;
  }
  .tabs button {
    font-size: 12px;
    padding: 7px 14px;
  }
  .course-detail {
    grid-template-columns: 1fr;
    gap: 35px;
  }
  .course-detail h1 {
    font-size: 37px;
  }
  .detail-aside {
    position: static;
    grid-row: 2;
  }
  .content-section {
    margin-top: 35px;
  }
  .lesson-layout {
    grid-template-columns: 1fr;
    padding: 25px 0;
    gap: 25px;
  }
  .lesson-sidebar {
    position: static;
  }
  .lesson-sidebar h3 {
    margin: 10px 0;
  }
  .lesson-sidebar nav {
    display: flex;
    overflow-x: auto;
    gap: 5px;
  }
  .lesson-sidebar a {
    flex: none;
    padding: 10px;
    font-size: 11px;
  }
  .lesson-main h1 {
    font-size: 31px;
  }
  .lesson-main > p {
    font-size: 14px;
  }
  .lesson-media {
    min-height: 260px;
    padding: 25px 20px 50px;
  }
  .lesson-media h2 {
    font-size: 28px;
  }
  .exercise {
    padding: 21px;
  }
  .exercise blockquote {
    font-size: 21px;
  }
  .lesson-end {
    flex-wrap: wrap;
  }
  .article-head {
    padding: 40px 0 20px;
  }
  .article-head h1 {
    font-size: 35px;
  }
  .article-layout {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .article-toc {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    padding: 0;
    border-bottom: 1px solid var(--line);
  }
  .article-toc small {
    display: none;
  }
  .article-toc a {
    margin: 10px 0;
  }
  .article-actions {
    grid-column: 1;
  }
  .article-body {
    font-size: 15px;
  }
  .article-body blockquote {
    font-size: 24px;
    padding: 17px;
  }
  .tool-hero,
  .about-hero {
    grid-template-columns: 1fr;
    padding: 43px 0;
    gap: 35px;
  }
  .tool-hero h1,
  .about-hero h1 {
    font-size: 41px;
  }
  .tool-hero p,
  .about-hero p {
    font-size: 14px;
  }
  .info-columns {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .info-columns > div + div {
    border-top: 1px solid var(--line);
    padding-top: 25px;
  }
  .letter {
    padding: 30px;
    transform: rotate(1deg);
    margin: 0 4px;
  }
  .letter p {
    font-size: 21px;
  }
  .social-list {
    grid-template-columns: 1fr 1fr;
    gap: 0 20px;
  }
  .social-list > div {
    font-size: 14px;
  }
  .social-list small {
    font-size: 10px;
  }
  .pricing-layout {
    grid-template-columns: 1fr;
    gap: 22px;
  }
  .price-card {
    padding: 27px;
  }
  .auth-layout {
    grid-template-columns: 1fr;
    gap: 30px;
    margin: 42px auto;
  }
  .auth-story h2 {
    font-size: 34px;
  }
  .auth-story p {
    margin-top: 13px;
    font-size: 14px;
  }
  .auth-story .milo-seal {
    display: none;
  }
  .form-card {
    padding: 26px;
  }
  .account-layout {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 25px 0;
  }
  .account-nav .brand {
    display: none;
  }
  .account-nav nav {
    display: flex;
    overflow-x: auto;
    gap: 5px;
    border-bottom: 1px solid var(--line);
  }
  .account-nav a {
    white-space: nowrap;
    padding: 10px;
    font-size: 12px;
  }
  .account-main h1 {
    font-size: 34px;
  }
  .continue-card {
    grid-template-columns: 1fr;
    padding: 23px;
    gap: 15px;
  }
  .continue-card > .course-art {
    display: none;
  }
  .setting-row {
    gap: 18px;
  }
  .setting-row p {
    font-size: 12px;
  }
  .setting-row select {
    max-width: 135px;
    font-size: 13px;
  }
  .status-panel {
    margin: 40px auto;
    padding: 28px 20px;
  }
  .status-panel h1 {
    font-size: 31px;
  }
  .status-panel p {
    font-size: 14px;
  }
  .legal {
    margin: 40px auto;
  }
  .legal h1 {
    font-size: 35px;
  }
  .header .theme-menu {
    right: -35px;
  }
  .notice {
    font-size: 12px;
  }
  .section-head p {
    font-size: 13px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *:before,
  *:after {
    transition: none !important;
    animation: none !important;
  }
}

/* 网格子项允许收缩，移动端账户导航在自身内部滚动。 */
.account-layout > * {
  min-width: 0;
}

/* 内容优先：研究索引、课纲目录与产品说明；延续已确认色系。 */
.research-masthead {
  padding: 42px 0 32px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
}
.research-masthead h1 {
  font-size: 42px;
  line-height: 1.25;
  letter-spacing: -0.035em;
}
.research-masthead p {
  color: var(--muted);
  font-size: 14px;
  margin-top: 13px;
  max-width: 670px;
}
.research-masthead .breadcrumbs {
  margin-bottom: 19px;
}
.edition-note {
  text-align: right;
  flex: none;
  font-size: 12px;
  color: var(--muted);
}
.edition-note span {
  display: block;
  font-weight: 500;
  color: var(--ink);
  margin-bottom: 4px;
}
.edition-note small {
  font-size: 11px;
}
.research-section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
  padding: 29px 0 23px;
}
.research-section-heading h2 {
  font: 500 23px/1.4 var(--sans);
  letter-spacing: -0.02em;
}
.research-section-heading p {
  font-size: 13px;
  color: var(--muted);
  margin-top: 9px;
}
.research-section-heading > .text-link {
  font-size: 12px;
  white-space: nowrap;
}
.research-lead-layout {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 39px;
  margin-bottom: 29px;
}
.research-lead {
  background: var(--soft);
  border-radius: 5px;
  padding: 30px 33px 25px;
  display: flex;
  flex-direction: column;
}
.section-kicker {
  font-size: 12px;
  color: var(--green);
  margin-bottom: 17px;
}
.research-lead h2 {
  font: 500 32px/1.5 var(--sans);
  letter-spacing: -0.03em;
  margin-bottom: 17px;
}
.research-lead h2 a:hover,
.research-row h3 a:hover,
.latest-notes h4 a:hover {
  color: var(--green);
}
.research-lead > p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.9;
  margin-bottom: 20px;
}
.lead-numbers {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  border-top: 1px solid var(--line);
  padding-top: 18px;
  margin-top: auto;
}
.lead-numbers > div {
  display: flex;
  flex-direction: column;
  gap: 7px;
}
.lead-numbers span {
  font-size: 11px;
  color: var(--muted);
}
.lead-numbers strong {
  font: 400 37px/1.3 var(--display);
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.lead-numbers strong small {
  font: 12px var(--sans);
  color: var(--muted);
}
.lead-scope {
  font-size: 10px;
  color: var(--muted);
  margin: 12px 0 22px;
}
.lead-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  border-top: 1px solid var(--line);
  padding-top: 17px;
}
.lead-footer > span {
  font-size: 11px;
  color: var(--muted);
}
.lead-footer .text-link {
  font-size: 12px;
  border: 0;
}
.latest-notes {
  min-width: 0;
}
.latest-notes > h3 {
  font-size: 14px;
  margin: 0 0 10px;
  color: var(--muted);
}
.latest-notes article {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.latest-notes article:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.latest-notes .note-meta {
  font-size: 11px;
  justify-content: space-between;
}
.latest-notes h4 {
  font-size: 17px;
  font-weight: 500;
  line-height: 1.6;
  margin: 6px 0;
}
.latest-notes small {
  font-size: 11px;
  color: var(--muted);
}
.research-tabs {
  display: flex;
  gap: 30px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--line);
  margin-bottom: 20px;
}
.research-tabs button {
  position: relative;
  border: 0;
  background: transparent;
  padding: 11px 0 14px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}
.research-tabs button[aria-pressed="true"] {
  color: var(--ink);
  font-weight: 600;
}
.research-tabs button[aria-pressed="true"]:after {
  content: "";
  position: absolute;
  bottom: -1px;
  height: 2px;
  left: 0;
  right: 0;
  background: var(--green);
}
.research-feed {
  margin: 0 0 30px;
}
.research-feed .research-row {
  display: grid;
