.page-about {
  --about-line: rgba(0, 255, 102, 0.25);
  --about-panel: rgba(19, 38, 66, 0.72);
}

.page-about .breadcrumb {
  margin-top: var(--space-2);
}

/* ===== 品牌使命 / hero ===== */
.page-about__hero {
  position: relative;
  padding: var(--space-4) 0 var(--space-5);
  background:
    radial-gradient(circle at 88% 18%, rgba(0, 255, 102, 0.10), transparent 46%),
    linear-gradient(180deg, var(--color-deep-blue) 0%, var(--color-dark-blue) 100%);
  overflow: hidden;
}

.page-about__hero::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-green), var(--color-orange));
}

.page-about__hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  align-items: center;
}

.page-about__hero-copy {
  position: relative;
}

.page-about__eyebrow {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-14);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-gray-blue);
}

.page-about__hero-copy h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 7vw, 64px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--color-white);
}

.page-about__slogan {
  margin: var(--space-1) 0 0;
  font-family: var(--font-display);
  font-size: clamp(24px, 5vw, 48px);
  line-height: 1.1;
  color: var(--color-green);
}

.page-about__lead {
  max-width: 58ch;
  margin: var(--space-3) 0 0;
  font-family: var(--font-mono);
  font-size: var(--text-16);
  line-height: 1.75;
  color: var(--color-gray-blue);
}

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

.page-about__hero-figure {
  position: relative;
  margin: 0;
}

.page-about__hero-figure::before {
  content: "";
  position: absolute;
  inset: 12px -8px -8px 12px;
  border: 1px solid rgba(0, 255, 102, 0.35);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about__hero-img {
  position: relative;
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about__hero-figure figcaption {
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-12);
  color: var(--color-gray-blue);
}

.page-about__float-tag {
  position: absolute;
  top: 18px;
  right: 8px;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: var(--text-12);
  color: var(--color-deep-blue);
  background: var(--color-green);
  transform: rotate(1deg);
}

.page-about__float-dot {
  width: 6px;
  height: 6px;
  background: var(--color-deep-blue);
}

/* ===== 章节通用 ===== */
.page-about__section-head {
  max-width: 760px;
  margin-bottom: var(--space-4);
}

.page-about__section-head h2 {
  position: relative;
  margin: 0;
  padding-left: 16px;
  font-family: var(--font-display);
  font-size: clamp(26px, 4vw, 40px);
  line-height: 1.12;
  color: var(--color-white);
}

.page-about__section-head h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8%;
  bottom: 8%;
  width: 4px;
  background: linear-gradient(180deg, var(--color-green), var(--color-bright-blue));
}

.page-about__section-desc {
  margin: var(--space-2) 0 0;
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.7;
  color: var(--color-gray-blue);
}

.page-about__timeline,
.page-about__coverage,
.page-about__tech,
.page-about__team,
.page-about__security {
  position: relative;
  padding: var(--space-5) 0;
  overflow: hidden;
}

/* ===== 发展里程碑 ===== */
.page-about__timeline {
  background: linear-gradient(180deg, var(--color-deep-blue) 0%, #060D1F 100%);
}

.page-about__timeline .container {
  position: relative;
  z-index: 1;
}

.page-about__timeline-bgwrap {
  display: none;
}

.page-about__timeline-track {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.page-about__milestone {
  position: relative;
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: var(--space-2);
}

.page-about__milestone-index {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.page-about__milestone-index::after {
  content: "";
  position: absolute;
  left: calc(50% - 1px);
  top: 22px;
  bottom: calc(-1 * var(--space-4));
  width: 2px;
  background: linear-gradient(180deg, var(--color-green), rgba(0, 255, 102, 0.10));
}

.page-about__milestone:last-child .page-about__milestone-index::after {
  display: none;
}

.page-about__milestone-dot {
  position: relative;
  z-index: 1;
  display: block;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-green);
  box-shadow: 0 0 0 6px rgba(0, 255, 102, 0.12);
}

.page-about__milestone-version {
  display: block;
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-20);
  font-weight: 700;
  line-height: 1;
  color: var(--color-green);
}

