/* ===========================================================
   page-about · 品牌中心
   纵向时间轴脊柱：左侧刻度 + 右侧叙述与数据卡
   =========================================================== */

.page-about {
  --about-rail: 26px;
  --about-line: rgba(111, 217, 230, 0.26);
}

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

/* ---------- 面板骨架 ---------- */

.page-about .panel {
  position: relative;
  padding-top: 56px;
  padding-bottom: 60px;
  border-top: 1px solid var(--line-soft);
}

.page-about .panel__head {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 34px;
  max-width: 74ch;
}

.page-about .panel__index {
  margin: 0;
  font-family: var(--font-num);
  font-size: var(--step-2);
  letter-spacing: 0.18em;
  color: var(--c-steel);
  text-transform: uppercase;
}

.page-about .panel__title {
  margin: 0;
  font-size: clamp(25px, 6.2vw, var(--step-6));
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.page-about .panel__meta {
  margin: 0;
  font-family: var(--font-num);
  font-size: var(--step-2);
  letter-spacing: 0.12em;
  color: var(--c-steel);
}

.page-about .panel__body {
  margin: 0;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .h-soft {
  font-weight: 400;
  color: var(--ink-soft);
}

/* ---------- P-01 封面 ---------- */

.page-about .cover-panel {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(120% 92% at 12% 0%, rgba(30, 59, 110, 0.92) 0%, rgba(10, 23, 51, 0) 62%),
    radial-gradient(70% 62% at 94% 12%, rgba(255, 107, 44, 0.14) 0%, rgba(10, 23, 51, 0) 72%);
}

.page-about .cover-panel::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(111, 217, 230, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(111, 217, 230, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 78%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 78%);
}

.page-about .cover {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 38px;
  padding-top: 34px;
  padding-bottom: 68px;
}

.page-about .cover-main h1 {
  margin: 14px 0 20px;
  font-size: clamp(34px, 8.4vw, var(--step-7));
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.022em;
  color: var(--ink);
}

.page-about .cover-note {
  margin: 18px 0 0;
  font-family: var(--font-num);
  font-size: var(--step-2);
  letter-spacing: 0.04em;
  color: var(--c-glacier);
}

.page-about .cover-toc {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .cover-toc a {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-num);
  font-size: var(--step-1);
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  text-decoration: none;
  transition: color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background var(--dur) var(--ease);
}

.page-about .cover-toc a:hover,
.page-about .cover-toc a:focus-visible {
  color: var(--c-lava);
  border-color: var(--c-lava);
  background: rgba(255, 107, 44, 0.08);
}

.page-about .cover-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
  background: var(--glass);
}

.page-about .cover-stats .stat {
  padding: 18px 16px;
  border-right: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .cover-stats .stat:nth-child(2n) {
  border-right: 0;
}

.page-about .cover-stats .stat:nth-last-child(-n + 2) {
  border-bottom: 0;
}

.page-about .cover-stats .stat__value {
  display: flex;
  align-items: baseline;
  gap: 3px;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 7vw, var(--step-6));
  font-weight: 800;
  line-height: 1;
  color: var(--ink);
}

.page-about .cover-stats .stat__unit {
  font-size: var(--step-2);
  font-weight: 500;
  color: var(--c-glacier);
}

.page-about .cover-stats .stat__label {
  display: block;
  margin-top: 10px;
  font-size: var(--step-1);
  line-height: 1.6;
  color: var(--ink-mute);
}

/* ---------- P-02 时间轴 ---------- */

.page-about .tl-layout {
  display: grid;
  gap: 34px;
}

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

.page-about .tl-list {
  position: relative;
  margin: 0;
  padding: 4px 0 0 var(--about-rail);
  list-style: none;
}

.page-about .tl-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--c-ice) 0%, var(--c-glacier) 55%, rgba(111, 217, 230, 0) 100%);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 34px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: calc(var(--about-rail) * -1 + 0.5px);
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-lava);
  box-shadow: 0 0 0 4px rgba(255, 107, 44, 0.15);
}

.page-about .tl-year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: var(--step-5);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-lava);
}

.page-about .tl-node summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  list-style: none;
  cursor: pointer;
  transition: color var(--dur) var(--ease);
}

.page-about .tl-node summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-node summary::after {
  content: "＋";
  margin-left: auto;
  padding-left: 12px;
  font-family: var(--font-num);
  font-size: var(--step-3);
  color: var(--c-steel);
  transition: color var(--dur) var(--ease);
}

.page-about .tl-node[open] summary::after {
  content: "－";
  color: var(--c-lava);
}

.page-about .tl-node summary:focus-visible {
  outline: 2px solid var(--c-signal);
  outline-offset: 4px;
  border-radius: var(--radius-s);
}