  grid-template-columns: 58px 1fr 28px;
  gap: 22px;
  padding: 23px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}
.research-feed .research-row:first-child {
  padding-top: 23px;
}
.note-symbol {
  font: 500 10px var(--sans);
  letter-spacing: 0.02em;
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--green);
  width: 58px;
  height: 58px;
  border-radius: 3px;
  margin-top: 4px;
}
.research-row h3 {
  font-size: 20px;
  line-height: 1.55;
  margin: 8px 0 7px;
}
.research-row p {
  font-size: 13px;
  line-height: 1.85;
  max-width: 890px;
  color: var(--muted);
}
.research-row .note-meta {
  font-size: 11px;
  gap: 14px;
  flex-wrap: wrap;
}
.topic-label {
  color: var(--green);
}
.research-open {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  margin-top: 20px;
  color: var(--muted);
}
.catalog-section {
  border-top: 1px solid var(--line);
  margin-top: 25px;
  padding-bottom: 45px;
}
.catalog-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 23px;
}
.catalog-course {
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--surface);
  padding: 22px;
  display: flex;
  flex-direction: column;
}
.catalog-course-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.course-sequence {
  font: 27px var(--display);
  color: var(--green);
}
.catalog-course h3 {
  font: 500 19px/1.5 var(--sans);
  margin: 0 0 13px;
}
.catalog-course > p {
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
  margin: 0 0 23px;
}
.course-facts {
  margin: auto 0 0;
  padding-top: 15px;
  border-top: 1px solid var(--line);
  font-size: 12px;
}
.course-facts > div {
  display: grid;
  grid-template-columns: 45px 1fr;
  gap: 10px;
  padding: 5px 0;
}
.course-facts dt {
  color: var(--muted);
}
.course-facts dd {
  margin: 0;
  line-height: 1.6;
}
.course-facts small {
  font-size: 10px;
  color: var(--muted);
}
.catalog-course-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  border-top: 1px solid var(--line);
  padding-top: 15px;
  margin-top: 17px;
  font-size: 11px;
  color: var(--muted);
}
.catalog-course-bottom .text-link {
  font-size: 12px;
  border: 0;
  white-space: nowrap;
  color: var(--green);
}
.alpha-summary {
  display: grid;
  grid-template-columns: 65px 1fr auto;
  gap: 28px;
  align-items: center;
  border-top: 1px solid var(--line);
  padding: 35px 0 15px;
  margin-bottom: 20px;
}
.alpha-monogram {
  font: 52px var(--display);
  background: var(--soft);
  color: var(--green);
  width: 65px;
  height: 72px;
  display: grid;
  place-items: center;
  border-radius: 4px;
}
.alpha-summary .section-kicker {
  margin-bottom: 5px;
}
.alpha-summary h2 {
  font: 400 33px var(--display);
}
.alpha-summary p {
  font-size: 13px;
  color: var(--muted);
  margin: 8px 0 14px;
}
.alpha-summary .tag {
  font-size: 10px;
}
.learning-path {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 30px 0 35px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--soft);
}
.learning-path a {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 21px;
  min-width: 0;
}
.learning-path a + a {
  border-left: 1px solid var(--line);
}
.learning-path b {
  font: 26px var(--display);
  color: var(--green);
}
.learning-path strong {
  font-size: 13px;
  font-weight: 500;
}
.learning-path small {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 5px;
}
.learning-path .icon {
  margin-left: auto;
  width: 16px;
}
.course-comparison {
  margin: 55px 0;
  border-top: 1px solid var(--line);
  padding-top: 30px;
}
.course-comparison h2 {
  font: 500 23px var(--sans);
  margin-bottom: 25px;
}
.detail-course-facts {
  margin: 30px 0;
  padding: 17px 20px;
  background: var(--soft);
  border-radius: 4px;
}
.detail-course-facts > div {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 16px;
  padding: 7px 0;
  font-size: 13px;
}
.detail-course-facts dt {
  color: var(--muted);
}
.detail-course-facts dd {
  margin: 0;
}
.library-toolbar {
  display: flex;
  align-items: center;
  gap: 15px;
  font-size: 12px;
  color: var(--muted);
  padding: 0 0 13px;
  border-bottom: 1px solid var(--line);
}
.library-toolbar select {
  padding: 6px 10px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--ink);
  font-size: 12px;
}
.library-toolbar > span {
  margin-left: auto;
}
.report-heading {
  max-width: 950px;
  padding: 45px 0 30px;
  margin-left: auto;
}
.report-heading .note-meta {
  gap: 16px;
  flex-wrap: wrap;
  font-size: 12px;
}
.report-heading h1 {
  font: 500 clamp(28px, 3.4vw, 43px)/1.45 var(--sans);
  letter-spacing: -0.035em;
  margin: 20px 0 16px;
}
.report-heading > p {
  font-size: 15px;
  color: var(--muted);
  max-width: 850px;
  line-height: 1.9;
}
.report-scope {
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-top: 25px;
  font-size: 12px;
  color: var(--muted);
}
.report-layout {
  display: grid;
  grid-template-columns: 195px minmax(0, 1fr);
  gap: 55px;
  margin: 10px 0 60px;
}
.report-sidebar {
  position: sticky;
  top: 25px;
  align-self: start;
  font-size: 13px;
}
.report-sidebar nav {
  border-left: 1px solid var(--line);
  padding-left: 17px;
  margin-bottom: 22px;
}
.report-sidebar nav a {
  display: block;
  padding: 9px 0;
  color: var(--muted);
}
.report-sidebar nav a:hover {
  color: var(--green);
}
.report-body {
  min-width: 0;
  max-width: 950px;
}
.report-body section {
  margin-bottom: 35px;
  scroll-margin-top: 25px;
}
.report-body h2 {
  font: 500 23px/1.5 var(--sans);
  margin-bottom: 17px;
  letter-spacing: -0.015em;
}
.report-body p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.95;
}
.report-body .report-question {
  font-size: 18px;
  color: var(--ink);
  margin-bottom: 20px;
}
.research-conclusion {
  padding: 22px 25px;
  background: var(--soft);
  border-radius: 4px;
}
.research-conclusion h3 {
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--green);
}
.research-conclusion p {
  color: var(--ink);
}
.data-table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 4px;
  margin: 15px 0 18px;
}
.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 550px;
  font-size: 13px;
  background: var(--surface);
  line-height: 1.65;
  font-variant-numeric: tabular-nums;
}
.data-table caption {
  text-align: left;
  padding: 12px 17px;
  font-size: 11px;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
}
.data-table th,
.data-table td {
  padding: 13px 17px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}
.data-table thead {
  background: var(--soft);
  font-size: 12px;
}
.data-table th {
  font-weight: 500;
}
.data-table tbody tr:last-child > * {
  border-bottom: 0;
}
.analysis-point {
  display: flex;
  gap: 16px;
  margin: 16px 0;
}
.analysis-point > span {
  flex: none;
  color: var(--green);
  font: 23px var(--display);
  padding-top: 3px;
}
.report-body ul {
  padding-left: 22px;
  font-size: 14px;
  color: var(--muted);
}
.report-body li {
  margin: 10px 0;
  line-height: 1.9;
}
.source-entry {
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 20px;
  display: flex;
  gap: 20px;
}
.source-entry > strong {
  font-size: 12px;
  color: var(--green);
}
.source-entry h3 {
  font-size: 14px;
  margin-bottom: 10px;
}
.source-entry p {
  font-size: 12px;
}
.report-related {
  padding-top: 24px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 12px;
  font-size: 12px;
  color: var(--muted);
}
.report-related a {
  justify-self: start;
  color: var(--ink);
}
.alpha-overview {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 70px;
  margin: 45px 0;
}
.alpha-overview h2,
.alpha-modules h2 {
  font: 500 24px var(--sans);
