.page-about {
  --about-rail: 176px;
  --about-gap: clamp(24px, 4vw, 56px);
  --about-hair: 1px solid var(--line-600);
  display: block;
  background: var(--ink-900);
  color: var(--mist-300);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(28px, 5vw, 64px) 0 clamp(26px, 4vw, 44px);
  border-bottom: var(--about-hair);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -18%;
  width: min(600px, 78%);
  height: 170%;
  background:
    linear-gradient(158deg, rgba(53, 224, 200, 0.12), rgba(201, 138, 46, 0.09) 46%, transparent 72%);
  clip-path: polygon(20% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

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

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(36px, 8.6vw, 82px);
  line-height: 0.96;
  letter-spacing: -0.02em;
  color: var(--paper-50);
}

.page-about .about-hero .lead {
  max-width: 66ch;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--mist-300);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-600);
  border: var(--about-hair);
}

.page-about .about-stats li {
  background: var(--ink-900);
  padding: 14px 14px 16px;
  min-width: 0;
}

.page-about .about-stats .stat-figure {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 6vw, 40px);
  line-height: 1;
  color: var(--gold-500);
  letter-spacing: -0.03em;
}

.page-about .about-stats .stat-unit {
  font-size: 0.58em;
  margin-left: 2px;
  color: var(--gold-300);
}

.page-about .about-stats .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--mist-500);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-layout {
  padding-top: clamp(26px, 4vw, 52px);
}

.page-about .about-body {
  min-width: 0;
}

.page-about .about-sec {
  position: relative;
  padding: clamp(28px, 4.4vw, 52px) 0;
  border-top: var(--about-hair);
}

.page-about .about-sec p {
  font-size: 16px;
  line-height: 1.9;
  color: var(--mist-300);
  margin: 0 0 16px;
  max-width: 68ch;
}

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

/* ---------- 章节标题组 ---------- */
.page-about .sec-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(12px, 2.6vw, 24px);
  align-items: center;
  margin-bottom: clamp(16px, 2.6vw, 26px);
}

.page-about .sec-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(40px, 11vw, 88px);
  line-height: 0.78;
  letter-spacing: -0.05em;
  color: var(--green-800);
  -webkit-text-stroke: 1px var(--gold-500);
}

.page-about .sec-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(23px, 5vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--paper-50);
}

.page-about .sec-anno {
  display: none;
  position: absolute;
  top: clamp(34px, 5vw, 62px);
  right: 0;
  letter-spacing: 0.18em;
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--mist-500);
}

/* ---------- 赛季节段列表 ---------- */
.page-about .seg-list {
  list-style: none;
  margin: 8px 0 0;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--line-600);
}

.page-about .seg {
  position: relative;
  padding: 0 0 22px 14px;
}

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

.page-about .seg::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--gold-500);
  border-radius: 50%;
}

.page-about .seg:first-child::before {
  background: var(--cyan-400);
  border-color: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(53, 224, 200, 0.14);
}

.page-about .seg-when {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold-300);
  border-bottom: 1px solid var(--line-600);
  padding-bottom: 4px;
}

.page-about .seg-what {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-300);
  max-width: 64ch;
}

/* ---------- 图片基础 ---------- */
.page-about .figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: var(--about-hair);
  background: var(--green-800);
}

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

.page-about .figure__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 20px 14px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist-300);
  background: linear-gradient(180deg, rgba(8, 20, 15, 0), rgba(8, 20, 15, 0.88));
}

/* ---------- 分工章节 ---------- */
.page-about .team-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-bottom: clamp(22px, 3vw, 34px);
}

.page-about .team-note p {
  font-size: 15px;
  line-height: 1.9;
}

.page-about .data-table-wrap {
  border: var(--about-hair);
  background: var(--ink-900);
  overflow-x: auto;
}

.page-about .data-table caption {
  text-align: left;
  padding: 12px 14px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist-500);
  border-bottom: var(--about-hair);
}

.page-about .data-table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  font-size: 14px;
}

.page-about .data-table th,
.page-about .data-table td {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line-600);
  vertical-align: top;
  line-height: 1.7;
}

.page-about .data-table thead th {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan-400);
  background: var(--carbon-950);
  white-space: nowrap;
}

.page-about .data-table tbody th {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--paper-50);
  white-space: nowrap;
}

.page-about .data-table tbody tr:nth-child(even) {
  background: rgba(22, 48, 42, 0.6);
}

.page-about .data-table tbody tr:last-child th,
.page-about .data-table tbody tr:last-child td {
  border-bottom: 0;
}

/* ---------- 校验章节 ---------- */
.page-about .about-check {
  margin: clamp(16px, 2.6vw, 26px) 0;
  border: var(--about-hair);
  background: var(--green-800);
}

