.page-about {
  --about-gap: clamp(30px, 4.6vw, 68px);
  --about-paper-shadow: 6px 6px 0 rgba(157, 184, 170, .13);
}

.page-about .about-hero {
  display: grid;
  gap: 26px;
  padding: 22px 0 10px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-rail-label {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .about-index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-index a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  background: rgba(15, 36, 27, .7);
  color: var(--moss);
  font-size: 13px;
  text-decoration: none;
  transition: color .22s var(--ease), background .22s var(--ease), border-color .22s var(--ease);
}

.page-about .about-index a .num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--amber);
  transition: color .22s var(--ease);
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink);
}

.page-about .about-index a:hover .num,
.page-about .about-index a:focus-visible .num {
  color: var(--ink);
}

.page-about .about-kicker {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0 0 18px;
}

.page-about .about-kicker-note {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--moss);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(32px, 8vw, 74px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--fog);
}

.page-about .about-lead {
  margin: 20px 0 0;
  max-width: 64ch;
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.82;
  color: var(--moss);
}

.page-about .about-facts {
  list-style: none;
  margin: 28px 0 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 12px;
}

.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .about-facts .num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(20px, 5vw, 27px);
  line-height: 1;
  color: var(--lime);
}

.page-about .about-facts li > span:last-child {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--moss);
}

/* ---------- 章节公共 ---------- */

.page-about .section {
  padding: var(--about-gap) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .chapter {
  position: relative;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line-strong);
}

.page-about .chapter-index {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--orange);
}

.page-about .chapter-title {
  margin: 10px 0 0;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(24px, 5.4vw, 44px);
  line-height: 1.14;
  letter-spacing: -.015em;
  color: var(--fog);
}

.page-about .chapter-note {
  margin: 10px 0 0;
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--moss);
}

.page-about .about-intro {
  margin: 24px 0 0;
  max-width: 70ch;
  font-size: 16px;
  line-height: 1.82;
  color: var(--moss);
}

.page-about .about-tail {
  margin: 26px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--moss);
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 26px 0 0;
}

.page-about .about-figure .media-frame {
  border: 1px solid var(--line-strong);
  overflow: hidden;
}

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

.page-about .about-figure .media-caption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--moss);
}

/* ---------- 01 版本时间线 ---------- */

.page-about .about-tl {
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 22px;
  border-left: 1px dashed var(--line-strong);
}

.page-about .about-tl-item {
  position: relative;
  margin-bottom: 12px;
}

.page-about .about-tl-item:last-child {
  margin-bottom: 0;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 20px;
  width: 10px;
  height: 10px;
  background: var(--ink);
  border: 2px solid var(--lime);
  transform: rotate(45deg);
}

.page-about .about-node {
  background: var(--deep);
  border: 1px solid var(--line);
  transition: border-color .22s var(--ease), background .22s var(--ease);
}

.page-about .about-node[open] {
  background: var(--lift);
  border-color: rgba(200, 255, 61, .45);
  box-shadow: var(--about-paper-shadow);
}

.page-about .about-node summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
}

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

.page-about .about-node summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1;
  color: var(--lime);
  transition: transform .22s var(--ease);
}

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

.page-about .about-node summary:hover {
  background: rgba(200, 255, 61, .07);
}

.page-about .about-node summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .about-node-year {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  min-width: 46px;
  color: var(--amber);
}

.page-about .about-node-name {
  font-family: var(--sans);
  font-weight: 800;
  font-size: 17px;
  color: var(--fog);
}

.page-about .about-node-body {
  padding: 0 16px 16px;
}

.page-about .about-node-body p {
  margin: 12px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 15px;
  line-height: 1.8;
  color: var(--moss);
}

/* ---------- 02 内容分层 ---------- */

.page-about .about-stack {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-sheet {
  position: relative;
  padding: 20px 20px 20px 24px;
  background: linear-gradient(180deg, var(--lift), var(--deep));
  border: 1px solid var(--line);
  box-shadow: var(--about-paper-shadow);
}

.page-about .about-sheet::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--lime);
}

.page-about .about-sheet-key {
  display: block;
  margin-bottom: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--cyan);
}

.page-about .about-sheet-title {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .01em;
  color: var(--fog);
}

.page-about .about-sheet-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--moss);
}

