.page-about {
  --about-marker: 22px;
  --about-gap: 18px;
  --about-spine-x: 11px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(28px, 5vw, 56px);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(28px, 5vw, 40px);
}

.page-about .about-hero-copy .display {
  margin: 16px 0 0;
  max-width: 16ch;
}

.page-about .about-hero-copy .lede {
  margin-top: 22px;
  max-width: 62ch;
}

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

.page-about .about-hero-figure .figure-media {
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: var(--shadow-1);
  position: relative;
}

.page-about .about-hero-figure .figure-media::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 28px;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 24px 20px;
  margin-top: clamp(32px, 5vw, 48px);
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.page-about .about-hero-stats .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-hero-stats .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-hero-stats .stat-value--warm {
  color: var(--orange);
}

.page-about .about-hero-stats .stat-label {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- 纵向轴线 ---------- */
.page-about .about-roadmap {
  position: relative;
  margin-top: clamp(40px, 7vw, 80px);
}

.page-about .about-spine {
  display: none;
}

.page-about .about-chapter {
  display: grid;
  grid-template-columns: var(--about-marker) minmax(0, 1fr);
  column-gap: var(--about-gap);
  padding-bottom: clamp(8px, 2vw, 20px);
}

.page-about .about-marker {
  grid-column: 1;
  position: relative;
}

.page-about .about-node {
  display: block;
  box-sizing: border-box;
  width: 12px;
  height: 12px;
  margin-left: 5px;
  margin-top: 8px;
  border: 2px solid var(--cyan-dim);
  border-radius: 50%;
  background: var(--ink);
  position: relative;
  z-index: 1;
  transition: border-color var(--ease), box-shadow var(--ease), background var(--ease);
}

.page-about .about-marker-num {
  display: block;
  margin-top: 12px;
  margin-left: 1px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--muted);
  transition: color var(--ease);
}

.page-about .about-chapter:hover .about-node,
.page-about .about-chapter:focus-within .about-node {
  border-color: var(--cyan);
  background: var(--panel);
  box-shadow: 0 0 0 4px rgba(47, 242, 196, .12);
}

.page-about .about-chapter:hover .about-marker-num,
.page-about .about-chapter:focus-within .about-marker-num {
  color: var(--cyan);
}

.page-about .about-chapter-body {
  grid-column: 2;
  min-width: 0;
}

.page-about .about-chapter-title {
  margin: 0 0 20px;
  font-size: clamp(30px, 5.4vw, 62px);
  max-width: 18ch;
}

.page-about .about-chapter-body .lede {
  max-width: 60ch;
  margin: 0 0 34px;
}

.page-about .about-chapter-body .prose {
  max-width: 68ch;
  margin: 0 0 30px;
}

/* ---------- 呼吸带 ---------- */
.page-about .about-breath {
  display: grid;
  grid-template-columns: var(--about-marker) minmax(0, 1fr);
  column-gap: var(--about-gap);
  padding: clamp(64px, 12vw, 150px) 0 clamp(28px, 5vw, 56px);
}

.page-about .about-breath-num {
  grid-column: 1;
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--line);
}

.page-about .about-breath-index {
  grid-column: 2;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 技能树 SVG ---------- */
.page-about .about-tree {
  display: block;
  width: 100%;
  height: auto;
  margin: 8px 0 36px;
  overflow: visible;
}

.page-about .about-tree .tree-links path {
  fill: none;
  stroke: var(--line);
  stroke-width: 1.5;
  transition: stroke var(--ease);
}

.page-about .about-tree .tree-node rect,
.page-about .about-tree .tree-hub rect {
  fill: var(--panel);
  stroke: var(--line);
  stroke-width: 1;
  transition: stroke var(--ease), fill var(--ease);
}

.page-about .about-tree .tree-hub rect {
  stroke: var(--cyan-dim);
}

.page-about .about-tree .tree-node:hover rect {
  stroke: var(--cyan);
}

.page-about .about-tree .tree-node:hover ~ .tree-links path {
  stroke: var(--cyan-dim);
}

.page-about .about-tree .tree-title {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: .02em;
  fill: var(--paper);
}

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

/* ---------- 三组角色 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-role {
  background: var(--panel);
  padding: clamp(20px, 3vw, 30px);
  transition: background var(--ease), box-shadow var(--ease);
}

.page-about .about-role:hover {
  background: #0E3025;
  box-shadow: var(--shadow-1);
}

.page-about .about-role-name {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .about-role-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 64ch;
}

/* ---------- 集锦四个环节 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-flow-item {
  position: relative;
  padding: 26px 0 26px 54px;
  border-bottom: 1px solid var(--line);
  transition: padding-left var(--ease);
}

.page-about .about-flow-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 30px;
  width: 14px;
  height: 1px;
  background: var(--cyan-dim);
  transition: width var(--ease), background var(--ease);
}

.page-about .about-flow-item:hover {
  padding-left: 62px;
}

.page-about .about-flow-item:hover::before {
  width: 30px;
  background: var(--orange);
}

.page-about .about-flow-step {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--muted);
  margin-bottom: 6px;
}

.page-about .about-flow-title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-flow-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 64ch;
}

/* ---------- 数据同步 ---------- */
.page-about .about-sync-figure {
  margin: 0 0 34px;
}

.page-about .about-sync-figure .figure-media {
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-sync {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-sync-item {
  background: var(--panel);
  padding: 22px clamp(18px, 3vw, 26px);
  display: grid;
  gap: 8px;
}

