.page-about {
  min-height: 100vh;
  background: var(--c-night);
  color: var(--c-pearl);
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ===== Hero 首屏 ===== */
.page-about__hero-wrap {
  position: relative;
  overflow: hidden;
  padding: 56px 20px 48px;
  background:
    linear-gradient(135deg, rgba(255, 84, 0, 0.18) 0%, rgba(11, 16, 32, 0) 50%),
    linear-gradient(180deg, var(--c-navy) 0%, var(--c-night) 100%);
}

.page-about__hero-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(circle at center, black, transparent 72%);
  -webkit-mask-image: radial-gradient(circle at center, black, transparent 72%);
  pointer-events: none;
}

.page-about__hero-wrap::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-orange) 0%, var(--c-gold) 40%, rgba(212, 175, 55, 0) 75%);
  z-index: 2;
}

.page-about__hero-ghost {
  position: absolute;
  top: 8px;
  right: 10px;
  font-size: clamp(80px, 20vw, 240px);
  font-weight: 900;
  line-height: 1;
  color: rgba(255, 84, 0, 0.07);
  letter-spacing: -0.06em;
  pointer-events: none;
  user-select: none;
}

.page-about__hero-swoosh {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.6;
}

.page-about__crumb {
  position: relative;
  z-index: 2;
  margin-bottom: 48px;
}

.page-about__crumb a {
  color: var(--c-gold);
  text-decoration: none;
  transition: color 0.15s ease;
}

.page-about__crumb a:hover {
  color: var(--c-orange);
}

.page-about__crumb .crumb-sep {
  color: var(--c-smoke);
  margin: 0 6px;
}

.page-about__crumb .crumb-current {
  color: var(--c-pearl);
}

.page-about__hero {
  position: relative;
  z-index: 2;
  max-width: 1240px;
}

.page-about__hero-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border: 1px solid rgba(255, 84, 0, 0.4);
  background: rgba(255, 84, 0, 0.08);
  color: var(--c-pearl);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.page-about__hero-chip .signal-dot {
  width: 7px;
  height: 7px;
}

.page-about__hero h1 {
  margin: 18px 0 18px;
  max-width: 14em;
  font-size: clamp(28px, 7vw, 60px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--c-pearl);
}

.page-about__hero-lead {
  max-width: 44em;
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(245, 247, 250, 0.82);
}

.page-about__hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  max-width: 680px;
  margin: 36px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid rgba(255, 84, 0, 0.3);
}

.page-about__hero-stat {
  position: relative;
  padding: 12px 16px 12px 20px;
  background: rgba(28, 33, 48, 0.6);
  border-left: 3px solid var(--c-orange);
}

.page-about__hero-stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 84, 0, 0.6), transparent);
}

.page-about__hero-stat dt {
  font-size: 12px;
  color: var(--c-smoke);
}

.page-about__hero-stat dd {
  margin: 4px 0 0;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--c-orange);
  line-height: 1.1;
}

/* ===== 轨道导航 ===== */
.page-about__rail {
  position: relative;
  z-index: 4;
  padding: 12px 16px;
  background: rgba(11, 16, 32, 0.88);
  border-bottom: 1px solid rgba(212, 175, 55, 0.25);
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about__rail-sticky {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-about__rail-kicker {
  display: none;
}

.page-about__rail-nav {
  display: flex;
  gap: 8px;
  flex-wrap: nowrap;
}

.page-about__rail-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  white-space: nowrap;
  font-size: 13px;
  font-weight: 600;
  color: var(--c-pearl);
  text-decoration: none;
  background: rgba(255, 84, 0, 0.06);
  border: 1px solid rgba(255, 84, 0, 0.35);
  clip-path: polygon(6px 0, 100% 0, calc(100% - 6px) 100%, 0 100%);
  transition: background 0.15s ease;
}

.page-about__rail-link span {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-gold);
}

.page-about__rail-link:hover,
.page-about__rail-link:focus {
  background: rgba(255, 84, 0, 0.2);
}

.page-about__rail-cta,
.page-about__rail-note {
  display: none;
}

/* ===== 故事主体 ===== */
.page-about__story {
  width: 100%;
  max-width: 980px;
}

.page-about__chapter {
  position: relative;
  padding: 64px 20px;
}

.page-about__chapter + .page-about__chapter {
  border-top: 1px solid rgba(255, 84, 0, 0.2);
}

