.page-about {
  --about-rail: 250px;
  --about-ink-soft: #332F28;
  background: var(--paper);
  color: var(--ink);
}

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

.page-about .media-frame {
  overflow: hidden;
  border: 2px solid var(--ink);
  background: var(--sand-2);
}

.page-about .media-frame--3x2 { aspect-ratio: 3 / 2; }
.page-about .media-frame--4x3 { aspect-ratio: 4 / 3; }

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

.page-about .media-caption {
  margin: 10px 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-size: 13px;
  color: var(--muted);
}

.page-about .crumbs a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--sand);
}

.page-about .crumbs a:hover { color: var(--red); }

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 3vw, 34px) 0 clamp(32px, 5vw, 60px);
  background: linear-gradient(158deg, var(--paper-2) 0%, var(--paper) 48%, var(--sand-2) 100%);
  border-bottom: 3px solid var(--deep);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 38%;
  height: 5px;
  background: var(--red);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
  align-items: center;
}

.page-about .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--deep-2);
  text-transform: uppercase;
}

.page-about h1 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.18;
  font-size: clamp(28px, 6vw, 50px);
  color: var(--ink);
}

.page-about .about-lead {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-hero-note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-hero-note a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--red);
}

.page-about .about-hero-art {
  margin: 0;
  border-left: 4px solid var(--sand);
  padding-left: 12px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(24px, 4vw, 40px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-stat {
  margin: 0;
  padding: 14px 16px;
  background: var(--paper-2);
}

.page-about .about-stat b {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 26px;
  line-height: 1.1;
  color: var(--deep);
}

.page-about .about-stat span {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  color: var(--muted);
}

/* ---------- 左右分屏主体 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  padding-top: clamp(32px, 5vw, 60px);
  padding-bottom: clamp(48px, 7vw, 88px);
}

.page-about .about-rail {
  border: 2px solid var(--deep);
  background: var(--paper-2);
  padding: 16px 16px 0;
}

.page-about .rail-title {
  margin: 0 0 12px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--sand);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--deep);
}

.page-about .rail-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .rail-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 6px;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .rail-list a:hover {
  background: var(--sand-2);
  border-left-color: var(--red);
}

.page-about .rail-no {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 700;
  color: var(--red);
}

.page-about .rail-stat {
  margin: 0 -16px;
  padding: 14px 16px;
  background: var(--deep);
  color: var(--paper);
}

.page-about .rail-stat-label {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--sand);
}

.page-about .rail-stat-line {
  margin: 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--paper);
  opacity: 0.88;
}

.page-about .about-flow {
  display: grid;
  gap: clamp(40px, 6vw, 72px);
  min-width: 0;
}

.page-about .flow-section { min-width: 0; }

.page-about .section-head {
  margin-bottom: 18px;
}

.page-about .section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.015em;
  line-height: 1.25;
  font-size: clamp(21px, 3.2vw, 30px);
  color: var(--ink);
}

.page-about .prose p {
  margin: 0 0 14px;
  max-width: 70ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .prose a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--red);
}

.page-about .prose a:hover { color: var(--red); }

.page-about .origin-panels {
  display: grid;
  gap: 14px;
  margin-top: 20px;
}

.page-about .flow-card {
  background: var(--paper-2);
  border: 2px solid var(--ink);
  padding: clamp(16px, 2.4vw, 22px);
  box-shadow: 6px 6px 0 var(--sand-2);
}

.page-about .flow-card:nth-child(2) {
  box-shadow: 6px 6px 0 var(--deep-2);
}

.page-about .flow-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--deep);
}

.page-about .flow-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline-art {
  margin: 0 0 22px;
}

.page-about .milestone {
  border: 2px solid var(--ink);
  background: var(--paper-2);
  margin-bottom: 12px;
}

.page-about .milestone > summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 14px 16px;
}

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

.page-about .milestone[open] > summary {
  background: var(--sand-2);
  border-bottom: 2px solid var(--ink);
}

.page-about .ms-no {
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 12px;
  color: var(--red);
}

.page-about .ms-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .ms-body {
  padding: 14px 16px 18px;
}

.page-about .ms-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .ms-body a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--red);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 14px;
  margin-top: 20px;
}

.page-about .team-card {
  border: 2px solid var(--deep);
  background: var(--paper-2);
  padding: 18px;
}

.page-about .team-card:nth-child(2) { border-color: var(--sand); }
.page-about .team-card:nth-child(3) { border-color: var(--ink); }

.page-about .team-role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--ink);
}

.page-about .team-count {
  margin: 6px 0 12px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--haze);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .team-card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

/* ---------- 资质 ---------- */
.page-about .cred-layout {
  display: grid;
  gap: 20px;
  align-items: start;
}

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

.page-about .cred-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 14px 16px;
  border: 2px solid var(--ink);
  background: var(--paper-2);
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

.page-about .cred-year {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  color: var(--red);
  min-width: 52px;
}

.page-about .cred-art { margin: 0; }

/* ---------- 合作生态 ---------- */
.page-about .partner-band {
  background: var(--deep);
  border: 2px solid var(--ink);
  padding: clamp(20px, 3vw, 30px);
  color: var(--paper);
}

.page-about .partner-lead {
  margin: 0 0 20px;
  max-width: 72ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--paper);
  opacity: 0.94;
}

.page-about .partner-grid {
  display: grid;
  gap: 12px;
}

.page-about .partner-cell {
  border: 1px solid var(--sand);
  background: rgba(247, 243, 234, 0.06);
  padding: 16px;
}

.page-about .partner-cell h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--sand);
}

.page-about .partner-cell p {
  margin: 0;
  font-size: 13px;
  line-height: 1.85;
  color: var(--paper);
  opacity: 0.86;
}

/* ---------- 联系 ---------- */
.page-about .service-panel {
  border: 2px solid var(--ink);
  background: linear-gradient(180deg, var(--paper-2) 0%, var(--sand-2) 100%);
  padding: clamp(20px, 3vw, 30px);
}

.page-about .service-intro {
  margin: 0 0 20px;
  max-width: 70ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .service-intro a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--red);
}

.page-about .service-intro a:hover { color: var(--red); }

.page-about .contact-grid {
  display: grid;
  gap: 12px;
}

.page-about .about-copy {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 13px 15px;
  text-align: left;
  border: 2px dashed var(--deep);
  background: var(--paper-2);
  color: var(--ink);
  font: inherit;
  cursor: pointer;
  transition: background 0.2s var(--ease), border-style 0.2s var(--ease);
}

.page-about .about-copy:hover {
  background: var(--sand-2);
  border-style: solid;
}

.page-about .about-copy--static {
  border-style: solid;
  border-color: var(--haze);
  cursor: default;
}

.page-about .about-copy--static:hover { background: var(--paper-2); }

.page-about .about-copy-label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--deep-2);
}

.page-about .about-copy-value {
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  word-break: break-all;
}

.page-about .about-copy-hint {
  font-size: 11px;
  color: var(--muted);
}

.page-about .about-copy[data-copied]::after {
  content: "已复制";
  align-self: flex-start;
  margin-top: 2px;
  font-size: 11px;
  font-weight: 700;
  color: var(--red);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .page-about .contact-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .origin-panels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .partner-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 760px) {
  .page-about .cred-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 26px;
  }
  .page-about .team-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  }
}

@media (min-width: 960px) {
  .page-about {
    --about-rail: 240px;
  }
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }
}

@media (min-width: 1180px) {
  .page-about {
    --about-rail: 272px;
  }
  .page-about .about-body { gap: 56px; }
}

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