.page-about {
  --about-rail-w: 148px;
  --about-line: rgba(28, 62, 99, 0.95);
  --about-cyan-soft: rgba(34, 224, 255, 0.08);
  --about-cyan-line: rgba(34, 224, 255, 0.34);
  --about-yellow-soft: rgba(255, 210, 74, 0.07);
  --about-yellow-line: rgba(255, 210, 74, 0.3);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 22px;
  padding-bottom: 6px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .about-crumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-crumbs span[aria-hidden="true"] {
  margin: 0 8px;
  opacity: 0.45;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 28px 0 56px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -260px;
  left: 54%;
  width: min(920px, 130vw);
  height: 640px;
  transform: translateX(-46%) rotate(-8deg);
  background: radial-gradient(closest-side, rgba(34, 224, 255, 0.16), transparent 72%);
  pointer-events: none;
}

.page-about .about-hero-grid {
  position: relative;
  display: grid;
  gap: 32px;
}

.page-about .about-kicker {
  margin: 0;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.95rem, 6.4vw, 3.85rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--white);
  max-width: 15em;
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 20px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--white);
}

.page-about .about-lede + .about-lede {
  margin-top: 12px;
  color: var(--muted);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 30px;
  padding: 1px;
  background: var(--steel);
}

.page-about .about-stat {
  background: var(--ink-750);
  padding: 14px 14px 16px;
  min-width: 0;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.45rem;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--yellow);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-hero-figure {
  margin: 0;
}

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

.page-about .about-hero-figure img {
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

/* ---------- 纵向骨架 ---------- */
.page-about .about-rail {
  padding: 8px 0 16px;
}

.page-about .about-rail-inner {
  position: relative;
}

.page-about .about-node {
  padding-bottom: 54px;
}

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

.page-about .about-node-aside {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.page-about .about-node-index {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--cyan);
  padding: 3px 9px;
  border: 1px solid var(--about-cyan-line);
  background: var(--about-cyan-soft);
}

.page-about .about-aside-label {
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .about-node-body h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.6vw, 2.35rem);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-node-body .prose p {
  max-width: 68ch;
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--white);
}

.page-about .about-node-body .prose p:last-child {
  margin-bottom: 0;
  color: var(--muted);
}

.page-about .about-node-lede {
  max-width: 68ch;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 流程 ---------- */
.page-about .about-flow-figure {
  margin: 22px 0 0;
}

.page-about .about-flow-figure img {
  aspect-ratio: 12 / 7;
  object-fit: cover;
}

.page-about .about-flow {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-flow-step {
  position: relative;
  padding: 18px 16px 20px;
  border-top: 2px solid var(--cyan);
}

.page-about .about-flow-step:nth-child(2) {
  border-top-color: var(--yellow);
}

.page-about .about-flow-step:nth-child(3) {
  border-top-color: var(--green);
}

.page-about .about-flow-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-flow-step:nth-child(2) .about-flow-num {
  color: var(--yellow);
}

.page-about .about-flow-step:nth-child(3) .about-flow-num {
  color: var(--green);
}

.page-about .about-flow-step h3 {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-flow-step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-flow-time {
  display: inline-block;
  margin-top: 14px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--yellow);
  border: 1px solid var(--about-yellow-line);
  background: var(--about-yellow-soft);
}

/* ---------- 三支小组 ---------- */
.page-about .about-teams {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-team {
  overflow: hidden;
}

.page-about .about-team > summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 15px 16px;
  min-height: 60px;
  transition: background 0.22s var(--ease);
}

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

.page-about .about-team > summary:hover {
  background: rgba(34, 224, 255, 0.05);
}

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

.page-about .about-team-count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-team-unit {
  margin-left: 3px;
  font-family: var(--font-body);
  font-size: 11.5px;
  font-weight: 400;
  color: var(--muted);
}

.page-about .about-team-name {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-team-toggle {
  position: relative;
  width: 16px;
  height: 16px;
  flex: none;
}

.page-about .about-team-toggle::before,
.page-about .about-team-toggle::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform 0.24s var(--ease), opacity 0.24s var(--ease);
}

.page-about .about-team-toggle::before {
  top: 7px;
  left: 0;
  width: 16px;
  height: 2px;
}

.page-about .about-team-toggle::after {
  top: 0;
  left: 7px;
  width: 2px;
  height: 16px;
}

.page-about .about-team[open] .about-team-toggle::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .about-team-body {
  border-top: 1px solid var(--steel);
  padding: 14px 16px 18px;
}

