.page-about {
  --about-rail: 190px;
  --about-aside: 236px;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: clamp(16px, 3vw, 28px);
  font-size: 14px;
  color: var(--muted);
}

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

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  border-bottom-color: var(--green);
}

/* ---------- 首屏拼贴 ---------- */
.page-about .about-hero {
  margin-top: clamp(16px, 3vw, 26px);
  border-top: var(--edge);
  border-bottom: var(--edge);
  background: var(--paper-2);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  padding-block: clamp(28px, 5vw, 56px);
}

.page-about .about-eyebrow {
  margin: 0 0 14px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--red);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  max-width: 22ch;
  font-family: var(--font-display);
  font-size: clamp(29px, 4.6vw, 44px);
  font-weight: 600;
  line-height: 1.18;
  color: var(--ink);
}

.page-about .about-hero .lede {
  max-width: 60ch;
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
}

/* 统计条 */
.page-about .about-stats {
  display: grid;
  margin-top: clamp(24px, 3.4vw, 36px);
  border: var(--edge);
  background: var(--paper);
  border-radius: var(--radius);
}

.page-about .about-stat {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-stat:last-child {
  border-bottom: 0;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--green);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted);
}

/* 深色编辑台卡片 */
.page-about .about-desk {
  padding: 20px;
  border: var(--edge);
  border-radius: var(--radius);
  background: var(--green);
  color: var(--paper);
  box-shadow: var(--hard);
}

.page-about .about-desk__title {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-desk__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-desk__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding-bottom: 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid rgba(244, 239, 228, 0.2);
}

.page-about .about-desk__item:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .about-desk__n {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-desk__k {
  display: block;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-desk__v {
  display: block;
  margin-top: 3px;
  font-size: 14px;
  line-height: 1.55;
  color: rgba(244, 239, 228, 0.74);
}

.page-about .about-desk__foot {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid rgba(244, 239, 228, 0.2);
  font-size: 14px;
  line-height: 1.6;
  color: rgba(244, 239, 228, 0.74);
}

/* ---------- 主区骨架 ---------- */
.page-about .about-main {
  display: grid;
  gap: clamp(28px, 4vw, 40px);
  padding-block: clamp(36px, 5vw, 64px);
}

.page-about .about-flow {
  display: grid;
  gap: clamp(44px, 6vw, 76px);
  min-width: 0;
}

/* ---------- 章节目录 ---------- */
.page-about .toc {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 10px;
  border-bottom: var(--edge-hair);
}

.page-about .toc__title {
  display: none;
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .toc__link {
  display: flex;
  flex: 0 0 auto;
  align-items: baseline;
  gap: 8px;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  border-left: 2px solid transparent;
  transition: background-color 0.12s ease, border-color 0.12s ease;
}

.page-about .toc__no {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.page-about .toc__link:hover,
.page-about .toc__link:focus-visible {
  background: var(--paper-2);
}

.page-about .toc__link[data-active] {
  border-left-color: var(--gold);
  background: var(--paper-2);
  color: var(--green);
  font-weight: 700;
}

.page-about .toc__link[data-active] .toc__no {
  color: var(--red);
}

/* ---------- 章节头 ---------- */
.page-about .about-flow > .section {
  min-width: 0;
}

.page-about .section-head__no {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--red);
}

.page-about .section-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.2vw, 32px);
  font-weight: 600;
  line-height: 1.26;
  color: var(--ink);
}

.page-about .section-head__meta {
  margin: 12px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--red);
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-flow p {
  max-width: 68ch;
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding: 0 0 0 32px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 12px;
  bottom: 12px;
  width: 3px;
  background: var(--green);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: clamp(20px, 2.6vw, 28px);
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 8px;
  width: 13px;
  height: 13px;
  background: var(--gold);
  border: 2px solid var(--ink);
}

.page-about .era {
  padding: 16px 18px;
  border: var(--edge);
  border-left-width: 6px;
  border-left-color: var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  transition: border-left-color 0.15s ease, box-shadow 0.15s ease;
}

.page-about .timeline__item:hover .era,
.page-about .timeline__item:focus-within .era {
  border-left-color: var(--green);
  box-shadow: var(--hard-sm);
}

.page-about .era__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
}

.page-about .era__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .era__phase {
  padding: 2px 7px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .era__body {
  margin: 10px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.72;
  color: var(--ink);
}

.page-about .era__delta {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .era__delta b {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--green);
}

/* ---------- 表格 ---------- */
.page-about .table-wrap {
  margin-top: clamp(20px, 3vw, 28px);
  overflow-x: auto;
  border: var(--edge);
  border-radius: var(--radius);
  background: var(--paper);
}

.page-about .about-table {
  width: 100%;
  min-width: 660px;
  border-collapse: collapse;
  font-size: 15px;
}