.page-about__chapter + .page-about__chapter::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 88px;
  height: 3px;
  background: var(--c-orange);
  transform: skewX(-18deg);
}

.page-about__chapter-head {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  margin-bottom: 36px;
}

.page-about__chapter-no {
  font-family: var(--font-mono);
  font-size: 36px;
  font-weight: 900;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px var(--c-orange);
}

.page-about__chapter-head h2 {
  margin: 0 0 6px;
  font-size: 28px;
  font-weight: 800;
  color: var(--c-pearl);
}

.page-about__chapter-unit {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-gold);
}

/* ===== 01 品牌起源 ===== */
.page-about__origin-grid {
  display: grid;
  gap: 32px;
}

.page-about__origin-copy p {
  margin: 0 0 16px;
  line-height: 1.85;
  color: rgba(245, 247, 250, 0.78);
}

.page-about__dropcap::first-letter {
  float: left;
  margin: 6px 10px 0 0;
  font-family: var(--font-mono);
  font-size: 56px;
  font-weight: 900;
  line-height: 0.86;
  color: var(--c-orange);
}

.page-about__quote-note {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-top: 24px;
  padding: 16px 18px;
  background: rgba(255, 84, 0, 0.06);
  border-left: 3px solid var(--c-orange);
}

.page-about__quote-note .signal-dot {
  margin-top: 7px;
  flex-shrink: 0;
}

.page-about__quote-note p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.85);
}

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

.page-about__origin-figure::before {
  content: "";
  position: absolute;
  top: -12px;
  left: -12px;
  width: 56%;
  height: 56%;
  border-top: 2px solid var(--c-orange);
  border-left: 2px solid var(--c-gold);
  pointer-events: none;
}

.page-about__origin-figure img {
  position: relative;
  z-index: 1;
}

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

.page-about__origin-figure figcaption,
.page-about__data-figure figcaption {
  margin-top: 10px;
  padding-left: 12px;
  border-left: 2px solid var(--c-gold);
  font-size: 13px;
  color: var(--c-smoke);
}

/* ===== 02 使命与愿景 ===== */
.page-about__chapter--mission {
  background: linear-gradient(180deg, rgba(11, 16, 32, 0.4), rgba(28, 33, 48, 0.5)), var(--c-navy);
}

.page-about__mission-figure {
  margin: 0 0 28px;
}

.page-about__mission-figure img {
  width: 100%;
  height: auto;
  box-shadow: var(--shadow-lg);
}

.page-about__mission-copy {
  max-width: 46em;
}

.page-about__mission-copy p {
  margin: 0 0 16px;
  line-height: 1.85;
  color: rgba(245, 247, 250, 0.78);
}

.page-about__mission-target {
  display: grid;
  gap: 24px;
  margin: 28px 0;
  padding: 24px 20px;
  border-top: 2px solid var(--c-orange);
  border-bottom: 1px solid rgba(212, 175, 55, 0.4);
}

.page-about__mission-target p {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.85);
}

.page-about__mission-target strong {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--c-gold);
}

.page-about__promise-list {
  display: grid;
  gap: 16px;
  margin-top: 28px;
}

.page-about__promise {
  position: relative;
  overflow: hidden;
  padding: 24px 20px;
  background: var(--c-dark);
  border-top: 3px solid var(--c-orange);
}

.page-about__promise::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, transparent 50%, rgba(255, 84, 0, 0.28) 50%);
}

.page-about__promise-index {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--c-gold);
  opacity: 0.75;
}

.page-about__promise h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  color: var(--c-pearl);
}

.page-about__promise p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.75);
}

/* ===== 03 发展里程碑 ===== */
.page-about__timeline {
  position: relative;
  margin-left: 16px;
  padding-left: 24px;
  border-left: 2px solid rgba(255, 84, 0, 0.45);
}

.page-about__tl-item {
  position: relative;
  padding: 0 0 32px 20px;
}

.page-about__tl-item::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--c-orange);
  border: 2px solid var(--c-night);
  outline: 1px solid var(--c-gold);
  transform: rotate(45deg);
}

.page-about__tl-item::after {
  content: "";
  position: absolute;
  left: -2px;
  top: 24px;
  width: 20px;
  height: 2px;
  background: var(--c-gold);
}

.page-about__tl-year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--c-orange);
}

.page-about__tl-card {
  padding: 16px 18px;
  background: rgba(28, 33, 48, 0.65);
  border: 1px solid rgba(255, 84, 0, 0.14);
  border-left: 3px solid var(--c-orange);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about__tl-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.page-about__tl-card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--c-pearl);
}

