.page-about {
  --about-rail: 180px;
  --about-gap: clamp(28px, 4vw, 56px);
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--deep);
  color: var(--paper);
  padding: calc(var(--header-h) + var(--s-4)) 0 120px;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 calc(100% - 52px));
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line-on-deep) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-on-deep) 1px, transparent 1px);
  background-size: 52px 52px;
  opacity: 0.55;
  pointer-events: none;
}

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

.page-about .about-hero .breadcrumb,
.page-about .about-hero .breadcrumb a {
  color: rgba(244, 241, 233, 0.7);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover,
.page-about .about-hero .breadcrumb a:focus-visible {
  color: var(--orange);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--s-4);
  margin-top: var(--s-4);
}

.page-about .about-hero .eyebrow {
  color: var(--yellow);
  letter-spacing: 0.14em;
}

.page-about .about-hero h1 {
  margin: var(--s-2) 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 6.4vw, 56px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__text {
  margin: var(--s-3) 0 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 241, 233, 0.82);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  margin-top: var(--s-4);
}

.page-about .about-hero__ghost {
  color: var(--paper);
}

.page-about .about-hero__stamp {
  position: relative;
  padding: var(--s-3) var(--s-3) var(--s-4);
  background: rgba(18, 62, 99, 0.78);
  clip-path: polygon(0 0, 100% 20px, 100% 100%, 0 100%);
}

.page-about .about-hero__stamp-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--yellow);
}

.page-about .about-hero__year {
  display: block;
  margin-top: var(--s-1);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(64px, 16vw, 118px);
  line-height: 0.84;
  letter-spacing: -0.05em;
  color: var(--orange);
}

.page-about .about-hero__stamp-text {
  margin: var(--s-2) 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(244, 241, 233, 0.76);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: var(--s-7);
  border-top: 1px solid var(--line-on-deep);
  background: var(--line-on-deep);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: var(--s-2) var(--s-2) var(--s-2) 0;
  background: var(--deep);
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 26px;
  line-height: 1;
  color: var(--yellow);
}

.page-about .about-fact__label {
  font-size: 13px;
  color: rgba(244, 241, 233, 0.68);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  padding: var(--s-7) 0 var(--s-12);
}

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

/* ---------- 左侧刻度轨道 ---------- */
.page-about .about-rail__title {
  margin: 0 0 var(--s-1);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--rock);
}

.page-about .about-rail__list {
  list-style: none;
  display: flex;
  gap: var(--s-1);
  margin: 0;
  padding: 0 0 var(--s-1);
  overflow-x: auto;
  scrollbar-width: none;
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 10px 12px;
  font-size: 13px;
  white-space: nowrap;
  color: var(--rock);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--clay);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--deep);
  border-bottom-color: var(--orange);
  background: rgba(242, 107, 33, 0.07);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-bottom: var(--s-7);
  margin-bottom: var(--s-7);
  border-bottom: 1px solid var(--line);
}

.page-about .about-section:last-of-type {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .about-head {
  display: grid;
  gap: 6px;
  margin-bottom: var(--s-4);
  padding-top: var(--s-1);
  border-top: 2px solid var(--deep);
}

.page-about .about-head__index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--clay);
}

.page-about .about-head h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(24px, 4.4vw, 38px);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-head__lead {
  margin: 0;
  font-size: 14px;
  color: var(--rock);
}

.page-about .about-flow .prose {
  max-width: 68ch;
}

.page-about .about-flow .prose p {
  margin: 0 0 var(--s-3);
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-flow .prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--s-3);
}

.page-about .about-note {
  padding: var(--s-2) 0 var(--s-2) var(--s-3);
  border-left: 3px solid var(--orange);
}

.page-about .about-note__kicker {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--deep);
}

.page-about .about-figure {
  margin: var(--s-4) 0 0;
}

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

.page-about .about-figure .frame__caption {
  margin-top: var(--s-1);
  font-size: 13px;
  color: var(--rock);
}

/* ---------- 梯队结构 ---------- */
.page-about .about-chart-block {
  margin-top: var(--s-4);
  padding: var(--s-3);
  background: var(--paper-2);
  border-left: 1px solid var(--line-strong);
}

.page-about .about-tierchart {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-tierchart text {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.page-about .about-tiers {
  margin-top: var(--s-4);
  border-top: 1px solid var(--line);
}

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

.page-about .about-tier summary {
  display: flex;
  align-items: baseline;
  gap: var(--s-2);
  padding: var(--s-2) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-tier summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
}

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

.page-about .about-tier__code {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 17px;
  color: var(--deep);
  min-width: 3.4em;
}

.page-about .about-tier__name {
  font-size: 14px;
  color: var(--turf);
  letter-spacing: 0.06em;
}

