.page-about {
  --about-rail-w: 212px;
  --about-gap: 64px;
  padding-bottom: 104px;
  background:
    linear-gradient(180deg, rgba(227, 169, 60, .055), rgba(227, 169, 60, 0) 440px),
    var(--ink-night);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: 22px 0 64px;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -80px -10% auto -10%;
  height: 460px;
  background-image:
    linear-gradient(rgba(58, 68, 89, .55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(58, 68, 89, .55) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: radial-gradient(70% 82% at 78% 24%, #000 0%, transparent 74%);
  mask-image: radial-gradient(70% 82% at 78% 24%, #000 0%, transparent 74%);
  z-index: -1;
  pointer-events: none;
}

.page-about .breadcrumbs {
  margin-bottom: 30px;
  font-size: .8rem;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 32px;
  align-items: end;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.06fr);
    gap: 52px;
  }
}

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

.page-about .about-hero__title {
  margin: 16px 0 22px;
  font-size: var(--fs-h1);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.025em;
  color: var(--paper);
}

.page-about .about-hero__title-line {
  display: block;
  margin-top: .16em;
  font-size: .46em;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--gold);
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 46ch;
  font-size: .98rem;
  line-height: 1.92;
  color: var(--paper-dim);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 30px 0 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-card);
  overflow: hidden;
}

.page-about .about-hero__facts li {
  background: rgba(10, 12, 18, .78);
  padding: 14px 16px;
}

.page-about .about-hero__fact-key {
  display: block;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .1em;
  color: var(--slate);
}

.page-about .about-hero__fact-val {
  display: block;
  margin-top: 7px;
  font-family: var(--font-mono);
  font-size: .96rem;
  letter-spacing: .02em;
  color: var(--paper);
}

.page-about .about-hero__fact-val--gold {
  color: var(--gold);
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
  box-shadow: 0 26px 64px rgba(0, 0, 0, .45);
}

.page-about .media-frame {
  max-width: 100%;
}

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

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: 36px;
  padding-top: 56px;
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    padding-top: 72px;
  }
}

.page-about .about-rail {
  padding: 18px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .rail-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
}

.page-about .rail-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: .9rem;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color .2s var(--ease);
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  color: var(--gold);
}

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

@media (min-width: 1040px) {
  .page-about .about-rail {
    position: sticky;
    top: 108px;
    align-self: start;
    border-bottom: 0;
    padding: 18px 0 0;
    z-index: 2;
  }

  .page-about .rail-list {
    display: grid;
    gap: 0;
    margin-top: 18px;
  }

  .page-about .rail-list li {
    border-top: 1px solid rgba(58, 68, 89, .7);
  }

  .page-about .rail-list li:last-child {
    border-bottom: 1px solid rgba(58, 68, 89, .7);
  }

  .page-about .rail-list a {
    display: flex;
    width: 100%;
    padding: 12px 0;
  }
}

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

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding-bottom: 52px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section + .about-section {
  padding-top: 52px;
}

.page-about .about-section--last {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-section .section-title {
  margin: 14px 0 22px;
  font-size: var(--fs-h2);
  font-weight: 800;
  line-height: 1.32;
  letter-spacing: -0.012em;
  color: var(--paper);
}

.page-about .prose p {
  margin: 0 0 16px;
  max-width: 64ch;
  font-size: .96rem;
  line-height: 1.92;
  color: var(--paper-dim);
}

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

.page-about .about-note {
  margin: 26px 0 0;
  padding: 14px 18px;
  border-left: 2px solid var(--gold);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  background: var(--gold-soft);
  font-size: .88rem;
  line-height: 1.86;
  color: var(--paper-dim);
}

/* ---------- 来源分层 ---------- */
.page-about .source-tiers {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

@media (min-width: 760px) {
  .page-about .source-tiers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .source-tier {
  padding: 18px;
  border: 1px solid var(--line);
  border-top-width: 3px;
  border-radius: var(--radius-card);
  background: rgba(10, 12, 18, .55);
}

