.page-about {
  --about-axis-col: 118px;
  --about-cut: 14px;
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(104px, 15vw, 152px);
  padding-bottom: clamp(30px, 5vw, 56px);
}

.page-about .about-hero__split {
  display: grid;
  gap: clamp(28px, 5vw, 54px);
  margin-top: clamp(22px, 4vw, 40px);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: .98;
  letter-spacing: -.015em;
  color: var(--paper);
  margin: 12px 0 0;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin: clamp(18px, 3vw, 26px) 0 0;
  max-width: 56ch;
}

.page-about .hero-facts {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .hero-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .hero-facts dt {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .hero-facts dd {
  margin: 0;
  font-family: var(--font-num);
  font-size: 14px;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__figure {
  margin: clamp(30px, 6vw, 62px) 0 0;
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

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

/* ---------- 年份时间轴 ---------- */
.page-about .about-axis {
  display: grid;
  gap: clamp(18px, 3vw, 34px);
  margin-top: clamp(30px, 5vw, 52px);
}

.page-about .about-axis__rail {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .about-axis__tick {
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--mist);
  text-decoration: none;
  padding: 8px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-axis__tick:hover,
.page-about .about-axis__tick:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
  background: var(--panel);
}

.page-about .about-axis__tick:focus-visible {
  outline: var(--ring);
  outline-offset: 3px;
}

.page-about .axis-block {
  padding: clamp(22px, 3.4vw, 34px) 0 clamp(26px, 4vw, 42px);
  border-top: 1px solid var(--line);
  scroll-margin-top: 112px;
}

.page-about .axis-block__year {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: clamp(34px, 7vw, 54px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--violet);
  margin: 0;
}

.page-about .axis-block__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 2.6vw, 27px);
  color: var(--paper);
  margin: 12px 0 0;
}

.page-about .axis-block__text {
  margin: 12px 0 0;
  max-width: 62ch;
  color: var(--mist);
  font-size: 16px;
  line-height: 1.78;
}

.page-about .axis-block__list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .axis-block__list li {
  position: relative;
  padding-left: 22px;
  font-family: var(--font-num);
  font-size: 13.5px;
  letter-spacing: .02em;
  color: var(--paper);
}

.page-about .axis-block__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 12px;
  height: 2px;
  background: var(--cyan);
}

/* ---------- 归档口径三段式 ---------- */
.page-about .rule-list {
  list-style: none;
  margin: clamp(28px, 5vw, 48px) 0 0;
  padding: 0;
}

.page-about .rule-item {
  position: relative;
  display: grid;
  grid-template-columns: clamp(34px, 8vw, 46px) minmax(0, 1fr);
  gap: clamp(12px, 3vw, 30px);
  padding: clamp(24px, 4vw, 40px) 0;
  border-top: 1px solid var(--line);
}

.page-about .rule-item::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 68px;
  height: 2px;
  background: var(--violet);
  transform: skewX(-34deg);
  transform-origin: left center;
}

.page-about .rule-item__no {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  letter-spacing: .06em;
  color: var(--cyan);
  padding-top: 4px;
}

.page-about .rule-item__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.4vw, 25px);
  color: var(--paper);
  margin: 0;
}

.page-about .rule-item__text {
  margin: 12px 0 0;
  max-width: 66ch;
  color: var(--mist);
  font-size: 16px;
  line-height: 1.78;
}

/* ---------- 分差区间 ---------- */
.page-about .range-grid {
  display: grid;
  gap: clamp(30px, 5vw, 58px);
}

.page-about .range-grid__copy p {
  max-width: 58ch;
  margin: 16px 0 0;
  color: var(--mist);
  font-size: 16px;
  line-height: 1.78;
}

.page-about .range-hint {
  font-family: var(--font-num);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--cyan) !important;
}

.page-about .band-group + .band-group {
  margin-top: clamp(26px, 3.4vw, 38px);
}

.page-about .band-group__label {
  margin: 0 0 10px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--paper);
}

.page-about .band {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  grid-template-areas:
    "range track"
    "note note";
  gap: 8px 14px;
  align-items: center;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .band:focus-visible,
.page-about .band:focus {
  outline: var(--ring);
  outline-offset: 4px;
}

.page-about .band__range {
  grid-area: range;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--paper);
}

.page-about .band__track {
  grid-area: track;
  position: relative;
  height: 10px;
  background: var(--panel-2);
  overflow: hidden;
  transition: background-color var(--dur) var(--ease);
}

.page-about .band__fill {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  transform-origin: left center;
  animation: about-band-grow .72s var(--ease) both;
}

.page-about .band__fill--a { width: 44%; }
.page-about .band__fill--b { width: 33%; }
.page-about .band__fill--c { width: 22%; }

.page-about .band-group--ball .band__fill {
  background: linear-gradient(90deg, var(--cyan), rgba(46, 230, 214, .22));
}

.page-about .band-group--court .band__fill {
  background: linear-gradient(90deg, var(--violet), rgba(123, 77, 255, .2));
}

.page-about .band__note {
  grid-area: note;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
  transition: color var(--dur) var(--ease);
}

.page-about .band:hover .band__note,
.page-about .band:focus .band__note,
.page-about .band:focus-within .band__note {
  color: var(--cyan);
}

.page-about .band:hover .band__track,
.page-about .band:focus .band__track {
  background: var(--line);
}

.page-about .about-range__figure {
  margin: clamp(34px, 5vw, 58px) 0 0;
}

@keyframes about-band-grow {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

/* ---------- 复核与停赛 ---------- */
.page-about .audit-grid {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .audit-grid__copy p {
  max-width: 62ch;
  margin: 16px 0 0;
  color: var(--mist);
  font-size: 16px;
  line-height: 1.78;
}

