.page-about {
  --about-mission-size: clamp(2.2rem, 4.6vw, 4rem);
  --about-timeline-line: rgba(0, 229, 255, 0.45);
  color: var(--text-main);
}

/* ========== 页面头部 ========== */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-height) + 20px);
  padding-bottom: 44px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 229, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 229, 255, 0.04) 1px, transparent 1px);
  background-size: 26px 26px;
  pointer-events: none;
}

.page-about .about-hero .container {
  position: relative;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 32px;
  align-items: end;
}

.page-about .about-hero-copy .section-index {
  margin-bottom: 14px;
}

.page-about .about-hero-copy h1 {
  font-size: clamp(2rem, 6vw, 3.8rem);
  font-weight: 900;
  font-style: italic;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
  max-width: 12em;
}

.page-about .about-hero-copy .page-sub {
  font-size: 1rem;
  color: var(--text-dim);
  line-height: 1.8;
  max-width: 34em;
  margin: 0;
}

.page-about .about-hero-side {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.page-about .about-stat {
  background: var(--bg-panel);
  border: 1px solid var(--border-dim);
  padding: 16px 10px;
  text-align: center;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.page-about .about-stat:hover {
  border-color: var(--border-blue);
  transform: translateY(-2px);
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--accent-blue);
  line-height: 1.2;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 6px;
  font-size: 0.78rem;
  color: var(--text-dim);
}

.page-about .about-hero-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-hero-index a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border: 1px solid var(--border-dim);
  color: var(--text-dim);
  background: rgba(20, 27, 45, 0.6);
  font-size: 0.78rem;
  font-family: var(--font-mono);
  text-decoration: none;
  transition: color 0.25s, border-color 0.25s, background 0.25s;
}

.page-about .about-hero-index a:hover {
  color: var(--accent-blue);
  border-color: var(--border-blue);
  background: var(--blue-glow);
}

/* ========== 品牌使命 ========== */
.page-about .about-mission {
  position: relative;
  padding: 52px 0;
  border-top: 1px solid var(--border-dim);
  border-bottom: 1px solid var(--border-dim);
  background:
    linear-gradient(rgba(0, 229, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 229, 255, 0.03) 1px, transparent 1px);
  background-size: 24px 24px;
}

.page-about .about-mission-layout {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}

.page-about .about-mission-copy h2 {
  font-size: var(--about-mission-size);
  font-style: italic;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  max-width: 9em;
}

.page-about .about-mission-copy p {
  color: var(--text-dim);
  line-height: 1.8;
  max-width: 40em;
  margin-bottom: 14px;
}

.page-about .about-mission-list {
  list-style: none;
  padding: 0;
  margin: 22px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-mission-list li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--bg-panel);
  border-left: 2px solid var(--accent-orange);
  color: var(--text-main);
  font-size: 0.88rem;
}

.page-about .about-mission-list li span {
  font-family: var(--font-mono);
  color: var(--accent-orange);
  font-size: 0.78rem;
}

.page-about .about-mission-figure {
  margin: 0;
  border: 1px solid var(--border-dim);
  background: var(--bg-panel);
  padding: 8px;
}

.page-about .about-mission-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 9 / 5;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
}

.page-about .about-mission-figure figcaption {
  padding: 10px 6px 4px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-dim);
  letter-spacing: 0.06em;
}

/* ========== 发展里程碑 ========== */
.page-about .about-milestones {
  padding: 52px 0;
  background-image:
    linear-gradient(rgba(0, 229, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 229, 255, 0.025) 1px, transparent 1px);
  background-size: 28px 28px;
}

.page-about .about-milestones h2,
.page-about .about-services h2,
.page-about .about-security h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.6rem);
  font-weight: 900;
  font-style: italic;
  letter-spacing: -0.01em;
  margin: 10px 0 8px;
}

.page-about .about-section-lead {
  color: var(--text-dim);
  max-width: 34em;
  line-height: 1.7;
  margin-bottom: 36px;
}

.page-about .about-timeline {
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 15px;
  width: 1px;
  background: linear-gradient(to bottom, var(--about-timeline-line), var(--border-blue) 60%, transparent);
  opacity: 0.65;
}

.page-about .timeline-item,
.page-about .timeline-figure {
  position: relative;
  margin-left: 36px;
}

