.page-about {
  --about-rail: 128px;
  background: var(--ink-900);
  color: var(--paper);
  padding-bottom: clamp(32px, 5vw, 64px);
  overflow-x: clip;
}

.page-about .about-crumbs {
  padding-top: clamp(96px, 12vw, 132px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(20px, 3vw, 40px) 0 clamp(48px, 7vw, 96px);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: center;
}

@media (min-width: 960px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }
}

.page-about .hero-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--cyan);
}

.page-about h1 {
  margin: 0 0 clamp(16px, 2vw, 24px);
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(32px, 6vw, 72px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-lead {
  margin: 0 0 clamp(22px, 3vw, 32px);
  max-width: 32em;
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.85;
  color: rgba(244, 233, 216, .78);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-hero-visual {
  margin: 0;
  padding: 6px;
  border-radius: var(--radius-lg);
  background: var(--grad-main);
  box-shadow: var(--shadow-soft);
}

.page-about .about-hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius-lg) - 6px);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  padding: clamp(56px, 8vw, 104px) 0;
  border-top: 2px solid var(--line-darker);
}

.page-about .about-chapter--paper {
  background-color: var(--paper);
  background-image: radial-gradient(rgba(27, 20, 16, .08) 1px, transparent 1px);
  background-size: 22px 22px;
  color: var(--brown);
  border-top: 2px solid var(--brown);
  border-bottom: 2px solid var(--brown);
}

.page-about .about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 40px);
}

@media (min-width: 880px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
  }
}

/* ---------- 左侧悬挂索引 ---------- */

.page-about .about-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--line-dark);
}

@media (min-width: 880px) {
  .page-about .about-rail {
    position: sticky;
    top: 112px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 0 0 0 14px;
    border-bottom: 0;
    border-left: 2px solid var(--line-dark);
  }
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 300;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--orange);
}

.page-about .rail-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: rgba(244, 233, 216, .55);
}

.page-about .about-chapter--paper .about-rail {
  border-color: rgba(27, 20, 16, .22);
}

.page-about .about-chapter--paper .rail-num {
  color: var(--red-orange);
}

.page-about .about-chapter--paper .rail-label {
  color: rgba(27, 20, 16, .55);
}

/* ---------- 正文 ---------- */

.page-about .about-body h2 {
  margin: 0 0 clamp(16px, 2vw, 26px);
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(26px, 4vw, 50px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.page-about .about-body > p {
  margin: 0 0 18px;
  max-width: 34em;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(244, 233, 216, .76);
}

.page-about .about-chapter--paper .about-body > p {
  color: rgba(27, 20, 16, .82);
}

.page-about .about-note {
  margin: clamp(24px, 3vw, 32px) 0 0;
  padding: 20px 22px;
  max-width: 34em;
  border-left: 3px solid var(--red-orange);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: rgba(244, 233, 216, .06);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 233, 216, .74);
}

.page-about .about-chapter--paper .about-note {
  background: rgba(27, 20, 16, .05);
  color: rgba(27, 20, 16, .78);
}

.page-about .note-key {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--gold);
}

.page-about .about-chapter--paper .note-key {
  color: var(--red-orange);
}

/* ---------- 维度刻度条 ---------- */

.page-about .dim-track {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0 0 14px;
  display: flex;
  gap: 12px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--orange) rgba(244, 233, 216, .1);
}

.page-about .dim-track::-webkit-scrollbar {
  height: 6px;
}

.page-about .dim-track::-webkit-scrollbar-track {
  background: rgba(244, 233, 216, .1);
  border-radius: var(--radius-pill);
}

.page-about .dim-track::-webkit-scrollbar-thumb {
  background: var(--grad-main);
  border-radius: var(--radius-pill);
}

.page-about .dim-item {
  position: relative;
  flex: 0 0 min(232px, 74vw);
  scroll-snap-align: start;
  padding: 22px 16px 22px;
  border: 2px solid var(--line-dark);
  border-radius: var(--radius-md);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .dim-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--grad-main);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .55s var(--ease);
}

.page-about .dim-item.is-visible::before {
  transform: scaleX(1);
}

.page-about .dim-item:nth-child(2)::before { transition-delay: .05s; }
.page-about .dim-item:nth-child(3)::before { transition-delay: .1s; }
.page-about .dim-item:nth-child(4)::before { transition-delay: .15s; }
.page-about .dim-item:nth-child(5)::before { transition-delay: .2s; }
.page-about .dim-item:nth-child(6)::before { transition-delay: .25s; }
.page-about .dim-item:nth-child(7)::before { transition-delay: .3s; }

.page-about .dim-idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .dim-name {
  margin: 10px 0 8px;
  font-size: clamp(18px, 2vw, 21px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .dim-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(244, 233, 216, .68);
}

