.page-about {
  --about-rail: 12.5rem;
  background: var(--ink);
  color: var(--text);
  padding-bottom: clamp(3rem, 8vw, 6rem);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  padding: 1.4rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--text-2);
}

.page-about .breadcrumb a {
  color: var(--text-2);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  margin-top: 1.6rem;
  padding: clamp(1.5rem, 4vw, 2.6rem) 0 clamp(2.4rem, 6vw, 4rem);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -30%;
  right: -18%;
  width: 72%;
  height: 150%;
  background: linear-gradient(140deg, rgba(34, 224, 208, 0.2), rgba(34, 224, 208, 0) 62%);
  clip-path: polygon(34% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.6rem, 4vw, 2.6rem);
}

.page-about .about-hero__main .eyebrow {
  margin: 0;
}

.page-about .display-title {
  margin: 0.9rem 0 0;
  line-height: 1.02;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.page-about .lede {
  margin: 1.3rem 0 0;
  max-width: 36rem;
  font-size: clamp(0.98rem, 1.7vw, 1.12rem);
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .about-hero__card {
  position: relative;
  padding: 1.2rem 1.3rem 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--glass-bg);
  box-shadow: var(--shadow-panel);
  align-self: start;
}

.page-about .about-hero__card-title {
  margin: 0 0 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--legacy);
}

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

.page-about .about-stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.72rem 0;
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-stat__key {
  font-size: 0.82rem;
  color: var(--text-2);
  letter-spacing: 0.04em;
}

.page-about .about-stat__val {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 3.2vw, 1.8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-stat--amber .about-stat__val {
  color: var(--amber);
}

.page-about .about-hero__card-note {
  margin: 0.85rem 0 0;
  padding-top: 0.75rem;
  border-top: 1px solid var(--line);
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: var(--legacy);
}

/* ---------- 档案主体 ---------- */
.page-about .about-archive {
  display: grid;
  gap: clamp(1.4rem, 4vw, 2.6rem);
  margin-top: clamp(1.8rem, 5vw, 3rem);
}

/* 左侧索引轨道 */
.page-about .archive-rail {
  border-top: 1px solid var(--line);
  padding-top: 0.9rem;
}

.page-about .archive-rail__title {
  margin: 0 0 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--legacy);
}

.page-about .archive-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.1rem;
}

.page-about .archive-rail__list a {
  display: flex;
  gap: 0.55rem;
  align-items: baseline;
  padding: 0.48rem 0.55rem 0.48rem 0.4rem;
  border-left: 2px solid transparent;
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.86rem;
  transition: color var(--ease), border-color var(--ease), background var(--ease);
}

.page-about .archive-rail__list a .mono {
  font-size: 0.7rem;
  color: var(--legacy);
  transition: color var(--ease);
}

.page-about .archive-rail__list a:hover,
.page-about .archive-rail__list a:focus-visible {
  color: var(--text);
  border-left-color: var(--cyan);
  background: var(--cyan-soft);
}

.page-about .archive-rail__list a:hover .mono,
.page-about .archive-rail__list a:focus-visible .mono {
  color: var(--cyan);
}

.page-about .archive-rail__list a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* 右侧叙事流 */
.page-about .archive-stream {
  display: grid;
  gap: clamp(2rem, 5vw, 3.4rem);
  min-width: 0;
}

.page-about .archive-entry {
  position: relative;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
  scroll-margin-top: 1.5rem;
  min-width: 0;
}

.page-about .archive-entry__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem 0.9rem;
  margin-bottom: 0.9rem;
}

.page-about .archive-entry h2 {
  margin: 0;
  font-size: clamp(1.35rem, 3.2vw, 1.95rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.page-about .archive-entry p {
  margin: 0 0 0.9rem;
  max-width: 44rem;
  line-height: 1.85;
  color: var(--text-2);
}

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

.page-about .archive-entry strong {
  color: var(--text);
  font-weight: 700;
}

.page-about .archive-entry a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 208, 0.4);
  transition: border-color var(--ease), color var(--ease);
}

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

/* 图片容器微调 */
.page-about .archive-entry .media-frame {
  margin: 1.3rem 0 1.1rem;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

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

/* ---------- 团队分工表 ---------- */
.page-about .team-table {
  margin: 1.2rem 0;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--ink-2);
  -webkit-overflow-scrolling: touch;
}

