.page-about {
  --pa-rail: 208px;
  --pa-gold-ink: #7A6212;
  --pa-ink-line: rgba(11, 26, 46, .14);
  --pa-ink-text: rgba(11, 26, 46, .74);
  --pa-ink-soft: rgba(11, 26, 46, .58);
  background: var(--ink);
  color: var(--paper);
}

/* ---------- 首屏 ---------- */

.page-about .about-masthead {
  padding-block: clamp(72px, 10vw, 112px) clamp(32px, 5vw, 56px);
}

.page-about .breadcrumbs {
  margin-bottom: clamp(20px, 4vw, 36px);
  font-size: 13px;
}

.page-about .about-frame {
  position: relative;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: clamp(18px, 3.2vw, 38px);
  background:
    linear-gradient(135deg, rgba(201, 162, 39, .08), transparent 48%),
    linear-gradient(180deg, rgba(20, 38, 60, .55), rgba(11, 26, 46, 0) 70%);
}

.page-about .about-frame::before,
.page-about .about-frame::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--gold);
  border-style: solid;
  pointer-events: none;
}

.page-about .about-frame::before {
  top: -1px;
  left: -1px;
  border-width: 2px 0 0 2px;
}

.page-about .about-frame::after {
  right: -1px;
  bottom: -1px;
  border-width: 0 2px 2px 0;
}

.page-about .about-masthead__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-masthead h1 {
  margin: 14px 0 0;
  font-size: clamp(32px, 6.2vw, 64px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: .01em;
  max-width: 18ch;
  color: var(--paper);
}

.page-about .about-masthead__intro {
  margin: 20px 0 0;
  max-width: 44ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-facts {
  padding: clamp(18px, 2.6vw, 26px);
}

.page-about .about-facts__list {
  margin: 14px 0 0;
}

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-facts__row:first-child {
  border-top: 0;
  padding-top: 2px;
}

.page-about .about-facts dt {
  font-size: 13px;
  color: var(--steel);
  letter-spacing: .02em;
}

.page-about .about-facts dd {
  margin: 0;
  font-size: 14px;
  text-align: right;
  color: var(--paper);
}

.page-about .about-facts dd .num {
  color: var(--gold);
  font-weight: 700;
}

/* ---------- 章节索引条 ---------- */

.page-about .about-index-wrap {
  border-block: 1px solid var(--line);
  background: var(--ink-3);
}

.page-about .about-index {
  padding-block: clamp(16px, 2.6vw, 24px);
}

.page-about .about-index__list {
  display: flex;
  gap: clamp(16px, 2.6vw, 34px);
  margin: 12px 0 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-index__list li {
  flex: 0 0 auto;
}

.page-about .about-index__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding-bottom: 4px;
  font-size: 14px;
  color: var(--steel);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--gold-hi);
  border-bottom-color: var(--gold-hi);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

/* ---------- 章节通用骨架 ---------- */

.page-about .about-body {
  padding-block: clamp(36px, 6vw, 80px);
}

.page-about .chapter {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
  padding-block: clamp(36px, 6vw, 72px);
  border-top: 1px solid var(--line);
}

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

.page-about .chapter__rail {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

.page-about .chapter__rail .chapter-num {
  display: block;
  line-height: .92;
}

.page-about .chapter-note {
  display: block;
  flex: 1 0 100%;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--steel);
}

.page-about .chapter__main h2 {
  margin: 0 0 16px;
  font-size: clamp(23px, 3.2vw, 36px);
  font-weight: 800;
  line-height: 1.22;
  color: var(--paper);
}

.page-about .chapter__main h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .chapter__main p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--steel);
}

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

.page-about .chapter__main p strong {
  color: var(--paper);
  font-weight: 700;
}

.page-about .chapter__outro {
  margin-top: 22px !important;
  padding-left: 16px;
  border-left: 2px solid var(--gold);
}

/* ---------- 图像框 ---------- */

.page-about .about-media {
  position: relative;
  margin: 26px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--ink-2);
}

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

.page-about .about-media--lead img {
  aspect-ratio: 16 / 9;
}

.page-about .about-media--tall {
  max-width: min(100%, 340px);
}

.page-about .about-media--tall img {
  aspect-ratio: 4 / 5;
}

.page-about .about-media--line img {
  aspect-ratio: 2 / 1;
}

.page-about .about-media__caption {
  display: block;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  background: var(--ink-3);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .03em;
  color: var(--steel);
}