  margin-bottom: 18px;
}
.alpha-overview p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.9;
}
.alpha-facts {
  margin: 25px 0 0;
}
.alpha-facts > div {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 20px;
  font-size: 13px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}
.alpha-facts dt {
  color: var(--muted);
}
.alpha-facts dd {
  margin: 0;
}
.alpha-specimen {
  background: var(--soft);
  padding: 28px;
  border-radius: 5px;
  align-self: start;
}
.alpha-specimen h3 {
  font-size: 23px;
  margin: 20px 0;
}
.alpha-specimen dl {
  margin: 0;
}
.alpha-specimen dl > div {
  display: grid;
  grid-template-columns: 65px 1fr;
  gap: 18px;
  border-top: 1px solid var(--line);
  padding: 15px 0;
  font-size: 13px;
}
.alpha-specimen dt {
  color: var(--muted);
}
.alpha-specimen dd {
  margin: 0;
}
.alpha-specimen small {
  font-size: 11px;
  color: var(--muted);
}
.alpha-modules {
  border-top: 1px solid var(--line);
  padding-top: 30px;
  margin-bottom: 45px;
}
@media (max-width: 1000px) {
  .research-lead-layout {
    grid-template-columns: 1.3fr 1fr;
    gap: 27px;
  }
  .research-lead {
    padding: 26px;
  }
  .research-lead h2 {
    font-size: 27px;
  }
  .lead-numbers {
    gap: 10px;
  }
  .lead-numbers strong {
    font-size: 31px;
  }
  .lead-footer {
    flex-wrap: wrap;
  }
  .catalog-grid {
    gap: 16px;
  }
  .catalog-course {
    padding: 19px;
  }
  .catalog-course h3 {
    font-size: 18px;
  }
  .course-facts > div {
    grid-template-columns: 1fr;
    gap: 1px;
  }
  .report-layout {
    grid-template-columns: 160px minmax(0, 1fr);
    gap: 30px;
  }
  .report-heading {
    margin-left: 190px;
  }
  .alpha-overview {
    gap: 35px;
  }
}
@media (max-width: 700px) {
  .research-masthead {
    align-items: start;
    padding: 32px 0 25px;
    flex-wrap: wrap;
    gap: 16px;
  }
  .research-masthead h1 {
    font-size: 35px;
  }
  .research-masthead p {
    font-size: 13px;
    margin-top: 10px;
  }
  .edition-note {
    text-align: left;
  }
  .edition-note span {
    display: inline;
    margin-right: 10px;
  }
  .research-section-heading {
    padding: 23px 0 19px;
  }
  .research-section-heading h2 {
    font-size: 21px;
  }
  .research-lead-layout {
    grid-template-columns: 1fr;
    gap: 22px;
  }
  .research-lead {
    padding: 24px;
  }
  .research-lead h2 {
    font-size: 27px;
    line-height: 1.5;
  }
  .research-lead > p {
    font-size: 13px;
  }
  .latest-notes > h3 {
    font-size: 13px;
  }
  .latest-notes h4 {
    font-size: 16px;
  }
  .latest-notes article {
    padding: 14px 0;
  }
  .research-tabs {
    gap: 22px;
    flex-wrap: nowrap;
    overflow-x: auto;
  }
  .research-tabs button {
    font-size: 12px;
    flex: none;
  }
  .research-feed .research-row {
    grid-template-columns: 43px 1fr;
    gap: 13px;
    padding: 20px 0;
  }
  .note-symbol {
    width: 43px;
    height: 45px;
    font-size: 8px;
  }
  .research-row h3 {
    font-size: 17px;
  }
  .research-row .note-meta {
    gap: 7px 12px;
    font-size: 10px;
  }
  .research-open {
    display: none;
  }
  .research-row p {
    font-size: 12px;
  }
  .catalog-section {
    margin-top: 18px;
    padding-bottom: 30px;
  }
  .catalog-grid {
    grid-template-columns: 1fr;
    gap: 15px;
  }
  .catalog-course {
    padding: 23px;
  }
  .catalog-course h3 {
    font-size: 21px;
  }
  .course-facts > div {
    grid-template-columns: 50px 1fr;
    gap: 12px;
  }
  .catalog-course > p {
    margin-bottom: 19px;
  }
  .alpha-summary {
    grid-template-columns: 45px 1fr;
    gap: 18px;
    padding-top: 29px;
  }
  .alpha-monogram {
    width: 45px;
    height: 54px;
    font-size: 37px;
  }
  .alpha-summary > .btn {
    grid-column: 2;
    justify-self: start;
  }
  .alpha-summary h2 {
    font-size: 29px;
  }
  .alpha-summary p {
    font-size: 12px;
  }
  .learning-path {
    grid-template-columns: 1fr;
    margin: 24px 0;
  }
  .learning-path a + a {
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .learning-path a {
    padding: 17px 20px;
  }
  .detail-course-facts > div {
    grid-template-columns: 1fr;
    gap: 3px;
  }
  .library-toolbar {
    gap: 10px;
    flex-wrap: wrap;
  }
  .library-toolbar > span {
    font-size: 11px;
  }
  .report-heading {
    margin: 0;
    padding: 30px 0 24px;
  }
  .report-heading h1 {
    font-size: 31px;
  }
  .report-heading > p {
    font-size: 14px;
  }
  .report-scope {
    flex-wrap: wrap;
    gap: 12px;
  }
  .report-layout {
    grid-template-columns: 1fr;
    gap: 25px;
  }
  .report-sidebar {
    position: static;
  }
  .report-sidebar nav {
    display: flex;
    overflow-x: auto;
    gap: 20px;
    border-left: 0;
    border-bottom: 1px solid var(--line);
    padding: 0;
    margin-bottom: 10px;
  }
  .report-sidebar nav a {
    white-space: nowrap;
    font-size: 12px;
  }
  .report-sidebar > .plain {
    padding-left: 0;
  }
  .report-body h2 {
    font-size: 22px;
  }
  .report-body .report-question {
    font-size: 17px;
  }
  .research-conclusion {
    padding: 20px;
  }
  .data-table {
    font-size: 12px;
    min-width: 500px;
  }
  .data-table th,
  .data-table td {
    padding: 12px;
  }
  .source-entry {
    padding: 17px;
    gap: 14px;
  }
  .alpha-overview {
    grid-template-columns: 1fr;
    gap: 25px;
    margin: 30px 0;
  }
  .alpha-facts > div {
    grid-template-columns: 75px 1fr;
    gap: 16px;
  }
  .alpha-specimen {
    padding: 23px;
  }
  .alpha-modules h2 {
    font-size: 22px;
  }
}

.lead-reading {
  border-left: 2px solid var(--green);
  padding: 1px 0 1px 16px;
  margin: 0 0 24px;
}
.lead-reading strong {
  font-size: 11px;
  font-weight: 500;
  color: var(--green);
}
.lead-reading p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.9;
  margin-top: 7px;
}
/* 长英文元信息可换行，研究目录与表格只在各自容器内滚动。 */
.edition-note {
  max-width: 100%;
  overflow-wrap: anywhere;
}
.report-layout > * {
  min-width: 0;
}

/* 精简内容结构：用留白区分内容，避免首页重复横线与目录控件。 */
.header-subscribe {
  font-size: 13px;
  color: var(--green);
  white-space: nowrap;
  padding: 8px 2px;
}
.quiet-home {
  padding-top: 33px;
}
.quiet-section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  margin-bottom: 25px;
}
.quiet-section-head h1,
.quiet-section-head h2 {
  font: 500 26px/1.4 var(--sans);
  letter-spacing: -0.025em;
}
.quiet-section-head > .text-link {
  font-size: 12px;
  border: 0;
  color: var(--muted);
}
.quiet-section-head > span {
  font-size: 12px;
  color: var(--muted);
}
.home-stream-grid {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 42px;
  align-items: start;
}
.stream-post {
  min-width: 0;
}
.stream-meta {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 19px;
}
.stream-meta time {
  display: block;
  font-size: 10px;
  color: var(--muted);
  line-height: 1.6;
}
.short-copy p {
  font-size: 15px;
  line-height: 1.95;
  margin: 0;
  color: var(--ink);
}
.short-copy p + p {
  margin-top: 13px;
}
.stream-post-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  font-size: 11px;
  color: var(--muted);
  margin-top: 19px;
}
.stream-post-foot .text-link {
  font-size: 12px;
  border: 0;
  color: var(--green);
}
.stream-post-foot .plain {
  padding: 4px;
}
.home-short-notes {
  display: grid;
  gap: 23px;
}
.home-short-notes .short-post {
  padding: 24px 27px;
  background: var(--surface);
  border-radius: 8px;
}
.featured-post {
  padding: 24px;
  background: var(--surface);
  border-radius: 8px;
}
.article-preview-cover {
  padding: 23px 25px;
  background: var(--soft);