/* ---------- 插图 ---------- */

.page-about .about-figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 6px;
  border: 2px solid var(--line-dark);
  border-radius: var(--radius-lg);
  background: var(--grad-soft);
}

.page-about .about-chapter--paper .about-figure {
  border-color: rgba(27, 20, 16, .2);
  background: rgba(27, 20, 16, .06);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius-lg) - 6px);
}

.page-about .about-figure .media-caption {
  margin: 12px 0 0;
  padding: 0 12px 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--sand);
}

.page-about .about-chapter--paper .about-figure .media-caption {
  color: rgba(27, 20, 16, .6);
}

/* ---------- 时间线 ---------- */

.page-about .timeline {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 clamp(26px, 3.4vw, 38px) 28px;
  border-left: 2px solid rgba(27, 20, 16, .2);
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -9px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--red-orange);
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .tl-year {
  display: inline-block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: clamp(15px, 1.8vw, 18px);
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--red-orange);
}

.page-about .tl-copy h3 {
  margin: 0 0 8px;
  font-size: clamp(18px, 2.2vw, 24px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--brown);
}

.page-about .tl-copy p {
  margin: 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(27, 20, 16, .78);
}

/* ---------- 团队 ---------- */

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: clamp(24px, 3vw, 36px);
}

@media (min-width: 620px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .team-card {
  display: grid;
  align-content: start;
  gap: 8px;
  padding: 22px 18px 24px;
  border: 2px solid var(--line-dark);
  border-radius: var(--radius-md);
  background: var(--ink-800);
  box-shadow: inset 0 3px 0 var(--orange);
}

.page-about .team-card:nth-child(2) { box-shadow: inset 0 3px 0 var(--violet); }
.page-about .team-card:nth-child(3) { box-shadow: inset 0 3px 0 var(--cyan); }
.page-about .team-card:nth-child(4) { box-shadow: inset 0 3px 0 var(--gold); }

.page-about .team-count {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .team-card h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(244, 233, 216, .68);
}

/* ---------- 协作数据 ---------- */

.page-about .eco-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: clamp(24px, 3vw, 36px);
}

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

.page-about .eco-stat {
  padding: 16px 14px 18px;
  border: 2px solid rgba(27, 20, 16, .18);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, .42);
}

.page-about .eco-num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 34px);
  font-weight: 300;
  line-height: 1.1;
  color: var(--red-orange);
}

.page-about .eco-lbl {
  display: block;
  font-size: 13px;
  line-height: 1.65;
  color: rgba(27, 20, 16, .72);
}

/* ---------- 更新节奏 ---------- */

.page-about .cadence {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: clamp(24px, 3vw, 36px);
}

@media (min-width: 860px) {
  .page-about .cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .cadence-item {
  padding: 22px 20px 24px;
  border-left: 3px solid var(--violet);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--ink-800);
}

.page-about .cadence-item:nth-child(2) { border-left-color: var(--orange); }
.page-about .cadence-item:nth-child(3) { border-left-color: var(--cyan); }

.page-about .cadence-tag {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  background: var(--violet);
  color: #ffffff;
}

.page-about .cadence-item:nth-child(2) .cadence-tag {
  background: var(--orange);
  color: var(--ink-900);
}

.page-about .cadence-item:nth-child(3) .cadence-tag {
  background: var(--cyan);
  color: var(--ink-900);
}

.page-about .cadence-item h3 {
  margin: 0 0 10px;
  font-size: clamp(19px, 2.2vw, 23px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .cadence-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(244, 233, 216, .7);
}

/* ---------- 继续了解 ---------- */

.page-about .next-list {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .next-list a {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 18px 20px;
  border: 2px solid rgba(27, 20, 16, .2);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, .42);
  color: var(--brown);
  text-decoration: none;
  transition: transform .3s var(--ease), border-color .3s var(--ease), background .3s var(--ease);
}

.page-about .next-key {
  flex: 0 0 auto;
  min-width: 6em;
  font-size: 16px;
  font-weight: 800;
}

.page-about .next-desc {
  flex: 1 1 auto;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(27, 20, 16, .72);
}

.page-about .next-arrow {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--red-orange);
  transition: transform .3s var(--ease);
}

@media (max-width: 640px) {
  .page-about .next-list a {
    flex-wrap: wrap;
    gap: 6px 10px;
  }

  .page-about .next-key {
    flex: 1 1 auto;
  }

  .page-about .next-desc {
    flex: 1 1 100%;
  }
}

@media (hover: hover) {
  .page-about .next-list a:hover {
    transform: translateX(4px);
    border-color: var(--red-orange);
    background: #ffffff;
  }

  .page-about .next-list a:hover .next-arrow {
    transform: translateX(4px);
  }
}

/* ---------- 焦点与降级 ---------- */

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

@media (max-width: 520px) {
  .page-about .dim-item {
    flex-basis: 82vw;
  }

  .page-about .about-lead {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}