.page-about {
  --about-rail: 210px;
  --about-gap: clamp(24px, 4vw, 60px);
  --about-prose: 62ch;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  padding: clamp(22px, 4vw, 40px) 0 clamp(36px, 5vw, 64px);
  background:
    radial-gradient(120% 90% at 92% -10%, rgba(255, 90, 31, 0.16), transparent 62%),
    radial-gradient(90% 80% at -10% 110%, rgba(34, 211, 197, 0.10), transparent 66%),
    linear-gradient(180deg, var(--navy-900) 0%, var(--navy-800) 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, rgba(22, 64, 92, 0.55) 0 1px, transparent 1px 96px);
  opacity: 0.55;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
}

.page-about .about-title {
  margin: 12px 0 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(2.1rem, 6.4vw, 4.6rem);
  line-height: 1.04;
  letter-spacing: -0.03em;
  color: var(--ice);
}

.page-about .about-lede {
  margin-top: clamp(16px, 2.4vw, 24px);
  max-width: 56ch;
  color: var(--text-soft);
  font-size: clamp(0.98rem, 1.6vw, 1.06rem);
  line-height: 1.8;
}

.page-about .about-hero-actions {
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-hero-media {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  background: var(--surface-2);
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
}

.page-about .about-hero-media::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 96px;
  height: 3px;
  background: var(--lava);
}

.page-about .media-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .about-hero-media .media-caption {
  position: absolute;
  left: 14px;
  bottom: 14px;
  right: 14px;
  margin: 0;
  padding: 6px 10px;
  background: rgba(4, 17, 29, 0.78);
  border-left: 2px solid var(--cyan);
  color: var(--ice);
  font-family: var(--font-sans);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  line-height: 1.5;
}

/* 首屏数据条 */
.page-about .about-hero-stats {
  margin-top: clamp(28px, 4.5vw, 48px);
  padding-top: clamp(18px, 2.6vw, 26px);
  border-top: 1px solid var(--line);
  display: grid;
  gap: 18px 28px;
  grid-template-columns: 1fr;
}

.page-about .about-hero-stats .data-figure {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stat {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .about-stat .data-number {
  font-family: var(--font-num);
  font-size: clamp(1.7rem, 4.4vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  color: var(--lava);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat .data-unit {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--mist);
}

.page-about .about-hero-stats .data-label {
  font-size: 0.82rem;
  line-height: 1.55;
  color: var(--text-soft);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  gap: var(--about-gap);
  padding: clamp(32px, 5vw, 72px) 0 clamp(56px, 8vw, 110px);
}

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

.page-about .about-rail-label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .about-anchors .anchor-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-anchors .anchor-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  white-space: nowrap;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text-soft);
  font-size: 0.82rem;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-anchor-no {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-about .about-anchors .anchor-link:hover,
.page-about .about-anchors .anchor-link:focus-visible {
  color: var(--ice);
  border-color: var(--steel);
  background: var(--surface-2);
}

.page-about .about-anchors .anchor-link:hover .about-anchor-no,
.page-about .about-anchors .anchor-link:focus-visible .about-anchor-no {
  color: var(--lava);
}

.page-about .about-content {
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  position: relative;
  padding-top: clamp(22px, 3.4vw, 34px);
  border-top: 1px solid var(--line);
  scroll-margin-top: 96px;
}

.page-about .about-sec + .about-sec {
  margin-top: clamp(40px, 6vw, 76px);
}

.page-about .sec-head {
  display: grid;
  gap: 8px;
  margin-bottom: clamp(18px, 2.8vw, 30px);
}

.page-about .sec-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--lava);
}

.page-about .sec-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(1.55rem, 4.2vw, 2.5rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--ice);
  max-width: 26ch;
}

.page-about .sec-sub {
  margin: 0;
  max-width: var(--about-prose);
  color: var(--text-soft);
  font-size: 0.92rem;
  line-height: 1.7;
}

.page-about .about-prose {
  max-width: var(--about-prose);
  display: grid;
  gap: 14px;
}

.page-about .about-prose p {
  margin: 0;
  color: var(--text-soft);
  font-size: clamp(0.95rem, 1.6vw, 1rem);
  line-height: 1.85;
}

.page-about .about-prose p:first-child {
  color: var(--ice);
}

.page-about .about-points {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  max-width: var(--about-prose);
}

.page-about .about-points li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line);
  color: var(--text-soft);
  font-size: 0.92rem;
  line-height: 1.6;
}