.page-about .about-sync-key {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--muted);
}

.page-about .about-sync-val {
  font-family: var(--font-mono);
  font-size: 28px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-sync-val.num-orange {
  color: var(--orange);
}

.page-about .about-sync-note {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 60ch;
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--line);
}

.page-about .about-tl-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 22px 0 22px clamp(20px, 3vw, 34px);
  border-bottom: 1px solid var(--line);
  cursor: default;
  outline: none;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 30px;
  width: 9px;
  height: 9px;
  box-sizing: border-box;
  border: 2px solid var(--cyan-dim);
  border-radius: 50%;
  background: var(--ink);
  transition: background var(--ease), border-color var(--ease), box-shadow var(--ease);
}

.page-about .about-tl-item:hover::before,
.page-about .about-tl-item:focus-within::before {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 242, 196, .14);
}

.page-about .about-tl-year {
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--muted);
  transition: color var(--ease);
}

.page-about .about-tl-item:hover .about-tl-year,
.page-about .about-tl-item:focus-within .about-tl-year {
  color: var(--orange);
}

.page-about .about-tl-title {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-tl-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 62ch;
  overflow: hidden;
  transition: opacity 240ms var(--ease), max-height 240ms var(--ease);
}

/* ---------- 工作台图 ---------- */
.page-about .about-desk-figure {
  margin: clamp(36px, 6vw, 64px) 0 0;
}

.page-about .about-desk-figure .figure-media {
  border: 1px solid var(--line);
  background: var(--panel);
}

@media (min-width: 860px) {
  .page-about .about-desk-figure {
    margin-left: calc(100% / 12);
    margin-right: calc(100% / 12);
  }
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-cover {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-bottom: 30px;
}

.page-about .about-cover-col {
  background: var(--panel);
  padding: 24px clamp(18px, 3vw, 26px);
}

.page-about .about-cover-key {
  display: block;
  margin-bottom: 14px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan-dim);
}

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

.page-about .about-cover-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .about-cover-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 7px;
  height: 1px;
  background: var(--cyan);
}

.page-about .about-cover-more {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 68ch;
}

.page-about .about-cover-more a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
  transition: border-color var(--ease), color var(--ease);
}

.page-about .about-cover-more a:hover,
.page-about .about-cover-more a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--orange);
}

/* ---------- 尾章 ---------- */
.page-about .about-tail {
  margin-top: clamp(56px, 9vw, 110px);
  border-top: 1px solid var(--line);
  padding-top: clamp(40px, 6vw, 70px);
}

.page-about .about-tail-inner {
  max-width: 62ch;
}

.page-about .about-tail-text {
  margin: 14px 0 26px;
  font-size: clamp(19px, 2.6vw, 26px);
  line-height: 1.65;
  color: var(--paper);
}

.page-about .about-tail-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.page-about .status-hint {
  margin-top: 20px;
}

/* ---------- 数字与等宽 ---------- */
.page-about .num {
  font-family: var(--font-mono);
  font-size: 1.15em;
  color: var(--cyan);
}

.page-about .num-orange {
  font-family: var(--font-mono);
  font-size: 1.15em;
  color: var(--orange);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .about-sync,
  .page-about .about-cover {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-hero-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: 24px;
    align-items: start;
  }

  .page-about .about-hero-copy {
    grid-column: 1 / span 5;
  }

  .page-about .about-hero-figure {
    grid-column: 6 / span 7;
    margin-top: 34px;
  }

  .page-about .about-spine {
    display: block;
    position: absolute;
    left: var(--about-spine-x);
    top: 24px;
    bottom: 60px;
    width: 1px;
    background: linear-gradient(to bottom,
        transparent 0,
        var(--line) 2%,
        var(--line) 98%,
        transparent 100%);
  }

  .page-about .about-chapter {
    grid-template-columns: var(--about-marker) repeat(11, minmax(0, 1fr));
    column-gap: 24px;
  }

  .page-about .about-marker {
    grid-column: 1;
  }

  .page-about .about-chapter-body {
    grid-column: 2 / span 8;
  }

  .page-about .about-chapter--wide .about-chapter-body {
    grid-column: 2 / span 10;
  }

  .page-about .about-chapter--offset .about-chapter-body {
    grid-column: 3 / span 8;
  }

  .page-about .about-breath {
    grid-template-columns: var(--about-marker) repeat(11, minmax(0, 1fr));
    column-gap: 24px;
  }

  .page-about .about-tree {
    max-width: 720px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-tl-item {
    grid-template-columns: 90px minmax(0, 1fr);
    column-gap: 24px;
    align-items: start;
  }

  .page-about .about-tl-year {
    font-size: 24px;
    padding-top: 2px;
  }
}

@media (hover: hover) and (min-width: 860px) {
  .page-about .about-tl-desc {
    max-height: 0;
    opacity: 0;
  }

  .page-about .about-tl-item:hover .about-tl-desc,
  .page-about .about-tl-item:focus-within .about-tl-desc {
    max-height: 8em;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node,
  .page-about .about-marker-num,
  .page-about .about-flow-item,
  .page-about .about-flow-item::before,
  .page-about .about-tl-item::before,
  .page-about .about-tl-year,
  .page-about .about-tl-desc {
    transition: none;
  }

  .page-about .about-flow-item:hover {
    padding-left: 54px;
  }

  .page-about .about-flow-item:hover::before {
    width: 14px;
  }
}