.page-about {
  background: var(--ink);
  color: var(--paper);
  padding-bottom: clamp(40px, 7vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .hist-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3.4vw, 40px) 0 clamp(36px, 5.5vw, 68px);
}

.page-about .hist-hero::before {
  content: "";
  position: absolute;
  top: -34%;
  right: -22%;
  width: min(660px, 92vw);
  aspect-ratio: 1 / 1;
  border-radius: 46% 54% 58% 42% / 52% 44% 56% 48%;
  background: radial-gradient(circle at 42% 42%, rgba(255, 159, 28, 0.30), rgba(255, 159, 28, 0) 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .hist-hero::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -16%;
  width: min(420px, 70vw);
  aspect-ratio: 1 / 1;
  border-radius: 58% 42% 46% 54% / 44% 56% 44% 56%;
  background: radial-gradient(circle at 55% 45%, rgba(52, 198, 211, 0.20), rgba(52, 198, 211, 0) 70%);
  pointer-events: none;
  z-index: 0;
}

.page-about .hist-hero > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .hist-hero .breadcrumb {
  margin-bottom: clamp(20px, 3.4vw, 36px);
}

.page-about .hist-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 7.4vw, 84px);
  line-height: 1.02;
  letter-spacing: -0.012em;
  margin: 14px 0 0;
  max-width: 17ch;
}

.page-about .hist-hero__lede {
  margin-top: clamp(16px, 2.6vw, 26px);
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.9;
  color: rgba(244, 239, 230, 0.82);
}

.page-about .hist-hero__facts {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .hist-fact {
  background: var(--ink);
  padding: 16px 16px 18px;
}

.page-about .hist-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 34px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--gold);
}

.page-about .hist-fact__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--slate);
}

/* ---------- 编年骨架 ---------- */
.page-about .hist-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
  position: relative;
  z-index: 1;
}

.page-about .hist-rail {
  min-width: 0;
}

.page-about .hist-rail__head {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--slate);
}

.page-about .hist-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .hist-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .hist-rail__item {
  flex: 0 0 auto;
}

.page-about .hist-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 13px;
  border-radius: var(--r-sm);
  border-left: 2px solid transparent;
  background: rgba(23, 27, 36, 0.85);
  color: var(--slate);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .hist-rail__link.is-current {
  color: var(--paper);
  border-left-color: var(--gold);
  background: rgba(255, 159, 28, 0.12);
}

.page-about .hist-rail__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .hist-rail__label {
  font-size: 13px;
}

/* ---------- 阶段面板 ---------- */
.page-about .hist-track {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  min-width: 0;
}

.page-about .hist-step {
  scroll-margin-top: 108px;
  min-width: 0;
}

.page-about .hist-panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: clamp(20px, 3.4vw, 40px);
  box-shadow: 8px 8px 0 0 rgba(30, 36, 48, 0.9);
}

.page-about .hist-panel--paper {
  background: var(--paper);
  color: var(--text);
  border-color: rgba(18, 18, 18, 0.1);
  box-shadow: 8px 8px 0 0 rgba(255, 159, 28, 0.32);
}

.page-about .hist-panel__coord {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .hist-panel--paper .hist-panel__coord {
  color: #A65A00;
}

.page-about .hist-panel__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 4vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.008em;
  margin: 12px 0 0;
}

.page-about .hist-panel__text {
  margin: 16px 0 0;
  max-width: 68ch;
  font-size: clamp(14px, 1.4vw, 15.5px);
  line-height: 1.95;
  color: rgba(244, 239, 230, 0.78);
}

.page-about .hist-panel--paper .hist-panel__text {
  color: rgba(18, 18, 18, 0.78);
}

.page-about .hist-panel__text--tight {
  margin-top: 20px;
}

.page-about .hist-points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 11px;
}

.page-about .hist-points li {
  position: relative;
  padding-left: 20px;
  font-size: clamp(13.5px, 1.35vw, 14.5px);
  line-height: 1.9;
  color: rgba(244, 239, 230, 0.74);
}

.page-about .hist-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.82em;
  width: 9px;
  height: 2px;
  background: var(--cyan);
}

.page-about .hist-panel--paper .hist-points li {
  color: rgba(18, 18, 18, 0.76);
}

.page-about .hist-panel--paper .hist-points li::before {
  background: var(--gold);
}

/* ---------- 图 ---------- */
.page-about .hist-figure {
  margin: 26px 0 0;
  border-radius: var(--r-md);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--panel-soft);
}