/* ---------- 四类档案 ---------- */

.page-about .archive-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .archive-list__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 14px;
  padding: 16px 0 16px 14px;
  border-bottom: 1px solid var(--line);
  border-left: 2px solid transparent;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .archive-list__item:hover {
  border-left-color: var(--gold);
  background: rgba(201, 162, 39, .05);
}

.page-about .archive-list__key {
  grid-column: 1;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .archive-list__val {
  grid-column: 2;
  justify-self: end;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: .02em;
}

.page-about .archive-list__desc {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--steel);
}

/* ---------- 数据来源 ---------- */

.page-about .source-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .source-list__item {
  display: grid;
  gap: 6px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .source-list__n {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--gold);
}

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

.page-about .source-list__p {
  margin: 0 !important;
  font-size: 15px !important;
  line-height: 1.72 !important;
  color: var(--steel);
}

.page-about .about-callout {
  margin-top: 28px;
  padding: clamp(18px, 2.6vw, 26px);
}

.page-about .about-callout p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-callout__num {
  font-size: 22px;
  font-weight: 700;
  color: var(--gold-hi);
  letter-spacing: .01em;
}

/* ---------- 校验流程 ---------- */

.page-about .verify-flow {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .verify-flow__node {
  position: relative;
  padding: 14px 12px 14px 0;
  border-top: 1px solid var(--line);
  outline-offset: 4px;
}

.page-about .verify-flow__n {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--gold);
}

.page-about .verify-flow__t {
  display: block;
  margin-top: 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .verify-flow__body {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height .3s var(--ease), opacity .25s var(--ease), margin-top .3s var(--ease);
}

.page-about .verify-flow__node:hover .verify-flow__body,
.page-about .verify-flow__node:focus-within .verify-flow__body {
  max-height: 160px;
  margin-top: 8px;
  opacity: 1;
}

.page-about .verify-flow__body p {
  margin: 0 !important;
  font-size: 13px;
  line-height: 1.62;
  color: var(--steel);
}

.page-about .verify-flow__node:focus-visible {
  outline: 2px solid var(--gold-hi);
}

/* ---------- 团队表格 ---------- */

.page-about .data-table caption {
  padding-bottom: 10px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--steel);
}

.page-about .about-subhead {
  margin: 30px 0 16px;
  font-size: 19px;
  color: var(--paper);
}

/* ---------- 深浅翻面 ---------- */

.page-about .about-turn {
  height: clamp(44px, 6vw, 88px);
  background: var(--paper);
  clip-path: polygon(0 100%, 100% 14%, 100% 100%);
}

.page-about .about-paper {
  padding-block: clamp(36px, 6vw, 76px) clamp(48px, 7vw, 96px);
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-paper .chapter {
  border-top: 1px solid var(--pa-ink-line);
}

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

.page-about .about-paper .chapter__main h2,
.page-about .about-paper .chapter__main h3,
.page-about .about-paper .about-subhead {
  color: var(--ink);
}

.page-about .about-paper .chapter__main p {
  color: var(--pa-ink-text);
}

.page-about .about-paper .chapter__main p strong {
  color: var(--ink);
}

.page-about .about-paper .chapter-note {
  color: var(--pa-ink-soft);
}

.page-about .about-paper .eyebrow {
  color: var(--pa-gold-ink);
}

.page-about .about-paper .chapter__rail .chapter-num {
  color: var(--ink);
  opacity: .82;
  -webkit-text-stroke: 0;
}

.page-about .about-paper [data-chapter].is-current .chapter-num {
  color: var(--ink);
  opacity: 1;
}

.page-about .about-paper [data-chapter].is-current .eyebrow {
  color: var(--pa-gold-ink);
}

.page-about .about-paper .about-media {
  border-color: var(--pa-ink-line);
  background: #E6E1D6;
}

.page-about .about-paper .about-media__caption {
  border-top-color: var(--pa-ink-line);
  background: #EAE5DA;
  color: var(--pa-ink-soft);
}

/* ---------- 赛季时间线 ---------- */

.page-about .season-track {
  position: relative;
  margin: 30px 0 0;
  padding: 0 0 0 26px;
  list-style: none;
  border-left: 1px solid var(--pa-ink-line);
}