  border-radius: 5px;
  min-height: 176px;
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 20px;
  color: var(--green);
}
.article-preview-cover > span {
  font: 13px var(--sans);
  padding-top: 3px;
}
.article-preview-cover > div {
  align-self: end;
  display: flex;
  flex-direction: column;
  align-items: end;
}
.article-preview-cover b {
  font: 400 66px var(--display);
  line-height: 1;
}
.article-preview-cover small {
  font-size: 10px;
  opacity: 0.7;
  margin-top: 11px;
}
.long-copy h2 {
  font: 500 23px/1.55 var(--sans);
  margin: 23px 0 12px;
  letter-spacing: -0.015em;
}
.long-copy > p {
  font-size: 13px;
  line-height: 1.9;
  color: var(--muted);
}
.home-courses {
  margin: 65px 0;
}
.focused-courses-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}
.focused-course {
  min-width: 0;
  background: var(--surface);
  border-radius: 8px;
  overflow: hidden;
}
.focused-cover {
  height: 190px;
  padding: 23px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--soft);
  color: var(--green);
}
.focused-cover.sand-cover {
  background: var(--yellow);
  color: #354630;
}
.focused-cover > span {
  font-size: 11px;
  opacity: 0.8;
}
.focused-cover > strong {
  font: 400 45px var(--display);
  align-self: center;
  line-height: 1.2;
}
.focused-cover > small {
  font-size: 10px;
  align-self: flex-end;
  opacity: 0.8;
}
.focused-course-copy {
  padding: 27px;
}
.focused-course-copy .tag {
  font-size: 10px;
  background: var(--soft);
  border: 0;
  padding: 3px 8px;
}
.focused-course-copy h3 {
  font-size: 23px;
  line-height: 1.5;
  margin: 16px 0 12px;
}
.focused-course-copy > p {
  font-size: 13px;
  line-height: 1.9;
  color: var(--muted);
}
.focused-course-copy .actions {
  margin-top: 23px;
}
.focused-course-copy .text-link {
  font-size: 13px;
  border: 0;
  color: var(--green);
}
.home-alpha-feature {
  display: grid;
  grid-template-columns: 0.8fr 1.45fr;
  gap: 45px;
  align-items: center;
  margin: 80px 0;
}
.home-alpha-copy h2 {
  font: 400 43px var(--display);
  margin: 10px 0 22px;
}
.home-alpha-copy > p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.9;
}
.home-alpha-copy > ul {
  padding-left: 17px;
  font-size: 12px;
  line-height: 1.9;
  color: var(--muted);
  margin: 23px 0;
}
.home-alpha-copy > ul li {
  margin: 6px 0;
}
.home-alpha-copy > small {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 16px;
}
.alpha-carousel {
  min-width: 0;
}
.alpha-slide-frame {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 15px 50px #16302012;
  background: var(--soft);
}
.alpha-slide-frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1100/680;
  object-fit: contain;
}
.alpha-slide-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 23px;
}
.slide-arrow {
  border: 0;
  background: var(--soft);
  width: 34px;
  height: 34px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  flex: none;
}
.slide-arrow[data-action="alpha-prev"] svg {
  transform: rotate(180deg);
}
.slide-arrow .icon {
  width: 15px;
  height: 15px;
}
.slide-tabs {
  display: flex;
  align-items: center;
  gap: 7px;
  justify-content: center;
}
.slide-tabs button {
  border: 0;
  background: transparent;
  padding: 7px 12px;
  font-size: 11px;
  color: var(--muted);
  border-radius: 20px;
}
.slide-tabs button[aria-pressed="true"] {
  background: var(--soft);
  color: var(--ink);
}
.alpha-caption {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 12px;
  color: var(--muted);
  margin-top: 17px;
  line-height: 1.8;
}
.alpha-caption small {
  font-size: 10px;
  flex: none;
}
.alpha-carousel.compact .alpha-caption > span {
  display: none;
}
.alpha-carousel.compact .alpha-caption {
  justify-content: center;
  margin-top: 10px;
}
.subscription-block {
  background: var(--soft);
  border-radius: 8px;
  padding: 36px 42px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 55px;
  align-items: center;
  margin: 60px 0 30px;
}
.subscription-block h2 {
  font: 500 28px/1.5 var(--sans);
  margin: 10px 0 13px;
}
.subscription-block p {
  font-size: 14px;
  color: var(--muted);
  max-width: 650px;
}
.subscription-block small {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 13px;
}
.subscription-price {
  min-width: 220px;
  text-align: right;
}
.subscription-price > div {
  display: flex;
  justify-content: flex-end;
  align-items: baseline;
  gap: 8px;
}
.subscription-price strong {
  font: 400 47px var(--display);
}
.subscription-price span {
  font-size: 13px;
  color: var(--muted);
}
.subscription-price .btn {
  margin-top: 18px;
  min-width: 170px;
}
.notes-stream-page {
  max-width: var(--content-width);
}
.plain-page-head {
  padding: 45px 0 32px;
}
.plain-page-head h1 {
  font: 500 32px/1.4 var(--sans);
  letter-spacing: -0.025em;
}
.plain-page-head > p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 12px;
}
.notes-stream {
  display: grid;
  gap: 36px;
}
.notes-stream .stream-post {
  background: var(--surface);
  padding: 29px 32px;
  border-radius: 8px;
}
.notes-stream .short-post {
  background: transparent;
  padding-top: 8px;
  padding-bottom: 8px;
}
.notes-stream .article-preview-cover {
  min-height: 210px;
}
.notes-stream .long-copy h2 {
  font-size: 26px;
}
.notes-stream .short-copy p {
  font-size: 16px;
  line-height: 2;
}
.stream-end {
  text-align: center;
  padding: 40px 0;
  font-size: 11px;
  color: var(--muted);
}
.focused-courses-page {
  max-width: var(--content-width);
}
.course-simple-next {
  display: flex;
  align-items: center;
  gap: 25px;
  flex-wrap: wrap;
  margin: 38px 0 65px;
}
.course-simple-next p {
  margin-right: auto;
  font-size: 13px;
  color: var(--muted);
}
.course-simple-next > .text-link {
  border: 0;
  font-size: 13px;
}
.alpha-product-page {
  max-width: var(--content-width);
}
.alpha-product-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 45px;
  padding: 45px 0 32px;
}
.alpha-product-head h1 {
  font: 400 47px/1.2 var(--display);
}
.alpha-product-head p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 14px;
  max-width: 700px;
}
.alpha-product-head > .btn {
  flex: none;
}
.alpha-product-foot {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 0 10px;
  font-size: 12px;
  color: var(--muted);
}
.alpha-product-foot > span {
  font-size: 10px;
  flex: none;
}
.about-simple {
  max-width: var(--content-width);
}
.profile-intro {
  display: grid;
  grid-template-columns: 290px 1fr;
  gap: 70px;
  align-items: center;
  padding: 65px 0;
}
.profile-portrait {
  aspect-ratio: 1/1.12;
  background: var(--soft);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  color: var(--green);
  gap: 24px;
}
.profile-portrait > span {
  font: 130px/0.8 var(--display);
}
.profile-portrait > small {
  font-size: 14px;
}
.profile-copy h1 {
  font: 400 43px/1.4 var(--display);
  margin: 0 0 12px;
}
.profile-copy .profile-role {
  font-size: 14px;
  color: var(--green);
  margin-bottom: 23px;
}
.profile-copy > p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.95;
}
.profile-copy > small {
  display: block;
  font-size: 10px;
  color: var(--muted);
  margin-top: 22px;
}
.social-matrix {
  padding: 10px 0 45px;
}
.social-matrix-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.social-account {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 22px;
  text-align: left;
  border: 0;
  border-radius: 6px;
  background: var(--surface);
  min-width: 0;
  transition: background 0.15s;
}
.social-account:hover {
  background: var(--soft);
}
.social-platform-icon {
  width: 39px;
