.page-about {
  --about-ease: var(--ease);
  position: relative;
  overflow-x: clip;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + clamp(24px, 4.5vw, 60px)) 0 clamp(36px, 5vw, 68px);
  background:
    radial-gradient(115% 88% at 90% -12%, rgba(139, 92, 255, 0.22), transparent 62%),
    radial-gradient(85% 76% at 2% 6%, rgba(51, 230, 255, 0.12), transparent 64%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(51, 230, 255, 0.07), transparent 52%),
    linear-gradient(315deg, rgba(139, 92, 255, 0.1), transparent 58%);
  clip-path: polygon(0 0, 100% 0, 100% 74%, 0 96%);
  pointer-events: none;
}

.page-about .about-hero > .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.6vw, 44px);
  margin-top: clamp(18px, 2.6vw, 30px);
}

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

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(28px, 5.2vw, 54px);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--ink);
  text-wrap: balance;
}

.page-about .about-hero__title::before {
  content: "";
  display: block;
  width: 58px;
  height: 3px;
  margin-bottom: 18px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.page-about .about-hero__text {
  margin: 20px 0 0;
  max-width: 64ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__actions {
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-hero__caption {
  display: block;
  padding: 11px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

/* 数据条 */
.page-about .about-stats {
  margin-top: clamp(28px, 4.2vw, 52px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(15px, 2.2vw, 24px);
  background: var(--bg);
  min-width: 0;
}

.page-about .about-stat__num {
  font-size: clamp(23px, 3.2vw, 34px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .about-stat:nth-child(2) .about-stat__num { color: var(--violet); }
.page-about .about-stat:nth-child(3) .about-stat__num { color: var(--orange); }
.page-about .about-stat:nth-child(4) .about-stat__num { color: var(--ok); }

.page-about .about-stat__label {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* ============ 主体骨架 ============ */
.page-about .about-body {
  padding-top: clamp(32px, 5vw, 66px);
  padding-bottom: clamp(40px, 6vw, 84px);
}

.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 26px);
}

.page-about .about-section + .about-section,
.page-about .about-body .about-next {
  margin-top: clamp(48px, 7vw, 96px);
}

/* 章节索引 */
.page-about .about-index {
  margin-bottom: clamp(24px, 3.4vw, 38px);
  padding: 12px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 2px 0 4px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  display: block;
  padding: 7px 13px;
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color 180ms var(--about-ease), border-color 180ms var(--about-ease),
    background-color 180ms var(--about-ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--ink);
  border-color: var(--cyan);
}

.page-about .about-index__link[data-current="true"] {
  color: var(--bg);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ============ 01 定位 ============ */
.page-about .about-lead {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 38px);
  margin-top: clamp(20px, 2.8vw, 32px);
}

.page-about .about-lead__text p {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: clamp(15px, 1.55vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-lead__text p:last-child {
  margin-bottom: 0;
}

.page-about .about-lead__points {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
  align-self: start;
}

.page-about .about-lead__points li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 5px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-lead__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-lead__v {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ink);
}

/* ============ 02 时间线 ============ */
.page-about .about-banner {
  margin: clamp(20px, 2.8vw, 32px) 0 clamp(26px, 3.4vw, 42px);
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 28px;
  list-style: none;
  display: grid;
  gap: clamp(22px, 3.2vw, 38px);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--violet) 62%, transparent);
}

.page-about .about-timeline__item {
  position: relative;
  min-width: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 7px;
  width: 11px;
  height: 11px;
  border: 2px solid var(--cyan);
  background: var(--bg);
  transform: rotate(45deg);
}

.page-about .about-timeline__item:nth-child(even)::before {
  border-color: var(--violet);
}

.page-about .about-timeline__year {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-timeline__title {
  margin: 0;
  font-size: clamp(17px, 1.9vw, 21px);
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .about-timeline__text {
  margin: 9px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ============ 03 内容专题 ============ */
.page-about .about-topics {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(20px, 2.8vw, 32px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-topic {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding: clamp(20px, 2.6vw, 28px);
  background: var(--bg);
  min-width: 0;
  transition: background-color 220ms var(--about-ease);
}

.page-about .about-topic:hover {
  background: var(--card);
}

.page-about .about-topic__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--violet);
}

.page-about .about-topic__title {
  margin: 0;
  font-size: 18px;
  font-weight: 800;
  color: var(--ink);
  transition: color 200ms var(--about-ease);
}

.page-about .about-topic:hover .about-topic__title {
  color: var(--cyan);
}

.page-about .about-topic__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 04 服务区域 ============ */
.page-about .about-coverage {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
  margin-top: clamp(20px, 2.8vw, 32px);
}

.page-about .about-coverage__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-coverage__figure img {
  display: block;
  width: 100%;
  aspect-ratio: 10 / 7;
  object-fit: cover;
}

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

.page-about .about-coverage__text {
  margin: 0 0 18px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-contact {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-contact__row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 12px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-contact__row dt {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-contact__row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
  overflow-wrap: anywhere;
}

.page-about .about-coverage__note {
  margin: 18px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--violet);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 05 服务能力 ============ */
.page-about .about-why {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  margin-top: clamp(20px, 2.8vw, 32px);
}

.page-about .about-why__item {
  position: relative;
  padding: clamp(20px, 2.4vw, 28px);
  background: var(--panel);
  border: 1px solid var(--line);
  overflow: hidden;
  min-width: 0;
  transition: border-color 220ms var(--about-ease), transform 220ms var(--about-ease);
}

.page-about .about-why__item::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: linear-gradient(180deg, var(--cyan), var(--violet));
}

.page-about .about-why__item:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .about-why__num {
  display: block;
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .about-why__item:nth-child(2) .about-why__num { color: var(--cyan); }
.page-about .about-why__item:nth-child(3) .about-why__num { color: var(--violet); }
.page-about .about-why__item:nth-child(4) .about-why__num { color: var(--orange); }

.page-about .about-why__label {
  display: block;
  margin-top: 9px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ============ 下一步 ============ */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line);
  background:
    linear-gradient(118deg, rgba(51, 230, 255, 0.08), transparent 46%),
    linear-gradient(300deg, rgba(139, 92, 255, 0.14), transparent 54%),
    var(--panel);
}

.page-about .about-next__title {
  margin: 10px 0 0;
  font-size: clamp(21px, 2.8vw, 30px);
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .about-next__text {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-content: start;
}

/* ============ 悬停与可达性 ============ */
.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ============ 响应式 ============ */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-lead__points li {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 14px;
    align-items: baseline;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-lead {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-next {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-next__links {
    justify-content: flex-end;
  }
}

@media (min-width: 1040px) {
  .page-about .about-topics {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-topics > .about-topic:nth-child(3n + 2) {
    margin-top: 22px;
  }

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

@media (min-width: 1080px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: 190px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 58px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 2px;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-index__link {
    padding: 9px 0 9px 15px;
    border: 0;
    border-left: 2px solid var(--line);
    white-space: normal;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-left-color: var(--cyan);
  }

  .page-about .about-index__link[data-current="true"] {
    background: transparent;
    color: var(--cyan);
    border-left-color: var(--cyan);
  }
}

@media (min-width: 1280px) {
  .page-about .about-timeline {
    padding-left: 32px;
  }

  .page-about .about-timeline__item::before {
    left: -32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-topic,
  .page-about .about-why__item,
  .page-about .about-index__link {
    transition: none;
  }

  .page-about .about-why__item:hover {
    transform: none;
  }
}