.page-about .about-tier p {
  margin: 0 0 var(--s-3);
  padding-right: var(--s-4);
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 赛季四段 ---------- */
.page-about .about-phases {
  list-style: none;
  margin: var(--s-4) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-phase {
  padding: var(--s-3);
  background: var(--paper);
}

.page-about .about-phase__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-phase h3 {
  margin: var(--s-1) 0 var(--s-1);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-phase p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--rock);
}

/* ---------- 团队侧栏 ---------- */
.page-about .about-side-card {
  padding: var(--s-3);
  background: var(--deep);
  color: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), 0 100%);
}

.page-about .about-side-card__title {
  margin: 0 0 var(--s-2);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--yellow);
}

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

.page-about .about-side-card__list li {
  display: flex;
  align-items: baseline;
  gap: var(--s-1);
  padding: 10px 0;
  font-size: 14px;
  border-bottom: 1px solid var(--line-on-deep);
  color: rgba(244, 241, 233, 0.88);
}

.page-about .about-side-card__list li:last-child {
  border-bottom: 0;
}

.page-about .about-side-card__num {
  min-width: 2em;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 20px;
  color: var(--orange);
}

.page-about .about-side-card__foot {
  margin: var(--s-2) 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(244, 241, 233, 0.62);
}

/* ---------- 海南深色分区 ---------- */
.page-about .about-section--deep {
  margin-left: calc(-1 * var(--gutter));
  margin-right: calc(-1 * var(--gutter));
  padding: var(--s-7) var(--gutter) var(--s-7);
  background: var(--deep);
  color: var(--paper);
  border-bottom: 0;
}

.page-about .about-section--deep .about-head {
  border-top-color: var(--orange);
}

.page-about .about-head--on-deep h2 {
  color: var(--paper);
}

.page-about .about-head--on-deep .about-head__lead,
.page-about .about-head--on-deep .index-num {
  color: rgba(244, 241, 233, 0.7);
}

.page-about .prose--on-deep p {
  color: rgba(244, 241, 233, 0.86);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: var(--s-4);
  background: var(--line-on-deep);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: var(--s-2);
  background: var(--deep);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 24px;
  line-height: 1;
  color: var(--yellow);
}

.page-about .about-stat__label {
  font-size: 13px;
  color: rgba(244, 241, 233, 0.68);
}

.page-about .about-figure--wide .frame__caption {
  color: rgba(244, 241, 233, 0.6);
}

/* ---------- 时间轴 ---------- */
.page-about .about-track {
  list-style: none;
  margin: var(--s-4) 0 0;
  padding: 0 0 0 var(--s-3);
  border-left: 1px solid var(--line-strong);
}

.page-about .about-track__item {
  position: relative;
  padding: 0 0 var(--s-4);
}

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

.page-about .about-track__dot {
  position: absolute;
  left: calc(-1 * var(--s-3) - 5px);
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--paper);
  border: 2px solid var(--turf);
  transform: rotate(45deg);
  transition: background-color 0.2s ease;
}

.page-about .about-track__item:hover .about-track__dot {
  background: var(--turf);
}

.page-about .about-track__label {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--clay);
}

.page-about .about-track__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  padding: 0 0 var(--s-12);
}

.page-about .about-cta__panel {
  padding: var(--s-4) var(--s-3) var(--s-4);
  background: var(--deep-2);
  color: var(--paper);
  clip-path: polygon(0 20px, 100% 0, 100% 100%, 0 100%);
}

.page-about .about-cta__panel .eyebrow {
  color: var(--yellow);
  letter-spacing: 0.14em;
}

.page-about .about-cta__panel h2 {
  margin: var(--s-2) 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(22px, 4vw, 32px);
  line-height: 1.2;
  color: var(--paper);
}

.page-about .about-cta__text {
  margin: var(--s-2) 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 241, 233, 0.8);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s-2) var(--s-3);
  margin-top: var(--s-3);
}

.page-about .about-cta__link {
  font-size: 14px;
  color: rgba(244, 241, 233, 0.82);
  text-decoration: none;
  border-bottom: 1px solid rgba(244, 241, 233, 0.34);
  padding-bottom: 2px;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-cta__link:hover,
.page-about .about-cta__link:focus-visible {
  color: var(--yellow);
  border-bottom-color: var(--yellow);
}

/* ---------- 焦点可见性 ---------- */
.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts,
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + var(--s-7)) 0 156px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--s-7);
    align-items: end;
    margin-top: var(--s-7);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--s-7);
    align-items: start;
  }

  .page-about .about-figure--wide {
    margin-left: calc(-1 * var(--s-3));
    margin-right: calc(-1 * var(--s-3));
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + var(--s-4));
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link {
    margin-left: -1px;
    white-space: normal;
    border-bottom: 0;
    border-left: 2px solid transparent;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-bottom-color: transparent;
    border-left-color: var(--orange);
  }

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

  .page-about .about-cta__panel {
    padding: var(--s-7) var(--s-4);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
  }
}