.page-about {
  --ab-line: rgba(127, 178, 166, 0.35);
  --ab-line-soft: rgba(127, 178, 166, 0.22);
  --ab-border: 2px solid var(--ab-line);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  overflow-x: clip;
}

.page-about a {
  color: var(--amber-lit);
  text-decoration: none;
  border-bottom: 1px solid rgba(231, 188, 91, 0.45);
}

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

.page-about :focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(24px, 5vw, 54px);
  padding-bottom: clamp(18px, 3vw, 30px);
}

.page-about .about-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--amber);
  text-transform: uppercase;
}

.page-about .about-eyebrow::after {
  content: "";
  flex: 1 1 auto;
  min-width: 40px;
  height: 2px;
  background: linear-gradient(90deg, var(--amber), transparent);
}

.page-about .about-title {
  max-width: 17em;
  margin: 0.35em 0 0.55em;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.2vw, 68px);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-title em {
  font-style: normal;
  color: var(--amber);
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 0;
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.9;
  color: var(--paper-2);
}

/* 版本轴 */
.page-about .about-axis {
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: clamp(16px, 2.4vw, 26px) clamp(12px, 2vw, 22px);
  border: var(--ab-border);
  background: var(--ink-2);
  box-shadow: var(--shadow-hard);
}

.page-about .about-axis svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-axis figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--silver);
}

.page-about .axis-ver {
  font-family: var(--font-mono);
  font-size: 20px;
  letter-spacing: 0.08em;
  fill: var(--amber);
}

.page-about .axis-ver-now {
  fill: var(--amber-lit);
}

.page-about .axis-note {
  font-family: var(--font-body);
  font-size: 14px;
  fill: var(--paper-2);
}

/* 首屏下方通栏图 */
.page-about .about-hero-media {
  margin-top: clamp(20px, 3vw, 34px);
}

.page-about .media-frame {
  border: var(--ab-border);
  background: var(--ink-2);
  box-shadow: var(--shadow-hard);
}

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

/* ---------- 主体与侧边章节带 ---------- */
.page-about .about-body {
  padding-top: clamp(24px, 4vw, 44px);
}

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

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

.page-about .about-sec {
  position: relative;
  padding-block: clamp(36px, 5.5vw, 68px);
}

.page-about .about-sec::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(180px, 42%);
  height: 8px;
  background: var(--amber);
}

.page-about .about-sec:nth-of-type(3n + 2)::before {
  background: var(--line);
}

.page-about .about-sec:nth-of-type(3n + 3)::before {
  background: var(--amber-lit);
}

/* 章节头 */
.page-about .section-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  align-items: baseline;
  margin-bottom: clamp(18px, 3vw, 32px);
}

.page-about .section-num {
  align-self: start;
  padding: 2px 8px;
  border: 2px solid var(--amber);
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.3;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.4vw, 38px);
  line-height: 1.22;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .section-note {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--paper-2);
}

/* 正文 */
.page-about .prose {
  max-width: 68ch;
}

.page-about .prose p {
  margin: 0 0 1.2em;
}

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

/* ---------- 版本列表 ---------- */
.page-about .version-list {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .version-item {
  border: var(--ab-border);
  background: var(--ink-2);
}

.page-about .version-item summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.03em;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .version-item summary::-webkit-details-marker {
  display: none;
}

.page-about .version-item summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--amber);
}

.page-about .version-item[open] summary::after {
  content: "－";
}

.page-about .version-item summary:hover {
  background: var(--ink-3);
}

.page-about .v-tag {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .version-body {
  padding: 0 18px 16px;
  border-top: 1px dashed var(--ab-line);
  color: var(--paper-2);
}

.page-about .version-body p {
  margin: 0.9em 0 0;
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .team-card {
  padding: 18px 18px 20px;
  border: 2px solid rgba(127, 178, 166, 0.42);
  background: var(--ink-2);
  transition: transform 0.3s var(--ease), background-color 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.page-about .team-card:hover {
  transform: translateY(-3px);
  background: var(--ink-3);
  border-color: var(--amber);
}

.page-about .tc-name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .tc-out {
  margin: 6px 0 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .team-card p:last-child {
  margin: 0;
  font-size: 15.5px;
  color: var(--paper-2);
}

.page-about .team-note {
  margin-top: clamp(20px, 3vw, 30px);
  padding-left: 16px;
  border-left: 4px solid var(--amber);
}

/* ---------- 派彩档位 ---------- */
.page-about .tier-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: clamp(20px, 3vw, 30px) 0;
}

