.page-about {
  color: var(--text);
  --rail-w: 232px;
}

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

.page-about .breadcrumbs {
  padding-top: 20px;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  padding-top: clamp(20px, 3.5vw, 36px);
  padding-bottom: clamp(28px, 4vw, 48px);
}

.page-about .about-hero-text {
  display: flex;
  flex-direction: column;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 6.4vw, 58px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 800;
  max-width: 15ch;
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.8;
  color: var(--text);
}

.page-about .hero-note {
  margin: 0;
  max-width: 52ch;
  padding-left: 14px;
  border-left: 2px solid var(--grid-line);
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-dim);
}

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

.page-about .hero-media {
  margin: 0;
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: end;
    column-gap: clamp(32px, 5vw, 64px);
  }
}

/* ---------- 数据条 ---------- */
.page-about .hero-stats {
  list-style: none;
  margin: 0;
  padding: clamp(18px, 3vw, 26px) 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.5vw, 28px);
  border-top: 1px solid var(--grid-line);
}

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

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .stat:nth-child(3) .stat-num {
  color: var(--orange);
}

.page-about .stat-num small {
  font-size: 0.5em;
  margin-left: 2px;
  letter-spacing: 0;
}

.page-about .stat-label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-dim);
}

/* ---------- 主体外壳与章节索引 ---------- */
.page-about .about-shell {
  display: grid;
  gap: 36px;
  padding-top: clamp(32px, 5vw, 56px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .chapter-rail {
  border-top: 1px solid var(--grid-line);
  padding-top: 18px;
}

.page-about .rail-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .rail-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 13px;
  border-radius: var(--r-pill);
  border: 1px solid var(--grid-line);
  color: var(--text-dim);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.2;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .rail-list a:hover,
.page-about .rail-list a:focus-visible {
  color: var(--cyan);
  border-color: rgba(0, 229, 255, 0.55);
  background: var(--cyan-soft);
}

.page-about .rail-no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .rail-foot {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px dashed var(--grid-line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-dim);
}

.page-about .rail-foot a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .rail-foot a:hover {
  text-decoration: underline;
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: minmax(0, 1fr) var(--rail-w);
    column-gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }

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

  .page-about .chapter-rail {
    grid-column: 2;
    grid-row: 1;
    border-top: 0;
    padding-top: 0;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .rail-list {
    display: block;
  }

  .page-about .rail-list li + li {
    margin-top: 4px;
  }

  .page-about .rail-list a {
    width: 100%;
    padding: 8px 10px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: var(--r-sm);
  }

  .page-about .rail-list a:hover,
  .page-about .rail-list a:focus-visible {
    border-left-color: var(--cyan);
  }
}

/* ---------- 章节通用 ---------- */
.page-about .chapter {
  padding-top: clamp(34px, 5vw, 64px);
  border-top: 1px solid var(--grid-line);
}

.page-about .chapter + .chapter {
  margin-top: clamp(28px, 4vw, 48px);
}

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

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 2vw, 22px);
  margin-bottom: 14px;
}

.page-about .chapter-no {
  flex: 0 0 auto;
  font-family: var(--font-display);
  font-size: clamp(34px, 5.6vw, 62px);
  font-weight: 800;
  line-height: 0.85;
  letter-spacing: -0.05em;
  color: var(--grid-line);
}

.page-about .chapter-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3vw, 32px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  font-weight: 700;
}

.page-about .chapter-lede {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--text-dim);
}

/* ---------- 01 日常工作 ---------- */
.page-about .daily-grid {
  display: grid;
  gap: 14px;
}

@media (min-width: 680px) {
  .page-about .daily-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .daily-item {
  position: relative;
  overflow: hidden;
  background: var(--ink-panel);
  border: 1px solid var(--grid-line);
  border-radius: var(--r-lg);
  padding: clamp(18px, 2.2vw, 24px);
}

.page-about .daily-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--cyan), rgba(0, 229, 255, 0));
}

.page-about .daily-metric {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .daily-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .daily-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .pull-quote {
  margin: clamp(28px, 4vw, 52px) 0 0;
  padding: clamp(6px, 1vw, 10px) 0 clamp(6px, 1vw, 10px) clamp(18px, 3vw, 30px);
  border-left: 3px solid var(--cyan);
  font-family: var(--font-serif);
  font-size: clamp(18px, 2.4vw, 25px);
  line-height: 1.65;
  color: var(--text);
}

.page-about .pull-quote p {
  margin: 0;
}

/* ---------- 02 流程 ---------- */
.page-about .flow-steps {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .flow-step {
  position: relative;
  background: var(--ink-sub);
  border: 1px solid var(--grid-line);
  border-radius: var(--r-lg);
  padding: clamp(16px, 2vw, 22px);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .flow-step:hover,
.page-about .flow-step:focus,
.page-about .flow-step:focus-within {
  border-color: rgba(0, 229, 255, 0.55);
  background: var(--ink-panel);
  outline: none;
}

.page-about .flow-step:focus-visible {
  box-shadow: 0 0 0 3px rgba(0, 229, 255, 0.28);
}

