.page-about {
  --about-gap: clamp(24px, 4vw, 48px);
  position: relative;
  color: var(--text);
  padding-bottom: clamp(48px, 9vw, 110px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 6vw, 64px) 0 clamp(36px, 7vw, 84px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -40% -15% auto -25%;
  height: 90%;
  background: radial-gradient(58% 58% at 22% 34%, rgba(53, 224, 200, .16), transparent 72%);
  pointer-events: none;
}

.page-about .about-hero__title {
  position: relative;
  font-family: var(--font-narrow);
  font-weight: 250;
  font-size: clamp(34px, 8.6vw, 104px);
  line-height: 0.99;
  letter-spacing: -0.03em;
  margin: 14px 0 clamp(18px, 3vw, 28px);
  max-width: 14ch;
}

.page-about .about-hero__lede {
  position: relative;
  max-width: 56ch;
  margin: 0;
  color: var(--muted);
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.85;
}

.page-about .about-hero__cue {
  position: relative;
  margin: clamp(20px, 3vw, 32px) 0 0;
  font-size: 14px;
}

/* ---------- 章节通用 ---------- */
.page-about .section {
  padding-block: clamp(44px, 7.5vw, 100px);
}

.page-about .section--tight {
  padding-block: clamp(32px, 5vw, 64px);
}

.page-about .section-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .section-head {
  max-width: 64ch;
  margin-bottom: clamp(26px, 4.5vw, 52px);
}

/* ---------- 档案概览 ---------- */
.page-about .overview__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .overview__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .stat {
  background: var(--panel);
  padding: clamp(18px, 2.4vw, 26px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 8px;
  min-height: 104px;
}

.page-about .stat__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.2vw, 32px);
  line-height: 1.1;
  letter-spacing: .02em;
  color: var(--text);
}

.page-about .stat--wide .stat__num {
  color: var(--cyan);
}

.page-about .stat__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 媒体框 ---------- */
.page-about .about-media {
  margin: 0;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
}

.page-about .about-media figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .about-media--flow {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-media--tiers {
  margin-bottom: clamp(22px, 3.4vw, 36px);
}

.page-about .about-media--tiers img {
  height: clamp(200px, 36vw, 420px);
  object-fit: cover;
  object-position: center;
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  display: grid;
  gap: clamp(22px, 3.4vw, 36px);
}

.page-about .tl__rail {
  display: none;
}

.page-about .tl__years {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .tl__year {
  display: block;
  padding: 3px 0;
  font-family: var(--font-narrow);
  font-weight: 200;
  font-size: clamp(22px, 2.6vw, 30px);
  letter-spacing: -0.01em;
  color: var(--muted);
  text-decoration: none;
  transition: color .2s ease, transform .2s ease;
}

.page-about .tl__year:hover,
.page-about .tl__year:focus-visible {
  color: var(--cyan);
  transform: translateX(4px);
}

.page-about .tl__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(16px, 2.6vw, 26px);
}

.page-about .tl-item {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 32px);
  scroll-margin-top: 140px;
  transition: border-color .25s ease;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 26px;
  bottom: 26px;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: var(--line);
  transition: background .25s ease;
}

.page-about .tl-item:hover,
.page-about .tl-item:focus-within {
  border-color: #26365a;
}

.page-about .tl-item:hover::before,
.page-about .tl-item:focus-within::before {
  background: var(--cyan);
}

.page-about .tl-item__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.page-about .tl-item__year {
  font-family: var(--font-narrow);
  font-weight: 200;
  font-size: clamp(36px, 6.4vw, 68px);
  line-height: 0.92;
  letter-spacing: -0.03em;
  color: var(--muted);
}

.page-about .tl-item__title {
  margin: 14px 0 10px;
  font-size: clamp(18px, 2.1vw, 23px);
  font-weight: 600;
  line-height: 1.4;
  color: var(--text);
}

.page-about .tl-item__body {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 四步流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .flow__step {
  background: var(--panel);
  padding: clamp(20px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .flow__n {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .flow__title {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
}

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

/* ---------- 机型分级 ---------- */
.page-about .tiers {
  display: grid;
  gap: clamp(14px, 2.2vw, 20px);
}

.page-about .tier {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 18px;
  overflow: hidden;
  transition: transform .25s ease, border-color .25s ease;
}

.page-about .tier::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 3px;
  background: var(--line);
}

.page-about .tier--entry::after { background: var(--violet); }
.page-about .tier--main::after  { background: var(--cyan); }
.page-about .tier--flag::after  { background: var(--amber); }

.page-about .tier:hover {
  transform: translateY(-3px);
  border-color: #26365a;
}

.page-about .tier__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.page-about .tier__name {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
}

.page-about .tier__specs {
  margin: 0;
  display: grid;
  gap: 10px;
}

.page-about .tier__specs > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .tier__specs > div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .tier__specs dt {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--muted);
}

.page-about .tier__specs dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--text);
  text-align: right;
}

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

.page-about .team__count {
  margin: 0 0 12px;
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--font-narrow);
  font-weight: 200;
  font-size: clamp(52px, 9vw, 92px);
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--text);
}

.page-about .team__unit {
  font-size: clamp(16px, 2vw, 22px);
  color: var(--muted);
}

.page-about .team__note {
  margin: 0 0 16px;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .team__roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .role {
  background: var(--panel);
  padding: clamp(18px, 2.4vw, 26px);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

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

.page-about .role__name {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}

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

/* ---------- 更新节奏 ---------- */
.page-about .cadence {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .cadence__item {
  background: var(--panel);
  padding: clamp(20px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

.page-about .cadence__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta__panel {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(26px, 4.6vw, 54px);
  overflow: hidden;
  background:
    radial-gradient(120% 170% at 100% 0%, rgba(124, 92, 255, .18), transparent 62%),
    radial-gradient(90% 140% at 0% 100%, rgba(53, 224, 200, .12), transparent 68%),
    var(--panel);
}

.page-about .about-cta__title {
  margin: 0 0 14px;
  font-family: var(--font-narrow);
  font-weight: 300;
  font-size: clamp(24px, 3.6vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  max-width: 22ch;
}

.page-about .about-cta__text {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 54ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .overview__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .stat--wide {
    grid-column: span 2;
  }

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

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

@media (min-width: 900px) {
  .page-about .overview__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: stretch;
  }

  .page-about .tl {
    grid-template-columns: minmax(140px, 176px) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .tl__rail {
    display: block;
    position: sticky;
    top: 128px;
    align-self: start;
    padding-top: 4px;
  }

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

  .page-about .team {
    grid-template-columns: minmax(0, .72fr) minmax(0, 1.28fr);
    align-items: start;
  }

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

@media (min-width: 1100px) {
  .page-about .about-hero {
    padding-top: clamp(48px, 7vw, 92px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__year,
  .page-about .tl-item,
  .page-about .tier {
    transition: none;
  }

  .page-about .tl__year:hover,
  .page-about .tl__year:focus-visible {
    transform: none;
  }

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