.page-about {
  --about-rail-w: 216px;
  background: var(--ink);
  color: var(--silver);
  font-family: var(--font-body);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb-bar {
  padding-top: clamp(18px, 3vw, 28px);
}
.page-about .breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: rgba(199, 208, 217, 0.62);
}
.page-about .breadcrumb a {
  color: rgba(199, 208, 217, 0.62);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.page-about .breadcrumb a:hover {
  color: var(--signal);
  border-bottom-color: rgba(255, 107, 53, 0.5);
}
.page-about .breadcrumb span[aria-current] {
  color: var(--silver);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(24px, 4vw, 44px) 0 clamp(34px, 6vw, 68px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(90% 70% at 88% 6%, rgba(255, 107, 53, 0.15), transparent 62%),
    radial-gradient(70% 60% at 2% 96%, rgba(95, 168, 159, 0.12), transparent 60%);
  pointer-events: none;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(199, 208, 217, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(199, 208, 217, 0.055) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.92), transparent 82%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.92), transparent 82%);
  pointer-events: none;
}
.page-about .about-hero-grid {
  display: grid;
  gap: 28px;
}
.page-about h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 6.2vw, 4.1rem);
  line-height: 1.07;
  letter-spacing: -0.01em;
  color: var(--white);
  margin: 14px 0 18px;
}
.page-about .about-hero-copy .lede {
  color: rgba(199, 208, 217, 0.86);
  max-width: 44ch;
}

.page-about .about-hero-figure {
  margin: 0;
  position: relative;
  padding: 10px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(19, 42, 71, 0.92), rgba(10, 14, 20, 0.72));
}
.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 2px;
}
.page-about .about-hero-figure figcaption {
  padding: 12px 6px 4px;
  font-size: 0.8125rem;
  line-height: 1.75;
  color: rgba(199, 208, 217, 0.72);
}
.page-about .about-hero-figure figcaption .mono {
  color: var(--teal-soft);
  margin-right: 6px;
}

.page-about .about-hero-stats {
  list-style: none;
  margin: clamp(28px, 5vw, 46px) 0 0;
  padding: clamp(18px, 3vw, 26px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
}
.page-about .about-hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .stat-num {
  font-size: clamp(1.45rem, 3.6vw, 2.05rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--signal);
}
.page-about .stat-label {
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
  color: rgba(199, 208, 217, 0.66);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-shell {
  display: grid;
  gap: 0;
  padding-top: clamp(18px, 3vw, 34px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-rail {
  position: sticky;
  top: 0;
  z-index: 6;
  margin: 0 calc(var(--gutter) * -1);
  padding: 10px var(--gutter);
  background: rgba(11, 27, 51, 0.94);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.page-about .about-rail::-webkit-scrollbar {
  display: none;
}
.page-about .about-rail-title {
  display: none;
}
.page-about .about-index {
  display: flex;
  flex-wrap: nowrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
}
.page-about .about-index li {
  flex: 0 0 auto;
}
.page-about .about-index a {
  display: inline-block;
  padding: 7px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: rgba(199, 208, 217, 0.78);
  text-decoration: none;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.page-about .about-index a:hover {
  color: var(--white);
  border-color: var(--line-strong);
}
.page-about .about-index a[aria-current="true"] {
  color: #0A0E14;
  background: var(--signal);
  border-color: var(--signal);
  font-weight: 600;
}

.page-about .about-block {
  padding-block: clamp(32px, 5.5vw, 58px);
  border-top: 1px solid var(--line);
  scroll-margin-top: 84px;
}
.page-about .about-flow > .about-block:first-child {
  border-top: 0;
  padding-top: clamp(26px, 4vw, 44px);
}
.page-about h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.6vw, 2.3rem);
  line-height: 1.18;
  letter-spacing: -0.005em;
  color: var(--white);
  margin: 10px 0 16px;
}
.page-about h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.02rem, 1.9vw, 1.22rem);
  line-height: 1.32;
  color: var(--white);
  margin: 0 0 8px;
}
.page-about .about-block > .lede {
  color: rgba(199, 208, 217, 0.74);
  max-width: 52ch;
}

/* ---------- 分栏与注记 ---------- */
.page-about .about-split {
  display: grid;
  gap: 24px;
  margin-top: 22px;
}
.page-about .about-note {
  padding: 22px 22px 24px;
  border-left: 2px solid var(--signal);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.page-about .about-note p {
  margin: 8px 0 14px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(199, 208, 217, 0.86);
}
.page-about .about-inline-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 107, 53, 0.4);
  padding-bottom: 2px;
}
.page-about .about-inline-link:hover {
  border-bottom-color: var(--signal);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 28px 0 0;
  padding: 0 0 0 28px;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 16px;
  width: 1px;
  background: linear-gradient(180deg, rgba(199, 208, 217, 0.2) 0%, rgba(199, 208, 217, 0.16) 62%, var(--signal) 100%);
}
.page-about .timeline > li {
  position: relative;
  padding-bottom: 30px;
}
.page-about .timeline > li:last-child {
  padding-bottom: 0;
}
.page-about .timeline > li::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid rgba(199, 208, 217, 0.42);
}
.page-about .timeline > li:last-child::before {
  border-color: var(--signal);
  box-shadow: 0 0 0 4px rgba(255, 107, 53, 0.14);
}
.page-about .timeline .chip {
  margin-bottom: 10px;
}
.page-about .timeline p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.82;
  color: rgba(199, 208, 217, 0.8);
  max-width: 58ch;
}

