.page-about {
  --about-gap: clamp(52px, 9vw, 104px);
  --about-tl-line: rgba(38, 58, 85, 0.9);
  --about-soft: #C6D2E1;
}

.page-about .section {
  padding-block: var(--about-gap) 0;
}

.page-about .about-head {
  max-width: 74ch;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-lede {
  margin: 14px 0 0;
  font-size: 17px;
  line-height: 1.85;
  color: var(--about-soft);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: clamp(16px, 3vw, 30px);
  background-image:
    radial-gradient(120% 90% at 88% 8%, rgba(74, 222, 208, 0.14), transparent 62%),
    radial-gradient(95% 80% at 2% 0%, rgba(255, 107, 26, 0.13), transparent 60%);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 30px;
  align-items: start;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 8.4vw, 66px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.9;
  color: var(--about-soft);
}

.page-about .about-hero .tag-row {
  margin-top: 22px;
}

.page-about .about-hero__card {
  position: relative;
  padding: 24px 22px 26px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background:
    linear-gradient(158deg, rgba(15, 29, 51, 0.96), rgba(7, 13, 24, 0.92)),
    linear-gradient(180deg, rgba(142, 155, 171, 0.12), transparent 45%);
}

.page-about .about-hero__card-title {
  margin: 0 0 16px;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-facts {
  margin: 0 0 22px;
  display: grid;
  gap: 14px;
}

.page-about .about-fact {
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-fact:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-fact dt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--mist);
}

.page-about .about-fact dd {
  margin: 6px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--metal);
}

/* ---------- 业务主线 ---------- */
.page-about .about-lines {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.page-about .about-line {
  display: grid;
  gap: 12px;
  padding: 24px 0;
  border-top: 1px solid var(--line-soft);
}

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

.page-about .about-line__code {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--orange);
  line-height: 1;
}

.page-about .about-line__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 21px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--mist);
}

.page-about .about-line__body p {
  margin: 10px 0 0;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.88;
  color: var(--about-soft);
}

.page-about .about-line__body .tag-row {
  margin-top: 14px;
}

.page-about .about-figure {
  margin: clamp(30px, 5vw, 52px) 0 0;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 20px;
  bottom: 20px;
  left: 21px;
  width: 2px;
  border-radius: var(--pill);
  background: linear-gradient(180deg, var(--orange), var(--cyan) 48%, var(--steel));
  opacity: 0.6;
}

.page-about .tl-node {
  position: relative;
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 0;
}

.page-about .tl-code {
  position: relative;
  z-index: 1;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: var(--pill);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink);
  background: var(--orange);
  box-shadow: 0 0 0 6px var(--ink);
}

.page-about .tl-node:nth-child(even) .tl-code {
  background: var(--cyan);
}

.page-about .tl-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .tl-head .panel-title {
  margin: 0;
  font-size: 19px;
  color: var(--mist);
}

.page-about .tl-body > p {
  margin: 10px 0 0;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--about-soft);
}

.page-about .tl-body .fold-trigger {
  margin-top: 12px;
}

.page-about .fold-panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--metal);
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: clamp(20px, 3vw, 30px);
  border-radius: var(--r-lg);
  background: linear-gradient(150deg, rgba(15, 29, 51, 0.95), rgba(7, 13, 24, 0.6));
  border: 1px solid var(--line-soft);
}

.page-about .about-stats .stat {
  padding: 14px 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-stats .stat:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-stats .stat-num {
  display: block;
  color: var(--cyan);
  letter-spacing: -0.02em;
  line-height: 1.05;
}

.page-about .about-stats .stat-label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--metal);
}

.page-about .about-notes {
  margin-top: clamp(22px, 3vw, 34px);
  display: grid;
  gap: 16px;
}

.page-about .about-notes p {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--steel);
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--about-soft);
}

.page-about .about-notes strong {
  color: var(--mist);
  font-weight: 700;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 28px;
}

.page-about .about-team__media figure {
  margin: 0;
}

.page-about .about-team__groups {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-group {
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  padding: 6px 16px;
  background: rgba(15, 29, 51, 0.55);
}

.page-about .about-group .fold-trigger {
  width: 100%;
  text-align: left;
  padding: 14px 0;
}

.page-about .about-team__note {
  margin: 6px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--metal);
}

.page-about .about-team__groups .btn {
  justify-self: start;
  margin-top: 6px;
}

/* ---------- 长期维护 ---------- */
.page-about .about-cred {
  display: grid;
  gap: 2px;
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-cred__item {
  display: grid;
  gap: 8px;
  padding: 18px 20px;
  background: rgba(15, 29, 51, 0.7);
}

.page-about .about-cred__item:nth-child(even) {
  background: rgba(38, 58, 85, 0.34);
}

.page-about .about-cred__key {
  font-size: 12.5px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .about-cred__val {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  gap: 26px;
}

.page-about .about-eco__figure {
  margin: 0;
}

.page-about .about-eco__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-eco__list li {
  display: grid;
  gap: 8px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-eco__list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-eco__role {
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-eco__list p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-soft);
}

.page-about .about-cta {
  margin-top: clamp(28px, 4vw, 46px);
  padding: clamp(24px, 4vw, 38px);
  border-radius: var(--r-lg);
  border: 1px solid rgba(255, 107, 26, 0.34);
  background:
    linear-gradient(140deg, rgba(255, 107, 26, 0.16), rgba(7, 13, 24, 0.2) 55%),
    linear-gradient(180deg, rgba(15, 29, 51, 0.95), rgba(7, 13, 24, 0.95));
}

.page-about .about-cta__copy .panel-title {
  margin: 0 0 12px;
  font-size: 22px;
  color: var(--mist);
}

.page-about .about-cta__copy p {
  margin: 0 0 14px;
  max-width: 70ch;
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--about-soft);
}

.page-about .about-cta__contact {
  padding: 14px 0 0;
  border-top: 1px solid var(--line-soft);
  font-size: 14px;
  line-height: 2;
  color: var(--metal);
}

.page-about .about-cta .tag-row {
  margin-top: 20px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 28px;
  }

  .page-about .about-stats .stat:nth-child(2) {
    padding-top: 0;
    border-top: 0;
  }

  .page-about .about-notes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 26px;
  }

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

  .page-about .about-cred__item:nth-child(even) {
    background: rgba(15, 29, 51, 0.7);
  }

  .page-about .about-cred__item:nth-child(4n + 2),
  .page-about .about-cred__item:nth-child(4n + 3) {
    background: rgba(38, 58, 85, 0.34);
  }
}

@media (min-width: 980px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.3fr) minmax(300px, 0.7fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-line {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 24px;
    padding: 28px 0;
  }

  .page-about .about-line__code {
    font-size: 30px;
  }

  .page-about .about-line__title {
    font-size: 24px;
  }

  .page-about .about-timeline::before {
    left: 27px;
  }

  .page-about .tl-node {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 28px;
    padding: 20px 0;
  }

  .page-about .tl-code {
    width: 56px;
    height: 56px;
    font-size: 15px;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-stats .stat {
    padding-top: 0;
    border-top: 0;
    border-left: 1px solid var(--line-soft);
    padding-left: 20px;
  }

  .page-about .about-stats .stat:first-child {
    border-left: 0;
    padding-left: 0;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 44px;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms;
  }
}