.page-about {
  --tl-col: 150px;
  --tl-dot: var(--c-mint);
  display: block;
}

/* ===== 面包屑 ===== */
.page-about .crumbs {
  margin-top: clamp(18px, 3vw, 30px);
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  padding: clamp(20px, 3.4vw, 38px) 0 clamp(34px, 5.5vw, 62px);
}

.page-about .hero-frame {
  position: relative;
  display: grid;
  gap: clamp(24px, 3.6vw, 46px);
  padding: clamp(22px, 3.6vw, 46px);
  border: 1px solid var(--c-hair);
  border-radius: var(--r);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(46, 230, 168, .07), transparent 56%),
    linear-gradient(180deg, rgba(17, 26, 58, .82), rgba(10, 17, 40, .58));
  box-shadow: var(--shadow-card);
}

.page-about .hero-frame::before,
.page-about .hero-frame::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  border: 1px solid var(--c-mint);
  pointer-events: none;
}

.page-about .hero-frame::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .hero-frame::after {
  bottom: -1px;
  right: -1px;
  border-left: 0;
  border-top: 0;
}

.page-about .hero-frame__copy h1 {
  margin: 12px 0 0;
  font-family: var(--ff-serif);
  font-size: clamp(28px, 5vw, 50px);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--c-ink);
}

.page-about .hero-frame__copy .lede {
  margin: 18px 0 0;
  max-width: 58ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--c-body);
}

.page-about .hero-stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 20px 0 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  border-top: 1px solid var(--c-hair);
}

.page-about .hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .hero-stats .data {
  font-size: clamp(22px, 3.6vw, 36px);
  line-height: 1.1;
}

.page-about .hero-stats__label {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--c-mute);
}

.page-about .hero-frame__figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--c-hair);
  border-radius: var(--r);
  background: var(--c-panel-soft);
  overflow: hidden;
}

.page-about .hero-frame__figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .hero-frame__figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--c-hair);
  font-size: 12px;
  line-height: 1.6;
  color: var(--c-mute);
}

/* ===== 时间轴 ===== */
.page-about .about-timeline {
  position: relative;
  padding: clamp(18px, 3vw, 30px) 0 clamp(38px, 6vw, 70px);
  overflow: hidden;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  inset: -10% -5% 0;
  background-image:
    linear-gradient(to right, rgba(42, 53, 86, .34) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(42, 53, 86, .34) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: .45;
  pointer-events: none;
}

.page-about .about-timeline > .container {
  position: relative;
  z-index: 1;
}

.page-about .sec-head {
  max-width: 64ch;
}

.page-about .sec-head h2 {
  margin: 10px 0 0;
  font-family: var(--ff-serif);
  font-size: clamp(23px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-ink);
}

.page-about .sec-head__lede {
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--c-body);
}

.page-about .timeline {
  position: relative;
  list-style: none;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom, var(--c-mint), var(--c-hair) 18%, var(--c-hair) 84%, transparent);
}

.page-about .tl-item {
  position: relative;
  display: grid;
  gap: 12px;
  padding: 0 0 clamp(30px, 4vw, 44px) 26px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 8px;
  width: 8px;
  height: 8px;
  margin-left: -3.5px;
  border-radius: 50%;
  background: var(--tl-dot, var(--c-mint));
  box-shadow: 0 0 10px 0 var(--tl-dot, var(--c-mint));
  z-index: 1;
}

.page-about .tl-item:nth-child(1) { --tl-dot: var(--c-mint); }
.page-about .tl-item:nth-child(2) { --tl-dot: var(--lg-epl); }
.page-about .tl-item:nth-child(3) { --tl-dot: var(--lg-ligue1); }
.page-about .tl-item:nth-child(4) { --tl-dot: var(--c-orange); }
.page-about .tl-item:nth-child(5) { --tl-dot: var(--lg-bundesliga); }
.page-about .tl-item:nth-child(6) { --tl-dot: var(--lg-seriea); }

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

.page-about .tl-year {
  font-family: var(--ff-cond);
  font-size: clamp(21px, 2.6vw, 27px);
  line-height: 1;
  letter-spacing: .08em;
  color: var(--c-ink);
}

.page-about .tl-ver {
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-mint);
  border: 1px solid rgba(46, 230, 168, .35);
  border-radius: 2px;
  padding: 3px 7px;
}

.page-about .tl-body {
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--c-hair);
  border-left: 2px solid var(--tl-dot, var(--c-mint));
  border-radius: var(--r);
  background: linear-gradient(180deg, rgba(17, 26, 58, .74), rgba(13, 21, 48, .56));
  box-shadow: var(--shadow-card);
}

.page-about .tl-body h3 {
  margin: 0 0 12px;
  font-family: var(--ff-serif);
  font-size: clamp(17px, 2.2vw, 22px);
  font-weight: 700;
  line-height: 1.42;
  color: var(--c-ink);
}

