.page-about {
  --about-rule: 1px solid var(--edge);
  background: var(--deep);
  color: var(--fog);
}

.page-about .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 32px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(24px, 4vw, 52px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4.5vw, 56px);
  align-items: center;
}

.page-about .about-hero__text {
  max-width: 32em;
}

.page-about .about-hero__lead {
  margin-top: 18px;
  font-size: 17px;
  line-height: 1.85;
  color: var(--fog);
  opacity: 0.84;
}

.page-about .about-hero__figure {
  margin: 0;
  border-radius: var(--r-organic);
  overflow: hidden;
}

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

/* ---------- 段落目录 ---------- */
.page-about .about-toc {
  display: grid;
  grid-template-columns: 1fr;
  border-top: var(--about-rule);
}

.page-about .about-toc__item {
  display: grid;
  grid-template-columns: 2.6rem 1fr auto;
  gap: 10px;
  align-items: baseline;
  padding: 15px 6px;
  border-bottom: var(--about-rule);
  color: var(--fog);
  text-decoration: none;
  transition: background var(--t-fast) var(--ease), padding-left var(--t-fast) var(--ease);
}

.page-about .about-toc__item:hover,
.page-about .about-toc__item:focus-visible {
  background: rgba(53, 223, 214, 0.07);
  padding-left: 14px;
}

.page-about .about-toc__item:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: -2px;
}

.page-about .about-toc__no {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .about-toc__label {
  font-size: 16px;
  line-height: 1.6;
}

.page-about .about-toc__meta {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
}

/* ---------- 01 指标口径 ---------- */
.page-about .about-metric__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.4vw, 44px);
}

.page-about .about-metric__side {
  align-self: start;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--panel);
  border: var(--about-rule);
  border-radius: var(--r-soft);
}

.page-about .about-defs {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 13px;
}

.page-about .about-defs li {
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-defs .mono {
  display: block;
  margin-bottom: 2px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

/* ---------- 02 双维度档案 ---------- */
.page-about .about-axes__intro,
.page-about .about-proof__intro {
  max-width: 48ch;
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-axes__pair {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2.2vw, 24px);
  margin-top: clamp(22px, 3vw, 36px);
}

.page-about .about-axis-card {
  padding: clamp(20px, 2.6vw, 30px);
  border: var(--about-rule);
  border-radius: var(--r-organic);
  transition: border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-axis-card--season {
  background: var(--panel);
}

.page-about .about-axis-card--league {
  background: rgba(16, 31, 60, 0.52);
}

.page-about .about-axis-card:focus-visible,
.page-about .about-axis-card:hover {
  border-color: var(--cyan);
}

.page-about .about-axis-card:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

.page-about .about-axis-card h3 {
  margin: 6px 0 12px;
}

.page-about .about-axis-card p {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--fog);
  opacity: 0.88;
}

.page-about .about-axis-card__foot {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--edge);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  opacity: 1;
}

.page-about .about-axes__figure {
  margin: clamp(26px, 3.6vw, 44px) 0 0;
}

.page-about .about-axes__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--r-soft);
}

.page-about .about-axes__close {
  max-width: 42em;
  margin-top: clamp(22px, 3vw, 34px);
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 03 校对流程 ---------- */
.page-about .about-proof__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 3.6vw, 48px);
  margin-top: clamp(22px, 3vw, 36px);
}

.page-about .flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: flowstep;
}

.page-about .flow-step {
  position: relative;
  counter-increment: flowstep;
  display: grid;
  grid-template-columns: 32px 1fr;
  column-gap: 18px;
  padding-bottom: 30px;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 34px;
  bottom: 0;
  width: 1px;
  transform: translateX(-50%);
  background: var(--edge);
}

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

.page-about .flow-step:last-child::before {
  display: none;
}

.page-about .flow-step__no {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--void);
  border: 1px solid var(--gold);
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  transition: background var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

.page-about .flow-step__no::before {
  content: counter(flowstep, decimal-leading-zero);
}

.page-about .flow-step:hover .flow-step__no,
.page-about .flow-step:focus-within .flow-step__no {
  background: var(--gold);
  color: var(--void);
}

.page-about .flow-step__body h3 {
  margin: 2px 0 8px;
}

.page-about .flow-step__body p {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--fog);
  opacity: 0.86;
}

.page-about .flow-step__hint {
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  opacity: 1;
  border-left: 2px solid var(--cyan);
  padding-left: 10px;
}

.page-about .about-proof__figure {
  margin: 0;
  align-self: start;
}

.page-about .about-proof__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--r-soft);
}

