.page-about {
  --about-rail: 68px;
  --about-gap: 18px;
  background: var(--pitch);
  color: var(--mist);
  font-family: var(--sans);
  padding: 0 0 64px;
}

.page-about .about-wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 18px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: 18px 0 0;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--grey);
}

.page-about .breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--line);
}

.page-about .breadcrumb__link {
  color: var(--grey);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 120ms ease, border-color 120ms ease;
}

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

/* ---------- 主题声明 ---------- */
.page-about .about-hero {
  padding: 26px 0 0;
}

.page-about .about-hero__kicker {
  margin: 0 0 16px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  max-width: 20ch;
  font-size: clamp(28px, 7vw, 48px);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.012em;
  color: var(--mist);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--grey);
}

.page-about .about-hero__figure {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  background: var(--stand);
}

.page-about .about-hero__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  filter: saturate(0.7) contrast(1.06) brightness(0.9);
}

.page-about .about-hero__caption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--grey);
}

/* ---------- 页内目录 ---------- */
.page-about .about-toc {
  margin: 22px 0 0;
  border: 1px solid var(--line);
  background: var(--stand);
  padding: 14px 16px 16px;
}

.page-about .about-toc__head {
  margin: 0 0 12px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--grey);
}

.page-about .about-toc__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc__link {
  display: block;
  padding: 10px 12px;
  font-size: 12px;
  letter-spacing: 0.06em;
  text-decoration: none;
  color: var(--grey);
  background: var(--pitch);
  border-left: 2px solid transparent;
  transition: color 120ms ease, border-color 120ms ease, background 120ms ease;
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--lime);
  border-left-color: var(--lime);
  background: var(--lime-mist);
}

/* ---------- 时间线主结构 ---------- */
.page-about .about-tl {
  position: relative;
  margin: 28px 0 0;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--about-rail) - 1px);
  width: 1px;
  background: var(--line);
  pointer-events: none;
}

.page-about .tl-item {
  display: grid;
  grid-template-columns: var(--about-rail) minmax(0, 1fr);
  align-items: start;
}

.page-about .tl-rail {
  position: relative;
  padding: 26px 14px 26px 0;
  text-align: right;
}

.page-about .tl-tick {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .tl-item::after {
  content: "";
  position: absolute;
  left: calc(var(--about-rail) - 4px);
  top: 31px;
  width: 7px;
  height: 7px;
  background: var(--pitch);
  border: 1px solid var(--line);
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item:target::after,
.page-about .tl-item:hover::after {
  border-color: var(--lime);
  background: var(--lime);
}

.page-about .tl-card {
  margin: 10px 0 14px 18px;
  padding: 22px 18px;
  background: var(--stand);
  border: 1px solid var(--line);
  transition: border-color 120ms ease;
}

.page-about .tl-item:target .tl-card {
  border-color: var(--lime);
}

.page-about .tl-eyebrow {
  margin: 0 0 12px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .tl-title {
  margin: 0 0 14px;
  font-size: clamp(20px, 4.4vw, 26px);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.005em;
  color: var(--mist);
}

.page-about .tl-text {
  margin: 0 0 6px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--grey);
  max-width: 62ch;
}

.page-about .tl-text--tight {
  margin-top: 14px;
}

.page-about .tl-links {
  margin: 18px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 阶段列表 ---------- */
.page-about .about-phases {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-phase {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-phase__year {
  font-size: 13px;
  font-weight: 700;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.page-about .about-phase__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--grey);
}

.page-about .about-phase__text strong {
  color: var(--mist);
  font-weight: 500;
}

/* ---------- 数据块 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 18px 0 0;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-stat {
  padding: 16px 14px;
  background: var(--pitch);
  border-left: 2px solid var(--lime);
}

.page-about .about-stat__num {
  display: block;
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat__num--orange {
  color: var(--orange);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--grey);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: 22px 0 0;
  border: 1px solid var(--line);
  background: var(--pitch);
}

.page-about .about-figure__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(0.7) contrast(1.06) brightness(0.9);
}

.page-about .about-figure__img--flow {
  aspect-ratio: 10 / 7;
}

.page-about .about-figure__caption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.6;
  color: var(--grey);
}

/* ---------- 四步流程 ---------- */
.page-about .about-flow {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .flow__step {
  border: 1px solid var(--line);
  background: var(--pitch);
}

.page-about .flow__step + .flow__step {
  border-top: 0;
}

.page-about .flow__details[open] {
  background: var(--lime-mist);
}

.page-about .flow__summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  transition: background 120ms ease;
}

