.page-about {
  background: var(--gray-050);
  color: var(--ink-900);
  font-family: var(--font-sans);
}

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  letter-spacing: -0.01em;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 20px 0 6px;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 24px;
  margin-top: 18px;
}

.page-about .about-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-kicker .num {
  display: inline-block;
  padding: 2px 9px;
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--cyan-300);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.page-about .about-hero h1 {
  margin: 0;
  max-width: 16em;
  font-size: clamp(30px, 7.4vw, 46px);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: -0.025em;
  color: var(--ink-950);
}

.page-about .about-hero-lede {
  margin: 16px 0 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero-facts {
  margin-top: 22px;
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.page-about .about-fact {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 9px 14px;
  border-radius: var(--radius-pill);
  background: #fff;
  border: 1px solid var(--gray-100);
  box-shadow: var(--shadow-1);
  font-size: 13px;
  color: var(--muted);
}

.page-about .about-fact b {
  font-size: 16px;
  color: var(--ink-800);
}

.page-about .about-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--ink-950);
  box-shadow: var(--shadow-2);
}

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

.page-about .about-figure .media-caption {
  margin: 0;
  padding: 12px 18px;
  background: var(--ink-800);
  color: var(--cyan-300);
  font-size: 12.5px;
  line-height: 1.6;
}

/* ---------- 目录 + 主体 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 20px;
  padding-top: 26px;
  padding-bottom: 48px;
}

.page-about .toc {
  background: #fff;
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-lg);
  padding: 14px;
  box-shadow: var(--shadow-1);
}

.page-about .toc-title {
  margin: 0 0 10px;
  font-size: 11.5px;
  font-weight: 800;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.page-about .toc-link {
  display: inline-block;
  padding: 7px 12px;
  border-radius: var(--radius-pill);
  background: var(--gray-050);
  border: 1px solid transparent;
  color: var(--ink-800);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.page-about .toc-link:hover {
  border-color: var(--cyan-500);
}

.page-about .toc-link[aria-current] {
  background: var(--ink-800);
  border-color: var(--ink-800);
  color: var(--cyan-300);
}

.page-about .about-main {
  display: grid;
  gap: 20px;
  min-width: 0;
}

.page-about .about-panel {
  min-width: 0;
  padding: 22px 18px;
  border-radius: var(--radius-lg);
  background: #fff;
  border: 1px solid var(--gray-100);
  box-shadow: var(--shadow-1);
  scroll-margin-top: 96px;
}

.page-about .about-panel h2 {
  margin: 0;
  font-size: clamp(22px, 4.6vw, 30px);
  line-height: 1.24;
  font-weight: 800;
  letter-spacing: -0.018em;
  color: var(--ink-950);
}

.page-about .about-panel-lede {
  margin: 10px 0 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-panel--tint {
  background: linear-gradient(150deg, #ffffff 0%, var(--gray-050) 55%, rgba(32, 227, 210, 0.12) 100%);
}

/* ---------- 起点 ---------- */
.page-about .about-prose p {
  margin: 14px 0 0;
  max-width: 44em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-900);
}

.page-about .about-goal-list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-goal-list li {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--gray-050);
  border-left: 3px solid var(--cyan-500);
}

.page-about .about-goal-list strong {
  font-size: 14.5px;
  color: var(--ink-950);
}

.page-about .about-goal-list span {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 版本时间线 ---------- */
.page-about .about-milestones {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 12px;
}

.page-about .about-milestone {
  position: relative;
  padding: 16px;
  border-radius: var(--radius-md);
  background: var(--gray-050);
  border: 1px solid var(--gray-100);
  border-left: 3px solid var(--cyan-500);
}

.page-about .about-milestone-year {
  display: inline-block;
  padding: 2px 9px;
  border-radius: var(--radius-pill);
  background: var(--cyan-300);
  color: var(--ink-950);
  font-size: 14px;
}

.page-about .about-milestone h3 {
  margin: 10px 0 0;
  font-size: 16px;
  line-height: 1.42;
  font-weight: 700;
  color: var(--ink-950);
}

.page-about .about-milestone p {
  margin: 7px 0 0;
  font-size: 13.5px;
  line-height: 1.68;
  color: var(--muted);
}

.page-about .about-milestones + .about-figure,
.page-about .about-rules + .about-figure {
  margin-top: 22px;
}

/* ---------- 流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-step {
  padding: 18px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-100);
  background: linear-gradient(180deg, #ffffff 0%, var(--gray-050) 100%);
}

.page-about .about-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--ink-800);
  color: var(--cyan-300);
  font-size: 14px;
}

.page-about .about-step h3 {
  margin: 10px 0 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-950);
}

.page-about .about-step p {
  margin: 6px 0 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-rules {
  margin-top: 18px;
  display: grid;
  gap: 10px;
}

.page-about .about-rule {
  display: grid;
  gap: 4px;
  padding: 13px 15px;
  border-radius: var(--radius-sm);
  background: var(--gray-050);
  border: 1px solid var(--gray-100);
}

.page-about .about-rule b {
  font-size: 14px;
  color: var(--ink-950);
}

.page-about .about-rule span {
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-roster {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 13px;
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr) 34px;
  align-items: center;
  gap: 10px;
}

.page-about .about-role-name {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-800);
}

.page-about .about-role-bar {
  display: block;
  height: 9px;
  border-radius: var(--radius-pill);
  background: var(--gray-100);
  overflow: hidden;
}

.page-about .about-role-fill {
  display: block;
  height: 100%;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--cyan-500), var(--cyan-300));
}

