.page-about {
  --rail-w: 178px;
  --gap-col: clamp(28px, 4.5vw, 64px);
  --card-surface: rgba(11, 18, 36, 0.82);
  display: block;
  background: var(--abyss);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about .num {
  font-family: var(--font-mono);
  font-size: 0.94em;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(55, 232, 211, 0.4);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--ink);
  outline: none;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 34px) 0 clamp(40px, 7vw, 84px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 140% at 92% -16%, rgba(169, 123, 255, 0.2), transparent 58%),
    radial-gradient(90% 120% at 2% 112%, rgba(55, 232, 211, 0.13), transparent 62%),
    var(--abyss);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    180deg,
    rgba(55, 232, 211, 0.05) 0 1px,
    transparent 1px 3px
  );
  pointer-events: none;
}

.page-about .about-hero .wrap {
  position: relative;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 7.4vw, 64px);
  line-height: 1.04;
  letter-spacing: -0.01em;
  margin: 0.34em 0 0.5em;
  max-width: 17ch;
  color: var(--ink);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 外壳与左侧索引 ---------- */

.page-about .about-shell {
  display: block;
}

.page-about .about-rail {
  position: sticky;
  top: var(--head-h);
  z-index: 6;
  margin: 0 calc(-1 * var(--gutter));
  padding: 0 var(--gutter);
  background: rgba(4, 6, 13, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.page-about .rail-kicker {
  display: none;
}

.page-about .rail-list {
  display: flex;
  align-items: stretch;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .rail-item {
  flex: 0 0 auto;
}

.page-about .rail-link {
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 13px 14px;
  border-right: 1px solid rgba(34, 49, 74, 0.8);
  text-decoration: none;
  white-space: nowrap;
  color: var(--muted);
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  color: var(--ink);
  background: rgba(55, 232, 211, 0.07);
  outline: none;
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .rail-text {
  font-size: 13px;
}

.page-about .rail-year {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: rgba(140, 154, 177, 0.6);
}

/* ---------- 分节通用 ---------- */

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

.page-about .about-section {
  position: relative;
  padding: clamp(52px, 9vw, 104px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section--jade {
  background: linear-gradient(168deg, rgba(12, 42, 42, 0.62) 0%, rgba(4, 6, 13, 0) 68%);
}

.page-about .about-section--violet {
  background: linear-gradient(168deg, rgba(21, 15, 51, 0.72) 0%, rgba(4, 6, 13, 0) 70%);
}

.page-about .about-section__head {
  margin-bottom: clamp(28px, 4.5vw, 52px);
}

.page-about .sec-index {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(54px, 10vw, 100px);
  line-height: 0.88;
  letter-spacing: -0.02em;
  color: rgba(169, 123, 255, 0.17);
  margin-bottom: 6px;
  user-select: none;
}

.page-about .about-section__head h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 5vw, 44px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  margin: 0 0 0.55em;
  max-width: 20ch;
  color: var(--ink);
}

.page-about .about-section__head p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 01 三条主线 ---------- */

.page-about .line-cards {
  display: grid;
  gap: 14px;
}

.page-about .line-card {
  position: relative;
  padding: 26px 22px 28px;
  border: 1px solid var(--line);
  border-top-width: 2px;
  background: var(--card-surface);
}

.page-about .line-card--jade {
  border-top-color: var(--cyan);
  background: linear-gradient(158deg, rgba(12, 42, 42, 0.86) 0%, rgba(11, 18, 36, 0.9) 72%);
}

.page-about .line-card--violet {
  border-top-color: var(--purple);
  background: linear-gradient(158deg, rgba(21, 15, 51, 0.9) 0%, rgba(11, 18, 36, 0.9) 72%);
}

.page-about .line-card--wine {
  border-top-color: var(--orange);
  background: linear-gradient(158deg, rgba(43, 13, 26, 0.86) 0%, rgba(11, 18, 36, 0.9) 72%);
}

.page-about .line-card__tag {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .line-card h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 21px;
  line-height: 1.24;
  color: var(--ink);
}

.page-about .line-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: var(--muted);
}

/* ---------- 02 团队 ---------- */

.page-about .split {
  display: grid;
  gap: 30px;
}

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

.page-about .role-list {
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .role {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2px 14px;
  padding: 16px 0;
  border-bottom: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .role__name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .role__count {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.03em;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .role__desc {
  grid-column: 1 / -1;
  margin-top: 4px;
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .split__note {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--orange);
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .split__media,
.page-about .roadmap-figure,
.page-about .partner-media {
  margin: 0;
}

