.page-about {
  --about-index-w: 230px;
  --about-space: clamp(3rem, 6vw, 6rem);
  position: relative;
  background: var(--bg-main);
  color: var(--text-main);
  overflow: hidden;
}

.page-about__top {
  position: absolute;
  top: 0;
  left: 0;
}

.page-about .about-hero {
  position: relative;
  padding: clamp(2rem, 5vw, 4.5rem) var(--space) 0;
}

.page-about .about-hero::before {
  content: "中欧体育在线";
  position: absolute;
  top: -0.3rem;
  right: -0.5rem;
  font-family: var(--font-display);
  font-size: clamp(5rem, 14vw, 11rem);
  line-height: 1;
  color: rgba(255, 255, 255, .035);
  white-space: nowrap;
  letter-spacing: -.04em;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
}

.page-about .about-index {
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: .6rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index a {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--text-sub);
  text-decoration: none;
  padding: .42rem .85rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .about-index a[data-chapter-active],
.page-about .about-index a.is-active {
  color: var(--accent);
  border-color: var(--accent);
}

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

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--text-sub);
  margin-bottom: 1.5rem;
}

.page-about .breadcrumb a {
  color: var(--text-sub);
  text-decoration: none;
  transition: color .2s ease;
}

.page-about .breadcrumb a:hover {
  color: var(--accent);
}

.page-about .about-kicker {
  font-family: var(--font-mono);
  font-size: .85rem;
  color: var(--accent);
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.page-about .about-hero__main h1 {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 4.4vw, 3.8rem);
  line-height: 1.04;
  letter-spacing: -.02em;
  margin: 0 0 1.1rem;
}

.page-about .about-title-sub {
  display: block;
  font-size: .62em;
  color: var(--text-sub);
  margin-top: .15em;
}

.page-about .about-hero__lead {
  max-width: 62ch;
  font-size: clamp(1rem, 1.5vw, 1.18rem);
  line-height: 1.8;
  color: var(--text-sub);
  margin: 0 0 2rem;
}

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

.page-about .about-section__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
}

.page-about .about-side {
  border-left: 2px solid var(--border);
  padding-left: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .45rem 1rem;
  min-width: 0;
}

.page-about .about-side__num {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 1.1rem;
  line-height: 1;
}

.page-about .about-side__label {
  font-family: var(--font-display);
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: .08em;
}

.page-about .about-side__note {
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--text-sub);
}

.page-about .data-badge {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--accent-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .3rem .7rem;
}

.page-about .data-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-2);
}

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

.page-about .about-section__body h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.4vw, 3rem);
  line-height: 1.1;
  letter-spacing: -.01em;
  margin: .2rem 0 1.2rem;
  display: flex;
  align-items: center;
  gap: .75rem;
}

.page-about .about-section__body h2::before {
  content: "";
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  clip-path: polygon(0 0, 100% 0, 0 100%);
}

.page-about .about-section__lead {
  font-size: clamp(1.15rem, 1.8vw, 1.4rem);
  line-height: 1.6;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.page-about .about-section__body > p {
  color: var(--text-sub);
  line-height: 1.8;
  max-width: 68ch;
}

.page-about .about-section__body a {
  color: var(--accent-2);
  text-decoration: underline;
  text-underline-offset: .2em;
  text-decoration-thickness: 1px;
}

.page-about .about-section__body a:hover {
  color: var(--accent);
}

.page-about .stat-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 2rem;
}

.page-about .stat-item {
  flex: 1 1 130px;
  background: var(--bg-panel);
  padding: 1.1rem 1rem;
}

.page-about .stat-item strong {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 3vw, 2.2rem);
  line-height: 1;
  color: var(--accent-2);
  margin-bottom: .5rem;
}

.page-about .stat-item span {
  font-size: .84rem;
  color: var(--text-sub);
}

.page-about .mech-pipeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .9rem;
  margin: 2rem 0 1.5rem;
}

.page-about .mech-step {
  padding: 1.1rem 1.2rem 1.3rem;
  background: linear-gradient(180deg, rgba(0, 229, 255, .08), rgba(11, 27, 58, 0));
  border-top: 2px solid var(--accent-2);
}

