.page-about {
  --about-rail: 210px;
  --about-gap: clamp(28px, 4vw, 56px);
  background: var(--mist);
  color: var(--ink);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(32px, 5.5vw, 76px));
  padding-bottom: clamp(40px, 6vw, 84px);
  background:
    radial-gradient(88% 66% at 88% 2%, rgba(24, 240, 200, .14), transparent 62%),
    linear-gradient(180deg, var(--mist) 0%, var(--mist-deep) 128%);
  overflow: hidden;
}

.page-about .about-hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-hero-copy {
  min-width: 0;
}

.page-about .about-hero-copy .breadcrumb {
  margin-bottom: clamp(16px, 2.6vw, 26px);
  font-size: 13px;
  color: var(--cursor);
}

.page-about .about-hero-copy .eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 12.5px;
  letter-spacing: .18em;
}

.page-about .about-hero-copy h1 {
  margin: 0 0 clamp(14px, 2.2vw, 22px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(29px, 5.4vw, 54px);
  line-height: 1.18;
  letter-spacing: -.025em;
  color: var(--ink-black);
}

.page-about .about-hero-copy .lede {
  margin: 0;
  max-width: 58ch;
  font-size: clamp(15px, 1.35vw, 17.5px);
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-hero-figure {
  margin: 0;
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--mist-deep);
}

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: clamp(240px, 48vw, 420px);
  object-fit: cover;
}

.page-about .about-hero-figure .figure-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 26px 18px 14px;
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--paper);
  background: linear-gradient(180deg, rgba(17, 25, 24, 0), rgba(17, 25, 24, .82));
}

.page-about .about-hero-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-hero-facts li {
  background: var(--paper);
  padding: 14px 16px 16px;
}

.page-about .about-fact-num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(21px, 3.2vw, 30px);
  letter-spacing: -.02em;
  line-height: 1.15;
  color: var(--ink-black);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--cursor);
}

/* ---------- 主体两栏 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(36px, 5.5vw, 80px) var(--gutter) clamp(44px, 6.5vw, 92px);
}

.page-about .about-rail {
  display: none;
}

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

/* ---------- 章节 ---------- */

.page-about .about-chapter {
  scroll-margin-top: calc(var(--header-h) + 26px);
  padding-bottom: clamp(30px, 4.5vw, 56px);
  margin-bottom: clamp(30px, 4.5vw, 56px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-chapter:last-of-type {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .chapter-head {
  display: block;
  margin-bottom: clamp(16px, 2.4vw, 24px);
}

.page-about .chapter-num {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--ink-black);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .14em;
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.3vw, 33px);
  line-height: 1.24;
  letter-spacing: -.02em;
  color: var(--ink-black);
}

.page-about .chapter-body > p {
  margin: 0 0 1.05em;
  max-width: 70ch;
  font-size: clamp(15px, 1.1vw, 16.5px);
  line-height: 1.9;
  color: var(--ink);
}

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

.page-about .sub-title {
  margin: clamp(26px, 3.6vw, 38px) 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 20px);
  letter-spacing: -.01em;
  color: var(--ink-black);
}

/* ---------- 字段清单 ---------- */

.page-about .field-list {
  margin: clamp(20px, 3vw, 28px) 0 clamp(20px, 3vw, 28px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .field-item {
  background: var(--paper);
  padding: 15px 17px;
}

.page-about .field-name {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--orange);
}

.page-about .field-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
}

/* ---------- 批次编号演示 ---------- */

.page-about .batch-demo {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 1.05em;
  padding: 9px 18px;
  border-radius: var(--radius-pill);
  background: var(--ink-black);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
}

.page-about .batch-demo span[aria-hidden="true"] {
  color: var(--cyan);
}

/* ---------- 图片块 ---------- */

.page-about .about-figure {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--mist-deep);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure .figure-caption {
  margin: 0;
  padding: 11px 16px 13px;
  background: var(--paper);
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--cursor);
}

/* ---------- 改版三处 ---------- */

.page-about .revision-list {
  list-style: none;
  margin: clamp(18px, 2.8vw, 26px) 0 clamp(18px, 2.8vw, 26px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .revision-list li {
  display: flex;
  gap: 14px;
  background: var(--paper);
  padding: 17px 18px 19px;
}

.page-about .rev-num {
  flex: none;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  color: var(--mist-deep);
}

.page-about .revision-list h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.4;
  color: var(--ink-black);
}

.page-about .revision-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 团队筛选 ---------- */

.page-about .about-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(16px, 2.6vw, 24px) 0 clamp(18px, 2.8vw, 26px);
}

.page-about .about-filter .filter-btn {
  padding: 7px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--paper);
  color: var(--cursor);
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.5;
  cursor: pointer;
  transition: color .2s var(--ease), background-color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-filter .filter-btn:hover {
  color: var(--ink-black);
  border-color: var(--mist-deep);
}

.page-about .about-filter .filter-btn[aria-pressed="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--paper);
  font-weight: 600;
}

.page-about .team-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .team-card {
  background: var(--paper);
  padding: 18px 18px 20px;
}

.page-about .team-card[hidden] {
  display: none;
}

.page-about .team-line {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .team-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.42;
  color: var(--ink-black);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .filter-empty {
  margin: 16px 0 0;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--peach);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-black);
}

