.page-about {
  --about-rail: 232px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(32px, 5vw, 64px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: end;
}

.page-about .about-hero__head {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-width: 0;
}

.page-about .breadcrumbs {
  margin-bottom: clamp(14px, 2vw, 22px);
}

.page-about .eyebrow {
  margin: 0 0 10px;
}

.page-about .page-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(42px, 7.4vw, 92px);
  line-height: 1;
  letter-spacing: -0.015em;
  color: var(--tvt-cream);
}

.page-about .lede {
  margin: clamp(16px, 2vw, 22px) 0 0;
  max-width: 46ch;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.75;
  color: var(--tvt-paper);
}

.page-about .about-hero__facts {
  width: 100%;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: clamp(16px, 3vw, 32px);
}

.page-about .about-hero__facts li {
  padding: 12px 0;
  border-top: 1px solid var(--hair);
  min-width: 0;
}

.page-about .about-hero__factnum {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 2.6vw, 32px);
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--tvt-lime);
}

.page-about .about-hero__facttext {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--tvt-sage);
}

.page-about .about-hero__media {
  margin: 0;
  min-width: 0;
}

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--hair);
  background: var(--tvt-alt);
}

.page-about .about-hero__frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-hero__card {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 12px;
  padding: 12px 14px;
  background: rgba(10, 13, 11, 0.82);
  border: 1px solid var(--hair-strong);
  box-shadow: var(--shadow-soft);
}

.page-about .about-hero__card p {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--tvt-paper);
}

.page-about .about-hero__card .num {
  color: var(--tvt-lime);
}

.page-about .about-hero__media .media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--tvt-sage);
}

/* ---------- 章节索引条 ---------- */
.page-about .about-index {
  padding-block: 12px;
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
  background: rgba(18, 38, 30, 0.62);
}

.page-about .about-index__inner {
  display: flex;
  align-items: center;
  gap: 14px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__label {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--tvt-sage);
}

.page-about .about-index__list {
  flex: 0 0 auto;
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  gap: 8px;
}

.page-about .about-index__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--hair);
  font-size: 13px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--tvt-paper);
  transition: color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease),
    border-color var(--t-mid) var(--ease);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  opacity: 0.72;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--tvt-deep);
  background: var(--tvt-lime);
  border-color: var(--tvt-lime);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter__grid {
  display: grid;
  gap: clamp(22px, 3.6vw, 42px);
}

.page-about .about-chapter__rail {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-start;
  min-width: 0;
}

.page-about .about-chapter__no {
  font-family: var(--font-mono);
  font-size: clamp(40px, 7vw, 80px);
  line-height: 0.9;
  letter-spacing: -0.05em;
  color: var(--tvt-lime);
  opacity: 0.24;
}

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

.page-about .section-title {
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--tvt-cream);
}

.page-about .about-chapter__body > p {
  margin: 0;
}

.page-about .about-chapter__body > p + p {
  margin-top: 1.5em;
  padding-top: 1.5em;
  border-top: 1px solid var(--hair);
}

/* ---------- 要点摘录 ---------- */
.page-about .excerpt {
  margin: 0;
  padding: 14px 16px;
  background: var(--tvt-cream);
  color: var(--tvt-deep);
  border-left: 2px solid var(--tvt-lime);
}

.page-about .excerpt > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.14em;
}

.page-about .excerpt > summary::-webkit-details-marker {
  display: none;
}

.page-about .excerpt > summary::after {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--tvt-deep);
}

.page-about .excerpt[open] > summary::after {
  content: "－";
}

.page-about .excerpt p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(11, 26, 20, 0.82);
}

/* ---------- 反色章节内的局部反转 ---------- */
.page-about .band--cream {
  color: var(--tvt-deep);
}

.page-about .band--cream .section-title,
.page-about .band--cream .about-chapter__body {
  color: var(--tvt-deep);
}

.page-about .band--cream .about-chapter__no {
  color: var(--tvt-deep);
  opacity: 0.2;
}

.page-about .band--cream .excerpt {
  background: var(--tvt-deep);
  color: var(--tvt-cream);
  border-left-color: var(--tvt-orange);
}

.page-about .band--cream .excerpt > summary::after {
  color: var(--tvt-lime);
}

.page-about .band--cream .excerpt p {
  color: rgba(243, 238, 225, 0.82);
}

.page-about .band--cream .about-figure .media__caption {
  color: rgba(11, 26, 20, 0.62);
}

.page-about .band--cream .ulink {
  color: var(--tvt-blue);
}

/* ---------- 四类对象清单 ---------- */
.page-about .about-objects {
  margin: clamp(20px, 3vw, 32px) 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--hair);
}

.page-about .about-objects li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 4px 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--hair);
  transition: background-color var(--t-fast) var(--ease);
}