/* ---------- 03 校对与审核 ---------- */

.page-about .about-audit {
  display: grid;
  gap: 26px;
  margin-top: 8px;
}

.page-about .about-steps {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-steps li {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 16px;
  border-bottom: 1px dashed var(--line);
}

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

.page-about .about-step-idx {
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  background: var(--amber);
  color: var(--ink);
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
}

.page-about .about-step-title {
  margin: 0 0 6px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: 16px;
  color: var(--fog);
}

.page-about .about-step-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--moss);
}

.page-about .about-figure--side {
  margin-top: 0;
}

/* ---------- 04 团队 ---------- */

.page-about .about-team {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-team-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px;
  background: var(--deep);
  border: 1px solid var(--line);
}

.page-about .about-team-card--accent {
  background: var(--lime);
  border-color: var(--lime);
}

.page-about .about-team-num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 34px;
  line-height: 1;
  color: var(--fog);
}

.page-about .about-team-card--accent .about-team-num {
  color: var(--ink);
}

.page-about .about-team-label {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--moss);
}

.page-about .about-team-card--accent .about-team-label {
  color: rgba(8, 18, 14, .74);
}

.page-about .about-cities {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cities li {
  padding: 8px 14px;
  border: 1px dashed var(--line-strong);
  font-family: var(--mono);
  font-size: 13px;
  color: var(--fog);
}

/* ---------- 05 赛事覆盖 ---------- */

.page-about .about-cover {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-ring {
  position: relative;
  width: 100%;
  max-width: 280px;
  margin: 0 auto;
}

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

.page-about .about-ring-center {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 4px;
  text-align: center;
}

.page-about .about-ring-center .num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 44px;
  line-height: 1;
  color: var(--fog);
}

.page-about .about-ring-center span:last-child {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--moss);
}

.page-about .about-cover-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-cover-list li {
  padding: 14px 16px;
  background: rgba(23, 59, 44, .62);
  border-left: 2px solid var(--lime);
}

.page-about .about-cover-list strong {
  display: block;
  font-family: var(--sans);
  font-weight: 800;
  font-size: 15px;
  color: var(--fog);
}

.page-about .about-cover-list span {
  display: block;
  margin-top: 5px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--moss);
}

/* ---------- 06 回访理由 ---------- */

.page-about .about-return {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-return-card {
  padding: 22px;
  background: var(--deep);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
}

.page-about .about-return-card h3 {
  margin: 0 0 10px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: 17px;
  color: var(--fog);
}

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

/* ---------- 07 账号安全 + 结尾 ---------- */

.page-about .about-safety {
  display: grid;
  gap: 16px;
  margin-top: 24px;
  max-width: 72ch;
}

.page-about .about-safety p {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--line-strong);
  font-size: 15px;
  line-height: 1.82;
  color: var(--moss);
}

.page-about .about-cta {
  margin-top: 32px;
  padding: 26px 20px;
  display: grid;
  gap: 20px;
  background: linear-gradient(135deg, var(--lift), var(--deep) 68%);
  border: 1px solid var(--line-strong);
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(20px, 4.4vw, 28px);
  line-height: 1.24;
  color: var(--fog);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--moss);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 760px) {
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-cta {
    padding: 34px 30px;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .about-cta-actions {
    justify-content: flex-end;
    max-width: 300px;
  }
}

@media (min-width: 900px) {
  .page-about .about-stack {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
    padding-bottom: 22px;
  }

  .page-about .about-sheet:nth-child(even) {
    transform: translateY(18px);
  }

  .page-about .about-audit {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-cover {
    grid-template-columns: 300px minmax(0, 1fr);
    gap: 44px;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 52px;
    padding: 44px 0 26px;
  }

  .page-about .about-rail {
    padding-right: 24px;
    border-right: 1px solid var(--line);
  }

  .page-about .about-index {
    flex-direction: column;
    flex-wrap: nowrap;
  }

  .page-about .about-index a {
    width: 100%;
    justify-content: flex-start;
  }

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

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

  .page-about .about-sheet-text,
  .page-about .about-return-card p {
    font-size: 14.5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index a,
  .page-about .about-node,
  .page-about .about-node summary::after {
    transition: none;
  }

  .page-about .about-sheet:nth-child(even) {
    transform: none;
  }
}

已完成。