.page-about .timeline-item {
  background: var(--bg-panel);
  border: 1px solid var(--border-dim);
  padding: 18px 20px;
  margin-bottom: 18px;
  transition: border-color 0.3s, transform 0.3s;
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 22px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-blue);
  box-shadow: 0 0 0 4px rgba(0, 229, 255, 0.12), 0 0 12px rgba(0, 229, 255, 0.5);
}

.page-about .timeline-item::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border: 1px solid var(--accent-blue);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  opacity: 0;
  transition: opacity 0.3s;
}

.page-about .timeline-item:hover {
  border-color: var(--border-blue);
  transform: translateY(-2px);
}

.page-about .timeline-item:hover::after {
  opacity: 1;
}

.page-about .timeline-code {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent-blue);
  letter-spacing: 0.12em;
  border: 1px solid var(--border-blue);
  background: var(--blue-glow);
  padding: 3px 8px;
  margin-bottom: 10px;
}

.page-about .timeline-item h3 {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.page-about .timeline-item p {
  font-size: 0.92rem;
  color: var(--text-dim);
  line-height: 1.75;
  margin: 0;
}

.page-about .timeline-figure {
  max-width: 300px;
  margin-top: 6px;
  margin-bottom: 24px;
  border: 1px solid var(--border-dim);
  background: var(--bg-panel);
  padding: 8px;
}

.page-about .timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
}

.page-about .timeline-figure figcaption {
  padding: 10px 4px 4px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-dim);
}

@supports (animation-timeline: view()) {
  .page-about .timeline-item {
    animation: about-item-reveal linear both;
    animation-timeline: view();
    animation-range: entry 25% entry 70%;
  }

  @keyframes about-item-reveal {
    from {
      opacity: 0;
      transform: translateY(18px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
}

/* ========== 服务体系 ========== */
.page-about .about-services {
  padding: 52px 0;
  background: var(--bg-panel-soft);
  border-top: 1px solid var(--border-dim);
  border-bottom: 1px solid var(--border-dim);
}

.page-about .about-service-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

.page-about .service-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  justify-content: flex-start;
  position: relative;
  background: var(--bg-panel);
  border: 1px solid var(--border-dim);
  padding: 24px 20px;
}

.page-about .service-icon {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-blue);
  border: 1px solid var(--border-blue);
  background: var(--blue-glow);
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
  margin-bottom: 2px;
}

.page-about .service-card h3 {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .service-card p {
  font-size: 0.92rem;
  color: var(--text-dim);
  line-height: 1.75;
  margin: 0;
  flex-grow: 1;
}

.page-about .service-card .btn {
  align-self: flex-start;
  margin-top: 8px;
}

/* ========== 安全与合规 ========== */
.page-about .about-security {
  padding: 52px 0;
  background:
    radial-gradient(circle at 90% 20%, rgba(255, 106, 0, 0.08), transparent 38%),
    linear-gradient(135deg, transparent 70%, rgba(0, 229, 255, 0.03) 100%);
}

.page-about .about-security-grid {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}

.page-about .about-security-copy h3 {
  display: inline-block;
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--accent-blue);
  border: 1px solid var(--border-blue);
  background: var(--blue-glow);
  padding: 5px 10px;
  margin: 18px 0 10px;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 0 100%);
}

.page-about .about-security-copy h3:first-child {
  margin-top: 0;
}

.page-about .about-security-copy p {
  color: var(--text-dim);
  line-height: 1.8;
  margin-bottom: 16px;
}

.page-about .about-security-copy .alert {
  margin-top: 4px;
  margin-bottom: 18px;
}

.page-about .about-security-figure {
  margin: 0;
  max-width: 360px;
  border: 1px solid var(--border-dim);
  background: var(--bg-panel);
  padding: 12px;
  clip-path: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
}

.page-about .about-security-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}

.page-about .about-security-figure figcaption {
  padding: 10px 4px 4px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-dim);
}

/* ========== 响应式 ========== */
@media (min-width: 768px) {
  .page-about .about-hero-grid {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: end;
  }

  .page-about .about-hero-side {
    gap: 22px;
  }

  .page-about .about-mission-layout {
    grid-template-columns: 1fr 0.9fr;
    gap: 44px;
    align-items: center;
  }

  .page-about .about-service-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .page-about .about-security-grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 40px;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding-top: 48px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-service-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}