.page-about {
  --about-hair: 1px solid var(--gold-500);
  --about-rule: 1px solid var(--paper-200);
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ---------- 顶部上下文 ---------- */
.page-about .about-topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding-top: clamp(20px, 4vw, 40px);
}

.page-about .about-topbar__note {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--gray-600);
}

/* ---------- 首屏导语 ---------- */
.page-about .about-lede {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding-top: clamp(24px, 4vw, 44px);
  padding-bottom: clamp(36px, 6vw, 64px);
}

.page-about .about-lede__main {
  max-width: 60ch;
}

.page-about .about-lede__main h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.1rem, 7vw, 3.6rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--ink-900);
  margin: 18px 0 20px;
}

.page-about .about-lede__text {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-900);
  margin: 0 0 1.1em;
}

.page-about .about-lede__text a {
  color: var(--ink-700);
  text-decoration-color: var(--gold-500);
  text-underline-offset: 3px;
  border-bottom: 1px solid var(--gold-500);
  text-decoration: none;
}

.page-about .about-lede__text a:hover,
.page-about .about-lede__text a:focus-visible {
  color: var(--gold-700);
}

/* 首屏右侧要点表 */
.page-about .about-lede__side {
  background: var(--ink-900);
  border-radius: var(--radius-panel);
  padding: clamp(20px, 3vw, 28px);
}

.page-about .about-facts {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid rgba(246, 242, 231, 0.14);
}

.page-about .about-facts__row:last-child {
  border-bottom: 0;
}

.page-about .about-facts dt {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--gray-400);
}

.page-about .about-facts dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  color: var(--paper-50);
}

.page-about .about-facts dd .unit {
  color: var(--gold-500);
}

/* ---------- 面板内通用 ---------- */
.page-about .about-section {
  padding: clamp(24px, 4vw, 48px);
}

.page-about .about-section .section-head {
  margin-bottom: clamp(18px, 3vw, 28px);
}

.page-about .about-section .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.4rem, 3.4vw, 2.1rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

.page-about .about-section--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), 0 100%);
  padding-bottom: clamp(48px, 7vw, 76px);
}

.page-about .about-section--cut .section-title {
  color: var(--paper-50);
}

.page-about .about-section .prose {
  max-width: var(--content-max);
}

.page-about .about-section .prose p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-900);
  margin: 0 0 1.05em;
}

.page-about .about-section .prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-linkline {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding-top: 16px;
  border-top: var(--about-rule);
  font-size: 14px;
  line-height: 1.8;
  color: var(--gray-600);
}

.page-about .about-linkline a {
  color: var(--teal-700);
  text-decoration: none;
  border-bottom: 1px solid var(--teal-500);
  text-underline-offset: 3px;
}

.page-about .about-linkline a:hover,
.page-about .about-linkline a:focus-visible {
  color: var(--ink-900);
  border-bottom-color: var(--gold-500);
}

/* ---------- 01 三件事 ---------- */
.page-about .about-brief {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-brief__item {
  padding-left: 18px;
  border-left: 3px solid var(--gold-500);
}

.page-about .about-brief__idx {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold-700);
}

.page-about .about-brief__title {
  margin: 4px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  line-height: 1.35;
  color: var(--ink-900);
}

.page-about .about-brief__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--gray-600);
}

/* ---------- 图幅 ---------- */
.page-about .about-figure {
  margin: clamp(22px, 3vw, 34px) 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--paper-200);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-card);
}

.page-about .about-figure figcaption {
  margin: 0;
  padding: 12px 16px 14px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--gray-600);
  background: var(--paper-200);
}

.page-about .about-figure--lead img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--ridge img {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure--stack img {
  aspect-ratio: 12 / 7;
}

.page-about .about-section--cut .about-figure figcaption {
  background: var(--ink-950);
  color: var(--gray-400);
}

/* ---------- 02 团队矩阵 ---------- */
.page-about .team-matrix {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .team-tile {
  position: relative;
  background: var(--paper-200);
  border-radius: var(--radius-card);
  padding: 18px 18px 16px;
  border-top: 3px solid var(--ink-400);
  transition: transform 220ms var(--ease), background-color 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .team-tile__code {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold-700);
  background: var(--paper-50);
  border-radius: var(--pill);
  padding: 3px 10px;
}

.page-about .team-tile__role {
  margin: 12px 0 2px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.02rem;
  line-height: 1.3;
  color: var(--ink-900);
}

.page-about .team-tile__line {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--gray-600);
}

.page-about .team-tile__duty {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-700);
  transition: max-height 340ms var(--ease), opacity 260ms var(--ease), margin-top 340ms var(--ease);
}

.page-about .team-tile:hover,
.page-about .team-tile:focus-within,
.page-about .team-tile:focus {
  background: var(--paper-50);
  border-top-color: var(--gold-500);
  transform: translateY(-3px);
}

.page-about .team-tile:hover .team-tile__duty,
.page-about .team-tile:focus-within .team-tile__duty,
.page-about .team-tile:focus .team-tile__duty {
  max-height: 180px;
  opacity: 1;
  margin-top: 10px;
}

.page-about .team-tile:focus-visible {
  outline: 2px solid var(--gold-500);
  outline-offset: 3px;
}

.page-about .about-tip {
  margin: 18px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--gray-600);
}

