.page-about {
  --about-cyan-rgb: 53, 224, 208;
  --about-purple-rgb: 124, 92, 191;
  --about-indigo-rgb: 49, 46, 129;
  background: var(--bg-space);
  color: var(--text-body);
}

.page-about .container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding-inline: 24px;
}

.page-about [data-reveal] {
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.page-about [data-reveal].is-visible {
  animation: about-arrive 0.6s var(--ease) both;
}

@keyframes about-arrive {
  from {
    opacity: 0;
    transform: translateY(26px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 24px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-muted);
}

.page-about .breadcrumbs a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .breadcrumbs a:hover {
  color: var(--text-body);
}

.page-about .breadcrumbs .sep {
  color: rgba(154, 166, 200, 0.5);
}

.page-about .breadcrumbs .current {
  color: var(--text-muted);
}

/* ===== 01 品牌宣言 ===== */
.page-about .brand-manifesto {
  position: relative;
  margin-top: 20px;
  padding: 32px 0 56px;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 82% 18%, rgba(124, 92, 191, 0.2) 0%, transparent 58%),
    linear-gradient(135deg, var(--bg-space) 0%, #131A38 100%);
}

.page-about .manifesto-grid {
  display: grid;
  gap: 24px;
}

.page-about .manifesto-media {
  position: relative;
  order: 2;
}

.page-about .manifesto-bg-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid rgba(124, 92, 191, 0.35);
}

.page-about .ring-emblem {
  position: absolute;
  right: 14px;
  bottom: 14px;
  width: 120px;
  height: 120px;
  opacity: 0.92;
  filter: drop-shadow(0 0 14px rgba(53, 224, 208, 0.35));
  pointer-events: none;
}

.page-about .manifesto-copy {
  position: relative;
  order: 1;
}

.page-about .manifesto-bg-num {
  position: absolute;
  top: -14px;
  right: -6px;
  font-family: var(--font-mono);
  font-size: 110px;
  line-height: 1;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.045);
  pointer-events: none;
  user-select: none;
  z-index: 0;
}

.page-about .section-index {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--accent-cyan);
  margin: 0 0 12px;
}

.page-about .brand-manifesto h1 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 5.2vw, 64px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text-body);
}

.page-about .brand-claim {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(18px, 2vw, 26px);
  line-height: 1.4;
  font-weight: 700;
  color: var(--accent-cyan);
}

.page-about .brand-text {
  margin: 0 0 22px;
  max-width: 640px;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-body);
}

.page-about .manifesto-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  padding: 6px 12px;
  border: 1px solid rgba(var(--about-cyan-rgb), 0.65);
  color: var(--accent-cyan);
  border-radius: 999px;
  background: rgba(var(--about-cyan-rgb), 0.06);
}

/* ===== 02 数据规模 ===== */
.page-about .data-archive {
  position: relative;
  padding: 56px 0 64px;
  background: var(--bg-space);
}

.page-about .section-head {
  max-width: 760px;
  margin-bottom: 32px;
}

.page-about .section-head h2 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.15;
  color: var(--text-body);
}

.page-about .section-desc {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-muted);
}

.page-about .archive-layout {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .data-panel {
  position: relative;
  padding: 24px;
  border-radius: 8px;
  border: 1px solid rgba(var(--about-purple-rgb), 0.35);
  background:
    linear-gradient(160deg, rgba(var(--about-purple-rgb), 0.14), rgba(var(--about-indigo-rgb), 0.28)),
    rgba(16, 23, 52, 0.72);
  box-shadow: 14px 14px 0 rgba(var(--about-indigo-rgb), 0.22);
}

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

.page-about .stat {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  min-height: 84px;
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.025);
  border-left: 3px solid rgba(var(--about-cyan-rgb), 0.45);
  min-width: 0;
}

.page-about .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3vw, 42px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--accent-cyan);
  white-space: nowrap;
}

.page-about .stat-label {
  font-size: 14px;
  line-height: 1.4;
  color: var(--text-muted);
}

.page-about .archive-visual {
  position: relative;
  margin: 0;
}

.page-about .archive-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid rgba(var(--about-cyan-rgb), 0.22);
}

.page-about .archive-visual figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
}

.page-about .data-footnote {
  margin: 28px 0 0;
  max-width: 820px;
  padding-top: 18px;
  border-top: 1px solid rgba(154, 166, 200, 0.18);
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-muted);
}

.page-about .data-footnote a,
.page-about .eco-support a,
.page-about .details-body a {
  color: var(--accent-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(var(--about-cyan-rgb), 0.35);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .data-footnote a:hover,
.page-about .eco-support a:hover,
.page-about .details-body a:hover {
  color: var(--text-body);
  border-color: var(--text-body);
}

/* ===== 03 发展里程碑 ===== */
.page-about .milestone-section {
  padding: 56px 0 64px;
  background: linear-gradient(180deg, var(--bg-space) 0%, #101735 50%, var(--bg-space) 100%);
}

.page-about .timeline {
  position: relative;
  padding: 8px 0 24px;
}

.page-about .timeline::before {
  content: '';
  position: absolute;
  top: 12px;
  bottom: 24px;
  left: 23px;
  width: 2px;
  z-index: 0;
  background: repeating-linear-gradient(
    to bottom,
    rgba(var(--about-cyan-rgb), 0.7) 0 6px,
    rgba(var(--about-cyan-rgb), 0.18) 6px 12px
  );
}

.page-about .milestone-item {
  position: relative;
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 0 20px;
  padding-bottom: 36px;
  z-index: 1;
}

