.page-about {
  --tl-rail: 76px;
  --about-panel: rgba(23, 51, 77, .72);
  --about-hair: rgba(42, 74, 99, .85);
  background: var(--navy);
  color: var(--paper);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-head);
}

.page-about .mono {
  letter-spacing: .04em;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 26px 0 0;
  background:
    radial-gradient(900px 320px at 88% -18%, rgba(14, 59, 46, .92), transparent 68%),
    linear-gradient(180deg, var(--ink) 0%, var(--navy) 58%, var(--navy) 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(42, 74, 99, .45) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 74, 99, .45) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: .22;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
}

.page-about .about-hero .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  max-width: 18ch;
  font-size: clamp(30px, 6.4vw, 54px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  margin: 16px 0 0;
  max-width: 60ch;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--paper);
}

.page-about .about-hero__lead--sub {
  margin-top: 10px;
  color: var(--mist);
  font-size: 15.5px;
}

.page-about .facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(132px, 1fr));
  gap: 10px;
}

.page-about .facts__cell {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 13px 14px;
  border: 1px solid var(--about-hair);
  border-radius: 14px;
  background: rgba(23, 51, 77, .82);
  border-left: 3px solid rgba(242, 179, 61, .75);
}

.page-about .facts__num {
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1.05;
  color: var(--amber);
}

.page-about .facts__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-hero__figwrap {
  padding-bottom: 4px;
}

.page-about .about-hero__fig {
  margin: 34px 0 0;
}

.page-about .about-hero__fig .fig__frame {
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-l);
  overflow: hidden;
}

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

.page-about .fig__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */

.page-about .tl {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .tl__item {
  position: relative;
  display: grid;
  grid-template-columns: var(--tl-rail) minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 32px;
}

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

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-rail) - 1px);
  top: 10px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, rgba(242, 179, 61, .8), rgba(42, 74, 99, .35));
}

.page-about .tl__item:last-child::before {
  background: linear-gradient(180deg, rgba(242, 179, 61, .8), transparent);
}

.page-about .tl__rail {
  display: flex;
  justify-content: flex-end;
  padding-right: 14px;
}

.page-about .tl__badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 48px;
  padding: 5px 9px;
  border-radius: var(--radius-pill);
  background: var(--amber);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .tl__body {
  min-width: 0;
  padding-top: 2px;
}

.page-about .tl__span {
  display: block;
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--amber-hi);
}

.page-about .tl__body h3 {
  margin: 0 0 10px;
  font-size: clamp(19px, 2.6vw, 24px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .tl__body p {
  margin: 0 0 10px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--mist);
}

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

/* ---------- 版本列表 ---------- */

.page-about .versions {
  display: grid;
  gap: 8px;
  margin-top: 28px;
}

.page-about .versions--archive {
  margin-top: 22px;
}

.page-about .vrow .panel__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 14px 16px;
  text-align: left;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  font: inherit;
  color: inherit;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-m);
  background: rgba(10, 27, 42, .62);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .vrow .panel__head:hover {
  border-color: rgba(242, 179, 61, .6);
  background: rgba(10, 27, 42, .88);
}

.page-about .vrow .panel__head:focus-visible {
  outline: 2px solid var(--amber-hi);
  outline-offset: 2px;
}

.page-about .vrow__ver {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  padding: 3px 10px;
  border: 1px solid rgba(242, 179, 61, .5);
  border-radius: var(--radius-pill);
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 13.5px;
  font-weight: 700;
  white-space: nowrap;
}

.page-about .vrow .panel__title {
  font-size: 15.5px;
  line-height: 1.55;
  font-weight: 600;
  color: var(--paper);
}

.page-about .vrow .panel__state {
  font-size: 12.5px;
  color: var(--amber-hi);
  white-space: nowrap;
}

.page-about .vrow .panel__inner {
  margin: 8px 0 0 4px;
  padding: 12px 16px 16px;
  border-left: 2px solid rgba(242, 179, 61, .45);
}

.page-about .vrow .panel__inner p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .vrow__list {
  margin: 10px 0 0;
  padding-left: 18px;
  list-style: disc;
}

.page-about .vrow__list li {
  margin-bottom: 6px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .vrow__list li::marker {
  color: var(--amber);
}

/* ---------- 新旧对照 ---------- */

.page-about .about-diff__lead {
  margin: 22px 0 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--paper);
}

.page-about .diff {
  position: relative;
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .diff__col {
  padding: 18px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-m);
  background: var(--about-panel);
}

.page-about .diff__col--old {
  background: rgba(5, 18, 29, .72);
}

.page-about .diff__col--new {
  background: rgba(14, 59, 46, .78);
  border-color: rgba(242, 179, 61, .38);
}

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

.page-about .diff__head h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .diff__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .diff__list li {
  display: grid;
  grid-template-columns: 16px minmax(0, 1fr);
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .diff__list li::before {
  content: "—";
  color: var(--amber);
  font-family: var(--font-mono);
}