.page-about .tier {
  padding: 16px 16px 18px;
  border: var(--ab-border);
  background: var(--ink-2);
}

.page-about .tier-name {
  margin: 10px 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .tier p:last-child {
  margin: 0;
  font-size: 15px;
  color: var(--paper-2);
}

.page-about .tag-red {
  display: inline-block;
  padding: 3px 9px;
  border: 2px solid var(--deep);
  background: var(--red);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  line-height: 1.4;
}

/* ---------- 记录结构示意 ---------- */
.page-about .wire {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: clamp(22px, 3.5vw, 34px) 0;
  padding: clamp(18px, 3vw, 30px) clamp(14px, 2.5vw, 26px);
  border: 2px dashed rgba(127, 178, 166, 0.5);
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
}

.page-about .wire-node {
  padding: 10px 20px;
  border: 2px solid var(--amber);
  background: var(--ink);
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--paper);
}

.page-about .wire-stem {
  width: 2px;
  height: 24px;
  background: var(--line);
}

.page-about .wire-bar {
  width: min(460px, 82%);
  height: 2px;
  background: var(--line);
}

.page-about .wire-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  width: 100%;
  max-width: 560px;
  padding-top: 24px;
}

.page-about .wire-branch {
  position: relative;
  padding: 12px 14px;
  border: 2px solid rgba(127, 178, 166, 0.5);
  background: var(--ink-2);
  text-align: center;
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.04em;
  color: var(--paper-2);
}

.page-about .wire-branch::before {
  content: "";
  position: absolute;
  top: -24px;
  left: 50%;
  width: 2px;
  height: 24px;
  background: var(--line);
}

/* ---------- 覆盖 ---------- */
.page-about .cover-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 36px);
}

.page-about .cover-list {
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--ab-line-soft);
}

.page-about .cover-list li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 2px solid var(--ab-line-soft);
}

.page-about .cover-area {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .cover-desc {
  font-size: 15px;
  color: var(--paper-2);
}

/* ---------- 合作 ---------- */
.page-about .kpi-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .kpi {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border-left: 4px solid var(--amber);
  background: var(--ink-2);
}

.page-about .kpi-value {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.4vw, 40px);
  line-height: 1.1;
  letter-spacing: 0.04em;
  color: var(--amber-lit);
  font-variant-numeric: tabular-nums;
}

.page-about .kpi-label {
  font-size: 14.5px;
  color: var(--paper-2);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  display: flex;
  gap: 16px;
  margin: 0;
  padding: 6px 4px 22px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .tl-card {
  flex: 0 0 240px;
  scroll-snap-align: start;
  padding: 16px;
  border: 2px solid rgba(127, 178, 166, 0.42);
  border-top: 8px solid var(--amber);
  background: var(--ink-2);
}

.page-about .tl-stage {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--silver);
}

.page-about .tl-title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.35;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .tl-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--paper-2);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: clamp(22px, 3vw, 32px);
}

/* ---------- 页脚上方轮廓线 ---------- */
.page-about .about-outro {
  margin-top: clamp(20px, 3vw, 36px);
  padding-bottom: clamp(24px, 4vw, 44px);
}

.page-about .mountain-divider svg {
  display: block;
  width: 100%;
  height: clamp(48px, 6vw, 80px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 561px) {
  .page-about .wire-split {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

  .page-about .cover-list li {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: baseline;
    gap: 16px;
  }

  .page-about .kpi-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 641px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .tier-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .tl-card {
    flex-basis: 280px;
  }
}

@media (min-width: 901px) {
  .page-about .team-layout {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .cover-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

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

@media (min-width: 961px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: 92px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

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

  .page-about .about-rail-inner {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .about-rail ol {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .page-about .about-rail a {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding-left: 10px;
    border-bottom: 0;
    border-left: 2px solid var(--ab-line);
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.1em;
    color: var(--silver);
    transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
  }

  .page-about .about-rail a:hover,
  .page-about .about-rail a:focus-visible {
    color: var(--amber-lit);
    border-left-color: var(--amber);
  }

  .page-about .rail-num {
    font-size: 15px;
    color: var(--amber);
  }
}

@media (min-width: 1101px) {
  .page-about .team-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .team-card:nth-child(1) {
    grid-column: span 7;
  }

  .page-about .team-card:nth-child(2) {
    grid-column: span 5;
    margin-top: 30px;
  }

  .page-about .team-card:nth-child(3) {
    grid-column: span 5;
  }

  .page-about .team-card:nth-child(4) {
    grid-column: span 7;
    margin-top: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .about-rail a {
    transition: opacity 0.12s linear;
  }

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