.page-about {
  position: relative;
  background-color: var(--color-bg);
  color: var(--color-text);
  overflow-x: hidden;
}

.page-about .container {
  position: relative;
  z-index: 2;
}

/* Hero */
.page-about__hero {
  position: relative;
  padding: var(--space-5) 0 var(--space-6);
  overflow: hidden;
  background:
    radial-gradient(ellipse at 82% 28%, rgba(0, 212, 255, 0.18) 0%, transparent 52%),
    radial-gradient(circle at 18% 82%, rgba(57, 255, 20, 0.1) 0%, transparent 40%),
    var(--color-bg);
}

.page-about__hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(90deg, transparent 20%, #000 90%);
  pointer-events: none;
}

.page-about__hero::after {
  content: "YB·DATA";
  position: absolute;
  right: -0.08em;
  bottom: -0.05em;
  font-family: var(--font-mono);
  font-size: clamp(84px, 20vw, 240px);
  font-weight: 900;
  line-height: 0.8;
  color: transparent;
  -webkit-text-stroke: 1px rgba(0, 212, 255, 0.16);
  pointer-events: none;
  user-select: none;
  z-index: 0;
}

.page-about__hero-inner {
  position: relative;
  z-index: 1;
  max-width: 860px;
}

.page-about__hero-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent-green);
  margin: 0 0 var(--space-3);
}

.page-about__hero h1 {
  margin: 0 0 var(--space-3);
  font-size: clamp(38px, 7vw, 64px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.03em;
}

.page-about__hero-lead {
  margin: 0 0 var(--space-3);
  font-size: clamp(18px, 2.6vw, 28px);
  font-weight: 500;
  color: var(--color-accent-cyan);
}

.page-about__hero-desc {
  margin: 0;
  max-width: 680px;
  color: var(--color-text-dim);
  line-height: 1.8;
  font-size: 16px;
}

.page-about__hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.page-about__hero-meta span {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius);
  border: 1px solid rgba(168, 178, 209, 0.22);
  background: rgba(17, 34, 64, 0.72);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-dim);
}

.page-about__hero-meta strong {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
}

/* 通用章节标题 */
.page-about__section-head {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.page-about__section-index {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
  color: var(--color-accent-green);
  padding: 8px 10px;
  border: 1px solid rgba(57, 255, 20, 0.35);
  border-radius: 4px;
  background: rgba(57, 255, 20, 0.06);
}

.page-about__section-head h2 {
  margin: 0 0 6px;
  font-size: clamp(26px, 4vw, 42px);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.page-about__section-head p {
  margin: 0;
  color: var(--color-text-dim);
  font-size: 15px;
  line-height: 1.6;
}

/* 品牌故事 */
.page-about__story {
  padding: var(--space-6) 0;
  border-top: 1px solid rgba(0, 212, 255, 0.14);
  background:
    linear-gradient(112deg, rgba(0, 212, 255, 0.06) 0%, transparent 52%),
    var(--color-bg);
}

.page-about__story-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  align-items: start;
}

.page-about__story-copy {
  font-size: 16px;
  line-height: 1.8;
}

.page-about__story-copy p {
  margin: 0 0 var(--space-3);
}

.page-about__story-lede {
  font-size: 19px;
  font-weight: 700;
  color: var(--color-text);
  padding-left: var(--space-3);
  border-left: 3px solid var(--color-accent-orange);
}

.page-about__quote {
  margin: var(--space-4) 0 0;
  padding: var(--space-3) var(--space-4);
  border-left: 3px solid var(--color-accent-orange);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: rgba(255, 107, 53, 0.08);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
}

.page-about__story-media,
.page-about__capability-media,
.page-about__mission-figure {
  margin: 0;
}

.page-about__story-media figcaption,
.page-about__capability-media figcaption,
.page-about__mission-figure figcaption {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--color-text-dim);
  margin-top: var(--space-2);
}

/* 时间线 */
.page-about__milestones {
  padding: var(--space-6) 0;
  border-top: 1px solid rgba(57, 255, 20, 0.16);
  border-bottom: 1px solid rgba(57, 255, 20, 0.16);
  background:
    linear-gradient(180deg, rgba(57, 255, 20, 0.04), transparent 40%),
    var(--color-bg);
}

.page-about__timeline {
  margin: 0;
  padding: 0;
  list-style: none;
  position: relative;
}

.page-about__timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 7px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(to bottom, var(--color-accent-green), var(--color-accent-cyan), var(--color-accent-orange));
  opacity: 0.45;
}

.page-about__timeline-item {
  position: relative;
  padding-left: 40px;
  margin-bottom: var(--space-4);
}

.page-about__timeline-marker {
  position: absolute;
  left: 1px;
  top: 18px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent-green);
  box-shadow: 0 0 0 4px rgba(57, 255, 20, 0.16), 0 0 16px rgba(57, 255, 20, 0.7);
}

.page-about__timeline-card {
  background: var(--color-panel);
  border: 1px solid rgba(168, 178, 209, 0.14);
  border-radius: var(--radius);
  padding: var(--space-4);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.page-about__timeline-card:hover,
.page-about__timeline-card:focus-within {
  border-color: rgba(57, 255, 20, 0.35);
  box-shadow: 0 12px 36px rgba(10, 17, 40, 0.48);
}

.page-about__timeline-year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(42px, 6vw, 64px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--color-accent-green), var(--color-accent-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: var(--space-2);
}

.page-about__timeline-card h3 {
  margin: 0 0 8px;
  font-size: 20px;
  line-height: 1.3;
}

.page-about__timeline-card > p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-dim);
}

.page-about__timeline-details {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px dashed rgba(168, 178, 209, 0.22);
}