/* ---------- 03 署名胶囊 ---------- */
.page-about .sig-list {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .sig-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  border: 1px solid var(--ink-400);
  border-radius: var(--pill);
  padding: 8px 16px;
  background: var(--paper-50);
}

.page-about .sig-pill__code {
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold-700);
}

.page-about .sig-pill__role {
  font-size: 13px;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .sig-pill__scope {
  font-size: 13px;
  color: var(--gray-600);
}

/* ---------- 04 时间线 ---------- */
.page-about .about-section--timeline {
  background: linear-gradient(180deg, var(--paper-50) 0%, var(--paper-50) 62%, var(--paper-200) 100%);
}

.page-about .tl-rail {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .tl-rail__item {
  margin: 0;
}

.page-about .tl-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 14px;
  border-radius: var(--pill);
  border: 1px solid var(--paper-200);
  background: var(--paper-50);
  font-size: 14px;
  color: var(--ink-900);
  text-decoration: none;
  transition: border-color 200ms var(--ease), color 200ms var(--ease);
}

.page-about .tl-rail__link:hover,
.page-about .tl-rail__link:focus-visible {
  border-color: var(--gold-500);
  color: var(--gold-700);
}

.page-about .tl-rail__link:focus-visible {
  outline: 2px solid var(--gold-500);
  outline-offset: 2px;
}

.page-about .tl-rail__year {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--ink-700);
}

.page-about .tl-stages {
  position: relative;
  margin-top: clamp(22px, 4vw, 34px);
  padding-left: 26px;
}

.page-about .tl-stages::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--gold-500);
}

.page-about .tl-stage {
  position: relative;
  padding: 0 0 clamp(22px, 3.5vw, 34px);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

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

.page-about .tl-stage::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--gold-500);
  background: var(--paper-50);
}

.page-about .tl-stage__year {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--gold-700);
}

.page-about .tl-stage__title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.12rem;
  line-height: 1.3;
  color: var(--ink-900);
}

.page-about .tl-stage__text {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink-700);
}

/* ---------- 05 内容边界 ---------- */
.page-about .about-onink {
  margin: 0 0 clamp(18px, 3vw, 26px);
  max-width: var(--content-max);
  font-size: 16px;
  line-height: 1.85;
  color: var(--paper-200);
}

.page-about .boundary {
  background: var(--ink-700);
  border-radius: var(--radius-card);
  padding: 4px 18px 18px;
  border-left: 3px solid var(--gold-500);
}

.page-about .boundary__summary {
  cursor: pointer;
  padding: 14px 0;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold-500);
  list-style: none;
}

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

.page-about .boundary__summary::before {
  content: "— ";
  color: var(--gold-500);
}

.page-about .boundary__summary:focus-visible {
  outline: 2px solid var(--gold-500);
  outline-offset: 3px;
  border-radius: 4px;
}

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

.page-about .boundary__item {
  display: flex;
  gap: 12px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--paper-50);
  padding-top: 12px;
  border-top: 1px solid rgba(246, 242, 231, 0.16);
}

.page-about .boundary__mark {
  flex: 0 0 auto;
  width: 16px;
  height: 1px;
  margin-top: 13px;
  background: var(--gold-500);
}

/* ---------- 06 纠错流程 ---------- */
.page-about .fix-flow {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .fix-flow__step {
  background: var(--paper-200);
  border-radius: var(--radius-card);
  padding: 18px;
  border-left: 3px solid var(--teal-500);
}

.page-about .fix-flow__num {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--teal-700);
}

.page-about .fix-flow__title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  line-height: 1.3;
  color: var(--ink-900);
}

.page-about .fix-flow__step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-700);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .team-matrix {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-brief {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 26px;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-lede {
    grid-template-columns: minmax(0, 7fr) minmax(260px, 4fr);
    align-items: start;
  }

  .page-about .about-lede__side {
    margin-top: 34px;
  }

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

  .page-about .tl-rail {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 10px;
  }

  .page-about .about-figure--lead {
    margin-top: 8px;
  }
}

@media (min-width: 1120px) {
  .page-about .team-matrix {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .team-tile:nth-child(1) { grid-column: span 5; }
  .page-about .team-tile:nth-child(2) { grid-column: span 4; }
  .page-about .team-tile:nth-child(3) { grid-column: span 3; }
  .page-about .team-tile:nth-child(4) { grid-column: span 4; }
  .page-about .team-tile:nth-child(5) { grid-column: span 4; }
  .page-about .team-tile:nth-child(6) { grid-column: span 4; }
  .page-about .team-tile:nth-child(7) { grid-column: span 7; }

  .page-about .team-tile {
    padding: 22px 22px 20px;
  }

  .page-about .about-section--timeline {
    padding-bottom: clamp(36px, 5vw, 56px);
  }

  .page-about .tl-stages {
    padding-left: 34px;
  }

  .page-about .tl-stage::before {
    left: -34px;
    width: 13px;
    height: 13px;
  }

  .page-about .about-figure--ridge {
    margin-inline: -12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-tile,
  .page-about .team-tile__duty,
  .page-about .tl-rail__link {
    transition-duration: 150ms;
  }

  .page-about .team-tile:hover,
  .page-about .team-tile:focus-within,
  .page-about .team-tile:focus {
    transform: none;
  }
}