.page-about .tl-node__title {
  font-size: var(--step-4);
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl-node summary:hover .tl-node__title {
  color: var(--c-glacier);
}

.page-about .tl-node__body {
  margin: 12px 0 0;
  max-width: 60ch;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- P-03 团队 ---------- */

.page-about .team-grid {
  display: grid;
  gap: 32px;
}

.page-about .team-copy p {
  margin: 0 0 18px;
  font-size: var(--step-3);
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .team-figure {
  margin: 26px 0 0;
}

.page-about .team-facts {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  align-self: start;
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
  background: var(--line-soft);
}

.page-about .team-facts li {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  align-items: baseline;
  gap: 12px;
  padding: 16px 18px;
  background: var(--glass);
  transition: background var(--dur) var(--ease);
}

.page-about .team-facts li:hover {
  background: var(--glass-hi);
}

.page-about .team-facts b {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: var(--step-4);
  font-weight: 700;
  line-height: 1.1;
  color: var(--c-glacier);
}

.page-about .team-facts span {
  font-size: var(--step-2);
  line-height: 1.65;
  color: var(--ink-soft);
}

/* ---------- P-04 机制 ---------- */

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

.page-about .flow__step {
  padding: 22px 20px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: var(--glass);
  transition: transform var(--dur) var(--ease),
              background var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.page-about .flow__step:hover {
  transform: translateY(-2px);
  background: var(--glass-hi);
  border-color: var(--c-glacier);
}

.page-about .flow__num {
  display: block;
  font-family: var(--font-num);
  font-size: var(--step-2);
  letter-spacing: 0.18em;
  color: var(--c-lava);
}

.page-about .flow__title {
  margin: 12px 0 8px;
  font-size: var(--step-4);
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .flow__text {
  margin: 0;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--ink-soft);
}

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

.page-about .audit-note {
  margin: 22px 0 0;
  max-width: 66ch;
  padding-left: 16px;
  border-left: 2px solid var(--c-signal);
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- P-05 合作 ---------- */

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

.page-about .partner-grid .card {
  display: flex;
  flex-direction: column;
  padding: 24px 22px 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: var(--glass);
  transition: transform var(--dur) var(--ease),
              background var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.page-about .partner-grid .card:hover {
  transform: translateY(-2px);
  background: var(--glass-hi);
  border-color: var(--c-glacier);
}

.page-about .card__top {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 16px;
}

.page-about .card__num {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-size: var(--step-6);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ink);
}

.page-about .card__unit {
  font-size: var(--step-2);
  color: var(--c-steel);
}

.page-about .partner-grid .card__title {
  margin: 0 0 10px;
  font-size: var(--step-4);
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .partner-grid .card__text {
  margin: 0;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- P-06 收束 ---------- */

.page-about .panel--closing {
  padding-bottom: 96px;
}

.page-about .closing-grid {
  display: grid;
  gap: 32px;
}

.page-about .closing-lede {
  margin: 0;
  max-width: 34ch;
  font-size: clamp(20px, 4.6vw, var(--step-5));
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: -0.008em;
  color: var(--ink);
}

.page-about .closing-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-self: end;
}

.page-about .closing-foot {
  margin: 34px 0 0;
  font-size: var(--step-2);
  line-height: 1.7;
  color: var(--ink-mute);
}

.page-about .inline-link {
  color: var(--c-glacier);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--c-lava);
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about {
    --about-rail: 92px;
  }

  .page-about .panel {
    padding-top: 72px;
    padding-bottom: 76px;
  }

  .page-about .cover {
    padding-top: 54px;
    padding-bottom: 96px;
  }
}

@media (min-width: 860px) {
  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 960px) {
  .page-about .cover {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 0.9fr);
    gap: 58px;
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 54px;
    align-items: start;
  }

  .page-about .closing-grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
    gap: 56px;
    align-items: end;
  }
}

@media (min-width: 1040px) {
  .page-about .tl-layout {
    grid-template-columns: 296px minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .tl-item {
    display: grid;
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 0 26px;
    padding-bottom: 40px;
  }

  .page-about .tl-item::before {
    top: 10px;
  }

  .page-about .tl-year {
    margin-bottom: 0;
  }

  .page-about .panel--closing {
    padding-bottom: 140px;
  }
}

@media (min-width: 1040px) and (min-height: 720px) {
  .page-about .tl-figure {
    position: sticky;
    top: calc(var(--bar-h-slim) + 26px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .cover-toc a,
  .page-about .flow__step,
  .page-about .partner-grid .card,
  .page-about .team-facts li,
  .page-about .tl-node summary,
  .page-about .tl-node summary::after,
  .page-about .inline-link {
    transition: opacity var(--dur) var(--ease);
    transform: none;
  }
}