.page-about {
  --about-gap: clamp(22px, 4vw, 44px);
  --about-gap-lg: clamp(48px, 9vw, 108px);
  --about-rail-w: 210px;
  --about-side-w: 268px;
  --about-sticky: calc(var(--header-h) + 16px);
  background: var(--ink-900);
  color: var(--paper);
  font-family: var(--font-body);
}

.page-about h2 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.04;
  font-size: clamp(1.65rem, 5.6vw, 2.85rem);
  margin: 0;
}

.page-about h3 {
  font-family: var(--font-body);
  font-weight: 800;
  line-height: 1.35;
  font-size: clamp(1.08rem, 3.4vw, 1.42rem);
  margin: 0;
  color: var(--paper);
}

.page-about p {
  margin: 0;
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .breadcrumb {
  padding-top: clamp(16px, 4vw, 34px);
}

/* 区块标题 */
.page-about .about-head {
  display: grid;
  gap: 10px;
  max-width: 46em;
  margin-bottom: clamp(24px, 5vw, 46px);
}

.page-about .about-head__note {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(10px, 3vw, 26px) 0 var(--about-gap-lg);
}

.page-about .about-hero__grid {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-hero__plate {
  color: var(--cyan);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: .96;
  font-size: clamp(2.15rem, 8.2vw, 4.8rem);
  margin: 12px 0 18px;
  max-width: 14em;
}

.page-about .about-hero__lede {
  max-width: 34em;
  color: var(--cyan-soft);
  font-size: var(--body-size);
  line-height: 1.75;
}

.page-about .about-anchors {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: var(--about-gap) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.page-about .about-anchor__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .about-anchor__num {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.1rem, 10vw, 3.6rem);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-anchor__num--alert {
  color: var(--orange);
}

.page-about .about-anchor__num--paper {
  color: var(--paper);
}

.page-about .about-anchor__unit {
  margin-top: 4px;
  font-size: 13px;
  color: var(--muted);
}

/* 章节指示栏 */
.page-about .about-rail__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--muted);
  margin-bottom: 10px;
}

.page-about .about-rail {
  position: static;
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line-soft);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  border-radius: var(--radius);
  transition: color .32s var(--ease), background-color .32s var(--ease), border-color .32s var(--ease);
}

.page-about .about-rail a:hover {
  color: var(--paper);
  border-color: var(--line);
}

.page-about .about-rail a.is-active {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink-900);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--orange);
}

.page-about .about-rail a.is-active .about-rail__num {
  color: var(--ink-900);
}

/* 图片 */
.page-about .about-figure {
  margin: var(--about-gap-lg) 0 0;
  position: relative;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: clamp(200px, 44vw, 430px);
  object-fit: cover;
  border-radius: var(--radius);
  border-top: 2px solid var(--line);
  filter: saturate(.8) contrast(1.06) brightness(.92);
}

.page-about .about-figure--flow {
  margin-top: clamp(34px, 6vw, 64px);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
}

.page-about .about-hero__story {
  margin-top: var(--about-gap);
  max-width: 46em;
}

.page-about .about-hero__story h2 {
  margin-bottom: 16px;
}

.page-about .about-hero__story-body {
  display: grid;
  gap: 14px;
  color: var(--paper);
  line-height: 1.75;
}

.page-about .about-hero__story-body p {
  max-width: 34em;
}

/* ---------- 流程 ---------- */
.page-about .about-flow__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-step {
  border-top: 1px solid var(--line-soft);
  padding: 22px 0 26px;
}

.page-about .about-step:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-step__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

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

.page-about .about-step__meta {
  display: grid;
  gap: 8px;
  margin: 16px 0 0;
}

.page-about .about-step__meta > div {
  display: grid;
  grid-template-columns: 4.2em minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
}

.page-about .about-step__meta dt {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .about-step__meta dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
}

.page-about .about-step details {
  margin-top: 16px;
  padding-left: 14px;
  border-left: 2px solid var(--line);
}

.page-about .about-step summary {
  cursor: pointer;
  color: var(--cyan);
  font-size: 14px;
  letter-spacing: .02em;
}