  height: 39px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: var(--soft);
  color: var(--green);
  font-size: 19px;
  font-weight: 500;
  flex: none;
}
.social-account > span:nth-child(2) {
  min-width: 0;
}
.social-account strong {
  font-size: 13px;
  font-weight: 500;
  display: block;
}
.social-account small {
  font-size: 11px;
  color: var(--muted);
  display: block;
  margin-top: 4px;
  overflow-wrap: anywhere;
}
.social-account > .icon {
  width: 14px;
  height: 14px;
  margin-left: auto;
  color: var(--muted);
}
.social-platform-icon.red,
.social-platform-icon.youtube {
  background: #f7e5dd;
  color: #a74e40;
}
.social-platform-icon.wechat {
  background: #e1ecd9;
  color: #56823c;
}
.social-platform-icon.substack {
  background: #f6e4d4;
  color: #aa6c3d;
}
.social-platform-icon.bili {
  background: #deeced;
  color: #4d8392;
}
@media (max-width: 1000px) {
  .home-stream-grid {
    gap: 25px;
  }
  .home-alpha-feature {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 30px;
  }
  .home-alpha-copy h2 {
    font-size: 37px;
  }
  .alpha-slide-controls {
    gap: 12px;
  }
  .slide-tabs {
    gap: 0;
  }
  .slide-tabs button {
    padding: 7px 9px;
    font-size: 10px;
  }
  .subscription-block {
    gap: 28px;
    padding: 32px;
  }
  .profile-intro {
    grid-template-columns: 240px 1fr;
    gap: 45px;
  }
  .social-account {
    padding: 18px;
    gap: 12px;
  }
}
@media (max-width: 700px) {
  .header-subscribe {
    display: none;
  }
  .quiet-home {
    padding-top: 27px;
  }
  .quiet-section-head {
    margin-bottom: 20px;
  }
  .quiet-section-head h1,
  .quiet-section-head h2 {
    font-size: 24px;
  }
  .home-stream-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .home-short-notes {
    gap: 22px;
  }
  .home-short-notes .short-post {
    padding: 21px 0;
    background: transparent;
  }
  .featured-post {
    padding: 22px;
  }
  .article-preview-cover {
    min-height: 165px;
    padding: 20px;
  }
  .article-preview-cover b {
    font-size: 56px;
  }
  .long-copy h2 {
    font-size: 22px;
    margin-top: 20px;
  }
  .home-courses {
    margin: 45px 0;
  }
  .focused-courses-grid {
    grid-template-columns: 1fr;
    gap: 25px;
  }
  .focused-cover {
    height: 180px;
    padding: 22px;
  }
  .focused-cover > strong {
    font-size: 38px;
  }
  .focused-course-copy {
    padding: 23px;
  }
  .focused-course-copy h3 {
    font-size: 22px;
  }
  .home-alpha-feature {
    grid-template-columns: 1fr;
    margin: 55px 0;
    gap: 28px;
  }
  .home-alpha-copy h2 {
    font-size: 39px;
    margin-bottom: 15px;
  }
  .home-alpha-copy > ul {
    margin: 18px 0;
  }
  .home-alpha-copy > small {
    display: inline-block;
    margin-left: 14px;
  }
  .alpha-slide-controls {
    gap: 13px;
    margin-top: 18px;
  }
  .slide-arrow {
    width: 32px;
    height: 32px;
  }
  .slide-tabs button {
    font-size: 10px;
    padding: 7px 9px;
  }
  .alpha-caption {
    flex-direction: column;
    gap: 8px;
    margin-top: 15px;
    font-size: 12px;
  }
  .alpha-caption small {
    text-align: center;
  }
  .subscription-block {
    grid-template-columns: 1fr;
    padding: 27px;
    margin: 40px 0 20px;
    gap: 23px;
  }
  .subscription-block h2 {
    font-size: 25px;
  }
  .subscription-block p {
    font-size: 13px;
  }
  .subscription-price {
    text-align: left;
    min-width: 0;
  }
  .subscription-price > div {
    justify-content: flex-start;
  }
  .subscription-price .btn {
    width: 100%;
  }
  .plain-page-head {
    padding: 32px 0 27px;
  }
  .plain-page-head h1 {
    font-size: 29px;
  }
  .notes-stream {
    gap: 28px;
  }
  .notes-stream .stream-post {
    padding: 23px;
  }
  .notes-stream .short-post {
    padding: 8px 0;
  }
  .notes-stream .article-preview-cover {
    min-height: 170px;
  }
  .notes-stream .long-copy h2 {
    font-size: 23px;
  }
  .notes-stream .short-copy p {
    font-size: 15px;
  }
  .course-simple-next {
    gap: 20px;
    margin-bottom: 40px;
  }
  .course-simple-next p {
    flex-basis: 100%;
    margin: 0;
  }
  .alpha-product-head {
    flex-direction: column;
    align-items: start;
    gap: 20px;
    padding: 32px 0 25px;
  }
  .alpha-product-head h1 {
    font-size: 39px;
  }
  .alpha-product-head p {
    font-size: 13px;
  }
  .alpha-product-foot {
    flex-direction: column;
    gap: 12px;
    font-size: 11px;
  }
  .profile-intro {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 35px 0;
  }
  .profile-portrait {
    width: 180px;
    aspect-ratio: 1;
  }
  .profile-portrait > span {
    font-size: 90px;
  }
  .profile-portrait > small {
    font-size: 12px;
  }
  .profile-copy h1 {
    font-size: 39px;
  }
  .social-matrix-grid {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }
  .social-account {
    padding: 17px 12px;
    gap: 10px;
  }
  .social-platform-icon {
    width: 31px;
    height: 31px;
    font-size: 16px;
    border-radius: 8px;
  }
  .social-account strong {
    font-size: 12px;
  }
  .social-account small {
    font-size: 10px;
  }
  .social-account > .icon {
    display: none;
  }
  .social-matrix .quiet-section-head > span {
    font-size: 10px;
  }
}

/* 视觉统一：共享页面边界，以字级、留白和纸面层次取代分割线。 */
:root[data-theme="dark"] {
  --card-shadow: 0 8px 28px #00000014;
}
.header {
  border-bottom: 0;
}
.header-inner {
  height: 92px;
}
.brand {
  gap: 13px;
}
.brand strong {
  font-size: 18px;
  letter-spacing: 0.015em;
}
.brand small {
  font-size: 10px;
  letter-spacing: 0.025em;
  margin-top: 3px;
}
.brand-mark {
  width: 37px;
  height: 40px;
}
.nav {
  gap: 30px;
}
.nav a {
  color: var(--muted);
}
.nav a[aria-current="page"],
.nav a:hover {
  color: var(--green);
}
.nav a[aria-current="page"]:after {
  height: 4px;
  width: 4px;
  left: calc(50% - 2px);
  bottom: 0;
  border-radius: 50%;
}
.btn {
  border-radius: 8px;
  min-height: 48px;
  padding-inline: 24px;
}
.btn.secondary {
  background: var(--surface);
  border-color: transparent;
  box-shadow: var(--card-shadow);
}
.btn.secondary:hover {
  background: var(--soft);
}
.header-tools .btn {
  box-shadow: none;
  border-radius: 7px;
}
.quiet-home {
  padding-top: 40px;
}
.quiet-section-head {
  margin-bottom: 28px;
}
.quiet-section-head h1,
.quiet-section-head h2 {
  font-size: 27px;
  letter-spacing: -0.035em;
}
.quiet-section-head > .text-link {
  font-size: 13px;
}
.home-stream-grid {
  gap: 32px;
}
.home-short-notes {
  gap: 24px;
}
.featured-post,
.home-short-notes .short-post,
.focused-course,
.social-account {
  border-radius: var(--card-radius);
  box-shadow: var(--card-shadow);
}
.featured-post {
  padding: 28px;
}
.home-short-notes .short-post {
  padding: 28px;
}
.stream-meta {
  gap: 12px;
  margin-bottom: 22px;
}
.stream-meta time {
  font-size: 11px;
  margin-top: 2px;
}
.article-preview-cover {
  border-radius: 9px;
  padding: 25px 29px;
  min-height: 185px;
  background: linear-gradient(
    125deg,
    var(--soft),
    color-mix(in srgb, var(--soft) 76%, var(--surface))
  );
}
.article-preview-cover > span {
  font-size: 11px;
  letter-spacing: 0.07em;
}
.article-preview-cover b {
  font-size: 75px;
  letter-spacing: -0.035em;
}
.article-preview-cover small {
  opacity: 1;
  color: var(--muted);
  font-size: 11px;
}
.long-copy h2 {
  font-size: 24px;
  line-height: 1.55;
  margin: 23px 0 14px;
  letter-spacing: -0.025em;
}
.long-copy > p {
  font-size: 14px;
  line-height: 1.95;
}
.stream-post-foot {
  margin-top: 23px;
  font-size: 12px;
}
.stream-post-foot .text-link {
  font-size: 13px;
}
.home-courses {