.page-about .about-fill--editor {
  width: 31.6%;
}

.page-about .about-fill--engineer {
  width: 26.3%;
}

.page-about .about-fill--design {
  width: 15.8%;
}

.page-about .about-fill--support {
  width: 26.3%;
}

.page-about .about-role-num {
  text-align: right;
  font-size: 15px;
  color: var(--ink-950);
}

.page-about .about-coverage {
  margin-top: 22px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 9px;
}

.page-about .about-cov {
  padding: 16px 10px;
  border-radius: var(--radius-md);
  background: var(--ink-950);
  text-align: center;
}

.page-about .about-cov-num {
  display: block;
  font-size: 25px;
  line-height: 1.1;
  color: var(--cyan-300);
}

.page-about .about-cov span:last-child {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.5;
  color: #a4bcc7;
}

.page-about .about-scale {
  margin-top: 12px;
  display: grid;
  gap: 9px;
}

.page-about .about-scale-item {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--gray-050);
  border: 1px solid var(--gray-100);
}

.page-about .about-scale-num {
  display: block;
  font-size: 20px;
  color: var(--ink-950);
}

.page-about .about-scale-item span:last-child {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 合作（深色面板） ---------- */
.page-about .about-panel--dark {
  background: var(--ink-950);
  border-color: rgba(138, 248, 238, 0.22);
}

.page-about .about-panel--dark h2 {
  color: #ffffff;
}

.page-about .about-panel--dark .about-panel-lede {
  color: #a4bcc7;
}

.page-about .about-kicker--dark {
  color: var(--cyan-300);
}

.page-about .about-kicker--dark .num {
  background: rgba(32, 227, 210, 0.16);
  color: var(--cyan-300);
}

.page-about .about-eco {
  margin-top: 22px;
  display: grid;
  gap: 11px;
}

.page-about .about-eco-node {
  position: relative;
  padding: 20px 18px 18px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(138, 248, 238, 0.26);
}

.page-about .about-eco-node::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 0;
  width: 28px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--cyan-500);
}

.page-about .about-eco-num {
  display: block;
  font-size: 30px;
  line-height: 1;
  color: var(--cyan-300);
}

.page-about .about-eco-node p {
  margin: 9px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: #a4bcc7;
}

.page-about .about-eco-note {
  margin: 18px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: #a4bcc7;
}

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

.page-about .about-eco-note a:hover {
  color: #ffffff;
}

/* ---------- 收尾 ---------- */
.page-about .about-reasons {
  margin-top: 18px;
  display: grid;
  gap: 11px;
}

.page-about .about-reason {
  padding: 18px 16px;
  border-radius: var(--radius-md);
  background: #ffffff;
  border: 1px solid var(--gray-100);
  box-shadow: var(--shadow-1);
}

.page-about .about-reason h3 {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-950);
}

.page-about .about-reason p {
  margin: 7px 0 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-cta {
  margin-top: 22px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about [data-reveal] {
  transition: opacity 0.45s ease, transform 0.45s ease;
}

/* ---------- 中等屏 ---------- */
@media (min-width: 640px) {
  .page-about .about-goal-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-role {
    grid-template-columns: 92px minmax(0, 1fr) 40px;
  }
}

@media (min-width: 720px) {
  .page-about .about-panel {
    padding: 32px;
  }

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

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

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

/* ---------- 版本横向刻度 ---------- */
@media (min-width: 860px) {
  .page-about .about-milestones {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    padding-top: 34px;
  }

  .page-about .about-milestones::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 12px;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--cyan-500) 0%, var(--violet-500) 56%, var(--coral-500) 100%);
  }

  .page-about .about-milestone {
    border-left: 1px solid var(--gray-100);
    padding: 18px 15px;
  }

  .page-about .about-milestone::before {
    content: "";
    position: absolute;
    left: 16px;
    top: -18px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--cyan-500);
    box-shadow: 0 0 0 4px rgba(32, 227, 210, 0.18);
  }

  .page-about .about-milestone:nth-child(2)::before {
    background: var(--cyan-300);
    box-shadow: 0 0 0 4px rgba(138, 248, 238, 0.24);
  }

  .page-about .about-milestone:nth-child(3)::before {
    background: var(--violet-500);
    box-shadow: 0 0 0 4px rgba(111, 92, 255, 0.2);
  }

  .page-about .about-milestone:nth-child(4)::before {
    background: var(--coral-500);
    box-shadow: 0 0 0 4px rgba(255, 107, 74, 0.2);
  }
}

/* ---------- 桌面双栏 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 26px 0 8px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: center;
    gap: 34px;
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: 238px minmax(0, 1fr);
    gap: 32px;
    align-items: start;
    padding-top: 40px;
    padding-bottom: 64px;
  }

  .page-about .about-toc-col {
    position: sticky;
    top: 88px;
  }

  .page-about .toc {
    padding: 18px;
  }

  .page-about .toc-list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }

  .page-about .toc-link {
    display: block;
    padding: 9px 12px;
    border-radius: var(--radius-sm);
    background: transparent;
    font-size: 13.5px;
  }

  .page-about .toc-link:hover {
    background: var(--gray-050);
    border-color: transparent;
  }

  .page-about .toc-link[aria-current] {
    background: rgba(32, 227, 210, 0.14);
    border-color: transparent;
    color: var(--ink-950);
    box-shadow: inset 3px 0 0 var(--cyan-500);
  }

  .page-about .about-panel {
    padding: 36px;
  }

  .page-about .about-main {
    gap: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .toc-link,
  .page-about [data-reveal] {
    transition: none;
  }
}