.page-about {
  --about-rail-w: 240px;
  --about-gap: 64px;
  font-family: var(--font-serif);
}

.page-about a {
  color: var(--sky);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--ink);
  color: var(--white);
  padding-block: 84px 64px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(115deg, rgba(30, 122, 140, .16) 0 1px, transparent 1px 46px),
    radial-gradient(120% 90% at 88% 6%, rgba(232, 163, 61, .18), transparent 58%),
    radial-gradient(90% 70% at 4% 100%, rgba(21, 156, 140, .22), transparent 62%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .crumbs {
  color: rgba(255, 255, 255, .68);
}

.page-about .about-hero .crumbs__link,
.page-about .about-hero .crumbs__item,
.page-about .about-hero .crumbs__sep {
  color: rgba(255, 255, 255, .68);
}

.page-about .about-hero .crumbs__link:hover,
.page-about .about-hero .crumbs__link:focus-visible {
  color: var(--white);
}

.page-about .about-hero__eyebrow {
  margin: 28px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--amber);
}

.page-about .about-hero__title {
  font-family: var(--font-sans);
  margin: 16px 0 0;
  max-width: 17em;
  font-size: clamp(30px, 5.2vw, 52px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(255, 255, 255, .78);
}

.page-about .about-facts {
  list-style: none;
  margin: 44px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 24px;
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, .22);
}

.page-about .fact__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--amber);
}

.page-about .fact__label {
  font-family: var(--font-sans);
  font-size: 13px;
  letter-spacing: .02em;
  color: rgba(255, 255, 255, .7);
}

/* ---------- 分屏骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
}

.page-about .about-flow {
  min-width: 0;
}

/* ---------- 时间轴 ---------- */
.page-about .about-rail {
  padding-top: 26px;
  padding-bottom: 6px;
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--slate);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 10px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .rail-node {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--slate);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  transition: color .2s linear, border-color .2s linear, background-color .2s linear;
}

.page-about .rail-node__year {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .02em;
}

.page-about .rail-node__text {
  font-family: var(--font-sans);
  font-size: 13px;
}

.page-about .rail-node:hover,
.page-about .rail-node:focus-visible {
  color: var(--sky);
  border-color: var(--sky);
}

/* ---------- 内容区块 ---------- */
.page-about .flow-block {
  padding-block: 52px;
  border-top: 1px solid var(--line);
}

.page-about .flow-block:first-child {
  border-top: 0;
  padding-top: 36px;
}

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

.page-about .block-eyebrow--light {
  color: var(--amber);
}

.page-about .block-title {
  font-family: var(--font-sans);
  margin: 0 0 14px;
  font-size: clamp(23px, 3vw, 32px);
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .block-title--light {
  color: var(--white);
}

.page-about .block-lead {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--slate);
}

.page-about .block-lead:last-child {
  margin-bottom: 0;
}

/* ---------- 发展阶段 ---------- */
.page-about .stage {
  display: grid;
  gap: 8px;
  padding: 26px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 28px);
}

.page-about .stage:first-of-type {
  border-top: 0;
  padding-top: 4px;
}

.page-about .stage__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--amber-deep);
}

.page-about .stage__title {
  font-family: var(--font-sans);
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.42;
  color: var(--ink);
}

.page-about .stage__text {
  margin: 0;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--slate);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 30px 0;
}

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

.page-about .img-frame__media {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .team-unit {
  padding: 22px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  transition: border-color .2s linear, transform .2s linear, box-shadow .2s linear;
}

.page-about .team-unit:hover,
.page-about .team-unit:focus-within {
  border-color: var(--sky);
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}

.page-about .team-unit__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--sky);
}

.page-about .team-unit__num span {
  margin-left: 3px;
  font-size: 13px;
  font-weight: 400;
  color: var(--slate);
}

.page-about .team-unit__title {
  font-family: var(--font-sans);
  margin: 10px 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .team-unit__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--slate);
}

