.page-about {
  --about-edge: max(clamp(16px, 3vw, 40px), calc((100% - 1280px) / 2));
  --about-node-w: clamp(252px, 76vw, 320px);
}

.page-about .about-crumb {
  padding-top: clamp(18px, 3vw, 30px);
}

/* ---------- 01 定位与三条服务线 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3vw, 34px) 0 clamp(56px, 8vw, 104px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -12% auto -12%;
  height: 660px;
  pointer-events: none;
  background:
    radial-gradient(520px 300px at 14% 22%, rgba(56, 225, 206, .10), transparent 70%),
    radial-gradient(620px 340px at 86% 4%, rgba(201, 161, 70, .14), transparent 72%);
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 4.5vw, 56px);
}

.page-about .about-hero__aside {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line-gold);
}

.page-about .about-hero__stage {
  margin: 0;
  font-size: var(--step--1);
  letter-spacing: .06em;
  color: var(--c-gold-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px 16px;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 12px;
  border-left: 2px solid var(--line-gold-strong);
}

.page-about .about-stat__num {
  font-size: clamp(1.75rem, 5.6vw, 2.5rem);
  font-weight: 800;
  font-stretch: condensed;
  letter-spacing: -.03em;
  line-height: 1;
  color: var(--c-gold);
}

.page-about .about-stat__unit {
  margin-left: 2px;
  font-size: .5em;
  color: var(--c-gold-soft);
}

.page-about .about-stat__label {
  font-size: var(--step--1);
  color: var(--c-mist);
  line-height: 1.5;
}

.page-about .about-hero__note {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .about-hero__body {
  display: flex;
  flex-direction: column;
  gap: clamp(22px, 3vw, 32px);
  min-width: 0;
}

.page-about .about-hero__title {
  margin: 0;
  font-size: clamp(2rem, 5.4vw, 3.5rem);
  font-weight: 800;
  font-stretch: condensed;
  letter-spacing: -.02em;
  line-height: 1.14;
  color: var(--c-cream);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 68ch;
  font-size: var(--step-1);
  line-height: 1.75;
  color: var(--c-mist);
}

.page-about .about-hero__figure {
  aspect-ratio: 1100 / 750;
  margin: 0;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-gold);
  background: var(--c-ink-2);
}

.page-about .about-hero__figure img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  display: block;
  border-radius: inherit;
}

.page-about .about-hero__figure .media-frame__caption {
  color: var(--c-gold-soft);
}

.page-about .about-lanes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-lane {
  position: relative;
  padding: 20px 20px 20px 44px;
  border: 1px solid var(--line-mist);
  border-radius: var(--r-md);
  background: linear-gradient(180deg, rgba(22, 48, 42, .55), rgba(14, 33, 27, .55));
  transition: border-color .3s var(--ease), transform .3s var(--ease);
}

.page-about .about-lane::before {
  content: "";
  position: absolute;
  left: 22px;
  top: 22px;
  bottom: 22px;
  width: 2px;
  border-radius: 2px;
  background: var(--c-gold);
  transition: width .3s var(--ease), background-color .3s var(--ease);
}

.page-about .about-lane:hover {
  border-color: rgba(56, 225, 206, .5);
  transform: translateY(-3px);
}

.page-about .about-lane:hover::before {
  width: 4px;
  background: var(--c-cyan);
}

.page-about .about-lane__num {
  display: block;
  margin-bottom: 6px;
  font-size: var(--step--1);
  letter-spacing: .12em;
  color: var(--c-gold-soft);
}

.page-about .about-lane__title {
  margin: 0 0 8px;
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--c-cream);
}

.page-about .about-lane__text {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.75;
  color: var(--c-mist);
}

/* ---------- 02 服务清单 ---------- */

.page-about .about-services {
  padding: clamp(56px, 8vw, 104px) 0;
  background: var(--c-ink-2);
  border-top: 1px solid var(--line-gold);
  border-bottom: 1px solid var(--line-gold);
}

.page-about .about-services__intro {
  margin: 24px 0 32px;
  max-width: 62ch;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-service-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-service__item {
  border: 1px solid var(--line-gold);
  border-radius: var(--r-md);
  background: rgba(7, 19, 15, .55);
  overflow: hidden;
  transition: border-color .3s var(--ease), background-color .3s var(--ease);
}

.page-about .about-service__item:hover {
  border-color: rgba(56, 225, 206, .45);
}

.page-about .about-service__item[open] {
  border-color: rgba(201, 161, 70, .6);
  background: rgba(22, 48, 42, .5);
}

