.page-about {
  --about-chart-h: clamp(120px, 22vw, 190px);
  padding-bottom: 0;
}

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 面包屑 ---------- */

.page-about .about-breadcrumb {
  padding-block: 10px 20px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--sage);
}

.page-about .breadcrumb__list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumb__link {
  color: var(--sage);
  text-decoration: none;
}

.page-about .breadcrumb__link:hover {
  color: var(--gold-bright);
}

.page-about .breadcrumb__list [aria-current="page"] {
  color: var(--paper);
}

/* ---------- 首屏框景 ---------- */

.page-about .about-hero {
  padding-bottom: clamp(30px, 5vw, 58px);
}

.page-about .about-hero__frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(30px, 6vw, 66px) clamp(20px, 5vw, 62px);
  background:
    radial-gradient(120% 92% at 6% 0%, rgba(78, 140, 123, 0.22), transparent 58%),
    radial-gradient(90% 80% at 100% 100%, rgba(201, 162, 39, 0.13), transparent 62%),
    var(--ink-800);
  box-shadow: var(--shadow);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  height: 8px;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 26px);
  pointer-events: none;
}

.page-about .about-hero__frame::before {
  top: 12px;
}

.page-about .about-hero__frame::after {
  bottom: 12px;
}

.page-about .about-hero__annot {
  position: absolute;
  top: clamp(34px, 7vw, 72px);
  right: 16px;
  display: none;
  color: var(--sage);
  letter-spacing: 0.18em;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 16px;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--gold);
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.05rem, 6.2vw, 3.5rem);
  line-height: 1.2;
  letter-spacing: 0.01em;
  color: var(--paper);
  max-width: 17em;
}

.page-about .about-hero__accent {
  color: var(--gold-bright);
  border-bottom: 3px solid var(--gold-deep);
  padding-bottom: 2px;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.82);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  list-style: none;
  margin: 30px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-hero__fact strong {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.35rem, 4vw, 1.75rem);
  line-height: 1.2;
  color: var(--gold-bright);
  letter-spacing: 0.02em;
}

.page-about .about-hero__fact span {
  display: block;
  margin-top: 6px;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--sage);
}

/* ---------- 布局与索引栏 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-block: 6px 76px;
}

.page-about .about-toc {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: var(--glass);
  padding: 14px 16px 12px;
}

.page-about .about-toc__label {
  margin: 0 0 10px;
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  color: var(--sage);
}

.page-about .about-toc__list {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  scrollbar-width: none;
}

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

.page-about .about-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--paper);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.page-about .about-toc__link .toc__no {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--gold);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link.is-current {
  color: var(--gold-bright);
  border-color: var(--gold-deep);
  background: rgba(201, 162, 39, 0.1);
}

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

/* ---------- 章节 ---------- */

.page-about .about-chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding-block: clamp(30px, 5vw, 50px);
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 110px;
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .about-chapter .chapter__no {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.5rem, 4.4vw, 2.3rem);
  line-height: 1;
  letter-spacing: 0.18em;
  color: var(--sage);
  transition: color 0.24s ease;
}

.page-about .about-chapter.is-current .chapter__no {
  color: var(--gold-bright);
}

.page-about .about-chapter .chapter__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.3rem, 3.2vw, 1.85rem);
  line-height: 1.42;
  color: var(--paper);
  max-width: 24em;
}

.page-about .about-chapter .chapter__body {
  margin: 0 0 14px;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.8);
}

.page-about .about-chapter__main > *:last-child {
  margin-bottom: 0;
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 24px 0 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: var(--ink-800);
  padding: 12px;
}

.page-about .about-figure .figure__media {
  overflow: hidden;
  border-radius: calc(var(--radius) - 4px);
  background: var(--ink-900);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.86) contrast(1.03);
}

.page-about .about-figure .figure__caption {
  margin: 12px 4px 2px;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 大数字块 ---------- */