.page-about .flow-index {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .flow-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .flow-brief {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .flow-detail {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--grid-line);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .flow-detail p {
  margin: 0;
}

@media (min-width: 880px) {
  .page-about .flow-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .flow-steps::before {
    content: "";
    position: absolute;
    left: 8%;
    right: 8%;
    top: 38px;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--cyan), var(--orange));
    opacity: 0.35;
  }
}

@media (hover: hover) and (pointer: fine) {
  .page-about .flow-detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    margin-top: 0;
    padding-top: 0;
    border-top-color: transparent;
    transition: max-height 0.3s ease, opacity 0.25s ease, margin 0.3s ease, padding 0.3s ease;
  }

  .page-about .flow-step:hover .flow-detail,
  .page-about .flow-step:focus .flow-detail,
  .page-about .flow-step:focus-within .flow-detail {
    max-height: 320px;
    opacity: 1;
    margin-top: 12px;
    padding-top: 12px;
    border-top-color: var(--grid-line);
  }
}

.page-about .flow-figure {
  margin: clamp(24px, 3.5vw, 40px) 0 0;
}

/* ---------- 03 时间线 ---------- */
.page-about .tl-intro {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  margin-bottom: clamp(28px, 4vw, 48px);
}

@media (min-width: 820px) {
  .page-about .tl-intro {
    grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
    align-items: start;
  }
}

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

.page-about .tl-intro-text p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .tl-intro-text p:last-child {
  margin-bottom: 0;
}

.page-about .tl {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  --tl-col: 58px;
  --tl-gap: 18px;
}

@media (min-width: 720px) {
  .page-about .tl {
    --tl-col: 84px;
    --tl-gap: 26px;
  }
}

.page-about .tl-spine {
  position: absolute;
  top: 8px;
  left: calc(var(--tl-col) - 1px);
  width: 2px;
  height: calc(100% - 16px);
  opacity: 0.75;
  pointer-events: none;
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: var(--tl-col) minmax(0, 1fr);
  column-gap: var(--tl-gap);
  padding-bottom: clamp(24px, 3vw, 34px);
}

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

.page-about .tl-item::after {
  content: "";
  position: absolute;
  top: 7px;
  left: calc(var(--tl-col) - 5px);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ink-deep);
  border: 2px solid var(--cyan);
}

.page-about .tl-item[data-state="live"]::after {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 26, 0.16);
}

.page-about .tl-year {
  padding-top: 3px;
  text-align: right;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

@media (min-width: 720px) {
  .page-about .tl-year {
    font-size: 18px;
  }
}

.page-about .tl-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.35;
}

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

.page-about .tl-tag {
  margin-left: 8px;
  vertical-align: middle;
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 14px;
}

@media (min-width: 680px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .team-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--ink-panel);
  border: 1px solid var(--grid-line);
  border-top: 3px solid rgba(0, 229, 255, 0.5);
  border-radius: var(--r-lg);
  padding: clamp(18px, 2.2vw, 24px);
}

.page-about .team-card:nth-child(2) {
  border-top-color: rgba(75, 227, 168, 0.55);
}

.page-about .team-card:nth-child(3) {
  border-top-color: rgba(255, 122, 26, 0.55);
}

.page-about .team-card:nth-child(4) {
  border-top-color: rgba(0, 229, 255, 0.28);
}

.page-about .team-role {
  margin: 0;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .team-duty {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .team-note {
  margin-top: 18px;
}

/* ---------- 05 合作 ---------- */
.page-about .partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .partner-item {
  display: grid;
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--grid-line);
}

.page-about .partner-item:first-child {
  border-top: 1px solid var(--grid-line);
}

@media (min-width: 780px) {
  .page-about .partner-item {
    grid-template-columns: 190px minmax(0, 1fr);
    column-gap: clamp(20px, 3vw, 40px);
    align-items: start;
  }
}

.page-about .partner-name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
}

.page-about .partner-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .partner-text a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 229, 255, 0.35);
}

.page-about .partner-text a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta {
  margin-top: clamp(40px, 6vw, 72px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid rgba(0, 229, 255, 0.28);
  border-radius: var(--r-lg);
  background:
    radial-gradient(120% 140% at 0% 0%, rgba(0, 229, 255, 0.1), rgba(5, 11, 20, 0) 60%),
    var(--ink-panel);
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  font-weight: 700;
}

.page-about .about-cta .chapter-lede {
  margin-bottom: 0;
}

.page-about .cta-grid {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

@media (min-width: 680px) {
  .page-about .cta-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .cta-item {
  display: block;
  padding: 16px 18px;
  border: 1px solid var(--grid-line);
  border-radius: var(--r-md);
  color: var(--text);
  text-decoration: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .cta-item:hover,
.page-about .cta-item:focus-visible {
  border-color: rgba(0, 229, 255, 0.6);
  background: var(--cyan-soft);
}

.page-about .cta-title {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
}

.page-about .cta-text {
  display: block;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-dim);
}

.page-about .cta-contact {
  margin: 22px 0 0;
  padding-top: 18px;
  border-top: 1px dashed var(--grid-line);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .cta-contact a {
  color: var(--cyan);
  text-decoration: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}