.page-about {
  background: var(--c-paper);
  color: var(--c-black);
  --about-rail-w: 64px;
  --about-card-lift: #FBF6EC;
}

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

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-mist);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-crumbs a {
  color: var(--c-gold-lt);
  text-decoration: none;
}

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

.page-about .about-crumbs span[aria-current="page"] {
  color: var(--c-paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3vw, 34px) 0 clamp(42px, 6vw, 76px);
  background: linear-gradient(158deg, #12343B 0%, #0F2A32 52%, #171C3A 100%);
  color: var(--c-paper);
}

.page-about .about-hero > .blueprint {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: center;
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--c-gold);
  text-transform: uppercase;
}

.page-about .about-kicker--dark { color: #A67C2E; }
.page-about .about-kicker--light { color: var(--c-gold-lt); }

.page-about .about-hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(30px, 5.6vw, 62px);
  line-height: 1.14;
  letter-spacing: -.01em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .about-lead {
  margin: 0 0 26px;
  max-width: 34em;
  font-size: clamp(14px, 1.5vw, 16.5px);
  line-height: 1.8;
  color: rgba(243, 235, 221, .84);
}

.page-about .about-hero-points {
  margin: 0 0 28px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .about-hero-points li {
  position: relative;
  padding-left: 22px;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(243, 235, 221, .78);
}

.page-about .about-hero-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 12px;
  height: 2px;
  background: var(--c-neon);
}

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

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

.page-about .about-hero-figure img {
  width: 100%;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 30px), calc(100% - 30px) 100%, 0 100%);
  border: 1px solid rgba(215, 165, 69, .32);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
  margin-top: clamp(34px, 5vw, 56px);
  padding-top: 24px;
  border-top: 1px solid rgba(241, 210, 140, .3);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stat-num {
  font-family: var(--font-num);
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1;
  font-weight: 700;
  color: var(--c-gold-lt);
  letter-spacing: .01em;
}

.page-about .about-stat-unit {
  font-size: .46em;
  margin-left: 2px;
  color: var(--c-mist);
}

.page-about .about-stat-label {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--c-mist);
}

/* ---------- 通用章节骨架 ---------- */
.page-about .about-band {
  position: relative;
  padding: var(--space-section) 0;
}

.page-about .about-band--paper {
  background: var(--c-paper);
  color: var(--c-black);
}

.page-about .about-band--indigo {
  background: #171C3A;
  color: var(--c-paper);
}

.page-about .about-band--wine {
  background: linear-gradient(148deg, #741F3C 0%, #521428 62%, #38101F 100%);
  color: var(--c-paper);
}

.page-about .about-band--deep {
  background: linear-gradient(200deg, #0F2A32 0%, #12343B 60%, #171C3A 100%);
  color: var(--c-paper);
}

.page-about .about-chapter {
  display: grid;
  gap: 18px;
}

.page-about .about-rail {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #A67C2E;
}

.page-about .about-rail-num {
  font-family: var(--font-num);
  font-size: 15px;
  letter-spacing: .1em;
  font-weight: 700;
}

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

.page-about .about-band--indigo .about-rail,
.page-about .about-band--wine .about-rail,
.page-about .about-band--deep .about-rail {
  color: var(--c-gold);
}

.page-about .about-head {
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-head h2 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.6vw, 40px);
  line-height: 1.24;
  letter-spacing: -.005em;
  font-weight: 800;
}

.page-about .about-head-lead {
  margin: 0;
  max-width: 40em;
  font-size: 14.5px;
  line-height: 1.78;
  opacity: .8;
}

.page-about .about-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: #8A6218;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 2px;
  transition: color .25s var(--ease);
}

.page-about .about-link::after {
  content: "→";
  transition: transform .25s var(--ease);
}

.page-about .about-link:hover {
  color: var(--c-black);
}

.page-about .about-link:hover::after {
  transform: translateX(4px);
}

.page-about .about-band--indigo .about-link,
.page-about .about-band--wine .about-link,
.page-about .about-band--deep .about-link {
  color: var(--c-gold-lt);
}

.page-about .about-more {
  margin: clamp(22px, 3vw, 32px) 0 0;
}

/* ---------- 服务线档案卡 ---------- */
.page-about .about-files {
  display: grid;
  gap: 16px;
}

.page-about .about-file {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 26px 22px 22px;
  background: var(--about-card-lift);
  border: 1px solid var(--c-ink-line);
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 0 100%);
  transition: transform .35s var(--ease), border-color .35s var(--ease), background .35s var(--ease);
}

.page-about .about-file:hover,
.page-about .about-file:focus-within {
  transform: translateY(-4px);
  border-color: var(--c-gold);
  background: #FFFDF7;
}

.page-about .about-file-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin: 0;
}

.page-about .about-file-index {
  font-family: var(--font-num);
  font-size: 22px;
  font-weight: 700;
  color: var(--c-gold);
  letter-spacing: .06em;
}

.page-about .about-file h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  line-height: 1.35;
}

.page-about .about-file p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: #33393C;
}

.page-about .about-file-scene {
  margin-top: auto !important;
  padding-left: 12px;
  border-left: 2px solid var(--c-gold);
  font-size: 13px !important;
  color: #5A6568 !important;
}

/* ---------- 机制章节 ---------- */
.page-about .about-mech {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .about-mech-list {
  display: grid;
  gap: 0;
  align-content: start;
}

.page-about .about-mech-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px solid rgba(126, 168, 162, .28);
}

.page-about .about-mech-item:last-child {
  border-bottom: 1px solid rgba(126, 168, 162, .28);
}