.page-about .about-check .tablist {
  border-bottom: var(--about-hair);
}

.page-about .about-check .tabpanel {
  padding: 18px 16px 20px;
  background: var(--ink-900);
}

.page-about .check-list {
  margin: 0;
}

.page-about .check-list dt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--gold-300);
  padding-left: 12px;
  border-left: 2px solid var(--gold-500);
  margin-bottom: 6px;
}

.page-about .check-list dd {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-300);
  max-width: 62ch;
}

.page-about .check-list dd:last-child {
  margin-bottom: 0;
}

.page-about .check-why {
  border-left: 2px solid var(--cyan-400);
  padding: 2px 0 2px 16px;
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .check-why h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--cyan-400);
  letter-spacing: 0.01em;
}

.page-about .check-figure {
  margin-top: clamp(22px, 3.4vw, 34px);
}

/* ---------- 勘误章节 ---------- */
.page-about .err-steps {
  margin: clamp(16px, 2.6vw, 26px) 0 0;
  border-top: var(--about-hair);
}

.page-about .err-step {
  border-bottom: var(--about-hair);
}

.page-about .err-step summary {
  cursor: pointer;
  list-style: none;
  padding: 15px 34px 15px 0;
  position: relative;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.02em;
  color: var(--paper-50);
}

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

.page-about .err-step summary::after {
  content: "+";
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--gold-500);
}

.page-about .err-step[open] summary::after {
  content: "–";
  color: var(--cyan-400);
}

.page-about .err-step[open] summary {
  color: var(--gold-300);
}

.page-about .err-step p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  max-width: 64ch;
}

.page-about .fix-note {
  margin-top: clamp(20px, 3vw, 30px);
  padding: 16px 16px 18px;
  background: var(--carbon-950);
  border: 1px solid var(--vermilion-500);
  border-left-width: 3px;
}

.page-about .fix-note-title {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--vermilion-500);
}

.page-about .fix-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-300);
}

.page-about .fix-note a {
  color: var(--gold-300);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 栏目演进章节 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--line-600);
}

.page-about .timeline-item {
  position: relative;
  padding: 0 0 26px 14px;
}

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

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 5px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold-500);
}

.page-about .timeline-item:last-child::before {
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(53, 224, 200, 0.14);
}

.page-about .timeline-time {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mist-500);
}

.page-about .timeline-body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  color: var(--paper-50);
  letter-spacing: 0.01em;
}

.page-about .timeline-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--mist-300);
  max-width: 64ch;
}

.page-about .evolve-figure {
  margin-top: clamp(22px, 3.4vw, 34px);
}

.page-about .evolve-tail {
  margin-top: 18px;
  font-size: 15px;
  color: var(--mist-500);
}

.page-about .evolve-tail a {
  color: var(--cyan-400);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 纸质规矩章节 ---------- */
.page-about .about-sec--paper {
  margin-top: clamp(22px, 3.4vw, 36px);
  border-top: 0;
  background: var(--paper-50);
  color: var(--ink-900);
  padding: clamp(24px, 4vw, 44px) clamp(16px, 3vw, 34px);
}

.page-about .sec-head--paper {
  align-items: center;
}

.page-about .sec-num--paper {
  color: var(--paper-200);
  -webkit-text-stroke: 1px var(--gold-500);
}

.page-about .sec-head--paper h2 {
  color: var(--ink-900);
}

.page-about .about-sec--paper .paper-lead {
  font-size: 16px;
  line-height: 1.9;
  color: #2f3d36;
  max-width: 60ch;
}

.page-about .rule-list {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  counter-reset: rule;
}

.page-about .rule {
  position: relative;
  padding: 16px 0 16px 22px;
  border-top: 1px solid var(--paper-200);
}

.page-about .rule::before {
  counter-increment: rule;
  content: "0" counter(rule);
  position: absolute;
  left: 0;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gold-500);
}

.page-about .rule h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink-900);
  letter-spacing: 0.01em;
}

.page-about .rule p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: #2f3d36;
  max-width: 62ch;
}

.page-about .rule-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
  padding-top: 20px;
  border-top: 1px solid var(--paper-200);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: clamp(18px, 3vw, 32px);
    align-items: start;
  }

  .page-about .about-check .tabpanel {
    padding: 22px 22px 24px;
  }

  .page-about .rule-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 0 clamp(20px, 3vw, 36px);
  }

  .page-about .rule {
    border-top: 1px solid var(--paper-200);
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-sec {
    padding-right: 44px;
  }

  .page-about .about-sec--paper {
    padding-right: clamp(20px, 3vw, 38px);
  }

  .page-about .sec-anno {
    display: block;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 20px);
  }
}

@media (min-width: 1240px) {
  .page-about {
    --about-rail: 196px;
  }

  .page-about .about-sec p {
    font-size: 16.5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .seg:first-child::before,
  .page-about .timeline-item:last-child::before {
    box-shadow: none;
  }
}