/* ============================================================
   品牌中心 /brand/ —— 页面专属样式，全部限定在 .page-about 内
   ============================================================ */

.page-about {
  --about-rail: 132px;
  --about-gap: 32px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 28px;
  padding-bottom: 4px;
  font-size: var(--fs-index);
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .breadcrumb .breadcrumb__sep {
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-masthead {
  padding: 24px 0 56px;
}

.page-about .about-masthead__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: start;
}

.page-about .about-masthead__media {
  margin: 0;
  max-width: 260px;
}

.page-about .about-masthead__copy h1 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(32px, 7.6vw, 68px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 14px 0 0;
}

.page-about .about-masthead__copy .lead {
  margin: 22px 0 0;
  max-width: 60ch;
  font-size: var(--fs-lead);
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-masthead__facts {
  list-style: none;
  margin: 34px 0 0;
  padding: 1px 0 0 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-masthead__facts li {
  background: var(--bg-base);
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-masthead__facts .mono {
  font-size: 26px;
  line-height: 1;
  color: var(--lime);
  letter-spacing: 0.02em;
}

.page-about .about-masthead__facts li > span:last-child {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.4;
}

/* ---------- 章节通用骨架 ---------- */
.page-about .about-chapter {
  padding: 52px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 90px;
}

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  align-items: start;
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-chapter__num {
  font-size: 40px;
  line-height: 0.9;
  font-weight: 700;
  color: var(--mauve);
  letter-spacing: 0.01em;
}

.page-about .about-chapter__mark {
  font-size: var(--fs-index);
  letter-spacing: 0.16em;
  color: var(--muted);
  text-transform: uppercase;
  padding-bottom: 2px;
  border-bottom: 1px dashed var(--line);
}

.page-about .about-chapter__title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(24px, 5.2vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 0;
}

.page-about .about-chapter__lede {
  margin: 18px 0 0;
  max-width: 66ch;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 01 三类内容 ---------- */
.page-about .about-pillars {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
}

.page-about .about-pillar {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 16px;
  padding: 22px 0;
  background: var(--bg-base);
  transition: background var(--t-fast) var(--ease);
}

.page-about .about-pillar:hover {
  background: var(--bg-panel);
}

.page-about .about-pillar__idx {
  font-size: 22px;
  line-height: 1;
  color: var(--coral);
  letter-spacing: 0.02em;
  padding-top: 4px;
}

.page-about .about-pillar__text h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: var(--fs-h4);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .about-pillar__text p {
  margin: 10px 0 0;
  max-width: 62ch;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-link {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid var(--lime-dim);
  padding-bottom: 2px;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

.page-about .about-link::after {
  content: " →";
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  border-bottom-color: var(--lime);
  color: var(--ink);
}

/* ---------- 02 分类体系 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
}

.page-about .about-taxonomy {
  margin-top: 32px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-tax {
  position: relative;
  background: var(--bg-panel);
  padding: 22px 20px 26px;
  transition: background var(--t-fast) var(--ease);
}

.page-about .about-tax:hover {
  background: var(--bg-deep);
}

.page-about .about-tax::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: transparent;
  transition: background var(--t-fast) var(--ease);
}

.page-about .about-tax:hover::before {
  background: var(--lime);
}

.page-about .about-tax__idx {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mauve);
  padding: 2px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
}

.page-about .about-tax__name {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  color: var(--ink);
}

.page-about .about-tax__desc {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-tax__tags {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .about-tax__tags li {
  font-size: 12px;
  line-height: 1;
  padding: 6px 9px;
  color: var(--ink);
  background: var(--bg-deep);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .about-tax__count {
  display: block;
  margin-top: 16px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color var(--t-fast) var(--ease);
}

.page-about .about-tax:hover .about-tax__count {
  color: var(--lime);
}

/* ---------- 03 时间轴 ---------- */
.page-about .about-timeline {
  display: flex;
  gap: 0;
  margin-top: 36px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 8px;
}

.page-about .about-timeline::-webkit-scrollbar {
  height: 4px;
}

.page-about .about-timeline::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 999px;
}

.page-about .about-timeline__step {
  flex: 0 0 84%;
  min-width: 0;
  scroll-snap-align: start;
}

.page-about .about-timeline__axis {
  position: relative;
  height: 24px;
  display: flex;
  align-items: center;
}

.page-about .about-timeline__axis::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: var(--line);
}

.page-about .about-timeline__dot {
  position: relative;
  z-index: 1;
  flex: none;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--coral);
  box-shadow: 0 0 0 4px var(--bg-base);
}

.page-about .about-timeline__year {
  position: relative;
  z-index: 1;
  margin-left: 10px;
  padding: 0 8px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--coral);
  background: var(--bg-base);
}

.page-about .about-timeline__card {
  margin: 10px 22px 0 0;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 16px;
  transition: border-color var(--t-fast) var(--ease);
}

