.page-about {
  --about-rail: 84px;
  --about-gap: clamp(16px, 3vw, 30px);
  position: relative;
  padding: clamp(18px, 3.6vw, 40px) var(--gut) calc(var(--dock-h) + 56px);
  color: var(--paper);
  overflow-x: clip;
}

.page-about::before {
  content: "";
  position: absolute;
  top: -70px;
  right: -90px;
  width: min(440px, 78vw);
  height: min(440px, 78vw);
  background: radial-gradient(circle at 42% 42%, rgba(56, 242, 196, 0.14), rgba(56, 242, 196, 0) 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-shell {
  position: relative;
  z-index: 1;
  max-width: 1120px;
}

.page-about .breadcrumb {
  font-size: 12px;
  margin-bottom: clamp(16px, 2.6vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-bottom: clamp(22px, 3.4vw, 34px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero h1 {
  font-family: var(--font-cond);
  font-size: clamp(31px, 7.4vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.022em;
  margin: 0.34em 0 0.5em;
  max-width: 21ch;
  color: var(--paper);
}

.page-about .h1-year {
  font-family: var(--font-mono);
  color: var(--amber);
  letter-spacing: -0.01em;
}

.page-about .about-lead {
  max-width: var(--measure);
  font-size: clamp(15px, 2.4vw, 17px);
  line-height: 1.85;
  color: rgba(242, 239, 228, 0.86);
  margin: 0;
}

.page-about .hero-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(22px, 3.6vw, 34px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .fig {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px 16px;
  background: var(--ink-zone);
}

.page-about .fig-num {
  font-family: var(--font-mono);
  font-size: clamp(21px, 4.6vw, 29px);
  line-height: 1.1;
  color: var(--cyan);
  letter-spacing: -0.01em;
}

.page-about .fig-num--amber {
  color: var(--amber);
}

.page-about .fig-k {
  font-size: 12px;
  line-height: 1.5;
  color: var(--stone);
  letter-spacing: 0.02em;
}

.page-about .media {
  border-radius: var(--radius);
}

.page-about .hero-media {
  margin: clamp(22px, 3.6vw, 38px) 0 0;
}

.page-about .media figcaption {
  padding-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--stone);
}

/* ---------- 章节跳转 ---------- */
.page-about .chapter-nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 14px 1px;
  margin: clamp(12px, 2vw, 20px) 0 0;
  border-bottom: 1px solid var(--line);
  scrollbar-width: none;
}

.page-about .chapter-nav::-webkit-scrollbar {
  display: none;
}

.page-about .chapter-nav a {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
  text-decoration: none;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.page-about .chapter-nav a:hover,
.page-about .chapter-nav a:focus-visible {
  color: var(--ink-night);
  background: var(--cyan);
  border-color: var(--cyan);
  outline: none;
}

/* ---------- 时间轴区块骨架 ---------- */
.page-about .about-block {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  padding: clamp(26px, 4.4vw, 46px) 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-block--last {
  border-bottom: none;
}

.page-about .block-rail {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  align-self: stretch;
}

.page-about .rail-year {
  font-size: clamp(17px, 3vw, 22px);
  color: var(--amber);
  letter-spacing: 0.04em;
}

.page-about .rail-idx {
  color: var(--cyan);
  opacity: 0.75;
}

.page-about .rail-line {
  flex: 1 1 auto;
  height: 1px;
  min-height: 1px;
  background: linear-gradient(90deg, var(--line-cyan), rgba(56, 242, 196, 0));
}

.page-about .block-body h2 {
  font-family: var(--font-cond);
  font-size: clamp(23px, 4.6vw, 37px);
  line-height: 1.16;
  letter-spacing: -0.018em;
  margin: 0.15em 0 0.55em;
  max-width: 24ch;
  color: var(--paper);
}

.page-about .block-body h3 {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
  margin: 0 0 6px;
  color: var(--paper);
  letter-spacing: 0.01em;
}

.page-about .block-body p {
  max-width: var(--measure);
  font-size: 15px;
  line-height: 1.85;
  color: rgba(242, 239, 228, 0.84);
  margin: 0 0 14px;
}

.page-about .block-body p:last-child {
  margin-bottom: 0;
}

.page-about .block-note {
  max-width: var(--measure);
  margin-top: 18px;
  border-left: 2px solid var(--clay);
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--stone);
}