.page-about .about-table caption {
  caption-side: top;
  padding: 12px 16px;
  border-bottom: var(--edge-hair);
  text-align: left;
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 12px 16px;
  border-bottom: var(--edge-hair);
  text-align: left;
  vertical-align: top;
  line-height: 1.6;
}

.page-about .about-table thead th {
  background: var(--green);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .about-table thead th.is-gold {
  color: var(--gold);
  font-family: var(--font-mono);
}

.page-about .about-table tbody th {
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}

.page-about .about-table tbody tr:nth-child(even) {
  background: var(--paper-2);
}

.page-about .about-table tbody tr:last-child th,
.page-about .about-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .about-table td.value {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--green);
  white-space: nowrap;
}

/* ---------- 口径提示条 ---------- */
.page-about .note {
  margin-top: 18px;
  padding: 14px 16px;
  border-left: 3px solid var(--red);
  background: var(--paper-2);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .note__tag {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--red);
}

/* ---------- 岗位卡 ---------- */
.page-about .roles {
  display: grid;
  gap: 16px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .role {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px;
  border: var(--edge);
  border-radius: var(--radius);
  background: var(--paper);
}

.page-about .role__n {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--green);
}

.page-about .role:nth-child(2) .role__n {
  color: var(--red);
}

.page-about .role:nth-child(3) .role__n {
  color: var(--board);
}

.page-about .role__name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .role__duty {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--muted);
}

/* ---------- 边界清单 ---------- */
.page-about .about-boundary {
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border: var(--edge);
  border-radius: var(--radius);
  background: var(--paper);
}

.page-about .about-boundary li {
  position: relative;
  padding: 14px 16px 14px 40px;
  border-bottom: var(--edge-hair);
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .about-boundary li:last-child {
  border-bottom: 0;
}

.page-about .about-boundary li::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 20px;
  width: 9px;
  height: 9px;
  background: var(--red);
}

/* ---------- 流程示意 ---------- */
.page-about .about-flow-wrap {
  margin-top: clamp(20px, 3vw, 28px);
  padding-bottom: 6px;
}

.page-about .flow-svg {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}

.page-about .flow-box {
  fill: var(--paper);
  stroke: var(--board);
  stroke-width: 2;
}

.page-about .flow-line {
  stroke: var(--board);
  stroke-width: 2;
}

.page-about .flow-arrow {
  fill: var(--board);
}

.page-about .flow-text {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 700;
  fill: var(--ink);
}

.page-about .flow-sub {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--muted);
}

/* ---------- 按钮组 ---------- */
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

/* ---------- 媒体验证 ---------- */
.page-about .media {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border: var(--edge);
  border-radius: var(--radius);
  background: var(--paper-2);
  overflow: hidden;
}

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

.page-about .media__cap {
  margin: 0;
  padding: 10px 14px;
  border-top: var(--edge-hair);
  background: var(--paper);
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 旁注栏 ---------- */
.page-about .about-notes {
  display: grid;
  gap: 24px;
  align-content: start;
}

.page-about .about-notes__title {
  margin: 0;
  padding-bottom: 8px;
  border-bottom: var(--edge-hair);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .aside-note {
  padding-left: 14px;
  border-left: 2px solid var(--muted);
  font-size: 14px;
  line-height: 1.68;
  color: var(--muted);
}

.page-about .aside-note__key {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 19px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .aside-note a {
  display: inline-block;
  margin-top: 6px;
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.page-about .aside-note a:hover,
.page-about .aside-note a:focus-visible {
  border-bottom-color: var(--green);
}

.page-about .about-note-figure {
  margin-top: 4px;
}

/* ---------- 返回顶部 ---------- */
.page-about .to-top {
  display: block;
  width: max-content;
  margin: 0 auto clamp(32px, 5vw, 56px);
  padding: 10px 18px;
  border: var(--edge);
  border-radius: 999px;
  background: var(--paper);
  box-shadow: var(--hard-sm);
  font-size: 14px;
  font-weight: 700;
  color: var(--green);
  text-decoration: none;
}

.page-about .to-top:hover,
.page-about .to-top:focus-visible {
  background: var(--paper-2);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-stat {
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

  .page-about .about-stat:last-child {
    border-right: 0;
  }
}

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(272px, 0.9fr);
    align-items: start;
  }
}

@media (min-width: 1040px) {
  .page-about .about-main {
    grid-template-columns: var(--about-rail) minmax(0, 1fr) var(--about-aside);
    gap: clamp(28px, 3.4vw, 44px);
  }

  .page-about .toc {
    position: sticky;
    top: 92px;
    align-self: start;
    display: block;
    overflow: visible;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .toc__title {
    display: block;
  }

  .page-about .toc__link {
    white-space: normal;
    margin-bottom: 2px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .era,
  .page-about .toc__link {
    transition: none;
  }

  .page-about .timeline__item:hover .era,
  .page-about .timeline__item:focus-within .era {
    box-shadow: none;
  }
}