.page-about .about-step details ul {
  margin: 12px 0 0;
  padding-left: 18px;
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* 流程侧栏 */
.page-about .about-flow__side {
  display: grid;
  gap: 20px;
  align-content: start;
}

.page-about .about-steps-nav {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
}

.page-about .about-steps-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-left: 3px solid var(--line);
  background: var(--wash);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: color .32s var(--ease), border-color .32s var(--ease), background-color .32s var(--ease);
}

.page-about .about-steps-nav a.is-active {
  border-left-color: var(--cyan);
  background: rgba(53, 240, 192, .14);
  color: var(--paper);
}

.page-about .about-steps-nav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--orange);
}

.page-about .about-ring {
  margin: 0;
  display: grid;
  gap: 10px;
  justify-items: start;
}

.page-about .about-ring svg {
  width: 132px;
  height: 132px;
  display: block;
}

.page-about .about-ring figcaption {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
}

/* ---------- 团队 ---------- */
.page-about .about-chips {
  margin-bottom: 22px;
}

.page-about .about-team__grid {
  display: grid;
  gap: 16px;
}

.page-about .about-team__card {
  display: grid;
  gap: 10px;
  align-content: start;
  background: var(--ink-700);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--cyan);
  padding: 22px 20px;
  border-radius: var(--radius);
}

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.4rem, 9vw, 3.4rem);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-team__num--alert {
  color: var(--orange);
}

.page-about .about-team__num--paper {
  color: var(--paper);
}

.page-about .about-team__card .card-text {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.72;
}

.page-about .about-team__card .card-meta {
  color: var(--cyan-soft);
  font-size: 13px;
  line-height: 1.65;
}

.page-about .about-numbers {
  list-style: none;
  margin: clamp(28px, 5vw, 48px) 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.page-about .about-numbers__v {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.5rem, 5vw, 2rem);
  color: var(--cyan);
}

.page-about .about-numbers__k {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 发展历程 ---------- */
.page-about .about-timeline {
  position: relative;
  isolation: isolate;
}

.page-about .about-tl__backdrop {
  position: absolute;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  opacity: .16;
}

.page-about .about-tl__backdrop img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.6) brightness(.8);
}

.page-about .about-timeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 30px;
  position: relative;
}

.page-about .about-tl__item {
  position: relative;
  padding-left: 36px;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 0;
  bottom: -30px;
  width: 1px;
  background: var(--line-soft);
}

.page-about .about-tl__item:last-child::before {
  display: none;
}

.page-about .about-tl__dot {
  position: absolute;
  left: 2px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink-600);
  border: 2px solid var(--muted);
  display: block;
  transition: background-color .32s var(--ease), border-color .32s var(--ease), box-shadow .32s var(--ease);
}

.page-about .about-tl__dot.is-active {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 6px rgba(53, 240, 192, .14);
}

.page-about .about-tl__item.is-active h3 {
  color: var(--cyan);
}

.page-about .about-tl__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--orange);
  margin-bottom: 8px;
}

.page-about .about-tl__item p:not(.about-tl__year) {
  margin-top: 10px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
  max-width: 34em;
}

/* ---------- 更正机制 ---------- */
.page-about .about-fix__grid {
  display: grid;
  gap: 16px;
}

.page-about .about-fix__item {
  border: 1px solid var(--line-soft);
  border-top: 3px solid var(--cyan);
  background: var(--wash);
  padding: 20px;
  border-radius: var(--radius);
}

.page-about .about-fix__item--alert {
  border-top-color: var(--orange);
  background: rgba(255, 90, 46, .07);
}

.page-about .about-fix__item--violet {
  border-top-color: var(--violet);
  background: var(--wash-violet);
}

.page-about .about-fix__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .about-fix__item--alert .about-fix__tag {
  color: var(--orange);
}

.page-about .about-fix__item--violet .about-fix__tag {
  color: #B7A2FF;
}

.page-about .about-fix__item p:not(.about-fix__tag) {
  color: var(--paper);
  font-size: 15px;
  line-height: 1.72;
}