.page-about__tl-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.72);
}

/* ===== 04 数据与规模 ===== */
.page-about__metric-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about__metric {
  position: relative;
  padding: 18px 16px;
  background: var(--c-pearl);
  border-left: 4px solid var(--c-orange);
  color: var(--c-dark);
}

.page-about__metric::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 24px;
  height: 24px;
  background: linear-gradient(225deg, transparent 50%, rgba(255, 84, 0, 0.35) 50%);
}

.page-about__metric dt {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-smoke);
}

.page-about__metric dd {
  margin: 8px 0 6px;
  font-size: 28px;
  font-weight: 900;
  color: var(--c-dark);
  line-height: 1.1;
}

.page-about__metric-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-smoke);
}

.page-about__data-figure {
  margin: 32px 0;
}

.page-about__data-figure img {
  width: 100%;
  height: auto;
  box-shadow: var(--shadow-lg);
}

.page-about__data-note {
  padding: 18px 20px;
}

.page-about__data-note p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 247, 250, 0.8);
}

/* ===== 05 团队与技术 ===== */
.page-about__team-grid {
  display: grid;
  gap: 16px;
}

.page-about__team-panel {
  padding: 20px;
}

.page-about__team-num {
  margin: 16px 0 8px;
  font-family: var(--font-mono);
  font-size: 52px;
  font-weight: 900;
  color: var(--c-orange);
  line-height: 1;
}

.page-about__team-unit {
  margin-left: 4px;
  font-size: 22px;
  color: var(--c-gold);
}

.page-about__team-panel > p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 247, 250, 0.78);
}

.page-about__tech-list {
  display: grid;
  gap: 10px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.page-about__tech-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 8px;
  border-bottom: 1px dashed rgba(255, 84, 0, 0.25);
  font-size: 14px;
  color: rgba(245, 247, 250, 0.8);
}

.page-about__tech-pill {
  padding: 4px 8px;
  font-size: 12px;
  color: var(--c-gold);
  background: rgba(255, 84, 0, 0.12);
  border: 1px solid rgba(255, 84, 0, 0.3);
}

.page-about__team-note {
  margin-top: 24px;
  padding: 18px 20px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 247, 250, 0.8);
  background: rgba(212, 175, 55, 0.06);
  border: 1px solid rgba(212, 175, 55, 0.26);
}

.page-about__team-note a {
  color: var(--c-cyber);
}

/* ===== 06 认证与合作 ===== */
.page-about__cert-grid {
  display: grid;
  gap: 16px;
}

.page-about__cert {
  padding: 24px 20px;
  background: var(--c-pearl);
  border-top: 4px solid var(--c-gold);
  color: var(--c-dark);
}

.page-about__cert h3 {
  margin: 14px 0 8px;
  font-size: 18px;
}

.page-about__cert p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-smoke);
}

.page-about__partner {
  display: grid;
  gap: 20px;
  margin-top: 28px;
  padding: 24px 20px;
  background: linear-gradient(120deg, rgba(255, 84, 0, 0.12), rgba(11, 16, 32, 0));
  border: 1px solid rgba(255, 84, 0, 0.18);
}

.page-about__partner h3 {
  margin: 0 0 8px;
  color: var(--c-pearl);
}

.page-about__partner p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 247, 250, 0.75);
}

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

.page-about__cert-note {
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid rgba(212, 175, 55, 0.3);
  font-size: 13px;
  line-height: 1.8;
  color: var(--c-smoke);
}

.page-about__acc {
  margin-top: 28px;
}

.page-about__acc .acc-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 16px 18px;
  background: rgba(28, 33, 48, 0.8);
  border: 1px solid rgba(212, 175, 55, 0.4);
  color: var(--c-pearl);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}

.page-about__acc .acc-content__inner {
  padding: 16px 18px;
  background: rgba(11, 16, 32, 0.6);
  border: 1px solid rgba(255, 84, 0, 0.18);
  border-top: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 247, 250, 0.8);
}

/* ===== 底部输出 ===== */
.page-about__outro {
  padding: 56px 20px 80px;
}

.page-about__outro-card {
  position: relative;
  padding: 40px 28px;
  background: linear-gradient(135deg, var(--c-orange) 0%, var(--c-lava) 85%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  color: var(--c-night);
}

.page-about__outro-eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(11, 16, 32, 0.7);
}