.page-about .milestone-marker {
  grid-column: 1;
  grid-row: 1;
  justify-self: center;
  width: 14px;
  height: 14px;
  margin-top: 32px;
  border-radius: 50%;
  background: var(--bg-space);
  border: 3px solid var(--accent-cyan);
  box-shadow:
    0 0 0 4px rgba(var(--about-cyan-rgb), 0.12),
    0 0 14px rgba(var(--about-cyan-rgb), 0.55);
}

.page-about .milestone-year {
  grid-column: 2;
  grid-row: 1;
  margin-top: 24px;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent-cyan);
}

.page-about .milestone-card {
  grid-column: 2;
  grid-row: 2;
  margin-top: 8px;
}

.page-about .milestone-details {
  background: rgba(var(--about-indigo-rgb), 0.3);
  border: 1px solid rgba(var(--about-purple-rgb), 0.32);
  border-radius: var(--radius);
  transition: border-color 0.25s var(--ease), background 0.25s var(--ease);
}

.page-about .milestone-details[open] {
  border-color: var(--accent-cyan);
  background: rgba(var(--about-indigo-rgb), 0.46);
}

.page-about .milestone-details summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  user-select: none;
}

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

.page-about .milestone-details summary::after {
  content: '+';
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--accent-cyan);
  transition: transform 0.22s var(--ease);
}

.page-about .milestone-details[open] summary::after {
  transform: rotate(45deg);
}

.page-about .summary-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--text-body);
}

.page-about .summary-tag {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  border: 1px solid rgba(154, 166, 200, 0.3);
  border-radius: 999px;
  padding: 3px 10px;
  white-space: nowrap;
}

.page-about .details-body {
  padding: 0 18px 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
  border-top: 1px solid rgba(var(--about-cyan-rgb), 0.15);
  margin: 0 18px;
  padding: 14px 0 18px;
}

/* ===== 04 技术架构与安全 ===== */
.page-about .tech-architecture {
  position: relative;
  padding: 56px 0 64px;
  background:
    radial-gradient(ellipse at 12% 82%, rgba(var(--about-indigo-rgb), 0.28) 0%, transparent 52%),
    linear-gradient(180deg, var(--bg-space) 0%, #141B3E 100%);
}

.page-about .tech-layout {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .tech-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 10 / 7;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid rgba(var(--about-indigo-rgb), 0.6);
  box-shadow: 12px 12px 0 rgba(16, 23, 52, 0.3);
}

.page-about .tech-list {
  display: grid;
  gap: 16px;
}

.page-about .tech-item {
  position: relative;
  padding: 20px 20px 20px 24px;
  background: rgba(var(--about-indigo-rgb), 0.22);
  border-left: 3px solid var(--accent-cyan);
  border-radius: 4px;
}

.page-about .tech-code {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent-cyan);
}

.page-about .tech-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--text-body);
}

.page-about .tech-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-body);
}

/* ===== 05 合作与运营生态 ===== */
.page-about .ecosystem-section {
  padding: 56px 0 72px;
  background: linear-gradient(180deg, var(--bg-space) 0%, #0F1735 100%);
}

.page-about .eco-grid {
  display: grid;
  gap: 20px;
}

.page-about .eco-card {
  padding: 24px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.page-about .eco-card h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--text-body);
}

.page-about .eco-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.page-about .panel--violet {
  background: linear-gradient(135deg, rgba(var(--about-purple-rgb), 0.26), rgba(var(--about-indigo-rgb), 0.36));
  border-color: rgba(var(--about-purple-rgb), 0.4);
}

.page-about .panel--teal {
  background: linear-gradient(135deg, rgba(15, 118, 110, 0.24), rgba(11, 16, 38, 0.5));
  border-color: rgba(15, 118, 110, 0.42);
}

.page-about .panel--wine {
  background: linear-gradient(135deg, rgba(159, 18, 57, 0.28), rgba(var(--about-indigo-rgb), 0.34));
  border-color: rgba(159, 18, 57, 0.44);
}

.page-about .eco-support {
  margin-top: 32px;
  padding: 24px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.07);
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .eco-support p {
  margin: 0;
}

/* ===== 平板与桌面 ===== */
@media (min-width: 600px) {
  .page-about .data-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .eco-support {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .container {
    padding-inline: 40px;
  }

  .page-about .brand-manifesto {
    padding: 48px 0 72px;
  }

  .page-about .manifesto-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 48px;
    align-items: center;
    min-height: 520px;
  }

  .page-about .manifesto-media {
    order: 1;
  }

  .page-about .manifesto-copy {
    order: 2;
  }

  .page-about .manifesto-bg-num {
    font-size: 150px;
    top: -20px;
    right: -12px;
  }

  .page-about .ring-emblem {
    width: 150px;
    height: 150px;
  }

  .page-about .archive-layout {
    grid-template-columns: 1fr 420px;
    gap: 48px;
  }

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

  .page-about .milestone-section,
  .page-about .tech-architecture,
  .page-about .ecosystem-section {
    padding: 72px 0 80px;
  }

  .page-about .timeline::before {
    left: 50%;
    transform: translateX(-1px);
  }

  .page-about .milestone-item {
    grid-template-columns: minmax(0, 1fr) 48px minmax(0, 1fr);
    gap: 0 32px;
  }

  .page-about .milestone-marker {
    grid-column: 2;
    grid-row: 1;
    margin-top: 34px;
  }

  .page-about .milestone-year {
    grid-column: 1;
    grid-row: 1;
    text-align: right;
    margin-top: 24px;
    font-size: 26px;
  }

  .page-about .milestone-card {
    grid-column: 3;
    grid-row: 1;
    margin-top: 8px;
  }

  .page-about .milestone-item:nth-child(even) .milestone-year {
    grid-column: 3;
    text-align: left;
  }

  .page-about .milestone-item:nth-child(even) .milestone-card {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .tech-layout {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 40px;
  }

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

  .page-about .eco-support p {
    max-width: 960px;
  }
}