.page-about .about-fix__foot {
  margin-top: clamp(24px, 4vw, 36px);
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-fix__foot a {
  color: var(--cyan);
  text-underline-offset: 4px;
}

/* ---------- 服务范围 ---------- */
.page-about .about-cover__grid {
  display: grid;
  gap: var(--about-gap);
  align-items: center;
}

.page-about .about-cover__text {
  display: grid;
  gap: 16px;
}

.page-about .about-cover__text p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.78;
  max-width: 34em;
}

.page-about .about-cover__note {
  color: var(--cyan-soft) !important;
  font-size: 14px !important;
  border-left: 3px solid var(--line);
  padding-left: 12px;
}

.page-about .about-map {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-auto-rows: minmax(62px, auto);
  gap: 8px;
}

.page-about .about-map__b {
  display: flex;
  align-items: flex-end;
  padding: 12px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  line-height: 1.3;
  color: var(--ink-900);
  background: var(--cyan);
  clip-path: polygon(0 10%, 100% 0, 100% 90%, 0 100%);
}

.page-about .about-map__b--core {
  grid-column: span 2;
  grid-row: span 2;
  font-size: 14px;
  align-items: flex-start;
  background: linear-gradient(150deg, var(--cyan) 0%, var(--cyan-soft) 100%);
}

.page-about .about-map__b--wide {
  grid-column: span 2;
  background: var(--paper);
  color: var(--ink-900);
}

.page-about .about-map__b--violet {
  grid-column: span 2;
  background: var(--wash-violet);
  border-left: 3px solid var(--violet);
  color: var(--paper);
}

.page-about .about-map__b--ink {
  background: var(--ink-600);
  color: var(--cyan-soft);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  padding-bottom: clamp(56px, 9vw, 110px);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 24px;
  border-top: 1px solid var(--line);
  padding-top: clamp(28px, 5vw, 48px);
}

.page-about .about-cta__inner h2 {
  margin: 10px 0 12px;
}

.page-about .about-cta__note {
  color: var(--muted);
  font-size: 15px;
  max-width: 32em;
}

.page-about .about-cta__btns {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 平板以上 ---------- */
@media (min-width: 760px) {
  .page-about .about-team__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
}

/* ---------- 桌面分屏 ---------- */
@media (min-width: 980px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) var(--about-rail-w);
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .about-hero__side {
    position: sticky;
    top: var(--about-sticky);
  }

  .page-about .about-rail {
    flex-direction: column;
    overflow: visible;
    gap: 6px;
  }

  .page-about .about-rail a {
    justify-content: flex-start;
    padding: 9px 12px;
  }

  .page-about .about-flow__grid {
    grid-template-columns: minmax(0, 1fr) var(--about-side-w);
    gap: clamp(30px, 5vw, 72px);
  }

  .page-about .about-flow__side {
    position: sticky;
    top: var(--about-sticky);
  }

  .page-about .about-steps-nav {
    flex-direction: column;
    overflow: visible;
    gap: 6px;
  }

  .page-about .about-steps-nav a {
    justify-content: flex-start;
    white-space: normal;
  }

  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: clamp(34px, 5vw, 72px);
  }

  /* 时间线左右交替 */
  .page-about .about-timeline__list {
    gap: 46px;
  }

  .page-about .about-timeline__list::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 6px;
    bottom: 0;
    width: 1px;
    background: var(--line-soft);
  }

  .page-about .about-tl__item {
    width: calc(50% - 40px);
    padding-left: 0;
  }

  .page-about .about-tl__item::before {
    display: none;
  }

  .page-about .about-tl__item:nth-child(odd) {
    margin-right: auto;
    text-align: right;
  }

  .page-about .about-tl__item:nth-child(odd) p:not(.about-tl__year) {
    margin-left: auto;
  }

  .page-about .about-tl__item:nth-child(even) {
    margin-left: auto;
  }

  .page-about .about-tl__item:nth-child(odd) .about-tl__dot {
    left: auto;
    right: -48px;
  }

  .page-about .about-tl__item:nth-child(even) .about-tl__dot {
    left: -48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail a,
  .page-about .about-steps-nav a,
  .page-about .about-tl__dot {
    transition: none;
  }
}