.page-about {
  --ab-rail-w: 172px;
  --ab-gap: clamp(20px, 3vw, 34px);
}

.page-about [id] {
  scroll-margin-top: calc(var(--head-h) + 24px);
}

/* 首屏框景 */
.page-about .ab-hero {
  padding: clamp(18px, 3vw, 38px) 0 clamp(26px, 4vw, 52px);
}

.page-about .ab-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  align-items: start;
}

.page-about .ab-hero-main {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 3.6vw, 42px);
  border: 1px solid var(--rule);
  border-radius: var(--radius-l);
  background:
    radial-gradient(120% 90% at 6% 0%, rgba(53, 224, 208, 0.12), transparent 62%),
    radial-gradient(90% 80% at 100% 100%, rgba(255, 122, 47, 0.10), transparent 60%),
    var(--ink-panel);
}

.page-about .ab-hero-main::before {
  content: "";
  position: absolute;
  top: 14px;
  left: 0;
  right: 0;
  height: 8px;
  background-image: repeating-linear-gradient(to right, rgba(53, 224, 208, 0.75) 0 1px, transparent 1px 14px);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .ab-hero-main .kicker {
  margin-bottom: 10px;
}

.page-about .ab-hero-main h1 {
  margin: 0 0 16px;
}

.page-about .ab-lede {
  max-width: 62ch;
  color: var(--mist);
}

.page-about .ab-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* 规模数据 */
.page-about .ab-hero-facts {
  padding: 20px 20px 22px;
  border: 1px solid var(--rule);
  border-radius: var(--radius-m);
  background: var(--ink-deepest);
}

.page-about .ab-facts-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
  margin: 0;
}

.page-about .ab-fact dt {
  font-size: 13px;
  color: var(--mist);
  line-height: 1.5;
}

.page-about .ab-fact dd {
  margin: 5px 0 0;
  font-size: 15px;
  color: var(--paper);
}

.page-about .ab-fact-num {
  font-size: 24px;
  line-height: 1.1;
  color: var(--cyan);
}

/* 主栅格：左刻度 + 右叙事 */
.page-about .ab-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  padding-bottom: clamp(40px, 6vw, 84px);
}

.page-about .ab-rail {
  border-top: 1px solid var(--rule);
  padding-top: 14px;
}

.page-about .ab-rail-title {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--mist);
}

.page-about .ab-rail-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .ab-rail-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 13px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--mist);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .ab-rail-idx {
  font-size: 12px;
  color: var(--cyan);
}

.page-about .ab-rail-list a:hover,
.page-about .ab-rail-list a:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(53, 224, 208, 0.08);
}

/* 内容块 */
.page-about .ab-stream {
  min-width: 0;
}

.page-about .ab-block {
  position: relative;
  padding: clamp(22px, 3.6vw, 42px);
  border: 1px solid var(--rule);
  border-radius: var(--radius-l);
  background: var(--ink-panel);
}

.page-about .ab-block + .ab-block,
.page-about .ab-block + .ab-cta {
  margin-top: var(--ab-gap);
}

.page-about .ab-block--deep {
  background: var(--ink-deepest);
}

.page-about .ab-block--paper {
  background: var(--paper);
  border-color: rgba(36, 30, 26, 0.16);
  color: var(--paper-ink);
}

.page-about .ab-block--paper h2,
.page-about .ab-block--paper h3,
.page-about .ab-block--paper .ab-year-num {
  color: var(--paper-ink);
}

.page-about .ab-block--paper .prose,
.page-about .ab-block--paper .ab-year-label {
  color: #4E443C;
}

.page-about .ab-block--paper .ab-note {
  color: #5A5048;
  border-left-color: var(--orange);
}

.page-about .ab-block-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 18px;
}

.page-about .ab-block-head h2 {
  margin: 0;
}

.page-about .ab-block--paper .ab-index {
  color: #B4521C;
  border-color: rgba(180, 82, 28, 0.5);
}

.page-about .ab-index {
  padding: 3px 9px;
  border: 1px solid rgba(255, 122, 47, 0.55);
  border-radius: 5px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--orange);
  white-space: nowrap;
}

.page-about .ab-cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .ab-col-main {
  min-width: 0;
}

.page-about .ab-col-main .prose {
  margin: 0 0 14px;
}

.page-about .ab-note {
  padding: 4px 0 4px 14px;
  border-left: 2px solid var(--orange);
  font-size: 13px;
  line-height: 1.85;
  color: var(--mist);
}

/* 年份刻度 */
.page-about .ab-years {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 22px;
}

.page-about .ab-year {
  padding-top: 10px;
  border-top: 2px solid rgba(180, 82, 28, 0.65);
}

.page-about .ab-block:not(.ab-block--paper) .ab-year {
  border-top-color: rgba(255, 122, 47, 0.7);
}

.page-about .ab-year-num {
  display: block;
  font-size: 19px;
  color: var(--orange);
}

.page-about .ab-year-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* 图片 */
.page-about .ab-figure {
  margin: 0 0 22px;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-m);
  object-fit: cover;
}

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

/* 团队 */
.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .ab-team-card {
  padding: 18px;
  border: 1px solid var(--rule);
  border-radius: var(--radius-m);
  background: var(--ink-deepest);
}