.page-about .team-unit__bar {
  margin-top: 16px;
  height: 8px;
  border-radius: var(--r-pill);
  background: var(--mist);
  overflow: hidden;
}

.page-about .team-unit__bar > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--sky);
  transition: width .3s linear;
}

.page-about .team-unit--edit .team-unit__bar > span { width: 26%; }
.page-about .team-unit--device .team-unit__bar > span { width: 14%; }
.page-about .team-unit--support .team-unit__bar > span { width: 60%; }

/* ---------- 复核流程 ---------- */
.page-about .review-steps {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
}

.page-about .review-step {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
  transition: border-color .2s linear;
}

.page-about .review-step:hover,
.page-about .review-step:focus-within {
  border-top-color: var(--amber);
}

.page-about .review-step__no {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--slate);
  transition: color .2s linear;
}

.page-about .review-step:hover .review-step__no,
.page-about .review-step:focus-within .review-step__no {
  color: var(--amber-deep);
}

.page-about .review-step__title {
  font-family: var(--font-sans);
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .review-step__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .notice {
  margin-top: 28px;
}

.page-about .notice a {
  color: var(--sky);
  text-decoration: underline;
}

/* ---------- 服务承诺 ---------- */
.page-about .about-promise {
  position: relative;
  margin-top: var(--step);
  padding-block: 68px;
  background: var(--ink);
  color: var(--white);
  overflow: hidden;
}

.page-about .about-promise::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(70% 60% at 88% 8%, rgba(30, 122, 140, .30), transparent 62%),
    repeating-linear-gradient(168deg, rgba(255, 255, 255, .05) 0 1px, transparent 1px 40px);
}

.page-about .about-promise__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 36px;
}

.page-about .about-promise__lead {
  margin: 0 0 24px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(255, 255, 255, .78);
}

.page-about .promise-list {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .promise-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(255, 255, 255, .86);
}

.page-about .promise-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .66em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--amber);
}

.page-about .about-promise__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0;
}

.page-about .contact-mini {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .contact-mini li {
  display: grid;
  gap: 4px;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, .16);
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.62;
  color: var(--white);
  word-break: break-word;
}

.page-about .contact-mini__key {
  font-family: var(--font-sans);
  font-size: 12px;
  letter-spacing: .12em;
  color: rgba(255, 255, 255, .58);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .stage {
    grid-template-columns: 116px minmax(0, 1fr);
    gap: 24px;
    padding: 30px 0;
  }

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

  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .team-unit--support {
    grid-column: 1 / -1;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
    padding-top: 60px;
    padding-bottom: 0;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    border-left: 1px solid var(--line);
  }

  .page-about .rail-node {
    display: grid;
    gap: 2px;
    padding: 12px 0 12px 18px;
    border: 0;
    border-radius: 0;
    white-space: normal;
    position: relative;
  }

  .page-about .rail-node::before {
    content: "";
    position: absolute;
    left: -5px;
    top: 18px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--mist);
    border: 1.5px solid var(--line);
    transition: background-color .2s linear, border-color .2s linear;
  }

  .page-about .rail-node:hover::before,
  .page-about .rail-node:focus-visible::before {
    background: var(--amber);
    border-color: var(--amber);
  }

  .page-about .flow-block {
    padding-block: var(--step);
  }

  .page-about .flow-block:first-child {
    padding-top: 60px;
  }

  .page-about .flow-block--narrow {
    max-width: 660px;
    margin-left: auto;
  }

  .page-about .about-promise__inner {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    gap: 56px;
    align-items: start;
  }
}

@media (min-width: 1200px) {
  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }

  .page-about .team-unit--support {
    grid-column: 1 / -1;
  }
}

@media (max-width: 400px) {
  .page-about .about-hero {
    padding-block: 64px 48px;
  }

  .page-about .review-step {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 12px;
  }
}