.page-about {
  --about-gap: clamp(2.5rem, 7vw, 5rem);
  --about-edge: clamp(1.25rem, 4vw, 2.5rem);
  position: relative;
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: calc(var(--bar-h) + clamp(2rem, 9vw, 5.5rem)) 0 clamp(2.5rem, 8vw, 4.5rem);
  overflow: hidden;
}

.page-about .about-hero__bg {
  position: absolute;
  top: -8%;
  left: -6%;
  width: 112%;
  height: 116%;
  z-index: -1;
  transform: rotate(var(--angle-a));
  opacity: .42;
}

.page-about .about-hero__bg img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  object-position: center 35%;
}

.page-about .about-hero__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(11, 26, 43, .74) 0%, rgba(11, 26, 43, .88) 52%, var(--c-ink) 100%),
    radial-gradient(120% 80% at 16% 10%, rgba(53, 224, 208, .16), transparent 62%),
    radial-gradient(90% 70% at 90% 82%, rgba(255, 90, 95, .13), transparent 64%),
    radial-gradient(70% 60% at 60% 40%, rgba(42, 31, 61, .55), transparent 70%);
}

.page-about .about-hero__inner {
  position: relative;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 7.6vw, 4rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--c-paper);
  margin: 1rem 0 0;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  max-width: 42ch;
  margin: 1.25rem 0 0;
  color: var(--c-text-sub);
  font-size: clamp(1rem, 2.6vw, 1.0625rem);
  line-height: 1.8;
}

.page-about .about-anchors {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: .5rem;
  margin-top: clamp(2rem, 6vw, 3.5rem);
  padding-top: 1.25rem;
  border-top: 1px solid var(--c-line-soft);
}

.page-about .about-anchor {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  min-width: 0;
}

.page-about .about-anchor__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.75rem, 8vw, 3.5rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--c-cyan);
  text-shadow: 0 0 32px rgba(53, 224, 208, .3);
}

.page-about .about-anchor__num--gold {
  color: var(--c-gold);
  text-shadow: 0 0 32px rgba(216, 183, 120, .26);
}

.page-about .about-anchor__num--coral {
  color: var(--c-coral);
  text-shadow: 0 0 32px rgba(255, 90, 95, .24);
}

.page-about .about-anchor__key {
  font-size: .8125rem;
  line-height: 1.5;
  color: var(--c-stone);
  letter-spacing: .02em;
}

/* ---------- 通用区块 ---------- */

.page-about .about-block {
  position: relative;
  padding: var(--about-gap) 0;
}

.page-about .about-head {
  max-width: 62ch;
  margin-bottom: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 4.6vw, 2.35rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--c-paper);
  margin: .45rem 0 0;
}

.page-about .about-sub {
  margin: .9rem 0 0;
  color: var(--c-text-sub);
  font-size: 1rem;
  line-height: 1.8;
}

.page-about .about-cross {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  font-size: .9375rem;
  line-height: 1.9;
  color: var(--c-stone);
}

.page-about .about-cross a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 208, .35);
}

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

/* ---------- 声明区 ---------- */

.page-about .about-declare {
  position: relative;
  padding: clamp(1.5rem, 5vw, 2.75rem);
  background: linear-gradient(155deg, rgba(18, 40, 63, .95), rgba(11, 26, 43, .72));
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-gold);
}

.page-about .about-declare::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 42%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--c-cyan));
}

.page-about .about-declare__text {
  max-width: 66ch;
  margin: 1.1rem 0 0;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--c-paper);
}

.page-about .about-declare__tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin: 1.5rem 0 0;
  padding: 0;
}

/* ---------- 展签墙 ---------- */

.page-about .about-wall {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.page-about .about-spec {
  position: relative;
  padding: 2.35rem 1.25rem 1.5rem;
  background: linear-gradient(160deg, rgba(18, 40, 63, .96), rgba(11, 26, 43, .9));
  border: 1px solid var(--c-line);
  min-width: 0;
  transition: border-color .35s var(--ease), transform .35s var(--ease);
}

.page-about .about-spec:hover {
  border-color: rgba(216, 183, 120, .6);
  transform: translateY(-2px);
}

.page-about .about-spec__stamp {
  position: absolute;
  top: 0;
  left: 0;
  padding: .3rem .65rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  background: var(--c-gold);
  color: var(--c-ink);
  transform: rotate(-1deg);
  transform-origin: top left;
}