.page-about__milestone-card {
  background: var(--color-glass);
  border-left: 2px solid var(--color-green);
  padding: var(--space-2);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about__milestone-card h3 {
  margin: 0 0 var(--space-1);
  font-family: var(--font-display);
  font-size: var(--text-20);
  line-height: 1.2;
  color: var(--color-white);
}

.page-about__milestone-card ul {
  margin: 0;
  padding-left: 18px;
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.7;
  color: var(--color-gray-blue);
}

.page-about__milestone-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: var(--space-2);
}

.page-about__milestone--current .page-about__milestone-dot {
  background: var(--color-orange);
  box-shadow: 0 0 0 6px rgba(255, 122, 0, 0.18);
}

.page-about__milestone--current .page-about__milestone-version {
  color: var(--color-orange);
}

.page-about__milestone--current .page-about__milestone-card {
  border-left-color: var(--color-orange);
}

@media (hover: hover) {
  .page-about__milestone-card {
    transition: background var(--transition-fast);
  }

  .page-about__milestone-card:hover {
    background: var(--color-glass-strong);
  }

  .page-about__milestone-card .page-about__milestone-tags {
    opacity: 0;
    transform: translateY(-4px);
    transition: opacity var(--transition-fast), transform var(--transition-fast);
  }

  .page-about__milestone-card:hover .page-about__milestone-tags {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 数据覆盖范围 ===== */
.page-about__coverage {
  background: var(--color-dark-blue);
}

.page-about__stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
}

.page-about__stat-card {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 128px;
  padding: var(--space-3);
  background: var(--color-deep-blue);
  border: 1px solid rgba(0, 255, 102, 0.16);
  overflow: hidden;
}

.page-about__stat-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-green);
}

.page-about__stat-card:nth-child(3n + 2)::before {
  background: var(--color-bright-blue);
}

.page-about__stat-card:nth-child(3n)::before {
  background: var(--color-orange);
}

.page-about__stat-num {
  font-family: var(--font-mono);
  font-size: clamp(34px, 9vw, 52px);
  font-weight: 700;
  line-height: 1;
  color: var(--color-white);
}

.page-about__stat-label {
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.6;
  color: var(--color-gray-blue);
}

.page-about__coverage-note {
  margin-top: var(--space-3);
  padding: var(--space-2) var(--space-3);
  background: var(--color-glass);
  border-left: 3px solid var(--color-orange);
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.8;
  color: var(--color-gray-blue);
}

.page-about__coverage-note p {
  margin: 0;
}

/* ===== 技术架构 ===== */
.page-about__tech {
  background:
    linear-gradient(135deg, rgba(0, 255, 102, 0.05) 0%, transparent 40%),
    linear-gradient(180deg, var(--color-deep-blue) 0%, var(--color-dark-blue) 100%);
}

.page-about__tech-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  align-items: start;
}

.page-about__tech-copy {
  display: grid;
  gap: var(--space-2);
}

.page-about__tech-layer {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: var(--space-2);
  align-items: start;
  padding: var(--space-2) var(--space-3);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(0, 255, 102, 0.14);
}

.page-about__tech-step {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--color-green);
  color: var(--color-deep-blue);
  font-family: var(--font-mono);
  font-size: var(--text-20);
  font-weight: 700;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%);
}

.page-about__tech-layer h3 {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-size: var(--text-20);
  color: var(--color-white);
}

.page-about__tech-layer p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.7;
  color: var(--color-gray-blue);
}

.page-about__tech-figure {
  margin: 0;
}

.page-about__tech-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about__tech-figure figcaption {
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-12);
  color: var(--color-gray-blue);
}

/* ===== 团队构成 ===== */
.page-about__team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
}

.page-about__team-card {
  position: relative;
  padding: var(--space-3);
  background: var(--color-glass);
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.page-about__team-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-green), transparent);
}

.page-about__team-card:nth-child(2)::after {
  background: linear-gradient(90deg, var(--color-bright-blue), transparent);
}

.page-about__team-card:nth-child(3)::after {
  background: linear-gradient(90deg, var(--color-orange), transparent);
}