.page-about .about-service__head {
  display: grid;
  grid-template-columns: 52px 1fr 22px;
  grid-template-areas:
    "num name chev"
    "num deliver chev";
  align-items: center;
  gap: 2px 14px;
  padding: 16px 18px 16px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-service__num {
  grid-area: num;
  align-self: stretch;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--step-0);
  font-weight: 700;
  color: var(--c-brown);
  background: var(--c-gold);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  letter-spacing: .04em;
}

.page-about .about-service__name {
  grid-area: name;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--c-cream);
  letter-spacing: -.01em;
}

.page-about .about-service__deliver {
  grid-area: deliver;
  font-size: var(--step--1);
  color: var(--c-mist);
  line-height: 1.6;
}

.page-about .about-service__chev {
  grid-area: chev;
  align-self: center;
  justify-self: center;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--c-gold-soft);
  border-bottom: 2px solid var(--c-gold-soft);
  transform: rotate(45deg);
  transition: transform .3s var(--ease), border-color .3s var(--ease);
}

.page-about .about-service__item[open] .about-service__chev {
  transform: rotate(-135deg);
  border-color: var(--c-cyan);
}

.page-about .about-service__body {
  padding: 0 22px 20px 52px;
}

.page-about .about-service__body p {
  margin: 0;
  max-width: 66ch;
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-services__foot {
  margin: 28px 0 0;
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-services__foot a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(56, 225, 206, .4);
}

.page-about .about-services__foot a:hover {
  color: var(--c-gold-soft);
  border-bottom-color: var(--c-gold-soft);
}

/* ---------- 03 发展历程 ---------- */

.page-about .about-timeline {
  position: relative;
  padding: clamp(56px, 8vw, 104px) 0 clamp(48px, 7vw, 84px);
  background-image:
    linear-gradient(rgba(143, 169, 161, .055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 169, 161, .055) 1px, transparent 1px);
  background-size: 72px 72px;
}

.page-about .about-timeline__intro {
  margin: 24px 0 0;
  max-width: 62ch;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-timeline__banner {
  margin: clamp(28px, 4vw, 44px) 0 0;
  aspect-ratio: 1400 / 560;
  border-top: 1px solid var(--line-gold);
  border-bottom: 1px solid var(--line-gold);
  background: var(--c-ink-2);
}

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

.page-about .about-timeline__track {
  margin-top: clamp(32px, 5vw, 56px);
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: rgba(201, 161, 70, .45) transparent;
  padding-bottom: 14px;
}

.page-about .about-timeline__track:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 4px;
}

.page-about .about-timeline__list {
  display: flex;
  gap: clamp(16px, 2.2vw, 26px);
  list-style: none;
  margin: 0;
  padding: 26px var(--about-edge) 8px;
}

.page-about .about-timeline__node {
  flex: 0 0 auto;
  width: var(--about-node-w);
  scroll-snap-align: start;
  position: relative;
  padding-top: 26px;
  border-top: 2px solid var(--line-gold);
}

.page-about .about-timeline__node::before {
  content: "";
  position: absolute;
  top: -9px;
  left: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-gold);
  box-shadow: 0 0 0 4px rgba(201, 161, 70, .16);
}

.page-about .about-timeline__node:last-child::before {
  background: var(--c-cyan);
  box-shadow: 0 0 0 4px rgba(56, 225, 206, .18);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 10px;
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1;
  color: var(--c-gold);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--c-cream);
}

.page-about .about-timeline__text {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-timeline__foot {
  margin: 32px 0 0;
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-timeline__foot a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(56, 225, 206, .4);
}

.page-about .about-timeline__foot a:hover {
  color: var(--c-gold-soft);
  border-bottom-color: var(--c-gold-soft);
}

/* ---------- 04 团队与协作 ---------- */

.page-about .about-team {
  padding: clamp(56px, 8vw, 104px) 0;
  background: var(--c-ink-2);
  border-bottom: 1px solid var(--line-gold);
}

.page-about .about-team__grid {
  margin-top: clamp(28px, 4vw, 44px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
  align-items: center;
}

.page-about .about-team__ring {
  display: flex;
  justify-content: center;
}

.page-about .about-ring {
  width: min(100%, 380px);
  height: auto;
}

.page-about .about-ring__track {
  fill: none;
  stroke: var(--line-gold);
  stroke-width: 2;
  stroke-dasharray: 6 10;
}

.page-about .about-ring__core {
  fill: rgba(22, 48, 42, .7);
  stroke: var(--line-gold-strong);
  stroke-width: 1;
}

.page-about .about-ring__dot {
  fill: var(--c-gold);
}

.page-about .about-ring__dot--live {
  fill: var(--c-cyan);
}

.page-about .about-ring__num {
  fill: var(--c-cream);
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 700;
}