.page-about .about-spec--cyan {
  border-top: 2px solid var(--c-cyan);
}

.page-about .about-spec--coral {
  border-top: 2px solid var(--c-coral);
}

.page-about .about-spec--moss {
  border-top: 2px solid var(--c-moss);
}

.page-about .about-spec__title {
  margin: .35rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.125rem, 3.4vw, 1.375rem);
  line-height: 1.3;
  letter-spacing: -0.015em;
  color: var(--c-paper);
}

.page-about .about-spec__text {
  margin: .85rem 0 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-text-sub);
  max-width: 46ch;
}

.page-about .about-spec__note {
  margin: 1.1rem 0 0;
  padding-top: .85rem;
  border-top: 1px dashed var(--c-line-soft);
  font-family: var(--font-serif);
  font-size: .8125rem;
  line-height: 1.9;
  color: var(--c-stone);
}

.page-about .about-figure {
  margin: clamp(1.75rem, 5vw, 3rem) 0 0;
}

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

/* ---------- 区域版本标签页 ---------- */

.page-about .about-regions {
  position: relative;
}

.page-about .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  padding-bottom: .85rem;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .tabs__tab {
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
  border: 1px solid var(--c-line-soft);
  border-radius: 0;
  color: var(--c-text-sub);
  font-family: var(--font-body);
  font-size: .9375rem;
  line-height: 1;
  padding: .7rem 1.15rem;
  cursor: pointer;
  letter-spacing: .01em;
  transition: color .3s var(--ease), border-color .3s var(--ease), background-color .3s var(--ease);
}

.page-about .tabs__tab:hover {
  border-color: var(--c-line);
  color: var(--c-paper);
}

.page-about .tabs__tab:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

.page-about .tabs__tab[aria-selected="true"] {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  color: var(--c-ink);
  font-weight: 600;
}

.page-about .tabs__panel {
  position: relative;
  padding-top: 1.75rem;
}

.page-about .tabs__panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--c-cyan), rgba(255, 90, 95, .6) 55%, transparent);
}

.page-about .about-region__lede {
  max-width: 64ch;
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--c-text-sub);
}

.page-about .about-region__rows {
  margin: 1.5rem 0 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--c-line-soft);
}

.page-about .about-region__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .25rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .about-region__row dt {
  font-family: var(--font-serif);
  font-size: .8125rem;
  letter-spacing: .04em;
  color: var(--c-stone);
}

.page-about .about-region__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .9375rem;
  line-height: 1.6;
  color: var(--c-paper);
}

/* ---------- 运营与排班 ---------- */

.page-about .about-ops {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.75rem;
  padding: clamp(1.5rem, 5vw, 2.75rem);
  background:
    linear-gradient(120deg, rgba(42, 31, 61, .7) 0%, rgba(18, 40, 63, .92) 45%, rgba(11, 26, 43, .95) 100%);
  border: 1px solid var(--c-line-soft);
  clip-path: polygon(0 1.75rem, 100% 0, 100% 100%, 0 calc(100% - 1.75rem));
}

.page-about .about-ops__text {
  margin: 1.1rem 0 0;
  max-width: 60ch;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--c-text-sub);
}

.page-about .about-ops__facts {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-line-soft);
  border: 1px solid var(--c-line-soft);
  align-self: start;
}

.page-about .about-ops__fact {
  background: rgba(11, 26, 43, .82);
  padding: .9rem .85rem;
}

.page-about .about-ops__fact dt {
  font-family: var(--font-serif);
  font-size: .75rem;
  letter-spacing: .06em;
  color: var(--c-stone);
}

.page-about .about-ops__fact dd {
  margin: .4rem 0 0;
  font-family: var(--font-mono);
  font-size: .875rem;
  line-height: 1.5;
  color: var(--c-gold);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline-wrap {
  position: relative;
  isolation: isolate;
  padding: clamp(2rem, 6vw, 3.5rem) 0;
}

.page-about .about-timeline-wrap__bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  opacity: .17;
}

.page-about .about-timeline-wrap__bg img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  -webkit-mask-image: linear-gradient(180deg, transparent, #000 22%, #000 78%, transparent);
  mask-image: linear-gradient(180deg, transparent, #000 22%, #000 78%, transparent);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: calc(4.75rem + 1rem);
  top: .6rem;
  bottom: .6rem;
  width: 1px;
  background: linear-gradient(180deg, var(--c-clay), var(--c-gold) 38%, var(--c-cyan) 88%);
  opacity: .55;
}

.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 4.75rem minmax(0, 1fr);
  gap: 2rem;
}