.page-about .about-team-body p {
  max-width: 64ch;
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 赛季时间线 ---------- */
.page-about .about-era {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-era-item {
  position: relative;
  padding-left: 26px;
}

.page-about .about-era-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 21px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(34, 224, 255, 0.14), 0 0 12px rgba(34, 224, 255, 0.55);
}

.page-about .about-era-item::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 34px;
  bottom: -16px;
  width: 1px;
  background: var(--steel);
}

.page-about .about-era-item:last-child::after {
  display: none;
}

.page-about .about-era-card {
  overflow: hidden;
}

.page-about .about-era-card > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
  padding: 13px 15px;
  min-height: 56px;
  transition: background 0.22s var(--ease);
}

.page-about .about-era-card > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-era-card > summary:hover {
  background: rgba(34, 224, 255, 0.05);
}

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

.page-about .about-era-card > summary::after {
  content: "＋";
  margin-left: auto;
  align-self: center;
  font-size: 14px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-era-card[open] > summary::after {
  content: "－";
}

.page-about .about-era-tag {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--yellow);
  padding: 2px 8px;
  border: 1px solid var(--about-yellow-line);
  background: var(--about-yellow-soft);
}

.page-about .about-era-head {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-era-body {
  border-top: 1px solid var(--steel);
  padding: 13px 15px 17px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-era-body p {
  max-width: 64ch;
  margin: 0;
}

/* ---------- 新用户入门 ---------- */
.page-about .about-start {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.page-about .about-start-figure {
  margin: 0;
}

.page-about .about-start-figure img {
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

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

.page-about .about-start-step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 15px 16px;
  border-left: 2px solid var(--steel);
  background: linear-gradient(90deg, rgba(12, 40, 68, 0.6), rgba(12, 40, 68, 0));
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .about-start-step:hover {
  border-left-color: var(--cyan);
  background: linear-gradient(90deg, rgba(34, 224, 255, 0.1), rgba(12, 40, 68, 0));
}

.page-about .about-start-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.15;
  color: var(--cyan);
}

.page-about .about-start-step h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-start-step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 合作与纠错 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .about-partner-card {
  padding: 20px 18px 22px;
}

.page-about .about-partner-card h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-partner-card p {
  max-width: 62ch;
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-partner-card-alert {
  border-left: 2px solid var(--red);
}

.page-about .about-partner-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.page-about .about-partner-actions .btn,
.page-about .about-partner-actions .btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  text-decoration: none;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  padding: 48px 0 72px;
}

.page-about .about-cta-panel {
  display: grid;
  gap: 22px;
  padding: 28px 22px 30px;
}

.page-about .about-cta-text h2 {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.4rem, 3.4vw, 2.05rem);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-cta-text p {
  max-width: 60ch;
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta-actions .btn,
.page-about .about-cta-actions .btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  text-decoration: none;
}

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

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-hero {
    padding: 40px 0 72px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-start {
    grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-cta-panel {
    grid-template-columns: minmax(0, 1.4fr) auto;
    align-items: center;
    gap: 32px;
    padding: 34px 32px 36px;
  }

  .page-about .about-cta-actions {
    justify-content: flex-end;
  }
}

@media (min-width: 900px) {
  .page-about .about-rail-inner::before {
    content: "";
    position: absolute;
    left: var(--about-rail-w);
    top: 12px;
    bottom: 56px;
    width: 1px;
    background: linear-gradient(180deg, rgba(34, 224, 255, 0.9), var(--about-line) 14%, var(--about-line) 86%, rgba(28, 62, 99, 0));
  }

  .page-about .about-node {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    padding-bottom: 0;
  }

  .page-about .about-node-aside {
    position: relative;
    display: block;
    margin-bottom: 0;
    padding: 8px 30px 0 0;
  }

  .page-about .about-node-aside::after {
    content: "";
    position: absolute;
    top: 13px;
    right: -4px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--cyan);
    box-shadow: 0 0 0 4px rgba(34, 224, 255, 0.13), 0 0 12px rgba(34, 224, 255, 0.7);
  }

  .page-about .about-aside-label {
    display: block;
    writing-mode: vertical-rl;
    margin-top: 16px;
    height: 74px;
  }

  .page-about .about-node-body {
    padding: 4px 0 78px 44px;
    min-width: 0;
  }

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

@media (min-width: 1080px) {
  .page-about .about-hero h1 {
    max-width: 12em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team-toggle::before,
  .page-about .about-team-toggle::after,
  .page-about .about-team > summary,
  .page-about .about-era-card > summary,
  .page-about .about-start-step,
  .page-about .about-crumbs a {
    transition: none;
  }
}