.page-about .about-mech-num {
  font-family: var(--font-num);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--c-neon);
  padding-top: 3px;
}

.page-about .about-mech-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
}

.page-about .about-mech-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 235, 221, .78);
}

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

.page-about .about-mech-figure img {
  width: 100%;
  border: 1px solid rgba(53, 230, 194, .22);
}

.page-about .about-mech-figure figcaption {
  margin-top: 12px;
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--c-mist);
}

/* ---------- 阶段节点 ---------- */
.page-about .about-nodes {
  display: grid;
  gap: 0;
}

.page-about .about-node {
  border-top: 1px solid rgba(241, 210, 140, .26);
}

.page-about .about-node:last-child {
  border-bottom: 1px solid rgba(241, 210, 140, .26);
}

.page-about .about-node summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 16px;
  align-items: center;
  gap: 12px;
  padding: 18px 2px;
  transition: color .25s var(--ease);
}

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

.page-about .about-node summary:hover { color: var(--c-gold-lt); }

.page-about .about-node-index {
  font-family: var(--font-num);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--c-gold);
}

.page-about .about-node-title {
  font-family: var(--font-display);
  font-size: clamp(15px, 2.2vw, 18px);
  font-weight: 700;
  line-height: 1.45;
}

.page-about .about-node-mark {
  position: relative;
  width: 14px;
  height: 14px;
}

.page-about .about-node-mark::before,
.page-about .about-node-mark::after {
  content: "";
  position: absolute;
  background: var(--c-gold-lt);
  transition: transform .3s var(--ease);
}

.page-about .about-node-mark::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .about-node-mark::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
}

.page-about .about-node[open] .about-node-mark::after {
  transform: scaleY(0);
}

.page-about .about-node-body {
  padding: 0 2px 22px 44px;
}

.page-about .about-node-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(243, 235, 221, .8);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  align-items: start;
}

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

.page-about .about-eco-figure img {
  width: 100%;
  clip-path: polygon(0 0, calc(100% - 26px) 0, 100% 26px, 100% 100%, 0 100%);
  border: 1px solid rgba(215, 165, 69, .3);
}

.page-about .about-eco-figure figcaption {
  margin-top: 12px;
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.72;
  color: var(--c-mist);
}

.page-about .about-eco-list {
  display: grid;
  gap: 10px;
}

.page-about .about-eco-group {
  background: rgba(243, 235, 221, .05);
  border: 1px solid rgba(126, 168, 162, .28);
  border-left: 3px solid var(--c-neon);
}

.page-about .about-eco-group summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-paper);
}

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

.page-about .about-eco-group[open] summary {
  color: var(--c-gold-lt);
}

.page-about .about-eco-count {
  font-family: var(--font-num);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-gold);
}

.page-about .about-eco-group p {
  margin: 0;
  padding: 0 16px 16px;
  font-size: 13.5px;
  line-height: 1.82;
  color: rgba(243, 235, 221, .78);
}

.page-about .about-eco-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
  margin-top: clamp(30px, 4vw, 46px);
  padding-top: 22px;
  border-top: 1px solid rgba(126, 168, 162, .3);
}

.page-about .about-eco-figure-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-eco-figure-item span {
  font-family: var(--font-num);
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-gold-lt);
}

.page-about .about-eco-figure-item span span {
  font-size: .55em;
  color: var(--c-mist);
  margin-left: 2px;
}

.page-about .about-eco-figure-item small {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-mist);
}

/* ---------- 运营支持 ---------- */
.page-about .about-support {
  display: grid;
  gap: 16px;
}

.page-about .about-support-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px;
  border: 1px solid var(--c-ink-line);
  border-top: 3px solid var(--c-wine);
  background: var(--about-card-lift);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}

.page-about .about-support-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 40px -28px rgba(10, 15, 18, .7);
}

.page-about .about-support-tag {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: .2em;
  color: #A67C2E;
}

.page-about .about-support-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
}

.page-about .about-support-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: #33393C;
}

.page-about .about-support-card .about-link {
  margin-top: auto;
  align-self: flex-start;
}

.page-about .about-contact {
  margin-top: clamp(26px, 4vw, 40px);
  padding: 24px 22px;
  background: #171C3A;
  color: var(--c-paper);
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
}

.page-about .about-contact-lead {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(243, 235, 221, .82);
}

.page-about .about-contact-line {
  margin: 0 0 6px;
  font-size: 14.5px;
  color: rgba(243, 235, 221, .9);
}

.page-about .about-contact-line a {
  color: var(--c-gold-lt);
  text-decoration: none;
  border-bottom: 1px solid rgba(241, 210, 140, .5);
}

.page-about .about-contact-line a:hover {
  color: #fff;
}

.page-about .about-contact-note {
  margin: 12px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--c-mist);
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-files {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-eco-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: center;
  }

  .page-about .about-chapter {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(22px, 3vw, 40px);
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    padding-top: 6px;
  }

  .page-about .about-rail-line {
    display: block;
    width: 1px;
    flex: 1 1 auto;
    min-height: 80px;
    background: linear-gradient(to bottom, currentColor, rgba(126, 168, 162, .05));
    opacity: .55;
  }

  .page-about .about-mech {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr);
    align-items: start;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) minmax(0, .92fr);
  }

  .page-about .about-body {
    max-width: 62rem;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero-figure img {
    margin-top: -8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-file,
  .page-about .about-support-card,
  .page-about .about-link::after,
  .page-about .about-node-mark::before,
  .page-about .about-node-mark::after {
    transition: none;
  }

  .page-about .about-file:hover,
  .page-about .about-support-card:hover {
    transform: none;
  }
}