.page-about .about-proof__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: clamp(24px, 3.4vw, 40px);
  padding-top: clamp(18px, 2.4vw, 26px);
  border-top: var(--about-rule);
}

.page-about .about-proof__actions p {
  flex: 1 1 22em;
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 04 主场地图 ---------- */
.page-about .about-venue__grid {
  align-items: start;
}

.page-about .about-venue__module {
  background: var(--panel);
}

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

.page-about .about-venue__fields li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.7;
  color: var(--fog);
  opacity: 0.86;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(31, 53, 96, 0.6);
}

.page-about .about-venue__fields li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-venue__fields .mono {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

/* ---------- 05 团队与测试版 ---------- */
.page-about .about-team__stats {
  margin-bottom: clamp(26px, 3.4vw, 42px);
}

.page-about .about-team__body {
  display: grid;
  gap: 18px;
  max-width: 46em;
}

.page-about .about-team__body .prose {
  margin: 0;
}

.page-about .about-team__beta {
  margin-top: clamp(26px, 3.6vw, 44px);
  padding: clamp(20px, 2.6vw, 30px);
  background: rgba(16, 31, 60, 0.55);
  border: var(--about-rule);
  border-radius: 8px 28px 8px 28px;
}

.page-about .about-beta-list {
  list-style: none;
  margin: 16px 0 20px;
  padding: 0;
  display: grid;
  gap: 11px;
}

.page-about .about-beta-list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--fog);
  opacity: 0.88;
}

.page-about .about-beta-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 06 边界与原则 ---------- */
.page-about .about-bounds .index-label {
  color: var(--edge);
}

.page-about .about-bounds h2 {
  color: var(--deep);
}

.page-about .about-bounds__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 38px);
  align-items: start;
}

.page-about .about-quote {
  margin: 0;
  padding: clamp(20px, 2.8vw, 32px);
  border-left: 3px solid var(--gold);
  background: rgba(5, 10, 22, 0.06);
  border-radius: 0 var(--r-soft) var(--r-soft) 0;
}

.page-about .about-quote p {
  margin: 0;
  font-size: 17px;
  line-height: 1.9;
  color: var(--deep);
  letter-spacing: 0.01em;
}

.page-about .about-bounds__prose p {
  color: var(--deep);
}

/* ---------- 折叠问答 ---------- */
.page-about .about-faq__list {
  border-top: var(--about-rule);
}

.page-about .faq-item {
  border-bottom: var(--about-rule);
}

.page-about .faq-item__q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 4px;
  background: none;
  border: 0;
  color: var(--fog);
  font: inherit;
  font-size: 16.5px;
  line-height: 1.6;
  text-align: left;
  cursor: pointer;
  transition: color var(--t-fast) var(--ease), padding-left var(--t-fast) var(--ease);
}

.page-about .faq-item__q:hover {
  color: var(--cyan);
  padding-left: 12px;
}

.page-about .faq-item__q:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

.page-about .expand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
}

.page-about .expand-mark::before,
.page-about .expand-mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform var(--t-fast) var(--ease);
}

.page-about .expand-mark::before {
  left: 0;
  top: 8px;
  width: 18px;
  height: 1.5px;
}

.page-about .expand-mark::after {
  left: 8px;
  top: 0;
  width: 1.5px;
  height: 18px;
}

.page-about .faq-item[data-open] .expand-mark::after {
  transform: scaleY(0);
}

.page-about .faq-item .expand-body {
  padding: 0 4px 20px;
}

.page-about .faq-item .expand-body p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  border-top: var(--about-rule);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-toc {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-toc__item:nth-child(odd) {
    border-right: var(--about-rule);
    padding-right: 18px;
  }

  .page-about .about-toc__item:nth-child(even) {
    padding-left: 18px;
  }

  .page-about .about-toc__item:hover,
  .page-about .about-toc__item:focus-visible {
    padding-left: 22px;
  }

  .page-about .about-axes__pair {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.08fr 0.92fr;
  }

  .page-about .about-metric__grid {
    grid-template-columns: 1.45fr 1fr;
  }

  .page-about .about-proof__layout {
    grid-template-columns: 1.35fr 1fr;
  }

  .page-about .about-bounds__grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .flow-list {
    padding-right: clamp(0px, 2vw, 24px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__item,
  .page-about .about-axis-card,
  .page-about .flow-step__no,
  .page-about .faq-item__q,
  .page-about .expand-mark::before,
  .page-about .expand-mark::after {
    transition: none;
  }
}