.page-about .mech-step span {
  font-family: var(--font-mono);
  color: var(--accent-2);
  font-size: .95rem;
}

.page-about .mech-step p {
  margin: .6rem 0 0;
  color: var(--text-sub);
  font-size: .9rem;
  line-height: 1.6;
}

.page-about .figure {
  margin: 2.25rem 0 0;
}

.page-about .figure__img,
.page-about .about-milestone-hero img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .about-milestone-hero {
  margin: 0 0 2.25rem;
}

.page-about .about-milestone-hero img {
  clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
  border-radius: var(--radius);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 2.1rem 1.6rem;
  border-left: 2px solid var(--border);
}

.page-about .timeline__item:last-child {
  padding-bottom: .5rem;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 5px;
  width: 12px;
  height: 12px;
  background: var(--accent);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  color: var(--accent-2);
  line-height: 1;
}

.page-about .timeline__content h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin: .35rem 0 .4rem;
}

.page-about .timeline__content p {
  color: var(--text-sub);
  font-size: .94rem;
  line-height: 1.7;
  margin: 0;
  max-width: 60ch;
}

.page-about .team-block {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
  margin: 2rem 0 1.75rem;
}

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

.page-about .team-figure img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .team-list details {
  border-bottom: 1px solid var(--border);
  padding: .95rem 0;
}

.page-about .team-list summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: .7rem;
}

.page-about .team-list summary::-webkit-details-marker {
  display: none;
}

.page-about .team-list summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.25rem;
  color: var(--accent);
  line-height: 1;
}

.page-about .team-list details[open] summary::before {
  content: "−";
}

.page-about .team-list details p {
  margin: .6rem 0 0 1.85rem;
  color: var(--text-sub);
  font-size: .93rem;
  line-height: 1.7;
  max-width: 56ch;
}

.page-about .about-support__line {
  font-size: .92rem;
  color: var(--text-sub);
  margin: 2rem 0 0;
}

.page-about .about-trust {
  margin-top: var(--about-space);
  padding: clamp(3.5rem, 7vw, 6rem) var(--space);
  background: linear-gradient(90deg, rgba(255, 107, 53, .16), rgba(0, 229, 255, .05));
  clip-path: polygon(0 5%, 100% 0, 100% 95%, 0 100%);
}

.page-about .about-trust__inner {
  max-width: 800px;
}

.page-about .about-trust__kicker {
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--accent-2);
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.page-about .about-trust h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.4vw, 3rem);
  line-height: 1.1;
  margin: 0 0 1.1rem;
}

.page-about .about-trust p {
  color: var(--text-sub);
  font-size: 1.05rem;
  line-height: 1.8;
  max-width: 58ch;
  margin: 0;
}

.page-about .about-trust__links {
  display: flex;
  flex-wrap: wrap;
  gap: .9rem;
  margin-top: 2rem;
}

.page-about .about-link-main,
.page-about .about-link-sub {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  font-weight: 600;
  padding: .82rem 1.65rem;
  border-radius: 999px;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}

.page-about .about-link-main {
  background: var(--accent);
  color: #FFFFFF;
}

.page-about .about-link-main:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(255, 107, 53, .35);
}

.page-about .about-link-sub {
  border: 1px solid var(--border);
  color: var(--text-main);
}

.page-about .about-link-sub:hover {
  border-color: var(--accent-2);
  color: var(--accent-2);
}

@media (min-width: 900px) {
  .page-about .about-hero__grid,
  .page-about .about-section__grid {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: clamp(2.5rem, 5vw, 5rem);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: .5rem;
    overflow: visible;
  }

  .page-about .about-index a {
    border: 0;
    border-radius: 0;
    padding: .3rem 0;
    border-bottom: 1px solid var(--border);
    display: block;
  }

  .page-about .about-index a[data-chapter-active],
  .page-about .about-index a.is-active {
    color: var(--accent);
    border-bottom-color: var(--accent);
  }

  .page-about .about-side {
    flex-direction: column;
    align-items: flex-start;
    gap: .55rem;
  }

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

  .page-about .team-block {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: center;
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero__grid,
  .page-about .about-section__grid {
    gap: clamp(3rem, 6vw, 6rem);
  }
}