/* ---------- 四条内容线 ---------- */
.page-about .line-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .line-list li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  padding: 15px 16px 16px;
  background: var(--moss);
}

.page-about .line-idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .line-list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 239, 228, 0.78);
}

/* ---------- 团队分工 ---------- */
.page-about .team-split {
  display: grid;
  gap: 14px;
  margin-top: 20px;
}

.page-about .team-card {
  position: relative;
  padding: 18px 18px 16px;
  background: linear-gradient(165deg, var(--moss), rgba(22, 61, 48, 0.42));
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .team-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 6vw, 38px);
  line-height: 1;
  color: var(--amber);
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}

.page-about .team-card p {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 239, 228, 0.78);
  margin-bottom: 0;
  max-width: none;
}

/* ---------- 折叠摘要 ---------- */
.page-about .tuck {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}

.page-about .tuck summary {
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .tuck summary::-webkit-details-marker {
  display: none;
}

.page-about .tuck summary::before {
  content: "+";
  font-size: 13px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .tuck[open] summary {
  color: var(--amber);
}

.page-about .tuck[open] summary::before {
  content: "−";
  color: var(--amber);
}

.page-about .tuck summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 3px;
}

.page-about .tuck p {
  margin: 9px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--stone);
  max-width: 46ch;
}

/* ---------- 比赛日三步 ---------- */
.page-about .steps {
  display: grid;
  gap: 1px;
  margin-top: 18px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .step {
  padding: 16px 16px 18px;
  background: var(--ink-zone);
  border-top: 2px solid var(--moss-hi);
}

.page-about .step:nth-child(2) {
  border-top-color: var(--cyan);
}

.page-about .step:nth-child(3) {
  border-top-color: var(--amber);
}

.page-about .step-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--stone);
}

.page-about .step h3 {
  margin: 8px 0 7px;
  font-size: 15px;
}

.page-about .step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: rgba(242, 239, 228, 0.76);
  max-width: none;
}

/* ---------- 协作网络 ---------- */
.page-about .network-grid {
  display: grid;
  gap: 18px;
  margin-top: 4px;
}

.page-about .network-list {
  list-style: none;
  margin: 16px 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .network-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(242, 239, 228, 0.84);
}

.page-about .network-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 9px;
  height: 2px;
  background: var(--cyan);
}

.page-about .network-media {
  margin: 0;
}

/* ---------- 版本演进 ---------- */
.page-about .version-spark {
  margin: 6px 0 18px;
  opacity: 0.9;
}

.page-about .version-spark svg {
  display: block;
  width: 100%;
  height: auto;
  max-height: 130px;
}

.page-about .version-rail {
  display: grid;
  gap: 14px;
  margin: 0 0 24px;
}

.page-about .v-node {
  position: relative;
  padding: 30px 16px 16px;
  background: linear-gradient(180deg, var(--moss), rgba(22, 61, 48, 0.3));
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .v-node::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 11px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(56, 242, 196, 0.14);
}

.page-about .v-node:last-child::before {
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(242, 181, 68, 0.16);
}

.page-about .v-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--amber);
  margin-bottom: 6px;
}

.page-about .v-node h3 {
  font-size: 15px;
  margin-bottom: 7px;
}

.page-about .v-node p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: rgba(242, 239, 228, 0.78);
  max-width: none;
}

.page-about .version-media {
  margin: 0;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-cta .btn {
  text-decoration: none;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-block {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .block-rail {
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 14px;
    padding-top: 8px;
    border-right: 1px solid var(--line-soft);
    padding-right: 12px;
  }

  .page-about .rail-line {
    width: 1px;
    height: auto;
    flex: 1 1 auto;
    min-height: 60px;
    background: linear-gradient(180deg, var(--line-cyan), rgba(56, 242, 196, 0));
  }

  .page-about .hero-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .team-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .network-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: start;
    gap: 24px;
  }

  .page-about .version-rail {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
    position: relative;
  }

  .page-about .version-rail::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 15px;
    height: 1px;
    background: var(--line-cyan);
  }

  .page-about .v-node {
    display: flex;
    flex-direction: column;
  }

  .page-about .team-split {
    grid-template-columns: 1.25fr 1fr 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .chapter-nav a,
  .page-about .tuck summary {
    transition: none;
  }
}
</final>
</final>