.page-about__outro-card h2 {
  margin: 0 0 10px;
  font-size: 30px;
  font-weight: 900;
  color: var(--c-night);
}

.page-about__outro-card > p:not(.page-about__outro-eyebrow) {
  max-width: 40em;
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(11, 16, 32, 0.8);
}

.page-about__outro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about__btn-solid,
.page-about__btn-line {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 12px 20px;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border: 2px solid var(--c-night);
  color: var(--c-night);
  transition: transform 0.15s ease, background 0.15s ease;
}

.page-about__btn-solid {
  background: var(--c-night);
  color: var(--c-pearl);
}

.page-about__btn-solid:hover {
  background: var(--c-dark);
  transform: translateY(-2px);
}

.page-about__btn-line:hover {
  background: rgba(11, 16, 32, 0.12);
  transform: translateY(-2px);
}

/* ===== 响应式：平板 ===== */
@media (min-width: 760px) {
  .page-about__hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about__team-grid {
    grid-template-columns: 1fr 1fr;
  }

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

  .page-about__partner {
    grid-template-columns: 1.4fr 0.8fr;
    align-items: center;
  }

  .page-about__partner-tags {
    justify-content: flex-end;
  }
}

@media (min-width: 800px) {
  .page-about__origin-grid {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: start;
  }
}

/* ===== 响应式：桌面 ===== */
@media (min-width: 1024px) {
  .page-about__hero-wrap {
    padding: 72px 40px 64px;
  }

  .page-about__hero-chip {
    font-size: 14px;
  }

  .page-about__hero-lead {
    font-size: 18px;
  }

  .page-about__layout {
    display: grid;
    grid-template-columns: 256px minmax(0, 1fr);
    align-items: stretch;
    max-width: 1440px;
    margin: 0 auto;
  }

  .page-about__rail {
    position: sticky;
    top: var(--header-h);
    align-self: start;
    min-height: calc(100vh - var(--header-h));
    padding: 40px 20px;
    background: rgba(11, 16, 32, 0.95);
    border-bottom: 0;
    border-right: 1px solid rgba(255, 84, 0, 0.2);
    overflow: visible;
  }

  .page-about__rail-sticky {
    flex-direction: column;
    align-items: flex-start;
    gap: 28px;
    position: sticky;
    top: calc(var(--header-h) + 40px);
  }

  .page-about__rail-kicker {
    display: block;
    margin: 0;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.22em;
    color: var(--c-gold);
  }

  .page-about__rail-nav {
    flex-direction: column;
    gap: 10px;
    width: 100%;
  }

  .page-about__rail-link {
    width: 100%;
    justify-content: space-between;
    padding: 10px 12px;
    background: transparent;
    border: 0;
    border-left: 3px solid rgba(255, 84, 0, 0.25);
    clip-path: none;
    font-size: 14px;
    transition: border-color 0.15s ease, background 0.15s ease;
  }

  .page-about__rail-link:hover,
  .page-about__rail-link:focus {
    background: rgba(255, 84, 0, 0.1);
    border-left-color: var(--c-orange);
  }

  .page-about__rail-cta {
    display: inline-flex;
  }

  .page-about__rail-note {
    display: block;
    margin: 0;
    font-size: 12px;
    line-height: 1.8;
    color: var(--c-smoke);
  }

  .page-about__story {
    padding: 0 48px 0 32px;
  }

  .page-about__chapter {
    padding: 88px 0;
  }

  .page-about__chapter-head {
    margin-bottom: 44px;
  }

  .page-about__chapter-no {
    font-size: 42px;
  }

  .page-about__chapter-head h2 {
    font-size: 32px;
  }

  .page-about__hero h1 {
    font-size: 56px;
  }

  .page-about__outro {
    padding: 64px 0 96px;
  }

  .page-about__outro-card {
    padding: 48px 40px;
  }

  .page-about__outro-card h2 {
    font-size: 34px;
  }
}

@media (prefers-reduced-motion: no-preference) {
  @keyframes pageAboutReveal {
    from {
      opacity: 0;
      transform: translateY(14px);
    }
    to {
      opacity: 1;
      transform: none;
    }
  }

  .page-about__hero h1,
  .page-about__hero-lead,
  .page-about__hero-stats {
    animation: pageAboutReveal 0.7s ease both;
  }

  .page-about__hero-lead {
    animation-delay: 0.08s;
  }

  .page-about__hero-stats {
    animation-delay: 0.16s;
  }
}