.page-about .about-point-mark {
  flex: none;
  width: 14px;
  height: 2px;
  margin-top: 0.7em;
  background: var(--cyan);
}

/* ---------- 四条主线 ---------- */
.page-about .mainlines {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .mainline {
  display: grid;
  gap: 8px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  transition: background var(--dur) var(--ease);
}

.page-about .mainline-no {
  font-family: var(--font-num);
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1;
  color: var(--steel);
  font-variant-numeric: tabular-nums;
  transition: color var(--dur) var(--ease);
}

.page-about .mainline-title {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 1.06rem;
  letter-spacing: 0.02em;
  color: var(--ice);
}

.page-about .mainline-body p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.9rem;
  line-height: 1.75;
}

.page-about .mainline-link {
  margin-top: 8px !important;
}

.page-about .mainline-link a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.84rem;
  color: var(--ember);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 138, 76, 0.4);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .mainline-link a::after {
  content: "→";
  font-family: var(--font-mono);
}

.page-about .mainline-link a:hover,
.page-about .mainline-link a:focus-visible {
  color: var(--lava);
  border-color: var(--lava);
}

.page-about .mainline:nth-child(1):hover .mainline-no { color: var(--lava); }
.page-about .mainline:nth-child(2):hover .mainline-no { color: var(--cyan); }
.page-about .mainline:nth-child(3):hover .mainline-no { color: var(--amber); }
.page-about .mainline:nth-child(4):hover .mainline-no { color: var(--ember); }

.page-about .mainline:nth-child(1) { box-shadow: inset 2px 0 0 transparent; }
.page-about .mainline:hover { background: rgba(11, 44, 69, 0.42); }

/* ---------- 团队四象限 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .quad {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  min-width: 0;
}

.page-about .quad-cell {
  position: relative;
  background: var(--surface);
  padding: clamp(16px, 2.6vw, 26px);
  transition: background var(--dur) var(--ease);
  outline-offset: -3px;
}

.page-about .quad-cell::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--lava);
  transition: height var(--dur) var(--ease);
}

.page-about .quad-cell:hover,
.page-about .quad-cell:focus-within,
.page-about .quad-cell:focus {
  background: var(--surface-2);
}

.page-about .quad-cell:hover::before,
.page-about .quad-cell:focus-within::before,
.page-about .quad-cell:focus::before {
  height: 100%;
}

.page-about .quad-index {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .quad-title {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 1.02rem;
  color: var(--ice);
}

.page-about .quad-text {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.86rem;
  line-height: 1.7;
}

.page-about .quad-list {
  list-style: none;
  margin: 12px 0 0;
  padding: 12px 0 0;
  border-top: 1px dashed var(--line);
  display: grid;
  gap: 6px;
}

.page-about .quad-list li {
  position: relative;
  padding-left: 14px;
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .quad-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--steel);
}

.page-about .about-team-media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 10px;
}

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

/* ---------- 版本演进 ---------- */
.page-about .about-sec--band::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--lava) 0%, var(--ember) 22%, var(--cyan) 52%, transparent 100%);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 clamp(20px, 3vw, 30px);
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-dot {
  position: absolute;
  left: -26px;
  top: 6px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--steel);
  background: var(--bg);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .tl-item--current .tl-dot {
  background: var(--lava);
  border-color: var(--lava);
  box-shadow: 0 0 0 4px rgba(255, 90, 31, 0.16);
}

.page-about .tl-item:hover .tl-dot {
  border-color: var(--cyan);
}

.page-about .tl-meta {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.page-about .tl-item--current .tl-meta {
  color: var(--lava);
}

.page-about .tl-title {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(1rem, 2.4vw, 1.14rem);
  line-height: 1.35;
  color: var(--ice);
}

.page-about .tl-text {
  margin: 0;
  max-width: var(--about-prose);
  color: var(--text-soft);
  font-size: 0.9rem;
  line-height: 1.8;
  transition: color var(--dur) var(--ease);
}

.page-about .tl-item:hover .tl-text {
  color: var(--ice);
}

.page-about .about-version-disclosure {
  margin-top: 12px;
  max-width: var(--about-prose);
  border: 1px solid var(--line);
  background: var(--surface);
}

.page-about .about-version-disclosure .disclosure-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 11px 14px;
  background: transparent;
  border: 0;
  color: var(--text-soft);
  font-family: var(--font-sans);
  font-size: 0.84rem;
  text-align: left;
  cursor: pointer;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-version-disclosure .disclosure-toggle:hover,
.page-about .about-version-disclosure .disclosure-toggle:focus-visible {
  color: var(--ice);
  background: var(--surface-2);
}

