.page-about {
  --ab-gap: clamp(14px, 2vw, 24px);
  --ab-accent: var(--cyan);
  color: var(--cream);
  font-family: var(--font-body);
  max-width: 1240px;
  padding: clamp(18px, 3vw, 34px) clamp(16px, 3.2vw, 44px) clamp(48px, 7vw, 92px);
}

.page-about .crumb {
  margin-bottom: clamp(20px, 3vw, 34px);
}

/* ---------- 首屏 ---------- */
.page-about .about-masthead {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
  padding-bottom: clamp(26px, 4vw, 48px);
  border-bottom: 2px solid var(--line);
}

.page-about .about-masthead-top {
  display: grid;
  gap: clamp(12px, 2vw, 20px);
}

.page-about .about-since {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(58px, 13vw, 122px);
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: rgba(53, 240, 200, 0.13);
  -webkit-text-stroke: 2px var(--cyan);
}

.page-about .about-masthead-text {
  display: grid;
  gap: 10px;
  align-content: end;
}

.page-about .about-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 5.2vw, 54px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--cream);
}

.page-about .about-lead {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(16px, 2vw, 20px);
  line-height: 1.8;
  color: var(--moss-soft);
  max-width: 60ch;
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 3px solid var(--moss);
}

.page-about .about-figures {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--line);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-hard);
}

.page-about .about-figure {
  background: var(--panel);
  padding: clamp(14px, 2vw, 22px);
  display: grid;
  gap: 8px;
  align-content: start;
}

.page-about .about-figure-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(28px, 4.6vw, 46px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-unit {
  font-size: 0.58em;
  margin-left: 2px;
}

.page-about .about-figure-cap {
  font-size: 13px;
  line-height: 1.55;
  color: var(--rock);
}

/* ---------- 外壳：主内容 + 旁注索引 ---------- */
.page-about .about-shell {
  display: grid;
  gap: clamp(24px, 3.4vw, 48px);
  margin-top: clamp(30px, 4.6vw, 62px);
}

.page-about .about-rail {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .about-rail-title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--rock);
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 2px;
  overflow-x: auto;
  border-top: 2px solid var(--line);
  border-bottom: 2px solid var(--line);
}

.page-about .toc-link {
  display: block;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  white-space: nowrap;
  color: var(--rock);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: color 0.16s ease, background-color 0.16s ease, border-color 0.16s ease;
}

.page-about .toc-link:hover,
.page-about .toc-link:focus-visible {
  color: var(--cyan);
  background: rgba(53, 240, 200, 0.08);
  border-left-color: var(--cyan);
}

.page-about .toc-link[aria-current="true"] {
  color: var(--night);
  background: var(--cyan);
  border-left-color: var(--cyan);
}

.page-about .about-rail-note {
  border: 2px solid var(--line);
  background: var(--panel);
  padding: 14px;
  display: grid;
  gap: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--rock);
}

.page-about .about-rail-note .rail-note-title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--moss-soft);
}

.page-about .about-rail-note p {
  margin: 0;
}

.page-about .about-rail-note .link-inline {
  color: var(--orange);
  font-family: var(--font-mono);
  font-size: 12px;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 154, 60, 0.5);
}

.page-about .about-rail-note .link-inline:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: clamp(28px, 4.4vw, 54px) 0;
  border-top: 2px solid var(--line);
}

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

.page-about .about-section .section-head {
  display: grid;
  gap: 8px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-about .section-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(21px, 3.1vw, 32px);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .prose p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(236, 241, 237, 0.84);
}

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

.page-about .link-inline {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 240, 200, 0.45);
}

.page-about .link-inline:hover {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

/* ---------- 图片 ---------- */
.page-about .about-shot {
  margin: clamp(20px, 3vw, 32px) 0 0;
  display: grid;
  gap: 10px;
}

.page-about .about-shot .img-frame {
  border: 2px solid var(--line);
  background: var(--panel-deep);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

.page-about .img-cap {
  font-size: 12px;
  line-height: 1.6;
  color: var(--rock);
  font-family: var(--font-mono);
}

/* ---------- 团队分工 ---------- */
.page-about .crew-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: clamp(18px, 2.6vw, 28px);
}

.page-about .crew-card {
  --card-accent: var(--cyan);
  background: var(--panel);
  border: 2px solid var(--line);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.42);
  padding: clamp(14px, 2vw, 20px);
  display: grid;
  gap: 8px;
  align-content: start;
  transition: border-color 0.16s ease, transform 0.16s ease, box-shadow 0.16s ease;
}

.page-about .crew-card--design {
  --card-accent: var(--orange);
}

.page-about .crew-card--editor {
  --card-accent: var(--moss-soft);
}

.page-about .crew-card--service {
  --card-accent: var(--clay);
}

.page-about .crew-card:hover {
  border-color: var(--card-accent);
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.52);
}

.page-about .crew-num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1;
  color: var(--card-accent);
}

.page-about .crew-name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.01em;
  color: var(--cream);
}

.page-about .crew-desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--rock);
}

/* ---------- 关系图 ---------- */
.page-about .about-flow {
  margin: clamp(22px, 3vw, 34px) 0 0;
  display: grid;
  gap: 10px;
}