  margin: 74px 0;
}
.focused-courses-grid {
  gap: 32px;
}
.focused-cover {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  height: 212px;
  padding: 28px 32px;
}
.focused-cover:before,
.focused-cover:after {
  content: "";
  position: absolute;
  width: 120px;
  height: 163px;
  right: 54px;
  top: 42px;
  border-radius: 5px;
  background: color-mix(in srgb, var(--surface) 48%, transparent);
  box-shadow: 0 10px 28px #173d3007;
  z-index: -1;
  transform: rotate(-12deg);
}
.focused-cover:after {
  right: 33px;
  top: 60px;
  transform: rotate(9deg);
  opacity: 0.6;
}
.focused-cover > strong {
  align-self: flex-start;
  font-size: 50px;
  letter-spacing: -0.025em;
}
.focused-cover > small {
  align-self: flex-start;
  font-size: 11px;
  opacity: 0.8;
}
.focused-course-copy {
  padding: 29px 32px 30px;
}
.focused-course-copy h3 {
  font-size: 24px;
  letter-spacing: -0.025em;
}
.focused-course-copy > p {
  font-size: 14px;
  max-width: 490px;
}
.focused-course-copy .tag {
  font-size: 11px;
  border-radius: 4px;
}
.focused-course-copy .actions {
  margin-top: 25px;
  gap: 25px;
}
.home-alpha-feature {
  margin: 86px 0;
  gap: 55px;
}
.home-alpha-copy h2 {
  font-size: 47px;
}
.home-alpha-copy > p {
  font-size: 15px;
}
.home-alpha-copy > ul {
  font-size: 13px;
  margin: 25px 0;
}
.alpha-slide-frame {
  border-radius: 12px;
  box-shadow: 0 16px 48px #16302012;
}
.alpha-slide-controls {
  margin-top: 25px;
}
.slide-arrow {
  background: var(--surface);
  box-shadow: var(--card-shadow);
  width: 36px;
  height: 36px;
}
.slide-tabs {
  gap: 6px;
}
.slide-tabs button {
  font-size: 12px;
  padding: 8px 13px;
}
.alpha-caption {
  margin-top: 17px;
}
.subscription-block {
  border-radius: var(--card-radius);
  padding: 42px 46px;
  gap: 60px;
  margin: 70px 0 40px;
}
.subscription-block h2 {
  font-size: 29px;
  letter-spacing: -0.025em;
}
.subscription-price strong {
  font-size: 55px;
  letter-spacing: -0.04em;
}
.subscription-price .btn {
  min-width: 188px;
}
.plain-page-head {
  padding: 40px 0 34px;
}
.plain-page-head h1 {
  font-size: 32px;
  letter-spacing: -0.035em;
}
.plain-page-head > p {
  margin-top: 13px;
}
.notes-stream {
  gap: 26px;
}
.notes-stream .stream-post {
  padding: 30px 34px;
  border-radius: var(--card-radius);
}
.notes-stream .long-post {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.3fr);
  gap: 0 34px;
  box-shadow: var(--card-shadow);
}
.notes-stream .long-post .stream-meta {
  grid-column: 1 / -1;
  margin-bottom: 25px;
}
.notes-stream .stream-cover-link {
  min-width: 0;
  align-self: stretch;
}
.notes-stream .article-preview-cover {
  height: 100%;
  min-height: 232px;
}
.notes-stream .long-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}
.notes-stream .long-copy h2 {
  font-size: 26px;
  margin-top: 0;
  line-height: 1.5;
}
.notes-stream .long-copy > p {
  max-width: 64ch;
}
.notes-stream .long-copy .stream-post-foot {
  margin-top: auto;
  padding-top: 23px;
}
.notes-stream .short-post {
  padding-top: 27px;
  padding-bottom: 27px;
}
.notes-stream .short-copy {
  max-width: 820px;
  margin-left: 0;
}
.notes-stream .short-copy p {
  font-size: 16px;
  line-height: 1.95;
}
.notes-stream .short-post .stream-post-foot {
  margin-left: 0;
  max-width: 820px;
}
.stream-end {
  padding: 25px 0 20px;
  text-align: left;
  padding-left: 34px;
}
.alpha-product-head {
  padding: 40px 0 36px;
}
.alpha-product-head h1 {
  font-size: 49px;
}
.profile-intro {
  grid-template-columns: 305px minmax(0, 1fr);
  gap: 76px;
  padding: 55px 0 65px;
}
.profile-portrait {
  border-radius: 12px;
  background: linear-gradient(
    135deg,
    var(--soft),
    color-mix(in srgb, var(--soft) 76%, var(--surface))
  );
}
.profile-copy {
  max-width: 690px;
}
.profile-copy h1 {
  font-size: 48px;
}
.profile-copy > p {
  font-size: 15px;
  line-height: 2;
}
.profile-copy .profile-role {
  font-size: 14px;
  margin-bottom: 22px;
}
.social-matrix {
  padding-top: 0;
}
.social-matrix-grid {
  gap: 20px;
}
.social-account {
  padding: 25px;
  gap: 18px;
}
.social-platform-icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
}
.social-account strong {
  font-size: 14px;
}
.social-account small {
  font-size: 12px;
}
.footer {
  border: 0;
  background: var(--surface);
  margin-top: 65px;
  padding: 40px 0 30px;
}
.footer-bottom {
  border: 0;
  margin-top: 28px;
  padding-top: 0;
  gap: 28px;
}
.footer-top p {
  margin-top: 15px;
}
.footer-nav {
  font-size: 13px;
}
@media (max-width: 1100px) {
  .nav {
    gap: 24px;
  }
  .notes-stream .long-post {
    gap: 0 27px;
  }
  .notes-stream .long-copy h2 {
    font-size: 23px;
  }
  .home-alpha-feature {
    gap: 30px;
  }
  .slide-tabs {
    gap: 0;
  }
  .slide-tabs button {
    padding-inline: 10px;
    font-size: 11px;
  }
  .profile-intro {
    gap: 50px;
    grid-template-columns: 260px minmax(0, 1fr);
  }
}
@media (max-width: 700px) {
  .header-inner {
    height: 78px;
  }
  .brand strong {
    font-size: 15px;
  }
  .brand-mark {
    width: 32px;
    height: 35px;
  }
  .quiet-home {
    padding-top: 25px;
  }
  .quiet-section-head {
    margin-bottom: 22px;
  }
  .quiet-section-head h1,
  .quiet-section-head h2 {
    font-size: 25px;
  }
  .home-stream-grid {
    gap: 20px;
  }
  .featured-post {
    padding: 23px;
  }
  .home-short-notes {
    gap: 13px;
  }
  .home-short-notes .short-post {
    padding: 20px 4px;
    background: transparent;
    box-shadow: none;
  }
  .stream-meta {
    margin-bottom: 18px;
  }
  .article-preview-cover {
    padding: 22px;
    min-height: 174px;
  }
  .article-preview-cover b {
    font-size: 64px;
  }
  .long-copy h2 {
    font-size: 23px;
  }
  .long-copy > p {
    font-size: 14px;
  }
  .home-courses {
    margin: 47px 0;
  }
  .focused-courses-grid {
    gap: 25px;
  }
  .focused-cover {
    height: 195px;
    padding: 25px;
  }
  .focused-cover > strong {
    font-size: 43px;
  }
  .focused-cover:before {
    right: 31px;
    width: 95px;
    height: 142px;
  }
  .focused-cover:after {
    right: 16px;
    width: 95px;
    height: 142px;
  }
  .focused-course-copy {
    padding: 25px;
  }
  .focused-course-copy h3 {
    font-size: 23px;
  }
  .home-alpha-feature {
    margin: 57px 0;
    gap: 29px;
  }
  .home-alpha-copy h2 {
    font-size: 41px;
  }
  .home-alpha-copy > p {
    font-size: 14px;
  }
  .slide-arrow {
    width: 32px;
    height: 32px;
  }
  .slide-tabs button {
    font-size: 10px;
    padding: 7px 9px;
  }
  .subscription-block {
    padding: 28px;
    margin: 44px 0 25px;
    gap: 22px;
  }
  .subscription-block h2 {
    font-size: 25px;
  }
  .subscription-price strong {
    font-size: 49px;
  }
  .plain-page-head {
    padding: 27px 0 28px;
  }
  .plain-page-head h1 {
    font-size: 29px;
  }
  .notes-stream {
    gap: 22px;
  }
  .notes-stream .long-post {
    display: block;
    padding: 23px;
  }
  .notes-stream .long-post .stream-meta {
    margin-bottom: 20px;
  }
  .notes-stream .article-preview-cover {
    min-height: 174px;
    height: auto;
  }
  .notes-stream .long-copy h2 {
    margin-top: 21px;
    font-size: 23px;
  }
  .notes-stream .short-post {
    padding: 19px 4px;
  }
  .notes-stream .short-copy {
    margin-left: 0;
    max-width: none;
  }
  .notes-stream .short-copy p {
    font-size: 15px;
  }
  .notes-stream .short-post .stream-post-foot {
    margin-left: 0;
  }
  .stream-end {
    padding-left: 4px;
  }
  .alpha-product-head {
    padding: 27px 0 28px;
  }
  .alpha-product-head h1 {