.page-about .source-tier--verified { border-top-color: var(--celadon); }
.page-about .source-tier--editorial { border-top-color: var(--gold); }
.page-about .source-tier--path { border-top-color: var(--violet); }

.page-about .source-tier__key {
  display: block;
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .07em;
  color: var(--paper);
}

.page-about .source-tier p {
  margin: 10px 0 0;
  font-size: .89rem;
  line-height: 1.82;
  color: var(--slate);
}

/* ---------- 城市分档矩阵 ---------- */
.page-about .about-figure {
  margin: 28px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.page-about .tier-matrix {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

@media (min-width: 780px) {
  .page-about .tier-matrix {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .tier {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: linear-gradient(180deg, rgba(10, 12, 18, .92), rgba(14, 23, 48, .68));
}

.page-about .tier__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}

.page-about .tier__count {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .06em;
  color: var(--slate);
}

.page-about .tier__num {
  margin-right: 3px;
  font-size: 1.65rem;
  color: var(--paper);
}

.page-about .dot-field {
  display: block;
  height: 46px;
  border: 1px solid rgba(58, 68, 89, .6);
  border-radius: 8px;
  background-color: rgba(10, 12, 18, .72);
  background-image: radial-gradient(circle, currentColor 1.1px, transparent 1.3px);
}

.page-about .dot-field--dense {
  color: var(--gold);
  background-size: 8px 8px;
}

.page-about .dot-field--mid {
  color: var(--celadon);
  background-size: 12px 12px;
}

.page-about .dot-field--sparse {
  color: var(--violet);
  background-size: 17px 17px;
}

.page-about .tier__desc {
  margin: 0;
  font-size: .88rem;
  line-height: 1.82;
  color: var(--slate);
}

.page-about .tier__details {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px dashed rgba(58, 68, 89, .85);
}

.page-about .tier__details summary {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--gold);
  cursor: pointer;
  list-style: none;
}

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

.page-about .tier__details summary::before {
  content: "[+]";
  font-family: var(--font-mono);
  font-size: .78rem;
}

.page-about .tier__details[open] summary::before {
  content: "[–]";
}

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

.page-about .tier__list {
  margin: 12px 0 0;
  padding-left: 18px;
  font-size: .85rem;
  line-height: 1.86;
  color: var(--paper-dim);
}

/* ---------- 发展历程色带 ---------- */
.page-about .timeline-scroll {
  margin-top: 28px;
  overflow-x: auto;
  padding-bottom: 10px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .timeline-scroll:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
  border-radius: 6px;
}

.page-about .timeline-track {
  display: flex;
  gap: 2px;
  min-width: 100%;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .stage {
  flex: 1 1 0;
  min-width: 150px;
  padding: 16px 14px 4px 0;
  border-top: 5px solid var(--line);
  scroll-snap-align: start;
}

.page-about .stage:nth-child(1) { border-top-color: var(--gold); }
.page-about .stage:nth-child(2) { border-top-color: var(--celadon); }
.page-about .stage:nth-child(3) { border-top-color: var(--violet); }
.page-about .stage:nth-child(4) { border-top-color: var(--gold); }
.page-about .stage:nth-child(5) { border-top-color: var(--celadon); }

.page-about .stage--wide { flex-grow: 2; }
.page-about .stage--mid { flex-grow: 1.3; }
.page-about .stage--narrow { flex-grow: 1; }

.page-about .stage__mark {
  display: block;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .08em;
  color: var(--slate);
}

.page-about .stage__title {
  margin: 8px 0 6px;
  font-size: .96rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .stage__note {
  margin: 0;
  max-width: 24ch;
  font-size: .84rem;
  line-height: 1.76;
  color: var(--slate);
}

/* ---------- 团队分工 ---------- */
.page-about .team-bar {
  display: flex;
  gap: 2px;
  height: 10px;
  margin: 28px 0 26px;
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.page-about .team-bar__seg {
  display: block;
}