.page-about .about-timeline__year {
  position: relative;
  font-family: var(--font-mono);
  font-size: clamp(1rem, 3vw, 1.25rem);
  font-weight: 600;
  letter-spacing: .04em;
  line-height: 1.4;
  color: var(--c-cyan);
  text-align: right;
}

.page-about .about-timeline__item.is-early .about-timeline__year {
  color: var(--c-clay);
}

.page-about .about-timeline__year::after {
  content: "";
  position: absolute;
  right: -1rem;
  top: .55em;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-ink);
  border: 1px solid var(--c-gold);
  transform: translateX(50%);
}

.page-about .about-timeline__item.is-early .about-timeline__year::after {
  border-color: var(--c-clay);
}

.page-about .about-timeline__body h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, 3.2vw, 1.25rem);
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--c-paper);
}

.page-about .about-timeline__body p {
  margin: .6rem 0 0;
  max-width: 58ch;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-text-sub);
}

.page-about .about-timeline__more {
  font-family: var(--font-serif);
  font-size: .8125rem;
  line-height: 1.9;
  color: var(--c-stone);
  opacity: .74;
  transform: translateY(-.15rem);
  transition: opacity .35s var(--ease), transform .35s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__more,
.page-about .about-timeline__item:focus-within .about-timeline__more {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 核对机制 ---------- */

.page-about .about-rules {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--c-line-soft);
  border-top: 1px solid var(--c-line-soft);
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .rule-item {
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr);
  gap: .5rem;
  padding: 1.35rem 0 1.35rem .25rem;
  background: var(--c-ink);
}

.page-about .rule-item__no {
  font-family: var(--font-mono);
  font-size: .875rem;
  letter-spacing: .06em;
  color: var(--c-gold);
  padding-top: .2rem;
}

.page-about .rule-item__body h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--c-paper);
}

.page-about .rule-item__body p {
  margin: .55rem 0 0;
  max-width: 62ch;
  font-size: .9375rem;
  line-height: 1.9;
  color: var(--c-text-sub);
}

/* ---------- 后续入口 ---------- */

.page-about .about-next {
  margin-top: clamp(2rem, 6vw, 3.25rem);
  padding-top: 1.5rem;
  border-top: 1px dashed var(--c-line);
}

.page-about .about-next__text {
  margin: 0;
  max-width: 58ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--c-text-sub);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.35rem;
}

/* ---------- 响应式 ---------- */

@media (min-width: 560px) {
  .page-about .about-anchors {
    gap: 1.25rem;
  }

  .page-about .about-region__row {
    grid-template-columns: 9.5rem minmax(0, 1fr);
    align-items: baseline;
    gap: 1rem;
  }

  .page-about .about-ops__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-wall {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 1.5rem 1.5rem;
  }

  .page-about .about-spec:nth-child(1) {
    grid-column: 1 / span 7;
  }

  .page-about .about-spec:nth-child(2) {
    grid-column: 8 / span 5;
    margin-top: 3.25rem;
  }

  .page-about .about-spec:nth-child(3) {
    grid-column: 3 / span 6;
    margin-top: -1rem;
  }

  .page-about .about-spec {
    padding: 2.6rem 1.75rem 1.75rem;
  }

  .page-about .about-spec__text {
    font-size: 1rem;
  }

  .page-about .about-ops {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
    gap: 2.5rem;
  }

  .page-about .about-ops__facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-figure {
    margin-left: 8.333%;
    width: 83.333%;
  }
}

@media (min-width: 1020px) {
  .page-about .about-hero {
    padding-top: calc(var(--bar-h) + clamp(4rem, 9vw, 7rem));
  }

  .page-about .about-hero__lede {
    max-width: 46ch;
  }

  .page-about .about-anchors {
    max-width: 42rem;
    gap: 2rem;
    margin-top: clamp(2.5rem, 6vw, 4rem);
  }

  .page-about .about-timeline::before {
    left: calc(5.5rem + 1.5rem);
  }

  .page-about .about-timeline__item {
    grid-template-columns: 5.5rem minmax(0, 1fr);
    gap: 3rem;
  }

  .page-about .about-timeline__year::after {
    right: -1.5rem;
  }

  .page-about .rule-item {
    grid-template-columns: 4rem minmax(0, 1fr);
    gap: 1.25rem;
    padding: 1.6rem 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-spec,
  .page-about .tabs__tab,
  .page-about .about-timeline__more {
    transition: none;
  }

  .page-about .about-spec:hover {
    transform: none;
  }
}