.page-about .about-version-disclosure .disclosure-icon {
  flex: none;
  width: 10px;
  height: 10px;
  border-right: 1px solid var(--lava);
  border-bottom: 1px solid var(--lava);
  transform: rotate(45deg);
  transition: transform var(--dur) var(--ease);
}

.page-about .about-version-disclosure [data-open] .disclosure-icon,
.page-about .about-version-disclosure .disclosure-toggle[aria-expanded="true"] .disclosure-icon {
  transform: rotate(-135deg);
}

.page-about .about-version-disclosure .disclosure-body {
  padding: 0 14px 12px;
  border-top: 1px solid var(--line);
}

.page-about .about-version-disclosure .disclosure-body p {
  margin: 10px 0 0;
  color: var(--text-soft);
  font-size: 0.85rem;
  line-height: 1.75;
}

.page-about .about-version-media {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 10px;
}

.page-about .about-version-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 2 / 1;
}

/* ---------- 维护节奏 ---------- */
.page-about .rhythm-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .rhythm-item {
  background: var(--surface);
  padding: clamp(16px, 2.6vw, 24px);
  display: grid;
  gap: 6px;
  transition: background var(--dur) var(--ease);
}

.page-about .rhythm-item:hover {
  background: var(--surface-2);
}

.page-about .rhythm-when {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .rhythm-title {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 0.98rem;
  line-height: 1.4;
  color: var(--ice);
}

.page-about .rhythm-text {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.86rem;
  line-height: 1.75;
}

/* ---------- 联系 ---------- */
.page-about .about-sec--contact {
  padding-top: clamp(26px, 4vw, 40px);
}

.page-about .contact-routes {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .route-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 4px 14px;
  align-items: start;
  padding: clamp(16px, 2.6vw, 22px);
  background: var(--surface);
  text-decoration: none;
  transition: background var(--dur) var(--ease);
}

.page-about .route-row:hover,
.page-about .route-row:focus-visible {
  background: var(--surface-2);
}

.page-about .route-index {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--steel);
  padding-top: 3px;
}

.page-about .route-main {
  display: grid;
  gap: 5px;
  min-width: 0;
}

.page-about .route-title {
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 0.98rem;
  color: var(--ice);
}

.page-about .route-text {
  color: var(--text-soft);
  font-size: 0.85rem;
  line-height: 1.72;
}

.page-about .route-arrow {
  font-family: var(--font-mono);
  color: var(--lava);
  transition: transform var(--dur) var(--ease);
}

.page-about .route-row:hover .route-arrow,
.page-about .route-row:focus-visible .route-arrow {
  transform: translateX(3px);
}

.page-about .about-sign {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--text-soft);
  font-size: 0.88rem;
  line-height: 1.7;
}

.page-about .about-sign a {
  color: var(--ember);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 138, 76, 0.4);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-sign a:hover,
.page-about .about-sign a:focus-visible {
  color: var(--lava);
  border-color: var(--lava);
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about [tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-hero-stats .data-figure + .data-figure {
    padding-left: 20px;
    border-left: 1px solid var(--line);
  }
}

@media (min-width: 720px) {
  .page-about .mainline {
    grid-template-columns: 56px minmax(0, 0.7fr) minmax(0, 1.6fr);
    gap: 6px 20px;
    align-items: start;
    padding: 20px 12px 20px 0;
  }

  .page-about .mainline-no {
    font-size: 1.6rem;
  }

  .page-about .mainline-title {
    font-size: 1.14rem;
    padding-top: 2px;
  }

  .page-about .quad {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .rhythm-list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-hero-media {
    aspect-ratio: 4 / 3;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 86%);
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

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

  .page-about .about-anchors .anchor-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-anchors .anchor-link {
    display: flex;
    width: 100%;
    padding: 9px 0;
    border: 0;
    border-bottom: 1px solid rgba(22, 64, 92, 0.7);
    background: transparent;
    font-size: 0.84rem;
  }

  .page-about .about-anchors .anchor-link:hover,
  .page-about .about-anchors .anchor-link:focus-visible {
    background: transparent;
    padding-left: 6px;
  }

  .page-about .about-sec {
    scroll-margin-top: 120px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 1ms !important;
  }
}
<<<END>>>