.page-about .audit-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .audit-list li {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  font-size: 14px;
  color: var(--paper);
}

.page-about .audit-list .mono {
  min-width: 46px;
  color: var(--violet);
  font-size: 13px;
  letter-spacing: .06em;
}

/* ---------- 分工 ---------- */
.page-about .duty-list {
  list-style: none;
  margin: clamp(28px, 5vw, 46px) 0 0;
  padding: 0;
}

.page-about .duty-item {
  display: grid;
  gap: 10px;
  padding: clamp(20px, 3vw, 30px) 0;
  border-top: 1px solid var(--line);
}

.page-about .duty-list .duty-item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .duty-item__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.3vw, 24px);
  color: var(--paper);
  margin: 0;
}

.page-about .duty-item__text {
  margin: 0;
  max-width: 60ch;
  color: var(--mist);
  font-size: 16px;
  line-height: 1.78;
}

/* ---------- 引用块（明暗反转） ---------- */
.page-about .about-quote {
  margin: clamp(40px, 7vw, 84px) 0;
  padding: clamp(38px, 6vw, 66px) 0;
  background: var(--paper-plain);
  color: var(--panel);
}

.page-about .about-quote__text {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.4vw, 34px);
  line-height: 1.34;
  letter-spacing: -.01em;
  color: var(--panel);
}

.page-about .about-quote__from {
  margin: 20px 0 0;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--panel-2);
}

/* ---------- 折叠面板 ---------- */
.page-about .about-folds__stack {
  margin-top: clamp(24px, 4vw, 38px);
}

.page-about .about-folds .fold {
  border-top: 1px solid var(--line);
}

.page-about .about-folds .fold:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-folds .fold__summary {
  cursor: pointer;
  padding: 18px 30px 18px 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(16px, 1.9vw, 20px);
  color: var(--paper);
  list-style: none;
  position: relative;
  transition: color var(--dur) var(--ease);
}

.page-about .about-folds .fold__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-folds .fold__summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-num);
  font-size: 18px;
  color: var(--cyan);
}

.page-about .about-folds .fold[open] .fold__summary::after {
  content: "–";
}

.page-about .about-folds .fold__summary:hover,
.page-about .about-folds .fold__summary:focus-visible {
  color: var(--cyan);
}

.page-about .about-folds .fold__summary:focus-visible {
  outline: var(--ring);
  outline-offset: 2px;
}

.page-about .about-folds .fold__body {
  padding: 0 0 22px;
}

.page-about .about-folds .fold__body p {
  margin: 0;
  max-width: 64ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.78;
}

/* ---------- 后续入口 ---------- */
.page-about .next-list {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
}

.page-about .next-link {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  grid-template-areas:
    "no label arrow"
    "no hint arrow";
  gap: 5px 16px;
  align-items: center;
  padding: clamp(16px, 2.6vw, 22px) 0;
  border-top: 1px solid var(--line);
  text-decoration: none;
  color: inherit;
  transition: padding-left var(--dur) var(--ease);
}

.page-about .next-list li:last-child .next-link {
  border-bottom: 1px solid var(--line);
}

.page-about .next-link__no {
  grid-area: no;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: var(--mist);
}

.page-about .next-link__label {
  grid-area: label;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2vw, 21px);
  color: var(--paper);
  transition: color var(--dur) var(--ease);
}

.page-about .next-link__hint {
  grid-area: hint;
  font-size: 13px;
  color: var(--mist);
  line-height: 1.55;
}

.page-about .next-link__arrow {
  grid-area: arrow;
  font-size: 18px;
  color: var(--cyan);
  transition: transform var(--dur) var(--ease);
}

.page-about .next-link:hover .next-link__label,
.page-about .next-link:focus-visible .next-link__label {
  color: var(--cyan);
}

.page-about .next-link:hover .next-link__arrow,
.page-about .next-link:focus-visible .next-link__arrow {
  transform: translateX(4px);
}

.page-about .next-link:hover {
  padding-left: 6px;
}

.page-about .next-link:focus-visible {
  outline: var(--ring);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .band {
    grid-template-columns: 66px minmax(0, 1fr) minmax(0, 1.05fr);
    grid-template-areas: "range track note";
    gap: 8px 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__split {
    grid-template-columns: minmax(0, 3fr) minmax(0, 1.12fr);
    align-items: end;
    gap: clamp(40px, 6vw, 88px);
  }

  .page-about .about-axis {
    grid-template-columns: var(--about-axis-col) minmax(0, 1fr);
    gap: clamp(30px, 5vw, 76px);
  }

  .page-about .about-axis__rail {
    position: sticky;
    top: 118px;
    align-self: start;
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-axis__tick {
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    padding: 11px 0 11px 14px;
    font-size: 14px;
  }

  .page-about .about-axis__tick:hover,
  .page-about .about-axis__tick:focus-visible {
    background: transparent;
    border-left-color: var(--cyan);
    color: var(--cyan);
  }

  .page-about .duty-item {
    grid-template-columns: minmax(0, 3fr) minmax(0, 5fr);
    gap: clamp(20px, 4vw, 56px);
    align-items: start;
    padding: clamp(24px, 3vw, 34px) 0;
  }

  .page-about .duty-item__text {
    margin-top: 2px;
  }
}

@media (min-width: 980px) {
  .page-about .range-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 3fr);
    align-items: start;
  }

  .page-about .audit-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 3fr);
    align-items: start;
  }

  .page-about .audit-grid__figure {
    margin-top: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .band__fill {
    animation: none;
  }

  .page-about .about-axis__tick,
  .page-about .next-link,
  .page-about .next-link__arrow,
  .page-about .next-link__label,
  .page-about .band__note,
  .page-about .fold__summary {
    transition: none;
  }

  .page-about .next-link:hover {
    padding-left: 0;
  }
}