.page-about .tl-body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.76;
  color: var(--c-body);
}

.page-about .tl-body p:last-child {
  margin-bottom: 0;
}

.page-about .tl-body .tl-note {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--c-hair);
  font-family: var(--ff-mono);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--c-mint);
}

/* ===== 版本脉络图 ===== */
.page-about .about-chart {
  padding: clamp(6px, 1.6vw, 16px) 0 clamp(38px, 6vw, 70px);
}

.page-about .chart-figure {
  margin: 0 auto;
  max-width: 640px;
  border: 1px solid var(--c-hair);
  border-radius: var(--r);
  background: linear-gradient(160deg, rgba(17, 26, 58, .8), rgba(10, 17, 40, .55));
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.page-about .chart-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.page-about .chart-figure figcaption {
  padding: 16px 20px;
  border-top: 1px solid var(--c-hair);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-mute);
}

/* ===== 团队 ===== */
.page-about .about-team {
  padding: clamp(34px, 5.5vw, 68px) 0;
  border-top: 1px solid var(--c-hair);
}

.page-about .team-grid {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .team-copy h2 {
  margin: 10px 0 0;
  font-family: var(--ff-serif);
  font-size: clamp(23px, 3.4vw, 33px);
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-ink);
}

.page-about .team-lede {
  margin: 16px 0 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--c-body);
}

.page-about .team-roster {
  list-style: none;
  margin: 26px 0 0;
  padding: 20px 0 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  border-top: 1px solid var(--c-hair);
}

.page-about .team-roster li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .team-roster .data {
  font-size: clamp(22px, 3.4vw, 34px);
  line-height: 1.1;
}

.page-about .team-roster span:last-child {
  font-size: 12.5px;
  letter-spacing: .05em;
  color: var(--c-mute);
}

.page-about .team-figure {
  margin: 0;
  border: 1px solid var(--c-hair);
  border-radius: var(--r);
  background: var(--c-panel-soft);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .team-figure figcaption {
  padding: 14px 18px;
  border-top: 1px solid var(--c-hair);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--c-mute);
}

/* ===== 响应承诺 ===== */
.page-about .about-promise {
  padding: clamp(14px, 2.4vw, 26px) 0 clamp(46px, 7vw, 86px);
}

.page-about .promise-panel {
  padding: clamp(24px, 4vw, 46px);
  border: 1px solid var(--c-hair);
  border-radius: var(--r);
  background:
    radial-gradient(90% 120% at 0% 0%, rgba(255, 138, 61, .07), transparent 58%),
    linear-gradient(140deg, rgba(17, 26, 58, .85), rgba(10, 17, 40, .6));
  box-shadow: var(--shadow-card);
}

.page-about .promise-panel h2 {
  margin: 10px 0 0;
  max-width: 30ch;
  font-family: var(--ff-serif);
  font-size: clamp(22px, 3.2vw, 32px);
  font-weight: 700;
  line-height: 1.32;
  color: var(--c-ink);
}

.page-about .promise-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .promise-list li {
  display: grid;
  gap: 6px 20px;
  padding: 18px 0;
  border-top: 1px solid var(--c-hair);
}

.page-about .promise-list__label {
  font-family: var(--ff-cond);
  font-size: 13px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--c-mint);
}

.page-about .promise-list__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--c-body);
}

.page-about .promise-cta {
  margin: 26px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--c-hair);
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-mute);
}

.page-about .promise-cta a {
  color: var(--c-ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 230, 168, .5);
  padding-bottom: 1px;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .promise-cta a:hover,
.page-about .promise-cta a:focus-visible {
  color: var(--c-mint);
  border-color: var(--c-mint);
}

/* ===== 断点 ===== */
@media (min-width: 820px) {
  .page-about .timeline::before {
    left: var(--tl-col);
  }

  .page-about .tl-item {
    grid-template-columns: var(--tl-col) minmax(0, 1fr);
    column-gap: clamp(28px, 4vw, 44px);
    padding-left: 0;
    padding-bottom: clamp(36px, 4.4vw, 52px);
  }

  .page-about .tl-item::before {
    left: var(--tl-col);
    top: 10px;
  }

  .page-about .tl-mark {
    position: sticky;
    top: 118px;
    align-self: start;
    flex-direction: column;
    align-items: flex-end;
    gap: 5px;
    text-align: right;
  }
}

@media (min-width: 900px) {
  .page-about .hero-frame {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, .85fr);
    align-items: center;
  }

  .page-about .promise-list li {
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: baseline;
  }
}

@media (max-width: 420px) {
  .page-about .hero-stats,
  .page-about .team-roster {
    gap: 10px;
  }

  .page-about .hero-stats__label,
  .page-about .team-roster span:last-child {
    font-size: 11px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .promise-cta a {
    transition: none;
  }
}