.page-about .diff__seam {
  display: none;
}

/* ---------- 团队 ---------- */

.page-about .team {
  display: grid;
  gap: 18px;
  margin-top: 26px;
}

.page-about .team__text p {
  margin: 0 0 12px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--mist);
}

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

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

.page-about .team__fig .fig__frame {
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-l);
  overflow: hidden;
}

.page-about .tree {
  margin-top: 34px;
  text-align: center;
}

.page-about .tree__root {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  margin: 0;
  padding: 10px 20px;
  border: 1px solid rgba(242, 179, 61, .6);
  border-radius: var(--radius-pill);
  background: rgba(242, 179, 61, .1);
  color: var(--amber-hi);
  font-size: 15px;
  font-weight: 600;
}

.page-about .tree__root .mono {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--amber);
}

.page-about .tree__root::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 100%;
  width: 1px;
  height: 26px;
  background: var(--about-hair);
}

.page-about .tree__row {
  list-style: none;
  position: relative;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .tree__node {
  position: relative;
  padding: 16px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-m);
  background: rgba(10, 27, 42, .6);
  text-align: left;
}

.page-about .tree__node h3 {
  margin: 0 0 8px;
  font-size: 16.5px;
  font-weight: 700;
  color: var(--amber);
}

.page-about .tree__node p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */

.page-about .eco {
  display: grid;
  gap: 18px;
  margin-top: 26px;
}

.page-about .badges {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
}

.page-about .badge {
  padding: 15px 16px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-m);
  background: var(--about-panel);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .badge:hover,
.page-about .badge:focus-within,
.page-about .badge:focus {
  border-color: rgba(242, 179, 61, .75);
  background: rgba(23, 51, 77, .95);
  outline: none;
}

.page-about .badge__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .07em;
  color: var(--amber);
}

.page-about .badge__name {
  display: block;
  margin-top: 6px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .badge__note {
  display: block;
  margin-top: 7px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--mist);
  transition: color var(--dur) var(--ease);
}

.page-about .badge:hover .badge__note,
.page-about .badge:focus .badge__note {
  color: var(--paper);
}

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

.page-about .eco__fig .fig__frame {
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-l);
  overflow: hidden;
}

/* ---------- 收束 ---------- */

.page-about .about-cta-section {
  padding-bottom: 56px;
}

.page-about .about-cta {
  padding: 22px 20px;
  border: 1px solid rgba(242, 179, 61, .3);
  border-radius: var(--radius-l);
  background: linear-gradient(120deg, rgba(14, 59, 46, .95) 0%, rgba(23, 51, 77, .92) 100%);
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--paper);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.page-about .about-cta__actions .btn {
  flex: 0 1 auto;
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about {
    --tl-rail: 96px;
  }

  .page-about .about-hero {
    padding-top: 34px;
  }

  .page-about .tl__body p {
    font-size: 16px;
  }

  .page-about .about-cta {
    padding: 30px 28px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --tl-rail: 112px;
  }

  .page-about .about-hero h1 {
    max-width: 20ch;
  }

  .page-about .about-hero__fig {
    margin-top: 42px;
  }

  .page-about .tl__item {
    gap: 26px;
    padding-bottom: 40px;
  }

  .page-about .tl__rail {
    padding-right: 20px;
  }

  .page-about .diff {
    grid-template-columns: 1fr 1fr;
    gap: 0;
  }

  .page-about .diff__col--old {
    border-right: 0;
    border-radius: var(--radius-m) 0 0 var(--radius-m);
    padding: 22px 26px 22px 22px;
  }

  .page-about .diff__col--new {
    border-radius: 0 var(--radius-m) var(--radius-m) 0;
    padding: 22px 22px 22px 26px;
  }

  .page-about .diff__seam {
    display: block;
    position: absolute;
    left: 50%;
    top: 14px;
    bottom: 14px;
    width: 1px;
    transform: translateX(-50%);
    background: linear-gradient(180deg, transparent, var(--amber), transparent);
  }

  .page-about .team {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 30px;
    align-items: center;
  }

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

  .page-about .tree__row::before {
    content: "";
    position: absolute;
    top: -14px;
    left: 16%;
    right: 16%;
    height: 1px;
    background: var(--about-hair);
  }

  .page-about .tree__node::before {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 100%;
    width: 1px;
    height: 14px;
    background: var(--about-hair);
  }

  .page-about .eco {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 30px;
    align-items: start;
  }

  .page-about .about-cta__actions {
    gap: 12px;
    margin-top: 22px;
  }
}

@media (min-width: 1160px) {
  .page-about .about-hero {
    padding-top: 44px;
  }

  .page-about .facts {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .vrow .panel__head,
  .page-about .badge,
  .page-about .badge__note {
    transition: none;
  }
}
</style>
<<<PAGE_CSS_END>>>