.page-about .filter-empty[hidden] {
  display: none;
}

/* ---------- 协作网络 ---------- */

.page-about .network-list {
  list-style: none;
  margin: clamp(16px, 2.6vw, 24px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .net-item {
  position: relative;
  padding: 14px 16px 14px 20px;
  border-radius: var(--radius-md);
  background: var(--paper);
  border-left: 3px solid var(--mist-deep);
  transition: border-color .22s var(--ease), background-color .22s var(--ease);
}

.page-about .net-item:hover,
.page-about .net-item:focus-within {
  border-left-color: var(--cyan);
  background: #fffdf7;
}

.page-about .net-region {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--ink-black);
  margin-bottom: 5px;
}

.page-about .net-desc {
  display: block;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--cursor);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--line);
}

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

.page-about .about-timeline li:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline li::before {
  content: "";
  position: absolute;
  left: calc(-20px - 1px);
  top: 7px;
  width: 7px;
  height: 7px;
  background: var(--cyan);
  box-shadow: 0 0 0 3px var(--mist);
}

.page-about .tl-year {
  display: block;
  position: relative;
  top: 1px;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .02em;
  color: var(--ink-black);
}

.page-about .tl-body h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.42;
  color: var(--ink-black);
}

.page-about .tl-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 服务方式 ---------- */

.page-about .principle-list {
  list-style: none;
  margin: 0 0 clamp(18px, 2.8vw, 26px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .principle-list li {
  display: flex;
  flex-direction: column;
  gap: 7px;
  background: var(--paper);
  padding: 17px 18px 19px;
}

.page-about .pr-kicker {
  display: inline-block;
  align-self: flex-start;
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  background: var(--peach);
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--ink-black);
}

.page-about .principle-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 结尾引导 ---------- */

.page-about .about-outro {
  margin-top: clamp(34px, 5vw, 56px);
  padding: clamp(24px, 4vw, 40px);
  border-radius: var(--radius-lg);
  background: var(--ink-black);
  color: var(--mist);
}

.page-about .outro-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.6vw, 26px);
  line-height: 1.3;
  letter-spacing: -.015em;
  color: var(--paper);
}

.page-about .outro-text {
  margin: 0 0 clamp(18px, 2.6vw, 24px);
  max-width: 62ch;
  font-size: clamp(14px, 1.1vw, 15.5px);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .outro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-outro .btn-ghost {
  border-color: rgba(220, 227, 225, .35);
  color: var(--mist);
}

.page-about .about-outro .btn-ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ---------- 平板 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .field-list,
  .page-about .revision-list,
  .page-about .network-list,
  .page-about .principle-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .principle-list li {
    padding: 18px 20px 20px;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 940px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    grid-template-rows: auto auto;
    column-gap: clamp(30px, 4.5vw, 60px);
    row-gap: clamp(24px, 3.4vw, 38px);
    align-items: start;
  }

  .page-about .about-hero-copy {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-hero-facts {
    grid-column: 1;
    grid-row: 2;
    align-self: stretch;
  }

  .page-about .about-hero-figure {
    grid-column: 2;
    grid-row: 1 / span 2;
  }

  .page-about .about-hero-figure img {
    height: 100%;
    min-height: 420px;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(34px, 4.5vw, 64px);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 30px);
    padding-left: 16px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail .anchor-index-title {
    margin: 0 0 14px;
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 12.5px;
    letter-spacing: .16em;
    color: var(--cursor);
  }

  .page-about .about-rail-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 1px;
  }

  .page-about .about-rail-link {
    display: flex;
    align-items: baseline;
    gap: 8px;
    margin-left: -18px;
    padding: 6px 0 6px 12px;
    border-left: 2px solid transparent;
    font-size: 13.5px;
    line-height: 1.55;
    color: var(--cursor);
    text-decoration: none;
    transition: color .2s var(--ease), border-color .2s var(--ease);
  }

  .page-about .about-rail-link:hover,
  .page-about .about-rail-link[data-active] {
    color: var(--ink-black);
    border-left-color: var(--orange);
  }

  .page-about .rail-num {
    flex: none;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .05em;
    color: var(--mist-deep);
  }

  .page-about .about-rail-link:hover .rail-num,
  .page-about .about-rail-link[data-active] .rail-num {
    color: var(--orange);
  }

  .page-about .team-cards {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .team-card {
    grid-column: span 6;
  }

  .page-about .team-card:nth-child(1) {
    grid-column: span 7;
  }

  .page-about .team-card:nth-child(2) {
    grid-column: span 5;
  }

  .page-about .team-card:nth-child(3) {
    grid-column: span 5;
  }

  .page-about .team-card:nth-child(4) {
    grid-column: span 7;
  }

  .page-about .network-list {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .net-item:nth-child(1),
  .page-about .net-item:nth-child(2),
  .page-about .net-item:nth-child(3) {
    grid-column: span 2;
  }

  .page-about .net-item:nth-child(4),
  .page-about .net-item:nth-child(5) {
    grid-column: span 3;
  }

  .page-about .about-timeline {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .about-timeline li {
    display: grid;
    grid-template-columns: 110px minmax(0, 1fr);
    column-gap: 26px;
    padding: 0 0 clamp(18px, 2.4vw, 26px) 20px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-timeline li::before {
    left: -4px;
  }

  .page-about .tl-year {
    top: 2px;
    margin-bottom: 0;
    font-size: 16px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero-copy h1 {
    max-width: 15ch;
  }

  .page-about .about-hero-figure img {
    min-height: 500px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-filter .filter-btn,
  .page-about .net-item,
  .page-about .about-rail-link {
    transition: none;
  }
}