.page-about {
  --about-glow: radial-gradient(circle at 78% 6%, rgba(255, 107, 53, .22), rgba(255, 107, 53, 0) 62%);
  --about-grid-line: rgba(154, 174, 201, .10);
  overflow-x: clip;
}

.page-about [id] {
  scroll-margin-top: 96px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 28px 0 48px;
  isolation: isolate;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -30%;
  right: -18%;
  width: min(780px, 100vw);
  height: min(780px, 100vw);
  background: var(--about-glow);
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 22px;
  margin-top: 26px;
}

.page-about .about-hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--orange);
  margin: 0;
}

.page-about .about-hero__aside-note {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.9;
  color: var(--steel);
  letter-spacing: .04em;
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2.05rem, 7vw, 4.2rem);
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--paper);
  max-width: 16ch;
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 640px;
  font-size: 1.0625rem;
  line-height: 1.78;
  color: var(--steel);
}

.page-about .about-hero__meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
  margin-top: 30px;
  padding-top: 22px;
  border-top: 1px solid var(--rule);
}

.page-about .about-hero__meta-key {
  display: block;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--steel);
}

.page-about .about-hero__meta-val {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 1.3rem;
  color: var(--paper);
  letter-spacing: -.01em;
}

.page-about .about-hero__meta-val em {
  font-style: normal;
  color: var(--orange);
}

/* ---------- 章节节奏 ---------- */
.page-about .section {
  padding: 52px 0;
}

.page-about .section--airy {
  padding-bottom: 96px;
}

.page-about .section__lede {
  max-width: 640px;
}

/* ---------- 时间线 ---------- */
.page-about .timeline-layout {
  display: grid;
  gap: 36px;
  margin-top: 34px;
}

.page-about .timeline {
  position: relative;
  padding-left: 30px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--orange) 0%, var(--rule-strong) 26%, var(--rule) 100%);
}

.page-about .stage {
  position: relative;
  padding: 0 0 26px;
}

.page-about .stage:last-child {
  padding-bottom: 0;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-800);
  border: 2px solid var(--rule-strong);
  box-sizing: border-box;
  transition: border-color .24s var(--ease), background-color .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .stage[open]::before {
  border-color: var(--orange);
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 107, 53, .16);
}

.page-about .stage__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  padding: 2px 0;
}

.page-about .stage__head::-webkit-details-marker {
  display: none;
}

.page-about .stage__head:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 4px;
}

.page-about .stage__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--orange);
}

.page-about .stage__title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .stage__year {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--steel);
}

.page-about .stage__body {
  margin-top: 10px;
  max-width: 62ch;
}

.page-about .stage__body p {
  margin: 0;
  font-size: .9688rem;
  line-height: 1.82;
  color: var(--steel);
}

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

/* ---------- 全宽数据带 ---------- */
.page-about .data-band {
  position: relative;
  margin-top: 44px;
  padding: 30px 22px;
  background: var(--ink-900);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  overflow: hidden;
}

.page-about .data-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-line) 1px, transparent 1px);
  background-size: 44px 44px;
  -webkit-mask-image: radial-gradient(120% 110% at 18% 0%, #000, transparent 76%);
  mask-image: radial-gradient(120% 110% at 18% 0%, #000, transparent 76%);
  pointer-events: none;
}

.page-about .data-band__inner {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 18px;
}

.page-about .data-band__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.55rem, 4.2vw, 2.35rem);
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .data-band__num em {
  font-style: normal;
  font-size: .55em;
  color: var(--orange);
  margin-left: 2px;
}

.page-about .data-band__label {
  margin: 8px 0 0;
  font-size: .8125rem;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--steel);
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  display: grid;
  gap: 34px;
  margin-top: 30px;
}

.page-about .team-bars {
  display: grid;
  gap: 24px;
}

.page-about .team-bar__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .team-bar__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-bar__count {
  font-family: var(--font-mono);
  font-size: .875rem;
  color: var(--steel);
}

.page-about .team-bar__track {
  position: relative;
  height: 8px;
  margin-top: 10px;
  background: rgba(154, 174, 201, .16);
  border: 1px solid var(--rule);
}

.page-about .team-bar__fill {
  display: block;
  height: 100%;
  width: 0;
  transition: width .7s var(--ease), filter .24s var(--ease);
}

.page-about .team-bar--product .team-bar__fill {
  width: 37.5%;
  background: var(--orange);
}

.page-about .team-bar--dev .team-bar__fill {
  width: 33.3%;
  background: var(--steel);
}

.page-about .team-bar--success .team-bar__fill {
  width: 16.7%;
  background: var(--teal);
}