.page-about__team-card:hover {
  background: var(--color-glass-strong);
  transform: translateX(4px);
}

.page-about__team-tag {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-12);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-bright-blue);
}

.page-about__team-card:nth-child(3) .page-about__team-tag {
  color: var(--color-orange);
}

.page-about__team-card h3 {
  margin: 0 0 var(--space-1);
  font-family: var(--font-display);
  font-size: var(--text-20);
  color: var(--color-white);
}

.page-about__team-card p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.7;
  color: var(--color-gray-blue);
}

.page-about__team-summary {
  margin: var(--space-3) 0 0;
  padding: var(--space-3) 0 0;
  border-top: 1px solid rgba(0, 255, 102, 0.18);
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.8;
  color: var(--color-gray-blue);
}

/* ===== 质量与安全 ===== */
.page-about__security {
  background:
    radial-gradient(circle at 12% 80%, rgba(255, 122, 0, 0.08), transparent 38%),
    var(--color-deep-blue);
}

.page-about__security-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
}

.page-about__security-item {
  padding: var(--space-3);
  background: var(--about-panel);
  border: 1px solid rgba(192, 202, 214, 0.14);
}

.page-about__security-item h3 {
  position: relative;
  margin: 0 0 var(--space-1);
  padding-left: 14px;
  font-family: var(--font-display);
  font-size: var(--text-20);
  color: var(--color-white);
}

.page-about__security-item h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8%;
  width: 3px;
  height: 84%;
  background: var(--color-orange);
}

.page-about__security-item p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-14);
  line-height: 1.7;
  color: var(--color-gray-blue);
}

.page-about__security-trust {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding: var(--space-3);
  background: linear-gradient(135deg, rgba(0, 255, 102, 0.08), rgba(255, 122, 0, 0.06));
  border: 1px solid rgba(0, 255, 102, 0.22);
}

.page-about__security-trust p {
  flex: 1 1 100%;
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--text-20);
  line-height: 1.4;
  color: var(--color-white);
}

/* ===== 延伸路径 ===== */
.page-about__related {
  padding: var(--space-3) 0 var(--space-5);
  border-top: 1px solid rgba(0, 255, 102, 0.18);
}

.page-about__related-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1) var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-14);
}

.page-about__related-label {
  margin-right: var(--space-1);
  color: var(--color-orange);
  letter-spacing: 0.1em;
}

.page-about__related a {
  color: var(--color-gray-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.page-about__related a:hover {
  color: var(--color-green);
}

.page-about__related-sep {
  color: rgba(192, 202, 214, 0.35);
}

/* ===== 响应式 ===== */
@media (min-width: 640px) {
  .page-about__stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .page-about__hero {
    padding-top: var(--space-5);
    padding-bottom: var(--space-6);
  }

  .page-about__hero-inner {
    grid-template-columns: 6fr 5fr;
    gap: var(--space-5);
  }

  .page-about__timeline,
  .page-about__coverage,
  .page-about__tech,
  .page-about__team,
  .page-about__security {
    padding-top: var(--space-6);
    padding-bottom: var(--space-6);
  }

  .page-about__timeline-bgwrap {
    display: block;
    position: absolute;
    right: 0;
    top: 50%;
    width: 42%;
    opacity: 0.25;
    transform: translateY(-50%);
    pointer-events: none;
    z-index: 0;
  }

  .page-about__timeline-bg {
    display: block;
    width: 100%;
    max-width: 100%;
    height: auto;
  }

  .page-about__timeline-track {
    gap: var(--space-5);
  }

  .page-about__milestone {
    grid-template-columns: 180px 1fr;
    gap: var(--space-4);
  }

  .page-about__milestone-index {
    padding-right: var(--space-2);
  }

  .page-about__milestone-version {
    font-size: var(--text-40);
  }

  .page-about__milestone-card {
    padding: var(--space-3);
    clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
  }

  .page-about__stats {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-3);
  }

  .page-about__tech-layout {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-5);
  }

  .page-about__team-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about__security-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about__security-trust p {
    flex: 1 1 auto;
  }
}