.page-about {
  --about-rail: 196px;
  position: relative;
  padding-block: 104px 96px;
  color: var(--ink);
  overflow-x: clip;
  background:
    radial-gradient(560px 380px at 94% 3%, rgba(255, 62, 157, .10), transparent 64%),
    radial-gradient(520px 400px at 2% 0%, rgba(46, 230, 222, .08), transparent 62%);
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 26px;
  font-size: 13px;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  max-width: 900px;
}

.page-about .about-kicker {
  display: inline-block;
  margin: 0;
  padding: 6px 13px;
  border: 1px solid rgba(46, 230, 222, .35);
  border-radius: var(--r-pill);
  background: rgba(46, 230, 222, .06);
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 20px 0 0;
  font-family: var(--font-head);
  font-size: clamp(30px, 6.2vw, 58px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: .01em;
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-lede--sub {
  margin-top: 12px;
  color: rgba(151, 163, 196, .82);
}

.page-about .about-stats {
  margin-top: 38px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: var(--line);
  overflow: hidden;
}

.page-about .about-stat {
  padding: 18px 16px;
  background: var(--panel);
}

.page-about .about-stat b {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(24px, 6vw, 38px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--gold);
}

.page-about .about-stat span {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 主体布局 ---------- */

.page-about .about-layout {
  margin-top: 56px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-rail {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: linear-gradient(180deg, rgba(22, 32, 60, .85), rgba(13, 20, 40, .6));
}

.page-about .rail-title {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .rail-years {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .rail-years li {
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(5, 7, 15, .5);
}

.page-about .rail-year {
  font-family: var(--font-num);
  font-size: 13px;
  color: var(--cyan);
}

.page-about .rail-note {
  font-size: 11px;
  color: var(--muted);
  white-space: nowrap;
}

.page-about .about-flow {
  display: grid;
  gap: 24px;
  min-width: 0;
}

/* ---------- 研究板卡片 ---------- */

.page-about .board {
  position: relative;
  padding: 26px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-l);
  background: var(--panel);
  overflow: hidden;
}

.page-about .board::after {
  content: "";
  position: absolute;
  top: -70px;
  right: -80px;
  width: 260px;
  height: 240px;
  border-radius: 46% 54% 60% 40% / 52% 44% 56% 48%;
  background: radial-gradient(circle at 40% 40%, rgba(46, 230, 222, .13), transparent 68%);
  pointer-events: none;
}

.page-about .board:nth-child(2)::after {
  top: auto;
  right: auto;
  bottom: -90px;
  left: -90px;
  background: radial-gradient(circle at 40% 40%, rgba(255, 62, 157, .13), transparent 68%);
}

.page-about .board:nth-child(3)::after {
  background: radial-gradient(circle at 40% 40%, rgba(122, 75, 255, .15), transparent 68%);
}

.page-about .section-head {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: 12px 14px;
  margin-bottom: 22px;
}

.page-about .section-index {
  margin: 0;
  padding-top: 6px;
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(21px, 3.6vw, 32px);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: .01em;
}

.page-about .section-note {
  display: none;
}

.page-about .board-lede {
  margin: 0 0 22px;
  max-width: 64ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 0 0 24px;
}

.page-about .about-split .about-figure,
.page-about .team-grid .about-figure {
  margin-bottom: 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: var(--raise);
  object-fit: cover;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  padding-left: 12px;
  border-left: 2px solid rgba(46, 230, 222, .5);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */

.page-about .about-split {
  display: grid;
  gap: 24px;
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--violet), transparent);
}

.page-about .about-timeline li {
  position: relative;
  padding-bottom: 20px;
}

.page-about .about-timeline li:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline li::before {
  content: "";
  position: absolute;
  left: -19px;
  top: 7px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--bg);
  transition: background .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .about-timeline li:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(46, 230, 222, .16);
}

.page-about .tl-year {
  font-family: var(--font-num);
  font-size: 20px;
  letter-spacing: -.01em;
  color: var(--gold);
}

.page-about .tl-sum {
  margin: 4px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 流程步骤 ---------- */

.page-about .flow-steps {
  display: grid;
  gap: 12px;
}

.page-about .flow-step {
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: rgba(5, 7, 15, .45);
  overflow: hidden;
  transition: border-color .24s var(--ease), background .24s var(--ease);
}

.page-about .flow-step[data-open="true"] {
  border-color: rgba(46, 230, 222, .55);
  background: rgba(22, 32, 60, .6);
}

.page-about .flow-step .disclosure-trigger {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 14px 16px;
  border: 0;
  background: transparent;
  color: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .flow-num {
  padding: 3px 9px;
  border: 1px solid rgba(46, 230, 222, .35);
  border-radius: var(--r-pill);
  font-family: var(--font-num);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .flow-name {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .flow-meta {
  font-family: var(--font-num);
  font-size: 11.5px;
  color: var(--muted);
  white-space: nowrap;
}

.page-about .flow-step .disclosure-body {
  padding: 0 16px 16px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .flow-step .disclosure-body p {
  margin: 0;
}

