.page-about {
  color: var(--paper);
  padding-bottom: clamp(48px, 8vw, 96px);
  overflow-x: clip;
}

.page-about .about-crumbs {
  padding-top: clamp(16px, 3vw, 28px);
}

.page-about .sec-head {
  display: grid;
  gap: 12px;
  max-width: 720px;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .sec-head--tight {
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .sec-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .sec-head__text {
  margin: 0;
  color: var(--muted);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
}

.page-about .eyebrow {
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  margin: 0;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-block: clamp(24px, 4vw, 44px) clamp(40px, 7vw, 78px);
  position: relative;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -10% -20% auto 40%;
  height: 420px;
  background: radial-gradient(closest-side, rgba(108, 62, 245, 0.28), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.4vw, 60px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-hero__title::after {
  content: "";
  display: block;
  width: clamp(64px, 14vw, 132px);
  height: 6px;
  margin-top: 18px;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
  transform: skewX(-22deg);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  color: var(--paper);
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.78;
  max-width: 46ch;
}

.page-about .about-hero__text {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.85;
  max-width: 52ch;
}

.page-about .about-figures {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 10px;
}

.page-about .about-figures__item {
  display: grid;
  gap: 4px;
  padding: 14px 14px 15px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
}

.page-about .about-figures__num {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  color: var(--paper);
  line-height: 1.1;
}

.page-about .about-figures__label {
  font-size: 12.5px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.page-about .img-frame {
  margin: 0;
  position: relative;
  overflow: hidden;
  background: var(--ink-700);
  border: 1px solid var(--line);
}

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

.page-about .img-frame__caption {
  display: block;
  padding: 10px 14px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
  background: var(--ink-800);
  border-top: 1px solid var(--line);
}

.page-about .about-hero__fig {
  border-top: 3px solid var(--cyan);
}

/* ---------- 四段路径 ---------- */

.page-about .about-path {
  border-block: 1px solid var(--line);
}

.page-about .path-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  counter-reset: path;
}

.page-about .path-card {
  position: relative;
  padding: 22px 18px 24px;
  background: linear-gradient(158deg, var(--ink-700), var(--ink-800) 68%);
  border: 1px solid var(--line);
  border-top: 2px solid var(--violet);
  transition: transform 0.28s var(--ease), border-color 0.28s var(--ease);
}

.page-about .path-card:hover {
  transform: translateY(-4px);
  border-top-color: var(--cyan);
}

.page-about .path-card__num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--violet-soft);
  margin-bottom: 12px;
}

.page-about .path-card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2vw, 19px);
  line-height: 1.4;
  color: var(--paper);
}

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

/* ---------- 团队 ---------- */

.page-about .about-crew__grid {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
}

.page-about .about-crew__fig {
  border-left: 3px solid var(--orange);
}

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

.page-about .crew__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .crew__radio {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.page-about .crew__tab {
  display: inline-flex;
  align-items: center;
  padding: 9px 14px;
  border: 1px solid var(--line);
  background: var(--ink-800);
  color: var(--muted);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

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

.page-about .crew__radio:checked + .crew__tab {
  color: var(--ink-900);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .crew__radio:focus-visible + .crew__tab {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .crew__panel {
  display: none;
  padding: 20px 18px 22px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
}

.page-about #crew-schedule:checked ~ .crew__panels #crew-panel-schedule,
.page-about #crew-review:checked ~ .crew__panels #crew-panel-review,
.page-about #crew-mobile:checked ~ .crew__panels #crew-panel-mobile,
.page-about #crew-proof:checked ~ .crew__panels #crew-panel-proof {
  display: block;
}

.page-about .crew__panel-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--paper);
}

.page-about .crew__panel-text {
  margin: 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.85;
}

.page-about .crew__panel-meta {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--violet-soft);
}

/* ---------- 变更标记 ---------- */

.page-about .about-marks__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

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

.page-about .mark-item {
  display: grid;
  gap: 8px;
  padding: 16px 16px 17px;
  background: var(--ink-800);
}

.page-about .mark-item__tag {
  justify-self: start;
}

.page-about .mark-item__text {
  margin: 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.75;
}

/* ---------- 时间轴 ---------- */

.page-about .about-track__fig {
  margin-bottom: clamp(24px, 4vw, 40px);
  border-bottom: 3px solid var(--violet);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 18px;
  position: relative;
  display: grid;
  gap: 12px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--violet) 55%, rgba(108, 62, 245, 0));
  opacity: 0.65;
}

.page-about .timeline__item {
  display: grid;
  gap: 8px;
  padding: 16px 16px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .timeline__item:hover {
  border-color: var(--line-strong);
  transform: translateX(4px);
}

.page-about .timeline__code {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.42;
  color: var(--paper);
}

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

/* ---------- 合作 ---------- */

.page-about .about-coop {
  border-block: 1px solid var(--line);
}

.page-about .about-coop__grid {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
}

.page-about .about-coop__left h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .about-coop__text {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

.page-about .cluster-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

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

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

.page-about .coop-item {
  padding: 20px 18px 22px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
}

.page-about .coop-item__title {
  margin: 0 0 9px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--paper);
}

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

/* ---------- 联系 ---------- */

.page-about .about-contact__inner {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  padding: clamp(24px, 4vw, 40px);
  background:
    linear-gradient(135deg, rgba(108, 62, 245, 0.22), rgba(45, 226, 230, 0.08) 62%, transparent),
    var(--ink-800);
  border: 1px solid var(--line-strong);
}

.page-about .about-contact__copy h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.2vw, 32px);
  line-height: 1.2;
  color: var(--paper);
}

.page-about .about-contact__text {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
  max-width: 52ch;
}

.page-about .about-contact__mail {
  margin: 0 0 16px;
  font-size: clamp(14px, 2vw, 18px);
  letter-spacing: 0.02em;
  color: var(--cyan);
  word-break: break-all;
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .path-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-contact__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
    align-items: end;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-crew__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-marks__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-coop__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    align-items: start;
  }

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

@media (min-width: 1024px) {
  .page-about .path-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .timeline {
    padding-left: 26px;
  }

  .page-about .timeline__item:nth-child(1) { margin-left: 0; }
  .page-about .timeline__item:nth-child(2) { margin-left: 3%; }
  .page-about .timeline__item:nth-child(3) { margin-left: 6%; }
  .page-about .timeline__item:nth-child(4) { margin-left: 9%; }
  .page-about .timeline__item:nth-child(5) { margin-left: 12%; }

  .page-about .timeline__item {
    grid-template-columns: 118px minmax(0, 1fr);
    align-items: start;
    gap: 18px;
  }

  .page-about .timeline__code {
    padding-top: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .path-card,
  .page-about .timeline__item,
  .page-about .crew__tab {
    transition: none;
  }

  .page-about .path-card:hover,
  .page-about .timeline__item:hover {
    transform: none;
  }
}