.page-about {
  --about-rail-w: 190px;
  --about-gap: clamp(20px, 3.2vw, 52px);
  --about-hair: rgba(43, 43, 43, .16);
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .shell {
  box-sizing: border-box;
}

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

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(24px, 4.6vw, 60px) 0 clamp(26px, 4vw, 52px);
  background: linear-gradient(180deg, var(--sand) 0%, var(--sand-deep) 100%);
  border-bottom: 3px solid var(--line);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 44px);
  align-items: end;
}

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

.page-about .crumbs {
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  padding: 0;
  list-style: none;
}

.page-about h1 {
  margin: 0 0 clamp(16px, 2.2vw, 24px);
  font-family: var(--font-title);
  font-weight: 600;
  font-size: clamp(30px, 5.6vw, 62px);
  line-height: 1.02;
  letter-spacing: -.01em;
  color: var(--ink-blue);
  text-wrap: balance;
}

.page-about .about-lead {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  max-width: 52ch;
  font-size: clamp(16.5px, 1.5vw, 19px);
  line-height: 1.82;
  color: var(--ink);
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ink);
}

.page-about .about-hero-meta li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .mono-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .about-hero-meta .mono-tag::after {
  content: "·";
  margin-left: 8px;
  color: var(--signal-dark);
}

.page-about .about-hero-figure {
  margin: 0;
  border: 3px solid var(--line);
  background: var(--paper);
  box-shadow: var(--shadow-hard-lg);
}

.page-about .about-hero-figure .figure-cap {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- 概览数据带 ---------- */

.page-about .about-stats {
  background: var(--ink-blue);
  border-bottom: 3px solid var(--line);
}

.page-about .about-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(232, 220, 200, .22);
}

.page-about .stat {
  background: var(--ink-blue);
  padding: clamp(18px, 2.6vw, 30px) clamp(14px, 2vw, 24px);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-title);
  font-weight: 600;
  font-size: clamp(30px, 4vw, 46px);
  line-height: 1;
  letter-spacing: .01em;
  color: var(--signal);
}

.page-about .stat-label {
  display: block;
  margin-top: 9px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: rgba(247, 243, 234, .78);
}

/* ---------- 主布局：索引轴 + 内容区 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  align-items: start;
  padding-top: clamp(28px, 4.4vw, 60px);
  padding-bottom: clamp(40px, 6vw, 88px);
}

.page-about .about-rail {
  border: 2px solid var(--line);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
  padding: 14px 12px 16px;
}

.page-about .about-rail-title {
  margin: 0 0 10px;
  padding-bottom: 9px;
  border-bottom: 2px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--muted);
}

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

.page-about .about-rail-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-left: 3px solid transparent;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  transition: background-color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-rail-list a::after {
  content: "";
  width: 7px;
  height: 7px;
  margin-left: auto;
  border-radius: 50%;
  background: var(--sand-deep);
  transition: background-color .2s var(--ease);
}

.page-about .about-rail-list a:hover,
.page-about .about-rail-list a:focus-visible {
  background: var(--sand-deep);
  border-left-color: var(--signal);
  outline: none;
}

.page-about .about-rail-list a:hover::after,
.page-about .about-rail-list a:focus-visible::after {
  background: var(--signal);
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
}

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

/* ---------- 章节通用 ---------- */

.page-about .about-section {
  padding: clamp(26px, 4.2vw, 54px) 0;
  border-top: 2px solid var(--about-hair);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-head {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(18px, 2.6vw, 30px);
}

.page-about .mono-eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .14em;
  color: var(--signal-dark);
}

.page-about .about-head h2 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 600;
  font-size: clamp(25px, 3.4vw, 40px);
  line-height: 1.08;
  letter-spacing: -.005em;
  color: var(--ink-blue);
  text-wrap: balance;
}

.page-about .about-spread {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2.4vw, 32px);
  align-items: start;
}

.page-about .about-panel {
  min-width: 0;
  max-width: 68ch;
}

.page-about .about-panel p {
  margin: 0 0 1em;
  font-size: 17px;
  line-height: 1.82;
  color: var(--ink);
}

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

.page-about .about-note {
  border: 2px solid var(--line);
  border-left: 6px solid var(--amber);
  background: var(--paper);
  padding: 18px 16px;
  box-shadow: 5px 5px 0 rgba(43, 43, 43, .10);
}