.page-about .flow-scroll {
  overflow-x: auto;
  border: 2px solid var(--line);
  background: linear-gradient(140deg, var(--panel-deep), var(--panel));
  padding: clamp(10px, 2vw, 20px);
}

.page-about .flow-svg {
  display: block;
  width: 100%;
  height: auto;
  min-width: 600px;
}

.page-about .flow-node {
  cursor: default;
  outline: none;
}

.page-about .flow-node rect {
  fill: var(--panel);
  stroke: var(--line);
  stroke-width: 2;
  transition: stroke 0.16s ease, fill 0.16s ease;
}

.page-about .flow-node text {
  fill: var(--cream);
  font-family: var(--font-mono);
  font-size: 15px;
  pointer-events: none;
}

.page-about .flow-link {
  fill: none;
  stroke: var(--line);
  stroke-width: 2;
  transition: stroke 0.16s ease;
}

.page-about .flow-node:hover rect,
.page-about .flow-node:focus-visible rect {
  stroke: var(--cyan);
  fill: rgba(53, 240, 200, 0.08);
}

.page-about .flow-node:hover .flow-link,
.page-about .flow-node:focus-visible .flow-link {
  stroke: var(--cyan);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-axis-intro {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-size: 14px;
  line-height: 1.7;
  color: var(--rock);
}

.page-about .about-axis {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-axis::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 8px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--clay), var(--moss), var(--cyan));
  opacity: 0.55;
}

.page-about .tl-item {
  position: relative;
  padding-left: 52px;
  padding-bottom: clamp(18px, 2.6vw, 28px);
}

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

.page-about .tl-item::before {
  content: attr(data-step);
  position: absolute;
  left: 0;
  top: 0;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  background: var(--night);
  border: 2px solid var(--clay);
  color: var(--clay);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  transition: border-color 0.16s ease, color 0.16s ease;
}

.page-about .tl-item:hover::before {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .tl-fold summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
  padding: 4px 0;
  font-family: var(--font-display);
  font-size: clamp(16px, 2.1vw, 20px);
  line-height: 1.35;
  color: var(--cream);
  transition: color 0.16s ease;
}

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

.page-about .tl-fold summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--rock);
}

.page-about .tl-fold summary:hover,
.page-about .tl-fold summary:focus-visible {
  color: var(--cyan);
}

.page-about .tl-fold summary:hover::after {
  color: var(--cyan);
}

.page-about .tl-fold[open] summary {
  color: var(--moss-soft);
}

.page-about .tl-fold[open] summary::after {
  content: "–";
  color: var(--cyan);
}

.page-about .tl-ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
  border: 1px solid rgba(255, 154, 60, 0.5);
  padding: 2px 7px;
  white-space: nowrap;
}

.page-about .tl-fold .fold-body {
  padding-top: 8px;
  border-left: 2px solid var(--line);
  padding-left: 14px;
  margin-top: 8px;
}

.page-about .tl-fold .fold-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(236, 241, 237, 0.78);
}

/* ---------- 伙伴 ---------- */
.page-about .partner-row {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .partner-cell {
  border: 2px solid var(--line);
  border-left: 6px solid var(--moss);
  background: var(--panel);
  padding: clamp(14px, 2vw, 20px);
  display: grid;
  gap: 5px;
  transition: border-left-color 0.16s ease, background-color 0.16s ease;
}

.page-about .partner-cell:hover {
  border-left-color: var(--cyan);
  background: rgba(78, 122, 92, 0.16);
}

.page-about .partner-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1;
  color: var(--orange);
}

.page-about .partner-label {
  font-family: var(--font-display);
  font-size: 16px;
  color: var(--cream);
}

.page-about .partner-desc {
  font-size: 13px;
  line-height: 1.6;
  color: var(--rock);
}

/* ---------- 结尾行动 ---------- */
.page-about .about-next {
  margin-top: clamp(30px, 4.6vw, 56px);
  border: 2px solid var(--line);
  background: linear-gradient(120deg, var(--panel), var(--panel-deep));
  box-shadow: var(--shadow-hard);
  padding: clamp(20px, 3vw, 34px);
  display: grid;
  gap: 12px;
}

.page-about .about-next-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
}

.page-about .about-next-text {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.7;
  color: var(--cream);
  max-width: 46ch;
}

.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 4px;
}

.page-about .about-next-actions .btn {
  text-decoration: none;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 720px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-masthead-top {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: end;
    gap: clamp(24px, 4vw, 56px);
  }

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

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

/* ---------- 桌面：旁注索引固定在右列 ---------- */
@media (min-width: 900px) {
  .page-about .about-shell {
    grid-template-columns: minmax(0, 1fr) 232px;
    grid-template-areas: "main rail";
    align-items: start;
  }

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

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

  .page-about .toc-list {
    display: grid;
    overflow-x: visible;
    border: 2px solid var(--line);
    background: var(--panel);
  }

  .page-about .toc-link {
    white-space: normal;
    border-left: 0;
    border-bottom: 1px solid var(--line);
  }

  .page-about .toc-list li:last-child .toc-link {
    border-bottom: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crew-card,
  .page-about .tl-item::before,
  .page-about .flow-node rect,
  .page-about .flow-link,
  .page-about .partner-cell,
  .page-about .toc-link,
  .page-about .tl-fold summary {
    transition: none;
  }

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