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

.page-about .media-frame__label {
  letter-spacing: 0.1em;
}

/* ---------- 03 数据来源 ---------- */

.page-about .data-notes {
  display: grid;
  gap: 1px;
  background: rgba(34, 49, 74, 0.8);
  border: 1px solid var(--line);
}

.page-about .note {
  padding: 24px 22px 26px;
  background: #060b18;
}

.page-about .note h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  color: var(--ink);
}

.page-about .note p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 04 年份 ---------- */

.page-about .year-list {
  margin: 0 0 clamp(28px, 4.5vw, 52px);
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .year-item {
  padding: 22px 0;
  border-bottom: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .year-num {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.08em;
  color: var(--purple);
}

.page-about .year-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 20px;
  line-height: 1.22;
  color: var(--ink);
}

.page-about .year-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: var(--muted);
}

/* ---------- 05 规模 ---------- */

.page-about .stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(34, 49, 74, 0.85);
  border: 1px solid var(--line);
}

.page-about .stat {
  padding: 22px 18px 24px;
  background: #060b18;
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 5.4vw, 36px);
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .stat__num span {
  margin-left: 5px;
  font-size: 0.44em;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .stat__label {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .scale-note {
  margin: clamp(22px, 3.5vw, 34px) 0 0;
  max-width: 60ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 06 合作 ---------- */

.page-about .partner-split {
  display: grid;
  gap: 30px;
}

.page-about .partner-list {
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .partner-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid rgba(34, 49, 74, 0.75);
}

.page-about .partner-key {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.05em;
  color: var(--purple);
}

.page-about .partner-val {
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .partner-note {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 行动区 ---------- */

.page-about .about-cta {
  padding: clamp(52px, 9vw, 104px) 0 clamp(24px, 4vw, 44px);
}

.page-about .about-cta__head {
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-cta__head .sec-index {
  color: rgba(55, 232, 211, 0.16);
  font-size: clamp(38px, 7vw, 64px);
}

.page-about .about-cta__head h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.1;
  margin: 0;
  color: var(--ink);
}

.page-about .about-cta__links {
  display: grid;
  gap: 12px;
}

.page-about .link-card {
  display: block;
  padding: 22px 22px 24px;
  border: 1px solid var(--line);
  background: var(--card-surface);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.22s var(--ease), background 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .link-card:hover,
.page-about .link-card:focus-visible {
  border-color: rgba(55, 232, 211, 0.6);
  background: rgba(11, 24, 36, 0.94);
  transform: translateY(-2px);
  outline: none;
}

.page-about .link-card:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan);
}

.page-about .link-card__title {
  display: block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .link-card__desc {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 平板 ---------- */

@media (min-width: 720px) {
  .page-about .line-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

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

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

  .page-about .about-cta__links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .year-item {
    display: grid;
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 6px 28px;
    padding: 26px 0;
  }

  .page-about .year-num {
    grid-row: 1 / span 2;
    margin: 0;
    padding-top: 3px;
    font-size: 17px;
  }

  .page-about .year-title {
    margin: 0;
  }

  .page-about .partner-item {
    grid-template-columns: 108px minmax(0, 1fr);
    align-items: baseline;
    gap: 0 20px;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 900px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: var(--gap-col);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--head-h) + 48px);
    margin: 0;
    padding: clamp(56px, 8vw, 96px) 0 0 18px;
    background: none;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  .page-about .rail-kicker {
    display: block;
    margin: 0 0 16px;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: rgba(140, 154, 177, 0.7);
  }

  .page-about .rail-list {
    display: block;
    overflow: visible;
  }

  .page-about .rail-item {
    border-bottom: 1px solid rgba(34, 49, 74, 0.55);
  }

  .page-about .rail-item:first-child {
    border-top: 1px solid rgba(34, 49, 74, 0.55);
  }

  .page-about .rail-link {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    gap: 2px 10px;
    padding: 13px 0;
    border-right: 0;
    align-items: baseline;
  }

  .page-about .rail-text {
    font-size: 13.5px;
    color: inherit;
  }

  .page-about .rail-year {
    grid-column: 1 / -1;
    font-size: 10px;
  }

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

  .page-about .split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

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

  .page-about .partner-split {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

  .page-about .about-section:first-child {
    padding-top: clamp(56px, 8vw, 96px);
  }

  .page-about .stat {
    padding: 26px 22px 28px;
  }
}

@media (min-width: 1180px) {
  .page-about {
    --rail-w: 200px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .link-card {
    transition: none;
  }

  .page-about .link-card:hover,
  .page-about .link-card:focus-visible {
    transform: none;
  }
}
</main>