.page-about .about-statglass {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin: 26px 0 8px;
  padding: clamp(20px, 4vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(78, 140, 123, 0.2), rgba(201, 162, 39, 0.09)),
    var(--glass);
  backdrop-filter: blur(6px);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.5rem, 6.5vw, 3rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold-bright);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 9px;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--sage);
}

/* ---------- 阶段折线 ---------- */

.page-about .about-chart {
  margin: 26px 0 4px;
  padding: 16px 14px 10px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: rgba(20, 58, 49, 0.5);
}

.page-about .about-chart svg {
  display: block;
  width: 100%;
  height: auto;
  max-height: var(--about-chart-h);
}

.page-about .about-chart__caption {
  margin: 8px 2px 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-stage {
  position: relative;
  padding: 0 0 30px 30px;
}

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 20px;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

.page-about .about-stage::after {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 3px rgba(201, 162, 39, 0.14);
  transition: background-color 0.24s ease, box-shadow 0.24s ease;
}

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

.page-about .about-stage:last-child::before {
  display: none;
}

.page-about .about-stage.is-tick::after {
  background: var(--gold-bright);
  box-shadow: 0 0 0 4px rgba(232, 199, 102, 0.2);
}

.page-about .about-stage__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: 0 0 7px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
}

.page-about .about-stage__year {
  color: var(--gold-bright);
}

.page-about .about-stage__label {
  color: var(--sage);
}

.page-about .about-stage__title {
  margin: 0 0 7px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-stage__text {
  margin: 0;
  max-width: 58ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(245, 241, 232, 0.72);
}

/* ---------- 三次简化 ---------- */

.page-about .about-simplify {
  margin-top: 30px;
  padding: clamp(20px, 4vw, 28px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--glass);
  backdrop-filter: blur(8px);
}

.page-about .about-simplify__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--gold-bright);
}

.page-about .about-simplify__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-simplify__item {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 10px;
  align-items: start;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(245, 241, 232, 0.84);
}

.page-about .about-simplify__no {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--gold);
}

/* ---------- 分类标签 ---------- */

.page-about .about-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 18px 0 20px;
  padding: 0;
}

.page-about .about-chips li {
  padding: 5px 13px;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  color: var(--sage);
}

/* ---------- 下一步入口 ---------- */

.page-about .about-next {
  margin-top: 44px;
  padding: clamp(22px, 4vw, 34px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(160deg, rgba(78, 140, 123, 0.16), rgba(201, 162, 39, 0.07)),
    var(--ink-800);
}

.page-about .about-next__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-next__item {
  padding: 2px 0 2px 16px;
  border-left: 2px solid var(--line);
  transition: border-color 0.22s ease;
}

.page-about .about-next__item:hover {
  border-left-color: var(--gold);
}

.page-about .about-next__link {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--paper);
  text-decoration: none;
  transition: color 0.2s ease;
}

.page-about .about-next__link:hover {
  color: var(--gold-bright);
}

.page-about .about-next__item p {
  margin: 6px 0 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 平板与桌面 ---------- */

@media (min-width: 680px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-chapter {
    grid-template-columns: 96px minmax(0, 1fr);
    column-gap: 32px;
  }

  .page-about .about-chapter .chapter__no {
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 26px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__annot {
    display: block;
  }

  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 218px;
    gap: 56px;
    padding-block: 10px 96px;
  }

  .page-about .about-body {
    grid-column: 1;
    grid-row: 1;
    min-width: 0;
  }

  .page-about .about-toc {
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: 104px;
    align-self: start;
    padding: 20px 18px;
  }

  .page-about .about-toc__list {
    flex-direction: column;
    gap: 4px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-toc__link {
    justify-content: flex-start;
    border-color: transparent;
    border-radius: 8px;
    padding: 8px 10px;
    font-size: 0.875rem;
  }

  .page-about .about-chapter {
    grid-template-columns: 112px minmax(0, 1fr);
    column-gap: 40px;
  }

  .page-about .about-simplify__list {
    gap: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-chapter .chapter__no,
  .page-about .about-stage::after,
  .page-about .about-next__item,
  .page-about .about-next__link {
    transition-duration: 0.01ms !important;
  }
}