.page-about .about-ring__sub {
  fill: var(--c-mist);
  font-family: var(--font-sans);
  font-size: 14px;
}

.page-about .about-ring__tag {
  fill: var(--c-gold-soft);
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: .04em;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-member {
  position: relative;
  padding: 18px 20px 18px 22px;
  border-left: 3px solid var(--c-gold);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: rgba(7, 19, 15, .5);
  transition: border-color .3s var(--ease), background-color .3s var(--ease);
}

.page-about .about-member:hover {
  border-left-color: var(--c-cyan);
  background: rgba(22, 48, 42, .62);
}

.page-about .about-member__num {
  display: block;
  margin-bottom: 6px;
  font-size: var(--step--1);
  letter-spacing: .12em;
  color: var(--c-gold-soft);
}

.page-about .about-member__name {
  margin: 0 0 6px;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--c-cream);
}

.page-about .about-member__text {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-team__figure {
  margin: clamp(32px, 5vw, 52px) 0 0;
  aspect-ratio: 1000 / 700;
  max-height: 420px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-gold);
  background: var(--c-ink);
  overflow: hidden;
}

.page-about .about-team__figure img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  display: block;
  border-radius: inherit;
}

.page-about .about-team__figure .media-frame__caption {
  color: var(--c-gold-soft);
}

/* ---------- 05 质量校验与归档 ---------- */

.page-about .about-quality {
  padding: clamp(56px, 8vw, 104px) 0;
}

.page-about .about-quality__panel {
  border-radius: var(--r-lg);
  padding: clamp(26px, 4vw, 52px);
}

.page-about .about-quality__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--c-brown);
}

.page-about .about-quality__num {
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--c-brown);
}

.page-about .about-quality__title {
  margin: 0;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 800;
  font-stretch: condensed;
  letter-spacing: -.02em;
  color: var(--c-brown);
}

.page-about .about-quality__lede {
  margin: 22px 0 30px;
  max-width: 64ch;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-brown);
}

.page-about .about-quality__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 44px 1fr;
  grid-template-areas:
    "num name"
    "num text";
  gap: 4px 14px;
  padding: 16px 18px;
  border: 1px solid rgba(26, 21, 18, .22);
  border-radius: var(--r-md);
  background: rgba(255, 255, 255, .32);
}

.page-about .about-step__num {
  grid-area: num;
  align-self: start;
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--c-brown);
  opacity: .5;
}

.page-about .about-step__name {
  grid-area: name;
  margin: 0;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--c-brown);
}

.page-about .about-step__text {
  grid-area: text;
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.8;
  color: rgba(26, 21, 18, .78);
}

.page-about .about-quality__metrics {
  margin-top: 30px;
  padding-top: 26px;
  border-top: 1px dashed rgba(26, 21, 18, .28);
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-metric {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-metric__num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 6vw, 3rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--c-brown);
}

.page-about .about-metric__label {
  font-size: var(--step--1);
  line-height: 1.7;
  color: rgba(26, 21, 18, .78);
}

/* ---------- 收尾入口 ---------- */

.page-about .about-next {
  padding: 0 0 clamp(56px, 8vw, 104px);
}

.page-about .about-next__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  padding: clamp(28px, 4vw, 48px);
  border: 1px solid var(--line-gold);
  border-radius: var(--r-lg);
  background:
    radial-gradient(420px 220px at 88% 10%, rgba(56, 225, 206, .10), transparent 72%),
    linear-gradient(160deg, rgba(22, 48, 42, .8), rgba(7, 19, 15, .8));
}

.page-about .about-next__title {
  margin: 0;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 800;
  font-stretch: condensed;
  letter-spacing: -.02em;
  color: var(--c-cream);
}

.page-about .about-next__text {
  margin: 0;
  max-width: 64ch;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

.page-about .about-next__actions .btn {
  text-decoration: none;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-lanes {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-quality__metrics {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }

  .page-about .about-metric {
    flex-direction: column;
    gap: 8px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(210px, 30%) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-hero__aside {
    position: sticky;
    top: 120px;
    align-self: start;
  }

  .page-about .about-stats {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-hero__body {
    gap: 28px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(260px, 34%) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-quality__steps {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 40px;
  }

  .page-about .about-next__title,
  .page-about .about-next__text {
    grid-column: 1;
  }

  .page-about .about-next__actions {
    grid-column: 2;
    grid-row: 1 / span 2;
    margin-top: 0;
    justify-content: flex-end;
  }
}

@media (min-width: 1240px) {
  .page-about .about-quality__steps {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-lane,
  .page-about .about-lane::before,
  .page-about .about-service__chev,
  .page-about .about-member {
    transition: none;
  }

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

  .page-about .about-timeline__track {
    scroll-behavior: auto;
  }
}