.page-about {
  --about-rail: 236px;
  --about-gap: clamp(24px, 4vw, 56px);
  --about-body: #C9DAE7;
  position: relative;
}

.page-about .breadcrumbs {
  margin-top: 20px;
}

/* ---------- 首屏 ---------- */
.page-about .story-hero {
  position: relative;
  padding: clamp(24px, 4vw, 44px) 0 clamp(30px, 5vw, 60px);
  overflow: hidden;
}

.page-about .story-hero::before {
  content: "";
  position: absolute;
  inset: -12% -18% -6% -18%;
  z-index: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(102deg, rgba(43, 232, 198, .07) 0 1px, transparent 1px 94px),
    radial-gradient(58% 68% at 78% 16%, rgba(43, 232, 198, .14), transparent 70%),
    radial-gradient(52% 62% at 4% 94%, rgba(255, 138, 61, .13), transparent 72%);
}

.page-about .story-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  align-items: center;
  min-width: 0;
}

.page-about .story-hero__text {
  min-width: 0;
}

.page-about .story-hero h1 {
  margin: .6rem 0 0;
  max-width: 20ch;
  font-size: clamp(2rem, 5.6vw, 3.85rem);
  line-height: 1.06;
  font-weight: 900;
  letter-spacing: -.02em;
  color: var(--mist);
}

.page-about .story-hero .lede {
  margin-top: 18px;
  max-width: 48ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.75;
  color: var(--about-body);
}

.page-about .hero-note {
  margin: 26px 0 0;
  padding-left: 16px;
  max-width: 42ch;
  border-left: 2px solid var(--orange);
  color: var(--mist);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .story-hero__media {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--night);
  box-shadow: var(--shadow-float);
}

.page-about .story-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .story-hero__media .media-caption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--slate);
  background: rgba(4, 18, 31, .62);
}

@media (min-width: 960px) {
  .page-about .story-hero__grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
    gap: clamp(32px, 4.5vw, 64px);
  }
}

/* ---------- 杂志式两栏 ---------- */
.page-about .story-body {
  display: grid;
  gap: 34px;
  margin-top: clamp(28px, 5vw, 56px);
  min-width: 0;
}

.page-about .story-rail {
  min-width: 0;
}

.page-about .story-toc {
  padding: 18px 0 6px;
  border-top: 1px solid var(--line);
}

.page-about .story-toc__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--slate);
}

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

.page-about .story-toc a {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 6px 0 6px 10px;
  border-left: 2px solid transparent;
  color: var(--about-body);
  font-size: 14px;
  line-height: 1.5;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .story-toc a .mono {
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .story-toc a:hover,
.page-about .story-toc a:focus-visible {
  color: var(--mist);
  border-left-color: var(--orange);
}

.page-about .story-toc a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .story-rail__note {
  margin: 18px 0 0;
  padding-left: 12px;
  border-left: 1px solid var(--line);
  color: var(--slate);
  font-size: 13px;
  line-height: 1.7;
}

@media (min-width: 1000px) {
  .page-about .story-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .story-rail {
    position: sticky;
    top: calc(var(--header-space) + 18px);
    align-self: start;
  }
}

.page-about .story-column {
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(28px, 4.4vw, 50px);
  border-top: 1px solid rgba(30, 68, 98, .9);
}

.page-about .story-column > .chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  margin-bottom: 18px;
}

.page-about .chapter-num {
  display: inline-block;
  padding-top: 5px;
  border-top: 2px solid var(--cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .chapter h2 {
  margin: 0;
  font-size: clamp(1.4rem, 2.7vw, 2.05rem);
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--mist);
}

.page-about .chapter p {
  max-width: 64ch;
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .chapter__more {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.page-about .pull-quote {
  margin: 26px 0 8px;
  padding: 4px 0 4px 20px;
  border-left: 2px solid var(--orange);
  font-size: clamp(1.02rem, 2.1vw, 1.3rem);
  line-height: 1.55;
  font-weight: 700;
  color: var(--mist);
}