.page-about .about-objects li:hover {
  background: rgba(201, 255, 61, 0.05);
}

.page-about .about-objects__key {
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.6;
  color: var(--tvt-lime);
}

.page-about .about-objects__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--tvt-cream);
}

.page-about .about-objects__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--tvt-paper);
}

.page-about .about-objects__desc .num {
  color: var(--tvt-lime);
}

/* ---------- 口径表 ---------- */
.page-about .about-table {
  margin: clamp(20px, 3vw, 32px) 0 0;
  border: 1px solid var(--hair);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-table table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 14.5px;
}

.page-about .about-table caption {
  padding: 12px 14px;
  text-align: left;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--tvt-sage);
  border-bottom: 1px solid var(--hair);
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-table tbody th {
  font-weight: 600;
  color: var(--tvt-cream);
  white-space: nowrap;
}

.page-about .about-table thead th {
  background: var(--tvt-alt);
  color: var(--tvt-cream);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 12.5px;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.page-about .about-table tbody tr {
  transition: background-color var(--t-fast) var(--ease);
}

.page-about .about-table tbody tr:hover {
  background: rgba(201, 255, 61, 0.06);
}

.page-about .about-table td.num {
  font-family: var(--font-mono);
  font-size: 13.5px;
  white-space: nowrap;
}

.page-about .about-table .about-table__cadence {
  color: var(--tvt-lime);
}

/* ---------- 图注 ---------- */
.page-about .about-figure {
  margin: clamp(24px, 4vw, 40px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--hair);
}

.page-about .about-figure .media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--tvt-sage);
}

/* ---------- 年份轴 ---------- */
.page-about .about-timeline {
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 20px 0 20px 30px;
  border-top: 1px solid var(--hair);
  transition: background-color var(--t-fast) var(--ease);
}

.page-about .about-timeline__item:last-child {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-timeline__item::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--hair);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 27px;
  width: 9px;
  height: 9px;
  background: var(--tvt-orange);
  z-index: 1;
  transition: transform var(--t-mid) var(--ease);
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  transform: scale(1.6);
}

.page-about .about-timeline__item:hover {
  background: rgba(10, 13, 11, 0.35);
}

.page-about .about-timeline__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(18px, 2vw, 24px);
  line-height: 1.2;
  letter-spacing: -0.03em;
  color: var(--tvt-lime);
}

.page-about .about-timeline__title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.25;
  color: var(--tvt-cream);
}

.page-about .about-timeline__desc {
  margin: 8px 0 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--tvt-paper);
}

/* ---------- 继续阅读 ---------- */
.page-about .about-next__inner {
  display: grid;
  gap: 16px;
}

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

.page-about .about-next__list li {
  border-top: 1px solid var(--hair);
}

.page-about .about-next__list li:last-child {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-next__list a {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 4px 16px;
  padding: 16px 4px;
  text-decoration: none;
  color: var(--tvt-cream);
  transition: color var(--t-fast) var(--ease), padding-left var(--t-mid) var(--ease),
    background-color var(--t-fast) var(--ease);
}

.page-about .about-next__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.2vw, 24px);
  line-height: 1.2;
}

.page-about .about-next__desc {
  grid-column: 1;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--tvt-sage);
}

.page-about .about-next__arrow {
  grid-column: 2;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--tvt-blue);
  transition: color var(--t-fast) var(--ease);
}

.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  color: var(--tvt-lime);
  padding-left: 12px;
  background: rgba(201, 255, 61, 0.05);
}

.page-about .about-next__list a:hover .about-next__arrow,
.page-about .about-next__list a:focus-visible .about-next__arrow {
  color: var(--tvt-lime);
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero__card {
    right: auto;
    width: min(340px, 78%);
  }

  .page-about .about-timeline__item {
    padding: 22px 0 22px 42px;
  }

  .page-about .about-timeline__item::before {
    top: 29px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }

  .page-about .about-chapter__grid {
    grid-template-columns: minmax(180px, var(--about-rail)) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 76px);
  }

  .page-about .about-chapter__rail {
    position: sticky;
    top: clamp(24px, 6vh, 72px);
    align-self: start;
  }

  .page-about .about-next__list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-next__list li:nth-last-child(-n + 2) {
    border-bottom: 1px solid var(--hair);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__list a,
  .page-about .about-objects li,
  .page-about .about-timeline__item,
  .page-about .about-timeline__item::before,
  .page-about .about-next__list a,
  .page-about .about-next__arrow,
  .page-about .about-table tbody tr {
    transition-duration: 1ms;
  }

  .page-about .about-timeline__item:hover::before,
  .page-about .about-timeline__item:focus-within::before {
    transform: none;
  }

  .page-about .about-next__list a:hover,
  .page-about .about-next__list a:focus-visible {
    padding-left: 4px;
  }
}