/* ---------- 方法论 ---------- */
.page-about .about-method-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--night);
}
.page-about .about-method-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.page-about .about-method-band {
  margin: 28px 0 0;
  padding: 15px 18px;
  font-size: clamp(0.8rem, 1.6vw, 0.95rem);
  letter-spacing: 0.04em;
  color: var(--teal-soft);
  background: linear-gradient(90deg, rgba(95, 168, 159, 0.18), rgba(95, 168, 159, 0.02));
  border-left: 3px solid var(--teal);
  border-radius: 0 var(--radius) var(--radius) 0;
}

/* ---------- 团队 ---------- */
.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 26px;
}
.page-about .about-role {
  position: relative;
  padding: 22px 20px 24px;
  border: 1px solid var(--line);
  border-top: 2px solid rgba(199, 208, 217, 0.28);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(19, 42, 71, 0.62), rgba(11, 27, 51, 0.24));
  transition: border-color var(--speed), transform var(--speed);
}
.page-about .about-role:hover,
.page-about .about-role:focus-within {
  border-color: rgba(255, 107, 53, 0.42);
  border-top-color: var(--signal);
  transform: translateY(-3px);
}
.page-about .about-role .role-no {
  display: block;
  margin-bottom: 12px;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--signal);
}
.page-about .about-role p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: rgba(199, 208, 217, 0.82);
}
.page-about .about-team-figure {
  margin: 30px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--night);
}
.page-about .about-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}
.page-about .about-team-figure figcaption {
  padding: 13px 16px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  line-height: 1.7;
  color: rgba(199, 208, 217, 0.68);
  background: rgba(10, 14, 20, 0.5);
  border-top: 1px solid var(--line);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}
.page-about .about-eco li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .about-eco .eco-num {
  font-size: clamp(1.25rem, 3vw, 1.7rem);
  line-height: 1.1;
  color: var(--teal);
}
.page-about .about-eco p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(199, 208, 217, 0.8);
}

/* ---------- 长期服务 ---------- */
.page-about .about-promise {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 13px;
}
.page-about .about-promise li {
  position: relative;
  padding-left: 24px;
  font-size: 0.9375rem;
  line-height: 1.82;
  color: rgba(199, 208, 217, 0.86);
}
.page-about .about-promise li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.66em;
  width: 8px;
  height: 8px;
  background: var(--amber);
  transform: rotate(45deg);
}

.page-about .about-cta {
  margin-top: 30px;
  padding: clamp(22px, 4vw, 34px);
  border: 1px solid rgba(255, 107, 53, 0.34);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(255, 107, 53, 0.14), rgba(255, 107, 53, 0.02) 58%),
    rgba(19, 42, 71, 0.66);
  display: grid;
  gap: 18px;
}
.page-about .about-cta h3 {
  margin-bottom: 10px;
}
.page-about .about-cta p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(199, 208, 217, 0.84);
  max-width: 52ch;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (min-width: 720px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-eco li {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 26px;
  }
}

@media (min-width: 860px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.24fr) minmax(0, 0.76fr);
    gap: 40px;
    align-items: start;
  }
  .page-about .about-split--media {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.96fr);
  }
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.82fr);
    gap: 52px;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 64px;
    padding-top: clamp(40px, 5.5vw, 68px);
  }
  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    margin: 0;
    padding: 0;
    background: none;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    border-bottom: 0;
    overflow: visible;
  }
  .page-about .about-rail-title {
    display: block;
    margin-bottom: 14px;
    color: rgba(199, 208, 217, 0.5);
  }
  .page-about .about-index {
    flex-direction: column;
    gap: 0;
    white-space: normal;
  }
  .page-about .about-index li {
    border-top: 1px solid var(--line);
  }
  .page-about .about-index li:last-child {
    border-bottom: 1px solid var(--line);
  }
  .page-about .about-index a {
    display: block;
    padding: 14px 10px 14px 0;
    border: 0;
    border-radius: 0;
    border-left: 2px solid transparent;
    font-size: 0.84rem;
    transition: color 0.2s, border-color 0.2s;
  }
  .page-about .about-index a:hover {
    border-color: transparent;
    border-left-color: rgba(199, 208, 217, 0.3);
  }
  .page-about .about-index a[aria-current="true"] {
    background: none;
    color: var(--signal);
    border-left-color: var(--signal);
    padding-left: 12px;
  }
  .page-about .about-block {
    scroll-margin-top: 120px;
  }
  .page-about .about-flow > .about-block:first-child {
    padding-top: 0;
  }
}

@media (min-width: 1100px) {
  .page-about .about-team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}