.page-about .hist-panel--paper .hist-figure {
  border-color: rgba(18, 18, 18, 0.12);
}

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

.page-about .hist-figure figcaption {
  padding: 11px 15px;
  font-size: 12px;
  line-height: 1.75;
  letter-spacing: 0.04em;
  color: var(--slate);
  background: var(--panel-soft);
}

.page-about .hist-panel--paper .hist-figure figcaption {
  background: var(--paper-deep);
  color: rgba(18, 18, 18, 0.68);
}

/* ---------- 双轨示意 ---------- */
.page-about .hist-dual {
  display: block;
  width: 100%;
  height: auto;
  margin: 26px 0 0;
  padding: 16px;
  box-sizing: border-box;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: rgba(11, 13, 18, 0.6);
}

.page-about .hist-dual text {
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
}

/* ---------- 联系方式 ---------- */
.page-about .hist-contact {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .hist-contact__row {
  background: var(--ink);
  padding: 13px 16px;
  display: grid;
  gap: 4px;
}

.page-about .hist-contact__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--slate);
}

.page-about .hist-contact__value {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(244, 239, 230, 0.84);
  word-break: break-word;
}

.page-about .hist-contact__value--strong {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--gold-soft);
}

.page-about .hist-inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(52, 198, 211, 0.4);
  transition: color 0.16s ease, border-color 0.16s ease;
}

.page-about .hist-inline-link:hover {
  color: var(--gold-soft);
  border-bottom-color: rgba(255, 196, 107, 0.6);
}

/* ---------- 节点索引 ---------- */
.page-about .hist-milelist {
  margin: 24px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .hist-mile {
  border-bottom: 1px solid var(--line);
}

.page-about .hist-mile summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 17px 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(16px, 1.9vw, 21px);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .hist-mile summary::-webkit-details-marker {
  display: none;
}

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

.page-about .hist-mile[open] summary::after {
  content: "–";
}

.page-about .hist-mile__tag {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  padding: 3px 8px;
  border-radius: 999px;
  border: 1px solid rgba(52, 198, 211, 0.4);
  color: var(--cyan);
  align-self: center;
}

.page-about .hist-mile__body {
  padding: 0 0 20px;
  max-width: 70ch;
  font-size: 14px;
  line-height: 1.95;
  color: rgba(244, 239, 230, 0.76);
}

/* ---------- 尾段导流 ---------- */
.page-about .hist-next {
  margin-top: clamp(48px, 7vw, 96px);
  padding-top: clamp(28px, 4vw, 48px);
  border-top: 1px solid var(--line);
}

.page-about .hist-next__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
}

.page-about .hist-next__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.15;
  margin: 10px 0 0;
  max-width: 16ch;
}

.page-about .hist-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .hist-next__item {
  background: var(--panel);
}

.page-about .hist-next__link {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  text-decoration: none;
  color: inherit;
  border-left: 2px solid transparent;
  transition: background-color 0.18s ease, border-color 0.18s ease;
}

.page-about .hist-next__link:hover {
  background: var(--panel-soft);
  border-left-color: var(--gold);
}

.page-about .hist-next__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .hist-next__desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--slate);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .hist-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .hist-contact__row {
    grid-template-columns: 120px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }

  .page-about .hist-next__grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .hist-timeline {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .hist-rail {
    position: sticky;
    top: 108px;
    align-self: start;
  }

  .page-about .hist-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .hist-rail__link {
    background: transparent;
    padding: 11px 12px;
    border-left: 2px solid var(--line);
    border-radius: 0 var(--r-sm) var(--r-sm) 0;
  }

  .page-about .hist-rail__link:hover {
    color: var(--paper);
    border-left-color: rgba(255, 159, 28, 0.5);
  }

  .page-about .hist-rail__link.is-current {
    background: rgba(255, 159, 28, 0.1);
    border-left-color: var(--gold);
  }

  .page-about .hist-panel {
    box-shadow: 12px 14px 0 0 rgba(30, 36, 48, 0.9);
  }

  .page-about .hist-panel--paper {
    box-shadow: 12px 14px 0 0 rgba(255, 159, 28, 0.32);
  }
}

@media (min-width: 1180px) {
  .page-about .hist-hero__title {
    max-width: 15ch;
  }

  .page-about .hist-step:nth-child(even) .hist-panel {
    margin-left: clamp(0px, 2.4vw, 34px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .hist-rail__link,
  .page-about .hist-inline-link,
  .page-about .hist-next__link {
    transition: none;
  }
}