.page-about .team-bar__note {
  margin: 10px 0 0;
  max-width: 60ch;
  font-size: .9rem;
  line-height: 1.74;
  color: var(--steel);
}

/* ---------- 服务半径 ---------- */
.page-about .coverage {
  display: grid;
  gap: 32px;
  margin-top: 30px;
}

.page-about .coverage__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
}

.page-about .coverage__item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 11px 0;
  font-size: .9375rem;
  line-height: 1.72;
  color: var(--graphite);
  border-bottom: 1px solid rgba(34, 48, 74, .12);
}

.page-about .coverage__item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .coverage__item::before {
  content: "▸";
  flex: none;
  font-size: .8rem;
  line-height: 1.9;
  color: var(--teal-deep);
}

/* ---------- 质量与安全 ---------- */
.page-about .quality-grid {
  display: grid;
  gap: 30px;
  margin-top: 30px;
}

.page-about .quality-copy .prose p + p {
  margin-top: 14px;
}

.page-about .quality-copy .note-strip {
  margin-top: 24px;
}

.page-about .quality-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 18px;
  align-content: start;
  padding-top: 6px;
  border-top: 1px solid var(--rule);
}

.page-about .quality-figure {
  padding-top: 14px;
}

.page-about .quality-figure__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 3.4vw, 1.85rem);
  letter-spacing: -.02em;
  color: var(--orange);
}

.page-about .quality-figure__label {
  margin: 8px 0 0;
  font-size: .8125rem;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--steel);
}

/* ---------- 生态 ---------- */
.page-about .eco-foot {
  margin-top: 32px;
  padding-top: 22px;
  border-top: 1px solid var(--rule);
}

.page-about .eco-foot__text {
  margin: 0;
  max-width: 68ch;
  font-size: .9688rem;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .eco-foot__text a {
  color: var(--orange-soft);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .eco-foot__text a:hover {
  color: var(--orange);
}

/* ---------- 选择理由 ---------- */
.page-about .why-list {
  display: grid;
  gap: 0;
  margin-top: 34px;
}

.page-about .why-item {
  padding: 22px 0;
  border-top: 1px solid var(--rule);
}

.page-about .why-item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .why-item__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .why-item__title {
  margin: 10px 0 0;
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .why-item__text {
  margin: 10px 0 0;
  max-width: 58ch;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--steel);
}

.page-about .why-item__text a {
  color: var(--orange-soft);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .why-item__text a:hover {
  color: var(--orange);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 44px;
}

.page-about .about-cta__note {
  flex: 1 1 260px;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-cta__note a {
  color: var(--orange-soft);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-cta__note a:hover {
  color: var(--orange);
}

/* ---------- 进入视口 ---------- */
.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}

.page-about [data-reveal][data-visible] {
  opacity: 1;
  transform: none;
}

.page-about [data-reveal][data-visible] .team-bar__fill {
  filter: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .team-bar__fill,
  .page-about .stage::before {
    transition: none;
  }
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 40px 0 58px;
  }

  .page-about .about-hero__meta {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .data-band {
    padding: 38px 30px;
  }

  .page-about .data-band__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .why-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 40px;
  }

  .page-about .why-item:nth-child(2) {
    border-top-color: transparent;
  }

  .page-about .timeline {
    padding-left: 34px;
  }

  .page-about .stage::before {
    left: -34px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 1000px) {
  .page-about .about-hero {
    padding: 52px 0 76px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(170px, .5fr) minmax(0, 2fr);
    gap: var(--gap);
    align-items: start;
    margin-top: 34px;
  }

  .page-about .about-hero__aside {
    padding-top: 8px;
    border-left: 1px solid var(--rule);
    padding-left: 18px;
  }

  .page-about .section {
    padding: 76px 0;
  }

  .page-about .section--airy {
    padding-bottom: 120px;
  }

  .page-about .timeline-layout {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .85fr);
    gap: 56px;
    align-items: start;
    margin-top: 40px;
  }

  .page-about .timeline-figure {
    position: sticky;
    top: 104px;
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 56px;
    align-items: center;
  }

  .page-about .team-bar__note {
    opacity: .82;
    transition: opacity .24s var(--ease), color .24s var(--ease);
  }

  .page-about .team-bar:hover .team-bar__note {
    opacity: 1;
    color: var(--paper);
  }

  .page-about .team-bar:hover .team-bar__fill {
    filter: brightness(1.12);
  }

  .page-about .coverage {
    grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .quality-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: 56px;
  }

  .page-about .why-item {
    padding: 26px 0;
  }

  .page-about .about-cta {
    margin-top: 56px;
  }
}