.page-about .about-timeline__card:hover,
.page-about .about-timeline__card[open] {
  border-color: var(--lime);
}

.page-about .about-timeline__card summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.4;
  color: var(--ink);
}

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

.page-about .about-timeline__card summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lime);
}

.page-about .about-timeline__card[open] summary::after {
  content: "–";
}

.page-about .about-timeline__card p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-timeline__hint {
  margin: 14px 0 0;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 数据带 ---------- */
.page-about .data-strip {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--bg-deep);
}

.page-about .data-strip__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  padding-top: 18px;
  padding-bottom: 18px;
}

.page-about .data-strip__label {
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--mauve);
}

.page-about .data-strip__value {
  font-size: 14px;
  color: var(--ink);
}

.page-about .data-strip__sep {
  width: 16px;
  height: 1px;
  background: var(--line);
}

/* ---------- 04 团队 ---------- */
.page-about .about-team {
  margin-top: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-panel);
  padding: 24px 20px;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .about-team__meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .about-team__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-team__val {
  font-size: 22px;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-team__track {
  display: block;
  margin-top: 10px;
  height: 6px;
  background: var(--bg-deep);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .about-team__fill {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--lime-dim), var(--lime));
}

.page-about .about-team__item:nth-child(1) .about-team__fill { width: 35.3%; }
.page-about .about-team__item:nth-child(2) .about-team__fill { width: 26.5%; }
.page-about .about-team__item:nth-child(3) .about-team__fill { width: 17.7%; }
.page-about .about-team__item:nth-child(4) .about-team__fill { width: 20.6%; }

.page-about .about-team__item:nth-child(2) .about-team__fill { background: linear-gradient(90deg, #3A2418, var(--coral)); }
.page-about .about-team__item:nth-child(3) .about-team__fill { background: linear-gradient(90deg, #2A2440, var(--mauve)); }
.page-about .about-team__item:nth-child(4) .about-team__fill { background: linear-gradient(90deg, #1E2E3F, var(--muted)); }

.page-about .about-team__note {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 05 三道关 ---------- */
.page-about .about-gates {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-gate {
  position: relative;
  background: var(--bg-panel);
  padding: 22px 20px 24px;
  border-left: 2px solid transparent;
  transition: border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-gate:hover {
  border-left-color: var(--coral);
  background: var(--bg-deep);
}

.page-about .about-gate__num {
  display: block;
  font-size: 30px;
  line-height: 1;
  color: var(--line);
  letter-spacing: 0.02em;
}

.page-about .about-gate__name {
  margin: 12px 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  color: var(--ink);
}

.page-about .about-gate p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-paper {
  margin-top: 28px;
}

.page-about .about-paper p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
}

/* ---------- 06 伙伴 ---------- */
.page-about .about-partners {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-partners__item {
  position: relative;
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-panel);
  transition: border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}

.page-about .about-partners__item:hover {
  border-color: var(--lime);
  transform: translateY(-2px);
}

.page-about .about-partners__idx {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mauve);
}

.page-about .about-partners__item h3 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
}

.page-about .about-partners__item p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 07 可复用能力 ---------- */
.page-about .about-accum {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 34px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-accum__stat {
  background: var(--bg-base);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-accum__num {
  font-size: 50px;
  line-height: 1;
  color: var(--lime);
  letter-spacing: 0.01em;
}

.page-about .about-accum__cap {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-accum__sub {
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .about-accum__text {
  margin: 24px 0 0;
  max-width: 66ch;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-cta {
  margin-top: 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta .btn {
  flex: 1 1 auto;
  min-width: 148px;
  text-align: center;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-taxonomy {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 900px) {
  .page-about {
    --about-rail: 156px;
    --about-gap: 48px;
  }

  .page-about .about-masthead {
    padding: 40px 0 76px;
  }

  .page-about .about-masthead__grid {
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-masthead__media {
    max-width: none;
    margin-top: 8px;
  }

  .page-about .about-masthead__copy .lead {
    margin-top: 26px;
  }

  .page-about .about-chapter {
    padding: 78px 0;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-chapter__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-chapter__num {
    font-size: 54px;
  }

  .page-about .about-chapter__mark {
    border-bottom: none;
    border-left: 1px solid var(--line);
    padding: 0 0 0 10px;
    line-height: 1.5;
  }

  .page-about .about-pillar {
    grid-template-columns: 60px minmax(0, 1fr);
    padding: 26px 0;
  }

  .page-about .about-timeline__step {
    flex: 0 0 248px;
  }

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

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

  .page-about .about-team {
    padding: 32px 30px;
  }

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

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

  .page-about .about-accum__num {
    font-size: 62px;
  }
}

@media (min-width: 1180px) {
  .page-about {
    --about-rail: 176px;
    --about-gap: 64px;
  }

  .page-about .about-masthead__grid {
    grid-template-columns: 320px minmax(0, 1fr);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-partners__item:hover {
    transform: none;
  }
}