.page-about .season-track__item {
  position: relative;
  padding-bottom: 30px;
}

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

.page-about .season-track__item::before {
  content: "";
  position: absolute;
  top: 6px;
  left: -31px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 3px var(--paper);
}

.page-about .season-track__mark {
  display: inline-block;
  margin-bottom: 8px;
  padding: 3px 9px;
  border: 1px solid rgba(201, 162, 39, .5);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--pa-gold-ink);
}

/* ---------- 合作与边界 ---------- */

.page-about .coop-list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--pa-ink-line);
}

.page-about .coop-list__item {
  display: grid;
  gap: 6px;
  padding: 18px 0 18px 14px;
  border-bottom: 1px solid var(--pa-ink-line);
  border-left: 2px solid transparent;
  transition: border-color .2s var(--ease);
}

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

.page-about .coop-list__label {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--pa-gold-ink);
}

.page-about .coop-list__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--pa-ink-text);
}

.page-about .coop-list__item .num {
  font-weight: 700;
  color: var(--ink);
}

.page-about .not-doing {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .not-doing__item {
  display: grid;
  gap: 8px;
  padding: 16px;
  border: 1px solid var(--pa-ink-line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .5);
}

.page-about .not-doing__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--pa-ink-text);
}

.page-about .not-doing__item strong {
  color: var(--ink);
  font-weight: 700;
}

.page-about .not-doing__item .tag {
  justify-self: start;
}

.page-about .about-next {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--pa-ink-line);
}

.page-about .about-next a {
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 162, 39, .55);
  padding-bottom: 3px;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-next a:hover,
.page-about .about-next a:focus-visible {
  color: var(--pa-gold-ink);
  border-bottom-color: var(--pa-gold-ink);
}

/* ---------- 平板及以上 ---------- */

@media (min-width: 760px) {
  .page-about .archive-list__item {
    grid-template-columns: 150px 132px minmax(0, 1fr);
    align-items: baseline;
    gap: 0 20px;
    padding-inline: 14px;
  }

  .page-about .archive-list__key {
    grid-column: 1;
  }

  .page-about .archive-list__val {
    grid-column: 2;
    justify-self: start;
  }

  .page-about .archive-list__desc {
    grid-column: 3;
  }

  .page-about .source-list__item {
    grid-template-columns: 104px minmax(0, 1fr);
    grid-template-areas:
      "n t"
      "n p";
    column-gap: 24px;
    align-items: start;
    row-gap: 8px;
  }

  .page-about .source-list__n {
    grid-area: n;
    padding-top: 4px;
  }

  .page-about .source-list__t {
    grid-area: t;
  }

  .page-about .source-list__p {
    grid-area: p;
  }

  .page-about .about-subhead {
    margin-top: 38px;
  }
}

/* ---------- 桌面结构 ---------- */

@media (min-width: 900px) {
  .page-about .about-masthead__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(280px, .85fr);
    align-items: end;
  }

  .page-about .verify-flow {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0;
  }

  .page-about .verify-flow__node {
    padding: 22px 18px 6px 0;
    border-top: 0;
  }

  .page-about .verify-flow__node::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--line-strong);
    transition: background .22s var(--ease);
  }

  .page-about .verify-flow__node:hover::before,
  .page-about .verify-flow__node:focus-within::before {
    background: var(--gold);
  }
}

@media (min-width: 980px) {
  .page-about .chapter {
    grid-template-columns: var(--pa-rail) minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 78px);
  }

  .page-about .chapter__rail {
    display: block;
    position: sticky;
    top: 108px;
    align-self: start;
  }

  .page-about .chapter__rail .chapter-num {
    font-size: clamp(52px, 6vw, 76px);
  }

  .page-about .chapter__rail .eyebrow {
    display: block;
    margin-top: 18px;
  }

  .page-about .chapter-note {
    flex: none;
    margin-top: 14px;
    max-width: 20ch;
  }

  .page-about .chapter__main {
    max-width: 74ch;
  }
}

/* ---------- 减少动效 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .verify-flow__body {
    transition: none;
  }

  .page-about .archive-list__item,
  .page-about .coop-list__item,
  .page-about .about-index__list a,
  .page-about .about-next a,
  .page-about .verify-flow__node::before {
    transition: none;
  }
}