/* ---------- 团队 ---------- */

.page-about .team-grid {
  display: grid;
  gap: 24px;
}

.page-about .team-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .team-list li {
  padding: 13px 16px;
  border-left: 2px solid var(--violet);
  border-radius: 0 var(--r-s) var(--r-s) 0;
  background: rgba(22, 32, 60, .5);
}

.page-about .team-list li:nth-child(1) {
  border-left-color: var(--cyan);
}

.page-about .team-list li:nth-child(2) {
  border-left-color: var(--violet);
}

.page-about .team-list li:nth-child(3) {
  border-left-color: var(--gold);
}

.page-about .team-name {
  display: block;
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .team-desc {
  margin: 5px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .team-facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .team-facts li {
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(5, 7, 15, .5);
  font-size: 12.5px;
  color: var(--muted);
}

/* ---------- 索引与术语 ---------- */

.page-about .index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .index-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding-left: 14px;
  border-left: 1px solid var(--line);
}

.page-about .index-key {
  font-family: var(--font-num);
  font-size: 16px;
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .index-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .glossary {
  display: grid;
  gap: 8px;
  margin-top: 24px;
}

.page-about .glossary .disclosure {
  border: 1px solid var(--line);
  border-radius: var(--r-s);
  background: rgba(13, 20, 40, .6);
  transition: border-color .24s var(--ease);
}

.page-about .glossary .disclosure[data-open="true"] {
  border-color: rgba(46, 230, 222, .5);
}

.page-about .glossary .disclosure-trigger {
  display: flex;
  align-items: baseline;
  gap: 10px;
  width: 100%;
  padding: 12px 14px;
  border: 0;
  background: transparent;
  color: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .glossary-term {
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 15px;
  color: var(--cyan);
}

.page-about .glossary-hint {
  flex: 1 1 auto;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .glossary .disclosure-trigger::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-num);
  font-size: 15px;
  color: var(--cyan);
}

.page-about .glossary .disclosure[data-open="true"] .disclosure-trigger::after {
  content: "–";
}

.page-about .glossary .disclosure-body {
  padding: 0 14px 14px;
}

.page-about .glossary .disclosure-body p {
  margin: 0;
  padding-left: 12px;
  border-left: 2px solid rgba(46, 230, 222, .45);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 用法 ---------- */

.page-about .use-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .use-item {
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: rgba(22, 32, 60, .55);
  transition: border-color .24s var(--ease), transform .24s var(--ease);
}

.page-about .use-item:hover {
  border-color: rgba(46, 230, 222, .5);
}

.page-about .use-num {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 9px;
  border: 1px solid rgba(255, 200, 90, .4);
  border-radius: var(--r-pill);
  font-family: var(--font-num);
  font-size: 12px;
  color: var(--gold);
}

.page-about .use-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--ink);
}

.page-about .use-item p {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .use-link {
  display: inline-block;
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 230, 222, .45);
  padding-bottom: 2px;
}

.page-about .use-link:hover,
.page-about .use-link:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--magenta);
}

.page-about .about-closing {
  margin: 26px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-closing a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px dashed rgba(46, 230, 222, .5);
}

.page-about .about-closing a:hover,
.page-about .about-closing a:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.page-about .about-legal {
  margin: 18px 0 0;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(151, 163, 196, .7);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .board {
    padding: 38px 34px;
  }

  .page-about .section-head .section-note {
    display: block;
    position: absolute;
    top: 2px;
    right: -4px;
    margin: 0;
    writing-mode: vertical-rl;
    font-size: 11px;
    letter-spacing: .26em;
    color: rgba(46, 230, 222, .72);
  }

  .page-about .section-title {
    padding-right: 34px;
  }

  .page-about .index-list li {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .rail-sticky {
    position: sticky;
    top: 104px;
  }

  .page-about .rail-years {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
  }

  .page-about .rail-years li {
    position: relative;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 8px 0 12px 18px;
    border: 0;
    border-radius: 0;
    background: transparent;
  }

  .page-about .rail-years li::before {
    content: "";
    position: absolute;
    left: 1px;
    top: 15px;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--cyan);
    box-shadow: 0 0 10px rgba(46, 230, 222, .7);
  }

  .page-about .rail-years li::after {
    content: "";
    position: absolute;
    left: 4px;
    top: 24px;
    bottom: 0;
    width: 1px;
    background: var(--line);
  }

  .page-about .rail-years li:last-child::after {
    display: none;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 30px;
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    gap: 30px;
    align-items: start;
  }

  .page-about .use-list {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .use-item:nth-child(1) {
    grid-column: 1 / span 7;
  }

  .page-about .use-item:nth-child(2) {
    grid-column: 6 / span 7;
  }

  .page-about .use-item:nth-child(3) {
    grid-column: 2 / span 7;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline li::before,
  .page-about .flow-step,
  .page-about .use-item,
  .page-about .glossary .disclosure {
    transition: none;
  }
}