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

.page-about .flow__summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1;
  color: var(--grey);
}

.page-about .flow__details[open] .flow__summary::after {
  content: "−";
  color: var(--lime);
}

.page-about .flow__summary:hover {
  background: var(--lime-mist);
}

.page-about .flow__idx {
  flex: 0 0 auto;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--lime);
}

.page-about .flow__name {
  flex: 1 1 auto;
  font-size: 15px;
  font-weight: 500;
  color: var(--mist);
}

.page-about .flow__text {
  margin: 0;
  padding: 0 18px 16px 18px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--grey);
  max-width: 62ch;
}

/* ---------- 赛事覆盖 ---------- */
.page-about .about-cover {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 20px 0 0;
}

.page-about .about-cover__main {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--lime);
  background: var(--pitch);
}

.page-about .about-cover__num {
  font-size: 52px;
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-cover__cap {
  font-size: 13px;
  line-height: 1.6;
  color: var(--grey);
}

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

.page-about .about-cover__stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 16px 0 0;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-cover__cell {
  padding: 14px;
  background: var(--pitch);
}

.page-about .about-cover__cell-num {
  display: block;
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--mist);
  font-variant-numeric: tabular-nums;
}

.page-about .about-cover__cell-num--orange {
  color: var(--orange);
}

.page-about .about-cover__cell-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--grey);
}

/* ---------- 顾问与合作 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-partner {
  padding: 16px;
  background: var(--pitch);
  border-top: 2px solid var(--line);
}

.page-about .about-partner__num {
  display: inline-block;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-partner__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--mist);
}

.page-about .about-partner__text {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--grey);
}

/* ---------- 认可与投入 ---------- */
.page-about .about-honors {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-honor {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 14px;
  align-items: center;
  padding: 14px;
  border: 1px solid var(--line);
  background: var(--pitch);
}

.page-about .about-honor__year {
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .about-honor__name {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 页脚前的山东服务说明 ---------- */
.page-about .about-foot {
  margin: 22px 0 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  background: var(--pitch);
}

.page-about .about-foot__text {
  margin: 0;
  font-size: 13px;
  line-height: 1.78;
  color: var(--grey);
}

.page-about .about-foot__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--grey);
}

/* ---------- 中屏 ---------- */
@media (min-width: 640px) {
  .page-about {
    --about-rail: 92px;
  }

  .page-about .about-wrap {
    padding: 0 28px;
  }

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

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

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

  .page-about .about-partner {
    border-top-width: 2px;
  }

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

  .page-about .tl-card {
    margin-left: 26px;
    padding: 26px 24px;
  }
}

/* ---------- 宽屏 ---------- */
@media (min-width: 1024px) {
  .page-about {
    --about-rail: 118px;
    padding-bottom: 88px;
  }

  .page-about .about-wrap {
    padding: 0 36px;
  }

  .page-about .about-hero {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    grid-template-areas:
      "kicker figure"
      "title  figure"
      "lede   figure";
    column-gap: 36px;
    align-items: start;
    padding-top: 34px;
  }

  .page-about .about-hero__kicker { grid-area: kicker; }
  .page-about .about-hero__title { grid-area: title; }
  .page-about .about-hero__lede { grid-area: lede; }

  .page-about .about-hero__figure {
    grid-area: figure;
    margin-top: 4px;
    align-self: stretch;
  }

  .page-about .about-hero__img {
    height: 100%;
    aspect-ratio: auto;
    min-height: 260px;
  }

  .page-about .about-toc {
    display: grid;
    grid-template-columns: 128px minmax(0, 1fr);
    align-items: center;
    gap: 0 18px;
    padding: 14px 18px;
  }

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

  .page-about .about-toc__list {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .about-toc__link {
    padding: 10px 8px;
  }

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

  .page-about .about-cover {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: stretch;
    gap: 1px;
    border: 1px solid var(--line);
    background: var(--line);
  }

  .page-about .about-cover__main {
    border: 0;
    border-left: 3px solid var(--lime);
    align-items: center;
  }

  .page-about .about-cover__tags {
    background: var(--pitch);
    padding: 16px;
    align-content: flex-start;
  }

  .page-about .about-cover__num {
    font-size: 64px;
  }

  .page-about .tl-card {
    margin-left: 34px;
    padding: 30px 30px 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .tl-card,
  .page-about .flow__summary,
  .page-about .breadcrumb__link {
    transition: none;
  }
}
</main>