.page-about .ab-team-card h3 {
  margin: 0 0 10px;
  color: var(--cyan);
}

.page-about .ab-team-card .prose {
  margin: 0;
  font-size: 15px;
  color: var(--mist);
}

/* 版本列表 */
.page-about .ab-versions {
  display: grid;
  gap: 12px;
  margin-top: 8px;
}

.page-about .ab-version {
  border: 1px solid var(--rule);
  border-radius: var(--radius-m);
  background: var(--ink-panel);
  overflow: hidden;
}

.page-about .ab-version[open] {
  border-color: rgba(53, 224, 208, 0.45);
}

.page-about .ab-version summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-version summary::after {
  content: "▾";
  margin-left: 4px;
  color: var(--mist);
  font-size: 12px;
  transition: transform 0.2s var(--ease);
}

.page-about .ab-version[open] summary::after {
  transform: rotate(180deg);
}

.page-about .ab-version-num {
  font-size: 19px;
  color: var(--cyan);
}

.page-about .ab-version-title {
  font-weight: 700;
  color: var(--paper);
  font-size: 16px;
}

.page-about .ab-version-tag {
  margin-left: auto;
  font-size: 12px;
  color: var(--mist);
}

.page-about .ab-version-body {
  margin: 0;
  padding: 14px 18px 18px;
  border-top: 1px dashed var(--rule);
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

/* 归档 */
.page-about .ab-arch {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 20px 0;
}

.page-about .ab-arch-card {
  padding: 14px 16px;
  border-top: 2px solid rgba(180, 82, 28, 0.65);
  border-radius: 0 0 var(--radius-s) var(--radius-s);
  background: rgba(36, 30, 26, 0.06);
}

.page-about .ab-arch-card h3 {
  margin: 0 0 8px;
  color: var(--paper-ink);
}

.page-about .ab-arch-card .prose {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: #4E443C;
}

/* 数据合作步骤 */
.page-about .ab-steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  counter-reset: abstep;
}

.page-about .ab-step {
  position: relative;
  padding: 18px 18px 18px 60px;
  border: 1px solid var(--rule);
  border-radius: var(--radius-m);
  background: var(--ink-panel);
}

.page-about .ab-step::before {
  counter-increment: abstep;
  content: counter(abstep, decimal-leading-zero);
  position: absolute;
  top: 18px;
  left: 18px;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
}

.page-about .ab-step h3 {
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .ab-step .prose {
  margin: 0;
  font-size: 15px;
  color: var(--mist);
}

/* 口碑数据 */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: 4px 0 24px;
}

.page-about .ab-stat {
  padding-left: 12px;
  border-left: 3px solid var(--orange);
}

.page-about .ab-stat b {
  display: block;
  font-size: 26px;
  line-height: 1.15;
  color: var(--paper-ink);
}

.page-about .ab-stat span {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  color: #5A5048;
}

/* 收束区 */
.page-about .ab-cta {
  margin-top: var(--ab-gap);
  padding: clamp(24px, 3.6vw, 42px);
  border: 1px solid var(--rule);
  border-radius: var(--radius-l);
  background:
    linear-gradient(135deg, rgba(53, 224, 208, 0.14), rgba(255, 122, 47, 0.12)),
    var(--ink-deepest);
}

.page-about .ab-cta h2 {
  margin: 0 0 12px;
}

.page-about .ab-cta-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-cta-list a {
  display: inline-flex;
  align-items: center;
  padding: 10px 16px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--paper);
  font-size: 15px;
  text-decoration: none;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .ab-cta-list a:hover,
.page-about .ab-cta-list a:focus-visible {
  color: var(--ink-deepest);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* 平板及桌面 */
@media (min-width: 760px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.9fr) minmax(260px, 0.85fr);
  }

  .page-about .ab-cols {
    grid-template-columns: minmax(0, 1.75fr) minmax(0, 1fr);
  }

  .page-about .ab-cols--split {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: start;
  }

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

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

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

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

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

@media (min-width: 960px) {
  .page-about .ab-shell {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--head-h) + 24px);
    border-top: 0;
    border-left: 1px solid var(--rule);
    padding: 4px 0 4px 16px;
  }

  .page-about .ab-rail-list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .ab-rail-list li + li {
    margin-top: 2px;
  }

  .page-about .ab-rail-list a {
    display: flex;
    padding: 9px 0 9px 14px;
    border: 0;
    border-radius: 0;
    background: none;
    position: relative;
  }

  .page-about .ab-rail-list a::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 8px;
    height: 1px;
    background: var(--rule);
    transition: width 0.2s var(--ease), background 0.2s var(--ease);
  }

  .page-about .ab-rail-list a:hover,
  .page-about .ab-rail-list a:focus-visible {
    background: none;
    border-color: transparent;
  }

  .page-about .ab-rail-list a:hover::before,
  .page-about .ab-rail-list a:focus-visible::before {
    width: 13px;
    background: var(--cyan);
  }
}

@media (min-width: 1200px) {
  .page-about .ab-rail {
    padding-left: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about,
  .page-about * {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}