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

.page-about .team-table table {
  width: 100%;
  min-width: 33rem;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.page-about .team-table caption {
  text-align: left;
}

.page-about .team-table thead th {
  padding: 0.75rem 1rem;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--legacy);
  background: rgba(41, 68, 82, 0.4);
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}

.page-about .team-table tbody th,
.page-about .team-table tbody td {
  padding: 0.8rem 1rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
  line-height: 1.65;
}

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

.page-about .team-table tbody td {
  color: var(--text-2);
}

.page-about .team-table tbody td.mono {
  color: var(--cyan);
  font-size: 1rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

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

/* ---------- 版本刻度 ---------- */
.page-about .version-scale {
  list-style: none;
  position: relative;
  margin: 1.5rem 0 0;
  padding: 0 0 0 1.5rem;
  display: grid;
  gap: 1.6rem;
}

.page-about .version-scale::before {
  content: "";
  position: absolute;
  left: 0.35rem;
  top: 0.35rem;
  bottom: 0.35rem;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--amber) 60%, var(--legacy));
}

.page-about .version-scale__item {
  position: relative;
  border-radius: var(--radius-sm);
}

.page-about .version-scale__item:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .version-scale__dot {
  position: absolute;
  left: -1.4rem;
  top: 0.42rem;
  width: 0.62rem;
  height: 0.62rem;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(34, 224, 208, 0.18);
}

.page-about .version-scale__dot--amber {
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(255, 194, 75, 0.18);
}

.page-about .version-scale__dot--legacy {
  background: var(--legacy);
  box-shadow: 0 0 0 3px rgba(111, 143, 134, 0.22);
}

.page-about .version-scale__tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .version-scale__title {
  margin: 0.2rem 0 0;
  font-size: 1.05rem;
  line-height: 1.4;
  color: var(--text);
}

.page-about .version-scale__note {
  margin: 0.4rem 0 0;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--text-2);
  max-height: 12rem;
  opacity: 1;
  overflow: hidden;
  transition: max-height 220ms var(--ease), opacity 180ms var(--ease);
}

/* ---------- 覆盖与节奏 ---------- */
.page-about .reach-list {
  margin: 1.2rem 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .reach-list__row {
  display: grid;
  gap: 0.25rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .reach-list__row dt {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--legacy);
}

.page-about .reach-list__row dd {
  margin: 0;
  color: var(--text-2);
  line-height: 1.75;
  font-size: 0.92rem;
}

/* ---------- 反馈卡 ---------- */
.page-about .feedback-card {
  padding: clamp(1.1rem, 3vw, 1.7rem);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(255, 138, 61, 0.1), rgba(11, 27, 40, 0.9) 55%);
}

.page-about .feedback-card p {
  max-width: 44rem;
}

.page-about .feedback-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.2rem !important;
}

.page-about .feedback-card__actions .btn {
  text-decoration: none;
  border-bottom: 0;
}

.page-about .feedback-card__actions .btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 46rem) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(15rem, 0.85fr);
    align-items: start;
  }

  .page-about .reach-list__row {
    grid-template-columns: 9rem minmax(0, 1fr);
    gap: 1.2rem;
    align-items: baseline;
  }
}

/* ---------- 桌面：侧栏常驻 + 横向版本轴 ---------- */
@media (min-width: 62rem) {
  .page-about .about-archive {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .archive-rail {
    position: sticky;
    top: 2rem;
  }

  .page-about .version-scale {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.2rem;
    padding: 2.2rem 0 0;
  }

  .page-about .version-scale::before {
    left: 0.3rem;
    right: 0.3rem;
    top: 0.5rem;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--cyan), var(--amber) 62%, var(--legacy));
  }

  .page-about .version-scale__dot {
    left: 0;
    top: 0.2rem;
  }

  .page-about .version-scale__note {
    max-height: 0;
    opacity: 0;
  }

  .page-about .version-scale__item:hover .version-scale__note,
  .page-about .version-scale__item:focus-within .version-scale__note {
    max-height: 12rem;
    opacity: 1;
  }
}

/* ---------- 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .version-scale__note,
  .page-about .archive-rail__list a,
  .page-about .breadcrumb a {
    transition: none;
  }
}