.page-about .story-figure {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--night);
}

.page-about .story-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .story-figure .media-caption {
  padding: 11px 15px;
  font-size: 13px;
  color: var(--slate);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  margin-top: 26px;
  padding-top: 36px;
}

.page-about .timeline__track {
  position: absolute;
  top: 6px;
  left: 0;
  width: 100%;
  height: 4px;
  display: block;
}

.page-about .timeline__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 20px;
  grid-template-columns: 1fr;
}

.page-about .timeline__list > li {
  min-width: 0;
}

.page-about .tl-node {
  position: relative;
  padding-top: 8px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  top: -34px;
  left: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 232, 198, .16);
}

.page-about .timeline__list > li:nth-child(2) .tl-node::before {
  background: var(--cyan-dim);
}

.page-about .timeline__list > li:nth-child(3) .tl-node::before {
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 138, 61, .16);
}

.page-about .timeline__list > li:nth-child(4) .tl-node::before {
  background: var(--orange-dim);
  box-shadow: 0 0 0 4px rgba(199, 90, 30, .18);
}

.page-about .tl-node summary {
  position: relative;
  display: block;
  padding: 0 26px 8px 0;
  border-bottom: 1px solid var(--line);
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl-node summary::after {
  content: "+";
  position: absolute;
  top: 0;
  right: 0;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
}

.page-about .tl-node[open] summary::after {
  content: "–";
  color: var(--cyan);
}

.page-about .tl-node summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .tl-node__step {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--slate);
}

.page-about .tl-node__title {
  display: block;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--mist);
}

.page-about .tl-node p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--about-body);
}

@media (min-width: 820px) {
  .page-about .timeline__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
  }
}

/* ---------- 团队分工 ---------- */
.page-about .tabs {
  margin-top: 22px;
}

.page-about .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .tab {
  padding: 9px 18px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: transparent;
  color: var(--about-body);
  font-family: inherit;
  font-size: 14px;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.page-about .tab:hover {
  border-color: var(--cyan);
  color: var(--mist);
}

.page-about .tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
  font-weight: 700;
}

.page-about .tab:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

.page-about .tab-panel {
  padding-top: 20px;
}

.page-about .tab-panel p {
  max-width: 62ch;
  margin: 0 0 12px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-body);
}

/* ---------- 统计 ---------- */
.page-about .stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin: 26px 0 22px;
  padding: 0;
  list-style: none;
}

.page-about .stat {
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  min-width: 0;
}

.page-about .stat:nth-child(even) {
  border-left-color: var(--orange);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.6vw, 2.15rem);
  line-height: 1.15;
  letter-spacing: .02em;
  color: var(--mist);
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--slate);
}

@media (min-width: 760px) {
  .page-about .stat-row {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
  }
}

/* ---------- 后续入口 ---------- */
.page-about .story-next {
  margin-top: clamp(34px, 5.5vw, 68px);
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

.page-about .story-next h2 {
  margin: 0;
  font-size: clamp(1.35rem, 2.5vw, 1.9rem);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--mist);
}

.page-about .story-next > p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .next-links {
  display: grid;
  gap: 12px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .next-links li {
  min-width: 0;
}

.page-about .next-links a {
  display: block;
  height: 100%;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--mist);
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  transition: border-color .2s ease, background-color .2s ease, transform .22s ease;
}

.page-about .next-links a span {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--slate);
}

.page-about .next-links a:hover,
.page-about .next-links a:focus-visible {
  border-color: var(--cyan);
  background: rgba(43, 232, 198, .07);
  transform: translateX(3px);
}

.page-about .next-links a:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

@media (min-width: 760px) {
  .page-about .next-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (min-width: 1080px) {
  .page-about .next-links {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next-links a:hover,
  .page-about .next-links a:focus-visible {
    transform: none;
  }
}
</main>