    font-size: 41px;
  }
  .profile-intro {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 30px 0 40px;
  }
  .profile-portrait {
    width: 190px;
  }
  .profile-copy h1 {
    font-size: 41px;
  }
  .profile-copy > p {
    font-size: 14px;
  }
  .social-matrix-grid {
    gap: 14px;
  }
  .social-account {
    padding: 18px 13px;
    gap: 11px;
  }
  .social-platform-icon {
    width: 32px;
    height: 32px;
    border-radius: 9px;
  }
  .social-account strong {
    font-size: 12px;
  }
  .social-account small {
    font-size: 10px;
  }
  .footer {
    margin-top: 40px;
    padding: 32px 0 26px;
  }
  .footer-bottom {
    gap: 17px;
    margin-top: 26px;
  }
}
/* 横向长文卡片在平板上也给封面标题留足空间。 */
.notes-stream .article-preview-cover {
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 18px;
}
.notes-stream .article-preview-cover b {
  font-size: clamp(38px, 4.4vw, 70px);
}

/* 单人笔记仅显示日期，不保留头像和作者栏的缩进。 */
.stream-meta {
  margin-bottom: 16px;
  line-height: 1.5;
}
.stream-meta time {
  margin: 0;
  font-size: 11px;
  color: var(--muted);
}
.notes-stream .long-post .stream-meta {
  margin-bottom: 18px;
}

/* 宋体承担阅读标题，黑体承担正文与操作信息。 */
:is(
  .quiet-section-head h1,
  .quiet-section-head h2,
  .plain-page-head h1,
  .long-copy h2,
  .focused-course-copy h3,
  .subscription-block h2,
  .course-detail h1,
  .report-heading h1,
  .report-body h2
) {
  font-family: var(--serif);
  font-weight: 500;
  letter-spacing: 0.005em;
}
html[lang="en"]
  :is(
    .quiet-section-head h1,
    .quiet-section-head h2,
    .plain-page-head h1,
    .long-copy h2,
    .focused-course-copy h3,
    .subscription-block h2,
    .course-detail h1,
    .report-heading h1,
    .report-body h2
  ) {
  letter-spacing: -0.02em;
}
body {
  font-weight: 400;
}
.short-copy p,
.notes-stream .short-copy p {
  font-weight: 400;
}
.long-copy h2,
.focused-course-copy h3 {
  line-height: 1.65;
}
.nav a,
.btn,
.stream-meta,
.stream-post-foot {
  font-family: var(--sans);
}

/* 中文遵循 Next Token 的无衬线方向；不照搬其超大首屏字号。 */
:root {
  --display: var(--sans);
  --condensed: var(--sans);
}
html[lang="en"] {
  --display: "Milo Anton", "Milo Inter", sans-serif;
  --condensed: "Milo Oswald", "Milo Inter", sans-serif;
}
:is(
  h1,
  h2,
  h3,
  .quiet-section-head h1,
  .quiet-section-head h2,
  .plain-page-head h1,
  .long-copy h2,
  .focused-course-copy h3,
  .subscription-block h2,
  .course-detail h1,
  .report-heading h1,
  .report-body h2
) {
  font-family: var(--display);
  font-weight: 600;
  letter-spacing: -0.025em;
}
html[lang="en"]
  :is(
    h1,
    h2,
    h3,
    .quiet-section-head h1,
    .quiet-section-head h2,
    .plain-page-head h1,
    .long-copy h2,
    .focused-course-copy h3,
    .subscription-block h2,
    .course-detail h1,
    .report-heading h1,
    .report-body h2
  ) {
  font-family: var(--display);
  font-weight: 400;
  letter-spacing: 0.005em;
  line-height: 1.3;
}
html[lang="en"]
  :is(
    .plain-page-head h1,
    .quiet-section-head h1,
    .quiet-section-head h2,
    .alpha-product-head h1
  ) {
  text-transform: uppercase;
}
html[lang="en"] :is(.section-kicker, .stream-meta, .tag, .slide-tabs button) {
  font-family: var(--condensed);
  letter-spacing: 0.025em;
}
.brand-mark,
.profile-portrait > span {
  font-family: var(--sans);
  font-weight: 500;
}
/* 笔记流共用同一条文字起线：封面右置，短记和长文不使用独立卡片底色。 */
.notes-stream .stream-post {
  padding: 27px 0;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
}
.notes-stream .long-post {
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.8fr);
  column-gap: 48px;
}
.notes-stream .long-post .stream-meta {
  grid-column: 1 / -1;
  grid-row: 1;
}
.notes-stream .long-post .long-copy {
  grid-column: 1;
  grid-row: 2;
}
.notes-stream .long-post .stream-cover-link {
  grid-column: 2;
  grid-row: 2;
}
.notes-stream .long-copy h2 {
  font-size: 25px;
}
.notes-stream .short-copy,
.notes-stream .short-post .stream-post-foot {
  margin-left: 0;
}
.notes-stream .short-copy {
  max-width: 820px;
}
.notes-stream .long-copy > p {
  font-size: 15px;
}
.notes-stream .article-preview-cover {
  min-height: 190px;
}
.stream-end {
  padding-left: 0;
}
/* 截图对应的功能说明，不另造复杂功能表。 */
.alpha-feature-section {
  margin: 48px 0 25px;
}
.alpha-feature-heading > span {
  font: 12px var(--condensed);
  color: var(--muted);
}
.alpha-feature-heading h2 {
  font-size: 27px;
  margin: 9px 0 25px;
}
.alpha-feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 36px;
}
.alpha-feature-grid h3 {
  font: 600 16px/1.5 var(--sans);
  margin-bottom: 12px;
}
.alpha-feature-grid p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.95;
}
/* 轻页脚：只保留版权与协议链接。 */
.footer.footer-minimal {
  background: transparent;
  border: 0;
  padding: 25px 0 30px;
  margin-top: 45px;
}
.footer-minimal-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 15px 30px;
  color: var(--muted);
}
.footer-minimal small {
  font-size: 11px;
}
.footer-minimal nav {
  display: flex;
  gap: 25px;
  font-size: 12px;
}
@media (max-width: 700px) {
  .notes-stream .stream-post {
    padding: 20px 0;
  }
  .notes-stream .long-post {
    display: flex;
    flex-direction: column;
    gap: 0;
  }
  .notes-stream .long-post .stream-meta {
    order: 0;
  }
  .notes-stream .long-post .long-copy {
    order: 1;
  }
  .notes-stream .long-post .stream-cover-link {
    order: 2;
    margin-top: 20px;
  }
  .notes-stream .long-copy h2 {
    margin-top: 0;
    font-size: 23px;
  }
  .notes-stream .article-preview-cover {
    min-height: 165px;
  }
  .alpha-feature-section {
    margin-top: 35px;
  }
  .alpha-feature-grid {
    grid-template-columns: 1fr;
    gap: 22px;
  }
  .alpha-feature-grid h3 {
    margin-bottom: 8px;
  }
  .alpha-feature-heading h2 {
    font-size: 24px;
  }
  .footer.footer-minimal {
    margin-top: 35px;
    padding: 22px 0;
  }
}

/* 两种内容明确区分：短记为正文气泡，长文为紧凑摘要与封面。 */
.notes-stream {
  gap: 34px;
}
.notes-stream .stream-post {
  padding: 10px 0;
}
.notes-stream .stream-meta {
  margin-bottom: 13px;
}
.short-bubble {
  max-width: 910px;
  padding: 24px 28px;
  background: var(--soft);
  border-radius: 4px 18px 18px 18px;
}
.notes-stream .short-copy {
  max-width: none;
}
.notes-stream .short-copy p {
  font-size: 15px;
  line-height: 1.95;
}
.notes-stream .short-post .stream-post-foot {
  margin: 16px 0 0;
  font-size: 11px;
}
.notes-stream .long-post {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  column-gap: 34px;
  align-items: start;
}
.notes-stream .long-post .stream-meta {
  grid-column: 1;
  grid-row: 1;
  margin-bottom: 13px;
}
.notes-stream .long-post .long-copy {
  grid-column: 1;
  grid-row: 2;
  justify-content: flex-start;
}
.notes-stream .long-post .stream-cover-link {
  grid-column: 2;
  grid-row: 1 / span 2;
  align-self: start;
}
.notes-stream .long-copy h2 {
  font-size: 24px;
  margin: 0 0 12px;
  line-height: 1.5;
}
.notes-stream .long-copy > p {
  font-size: 14px;
  line-height: 1.85;
}
.notes-stream .long-copy .stream-post-foot {
  margin-top: 17px;
  padding: 0;
}
.notes-stream .article-preview-cover {
  min-height: 0;
  height: 162px;
  padding: 20px;
}
.notes-stream .article-preview-cover b {
  font-size: 40px;
}
.notes-stream .article-preview-cover small {
  font-size: 9px;
}
/* 阅读页只留居中的标题与正文，无侧栏。 */
.report-heading,
.report-layout {
  max-width: 880px;
  margin-left: auto;
  margin-right: auto;
}
.report-layout {
  display: block;
}
.report-body {
  max-width: none;
}
/* 产品页：左功能、右截图，同一画面索引驱动两侧。 */
.alpha-product-stage {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.5fr);