.page-about__timeline-details summary {
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent-orange);
}

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

.page-about__timeline-details summary::after {
  content: "+";
  font-size: 17px;
  font-weight: 700;
  transition: transform var(--transition);
}

.page-about__timeline-details summary:focus-visible {
  outline: 2px solid var(--color-accent-green);
  outline-offset: 4px;
  border-radius: 4px;
}

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

.page-about__timeline-details p {
  margin: var(--space-2) 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text-dim);
}

/* 数据实力 */
.page-about__capability {
  padding: var(--space-6) 0;
  background:
    linear-gradient(115deg, rgba(255, 107, 53, 0.07), transparent 46%),
    var(--color-bg);
}

.page-about__metric-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.page-about__metric-card {
  position: relative;
  padding: var(--space-4) var(--space-3);
  background: var(--color-panel);
  border: 1px solid rgba(168, 178, 209, 0.13);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about__metric-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--color-accent-cyan);
  opacity: 0.55;
}

.page-about__metric-card--primary::before {
  background: var(--color-accent-green);
  opacity: 0.9;
}

.page-about__metric-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--color-text);
  animation: page-about-pulse 3.4s ease-in-out infinite;
}

.page-about__metric-card--primary .page-about__metric-num {
  color: var(--color-accent-green);
}

.page-about__metric-label {
  display: block;
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-text-dim);
}

.page-about__metric-card p {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-dim);
}

@keyframes page-about-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.82; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about__metric-num {
    animation: none;
  }
}

.page-about__capability-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

.page-about__capability-panel h3 {
  margin: 0 0 var(--space-2);
  font-size: 20px;
}

.page-about__capability-panel ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about__capability-panel li {
  display: flex;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid rgba(168, 178, 209, 0.08);
  font-size: 15px;
  color: var(--color-text);
}

.page-about__capability-panel li:last-child {
  border-bottom: 0;
}

.page-about__capability-panel li::before {
  content: "▹";
  flex: 0 0 auto;
  color: var(--color-accent-green);
  font-size: 14px;
  line-height: 1.7;
}

.page-about__capability-media {
  grid-column: 1 / -1;
}

.page-about__capability-media img,
.page-about__mission-figure img,
.page-about__story-media img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
}

/* 团队与使命 */
.page-about__mission {
  padding: var(--space-6) 0;
  border-top: 1px solid rgba(255, 107, 53, 0.18);
  background:
    radial-gradient(ellipse at 20% 80%, rgba(57, 255, 20, 0.06), transparent 50%),
    var(--color-bg);
}

.page-about__mission-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  align-items: center;
}

.page-about__mission-copy {
  font-size: 16px;
  line-height: 1.8;
}

.page-about__mission-copy p {
  margin: 0 0 var(--space-3);
  color: var(--color-text);
}

.page-about__mission-copy .page-about__section-head {
  margin-bottom: var(--space-3);
}

.page-about__mission-copy .page-about__section-head h2 {
  margin-bottom: 0;
}

.page-about__mission-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

/* 资质认证与合作 */
.page-about__credentials {
  padding: var(--space-6) 0;
  border-top: 1px solid rgba(255, 212, 0, 0.18);
  background:
    linear-gradient(180deg, var(--color-bg), var(--color-panel-deep) 130%);
}

.page-about__credential-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
}

.page-about__credential-card {
  position: relative;
  padding: var(--space-4);
  background: rgba(17, 34, 64, 0.7);
  border: 1px solid rgba(168, 178, 209, 0.14);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform var(--transition), border-color var(--transition);
}

.page-about__credential-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 212, 255, 0.4);
}

.page-about__credential-card::after {
  content: "";
  position: absolute;
  right: -52px;
  bottom: -52px;
  width: 130px;
  height: 130px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.18), transparent 70%);
  pointer-events: none;
}

.page-about__credential-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-accent-cyan);
  border: 1px solid rgba(0, 212, 255, 0.32);
  border-radius: 999px;
  padding: 4px 12px;
  margin-bottom: var(--space-3);
}

.page-about__credential-card h3 {
  margin: 0 0 var(--space-2);
  font-size: 19px;
  line-height: 1.3;
}

.page-about__credential-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text-dim);
}

.page-about__credential-card--eco {
  border-style: dashed;
  border-color: rgba(255, 212, 0, 0.4);
}

.page-about__credential-card--eco:hover {
  border-color: rgba(255, 212, 0, 0.7);
}

/* 相关导航 */
.page-about__related {
  padding: var(--space-5) 0;
  border-top: 1px solid rgba(57, 255, 20, 0.22);
  background: var(--color-bg);
}

.page-about__related-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  align-items: flex-start;
}

.page-about__related-inner p {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
}

.page-about__related-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* 响应式 */
@media (min-width: 768px) {
  .page-about__metric-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about__credential-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about__related-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (min-width: 1024px) {
  .page-about__story-grid {
    grid-template-columns: 1.05fr 0.95fr;
  }

  .page-about__capability-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about__mission-grid {
    grid-template-columns: 0.9fr 1.1fr;
  }

  .page-about__credential-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about__timeline::before {
    left: 50%;
  }

  .page-about__timeline-item {
    width: 50%;
    padding-left: 0;
    padding-right: 56px;
    margin-left: 0;
  }

  .page-about__timeline-item:nth-child(even) {
    margin-left: 50%;
    padding-left: 56px;
    padding-right: 0;
  }

  .page-about__timeline-marker {
    left: auto;
    right: -7px;
    top: 22px;
  }

  .page-about__timeline-item:nth-child(even) .page-about__timeline-marker {
    left: -7px;
    right: auto;
  }
}