.page-about .about-note .note-label {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .about-note p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--ink);
}

/* ---------- 索引分类卡片 ---------- */

.page-about .index-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .index-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  border: 2px solid var(--line);
  background: var(--paper);
  padding: 20px 18px 22px;
  box-shadow: var(--shadow-hard);
  transition: transform .22s var(--ease), box-shadow .22s var(--ease), border-color .22s var(--ease);
}

.page-about .index-card-no {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--amber);
}

.page-about .index-card h3 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 600;
  font-size: 22px;
  letter-spacing: .01em;
  color: var(--ink-blue);
}

.page-about .index-card p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.74;
  color: var(--ink);
}

.page-about .index-figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border: 2px solid var(--line);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
}

.page-about .index-figure .figure-cap {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 更新节奏列表 ---------- */

.page-about .scope-list {
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--line);
}

.page-about .scope-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 2px solid var(--about-hair);
}

.page-about .scope-name {
  font-family: var(--font-title);
  font-weight: 600;
  font-size: 20px;
  letter-spacing: .01em;
  color: var(--ink-blue);
}

.page-about .scope-detail {
  font-size: 15px;
  line-height: 1.74;
  color: var(--ink);
}

.page-about .scope-meta {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--signal-dark);
}

/* ---------- 合作生态图 ---------- */

.page-about .partner-figure {
  margin: clamp(20px, 3vw, 32px) 0 0;
  border: 2px solid var(--line);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
}

.page-about .partner-figure .figure-cap {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 常用入口 ---------- */

.page-about .entry-list {
  display: grid;
  margin: 0 0 clamp(20px, 3vw, 32px);
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--line);
}

.page-about .entry-item a {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 14px;
  align-items: start;
  padding: 18px 8px;
  border-bottom: 2px solid var(--about-hair);
  text-decoration: none;
  color: var(--ink);
  transition: background-color .2s var(--ease), padding-left .2s var(--ease);
}

.page-about .entry-item a:hover,
.page-about .entry-item a:focus-visible {
  background: var(--sand-deep);
  padding-left: 16px;
  outline: none;
}

.page-about .entry-no {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--amber);
}

.page-about .entry-body {
  display: grid;
  gap: 5px;
  min-width: 0;
}

.page-about .entry-body strong {
  font-family: var(--font-title);
  font-weight: 600;
  font-size: 20px;
  letter-spacing: .01em;
  color: var(--ink-blue);
}

.page-about .entry-body span {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .entry-arrow {
  padding-top: 4px;
  font-family: var(--font-mono);
  color: var(--signal-dark);
  transition: transform .2s var(--ease);
}

.page-about .entry-item a:hover .entry-arrow,
.page-about .entry-item a:focus-visible .entry-arrow {
  transform: translateX(4px);
}

/* ---------- 联系方式 ---------- */

.page-about .about-contact {
  display: grid;
  gap: 10px;
  border: 2px solid var(--line);
  border-left: 6px solid var(--signal);
  background: var(--paper);
  padding: 20px 18px;
  box-shadow: var(--shadow-hard);
}

.page-about .contact-line {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink);
  word-break: break-word;
}

.page-about .contact-note {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .index-cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .scope-item {
    grid-template-columns: 150px minmax(0, 1fr) 130px;
    align-items: baseline;
    gap: 20px;
  }
}

@media (min-width: 800px) {
  .page-about .about-spread {
    grid-template-columns: minmax(0, 1.6fr) minmax(200px, .8fr);
    gap: clamp(22px, 3.2vw, 44px);
  }

  .page-about .about-spread--flip {
    grid-template-columns: minmax(200px, .8fr) minmax(0, 1.6fr);
  }

  .page-about .about-spread--flip > .about-note {
    order: -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 20px;
  }
}

@media (min-width: 1180px) {
  .page-about {
    --about-rail-w: 216px;
  }
}

@media (hover: hover) {
  .page-about .index-card:hover {
    transform: translate(-3px, -3px);
    box-shadow: var(--shadow-hard-lg);
    border-color: var(--signal-dark);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .index-card,
  .page-about .about-rail-list a,
  .page-about .entry-item a,
  .page-about .entry-arrow {
    transition: none;
  }

  .page-about .index-card:hover {
    transform: none;
  }

  .page-about .entry-item a:hover .entry-arrow {
    transform: none;
  }
}