  gap: 48px;
  align-items: center;
  margin: 12px 0 25px;
}
.alpha-product-stage > * {
  min-width: 0;
}
.alpha-product-stage .alpha-feature-section {
  margin: 0;
}
.alpha-product-stage .alpha-feature-heading h2 {
  margin: 10px 0 24px;
  font-size: 29px;
}
.alpha-product-stage .alpha-feature-grid {
  grid-template-columns: 1fr;
  gap: 22px;
}
.alpha-product-stage .alpha-feature-grid h3 {
  font-size: 16px;
  margin-bottom: 7px;
}
.alpha-product-stage .alpha-feature-grid p {
  font-size: 13px;
  line-height: 1.95;
}
.alpha-product-stage .alpha-caption > span {
  display: none;
}
.alpha-product-stage .alpha-caption {
  justify-content: center;
}
@media (max-width: 1000px) {
  .alpha-product-stage {
    gap: 30px;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.3fr);
  }
  .notes-stream .long-post {
    grid-template-columns: minmax(0, 1fr) 235px;
    gap: 0 27px;
  }
}
@media (max-width: 700px) {
  .notes-stream {
    gap: 27px;
  }
  .short-bubble {
    padding: 21px 23px;
    border-radius: 4px 15px 15px 15px;
  }
  .notes-stream .long-post {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 108px;
    column-gap: 17px;
  }
  .notes-stream .long-post .stream-cover-link {
    margin: 0;
  }
  .notes-stream .long-copy h2 {
    font-size: 19px;
    margin: 0 0 9px;
  }
  .notes-stream .long-copy > p {
    font-size: 12px;
    line-height: 1.8;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  .notes-stream .long-copy .stream-post-foot {
    flex-wrap: wrap;
    gap: 8px;
    font-size: 10px;
    margin-top: 12px;
  }
  .notes-stream .long-copy .text-link {
    font-size: 11px;
  }
  .notes-stream .article-preview-cover {
    height: 108px;
    padding: 13px;
    border-radius: 6px;
    gap: 9px;
  }
  .notes-stream .article-preview-cover > span {
    font-size: 8px;
  }
  .notes-stream .article-preview-cover b {
    font-size: 18px;
  }
  .notes-stream .article-preview-cover small {
    display: none;
  }
  .report-heading {
    padding-top: 30px;
  }
  .alpha-product-stage {
    grid-template-columns: 1fr;
    gap: 28px;
    align-items: start;
  }
  .alpha-product-stage .alpha-feature-grid {
    gap: 16px;
  }
  .alpha-product-stage .alpha-feature-heading h2 {
    font-size: 26px;
    margin-bottom: 20px;
  }
}

/* 学习中心沿用公共站视觉，不重复品牌，不做第二个仪表盘。 */
.account-layout {
  grid-template-columns: 176px minmax(0, 1fr);
  gap: 62px;
  padding: 43px 0 38px;
  min-height: 630px;
}
.account-nav nav {
  padding-top: 3px;
}
.account-nav a {
  margin: 0 0 7px;
  padding: 12px 15px;
  gap: 11px;
  border-radius: 8px;
  color: var(--muted);
}
.account-nav a.active {
  color: var(--green);
  background: var(--soft);
}
.account-nav .icon {
  width: 17px;
  height: 17px;
}
.account-main h1 {
  font-size: 32px;
  letter-spacing: -0.025em;
}
.study-heading {
  display: flex;
  justify-content: space-between;
  gap: 25px;
  align-items: start;
  margin: 0 0 31px;
}
.study-heading p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 12px;
}
.study-heading > .tag {
  border: 0;
  background: var(--soft);
  margin-top: 5px;
  font-size: 11px;
}
.study-course {
  padding: 32px;
  background: var(--surface);
  border-radius: 14px;
  box-shadow: var(--card-shadow);
}
.study-course-head {
  display: flex;
  align-items: center;
  gap: 25px;
}
.study-course-cover {
  width: 98px;
  height: 108px;
  flex: none;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--soft);
  font: 400 35px var(--display);
  color: var(--green);
}
.study-course-head .tag {
  font-size: 10px;
}
.study-course-head h2 {
  font-size: 24px;
  line-height: 1.5;
  margin: 10px 0 8px;
}
.study-course-head p {
  font-size: 13px;
  color: var(--muted);
}
.study-progress {
  margin: 28px 0 24px;
}
.study-progress > div:first-child {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--muted);
}
.study-progress .progress {
  margin: 12px 0 0;
  height: 5px;
}
.study-course-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
.study-course-actions small {
  color: var(--muted);
  font-size: 11px;
}
.study-course-actions .btn {
  min-width: 160px;
}
.account-utilities {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 25px;
  margin-top: 30px;
}
.account-utility {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 19px 0;
}
.account-utility > .icon:first-child {
  width: 20px;
  height: 20px;
  color: var(--green);
}
.account-utility > .icon:last-child {
  width: 15px;
  margin-left: auto;
  color: var(--muted);
}
.account-utility > span {
  min-width: 0;
}
.account-utility strong {
  display: block;
  font-size: 14px;
  font-weight: 500;
}
.account-utility small {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 6px;
  line-height: 1.8;
}
@media (max-width: 900px) {
  .account-layout {
    gap: 32px;
    grid-template-columns: 150px minmax(0, 1fr);
  }
  .study-course {
    padding: 26px;
  }
  .study-course-head {
    gap: 20px;
  }
  .study-course-cover {
    width: 78px;
    height: 90px;
  }
  .study-course-head h2 {
    font-size: 22px;
  }
  .account-utilities {
    grid-template-columns: 1fr;
    gap: 0;
  }
}
@media (max-width: 620px) {
  .account-layout {
    display: block;
    padding-top: 23px;
    min-height: 0;
  }
  .account-nav {
    margin-bottom: 31px;
  }
  .account-nav nav {
    display: flex;
    flex-wrap: wrap;
    overflow: visible;
    gap: 7px;
    border: 0;
    padding: 0;
  }
  .account-nav a {
    font-size: 11px;
    padding: 9px 11px;
    gap: 7px;
    margin: 0;
  }
  .account-nav .icon {
    width: 15px;
    height: 15px;
  }
  .account-main h1 {
    font-size: 29px;
  }
  .study-heading {
    margin-bottom: 25px;
    gap: 15px;
  }
  .study-heading p {
    font-size: 13px;
    max-width: 230px;
  }
  .study-heading > .tag {
    font-size: 9px;
    white-space: nowrap;
    padding: 4px 7px;
  }
  .study-course {
    padding: 23px;
  }
  .study-course-head {
    gap: 16px;
    align-items: start;
  }
  .study-course-cover {
    width: 57px;
    height: 67px;
    font-size: 26px;
  }
  .study-course-head h2 {
    font-size: 20px;
    margin-top: 8px;
  }
  .study-course-head p {
    font-size: 12px;
    line-height: 1.8;
  }
  .study-progress {
    margin: 23px 0;
  }
  .study-course-actions {
    flex-direction: column-reverse;
    align-items: stretch;
    gap: 15px;
    text-align: center;
  }
  .study-course-actions .btn {
    width: 100%;
  }
  .account-utilities {
    margin-top: 18px;
  }
}

/* 长文按用户确认的常规列表：封面左，标题与摘要右。 */
.notes-stream .long-post {
  grid-template-columns: 250px minmax(0, 1fr);
  column-gap: 32px;
}
.notes-stream .long-post .stream-cover-link {
  grid-column: 1;
  grid-row: 1 / span 2;
}
.notes-stream .long-post .stream-meta {
  grid-column: 2;
  grid-row: 1;
}
.notes-stream .long-post .long-copy {
  grid-column: 2;
  grid-row: 2;
}
.notes-stream .long-copy .stream-post-foot {
  justify-content: flex-start;
  gap: 24px;
}
@media (max-width: 1000px) {
  .notes-stream .long-post {
    grid-template-columns: 210px minmax(0, 1fr);
    column-gap: 27px;
  }
}
@media (max-width: 700px) {
  .notes-stream .long-post {
    grid-template-columns: 100px minmax(0, 1fr);
    column-gap: 17px;
  }
  .notes-stream .long-copy h2 {
    font-size: 18px;
    line-height: 1.55;
  }
  .notes-stream .long-copy .stream-post-foot {
    gap: 9px;
  }
}

/* 首页和笔记流共用短记气泡，不再额外包裹首页白色卡片。 */
.home-short-notes .short-post {
  padding: 0;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
}
.short-bubble .stream-post-foot {
  margin: 16px 0 0;
  font-size: 11px;
}