.page-about .team-bar__seg--a { flex: 12 1 0; background: var(--gold); }
.page-about .team-bar__seg--b { flex: 15 1 0; background: var(--celadon); }
.page-about .team-bar__seg--c { flex: 18 1 0; background: var(--violet); }
.page-about .team-bar__seg--d { flex: 11 1 0; background: var(--cinnabar); }

.page-about .team-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

@media (min-width: 700px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .team-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: rgba(10, 12, 18, .5);
}

.page-about .team-card__num {
  font-family: var(--font-mono);
  font-size: 1.9rem;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold);
}

.page-about .team-card__num small {
  margin-left: 4px;
  font-size: .78rem;
  color: var(--slate);
}

.page-about .team-card__name {
  margin: 12px 0 8px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  font-size: .87rem;
  line-height: 1.84;
  color: var(--slate);
}

/* ---------- 资质条目 ---------- */
.page-about .cred-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .cred {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left-width: 3px;
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
}

@media (min-width: 780px) {
  .page-about .cred {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.7fr) auto;
    align-items: center;
    gap: 18px;
  }
}

.page-about .cred--verified {
  border-left-color: var(--celadon);
  background: linear-gradient(90deg, var(--celadon-soft), rgba(10, 12, 18, .55) 46%);
}

.page-about .cred--editorial {
  border-left-color: var(--gold);
  background: linear-gradient(90deg, var(--gold-soft), rgba(10, 12, 18, .55) 46%);
}

.page-about .cred__key {
  font-size: .94rem;
  font-weight: 600;
  color: var(--paper);
}

.page-about .cred__val {
  font-size: .86rem;
  letter-spacing: .02em;
  line-height: 1.7;
  color: var(--paper-dim);
}

/* ---------- 更正通道 ---------- */
.page-about .contact-rows {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.page-about .contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  padding: 14px 18px;
  background: rgba(10, 12, 18, .8);
}

.page-about .contact-key {
  min-width: 92px;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .09em;
  color: var(--slate);
}

.page-about .contact-value {
  font-size: .9rem;
  color: var(--paper);
}

.page-about .contact-value a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(227, 169, 60, .42);
}

.page-about .contact-value a:hover,
.page-about .contact-value a:focus-visible {
  border-bottom-color: var(--gold);
}

/* ---------- 延伸阅读 ---------- */
.page-about .about-readmore {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.page-about .readmore-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

@media (min-width: 720px) {
  .page-about .readmore-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px 26px;
  }
}

.page-about .readmore-list a {
  display: block;
  padding: 12px 0;
  border-bottom: 1px dashed rgba(58, 68, 89, .7);
  font-size: .91rem;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color .2s var(--ease), padding-left .2s var(--ease);
}

.page-about .readmore-list a:hover,
.page-about .readmore-list a:focus-visible {
  color: var(--gold);
  padding-left: 6px;
}

/* ---------- 窄屏收敛 ---------- */
@media (max-width: 600px) {
  .page-about {
    padding-bottom: 72px;
  }

  .page-about .about-hero {
    padding-bottom: 44px;
  }

  .page-about .about-hero__title {
    letter-spacing: -0.015em;
  }

  .page-about .about-hero__facts {
    margin-top: 24px;
  }

  .page-about .about-section {
    padding-bottom: 40px;
  }

  .page-about .about-section + .about-section {
    padding-top: 40px;
  }

  .page-about .contact-row {
    gap: 4px;
  }

  .page-about .contact-key {
    min-width: 100%;
  }

  .page-about .timeline-track {
    flex-direction: column;
  }

  .page-about .stage {
    min-width: 0;
    width: 100%;
    padding-right: 0;
  }

  .page-about .stage__note {
    max-width: 46ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-list a,
  .page-about .readmore-list a,
  .page-about .contact-value a {
    transition: none;
  }
}