.page-about {
  --about-rail-x: 11px;
  --about-gutter: 34px;
  --about-body: rgba(242, 233, 216, 0.82);
  --about-body-dim: rgba(242, 233, 216, 0.66);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 20px;
  padding-bottom: 4px;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding-top: 12px;
  background:
    radial-gradient(120% 90% at 8% 0%, rgba(47, 227, 154, 0.09), transparent 58%),
    radial-gradient(90% 70% at 100% 20%, rgba(255, 154, 60, 0.06), transparent 60%);
}

.page-about .about-hero-frame {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: linear-gradient(158deg, var(--deep) 0%, var(--ink) 72%);
  padding: clamp(24px, 4.2vw, 54px);
  overflow: hidden;
}

.page-about .about-hero-frame::before {
  content: "";
  position: absolute;
  top: 14px;
  left: 14px;
  right: 14px;
  height: 7px;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(159, 181, 172, 0.34) 0 1px,
    transparent 1px 20px
  );
  pointer-events: none;
}

.page-about .about-hero-frame::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle at 100% 0%, rgba(47, 227, 154, 0.16), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero-head {
  position: relative;
  z-index: 1;
  padding-top: 18px;
}

.page-about .about-hero-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--aqua);
}

.page-about .about-hero h1 {
  margin: 16px 0 0;
  max-width: 18em;
  font-size: clamp(2.05rem, 6.4vw, 4.1rem);
  line-height: 1.06;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero-lead {
  margin: 22px 0 0;
  max-width: 36em;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--about-body);
}

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

.page-about .about-hero-figure {
  position: relative;
  z-index: 1;
  margin: 34px 0 0;
}

.page-about .about-hero-figure .media-frame {
  border-radius: var(--radius-m);
  overflow: hidden;
  border: 1px solid var(--line-soft);
}

.page-about .about-hero-figure img,
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-caption {
  display: block;
  margin-top: 10px;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 首屏数据带 ---------- */
.page-about .about-hero-stats {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-hero-stats .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  border-left: 3px solid var(--mint);
  border-radius: var(--radius-s);
  background: var(--panel);
}

.page-about .about-hero-stats .stat:nth-child(2) {
  border-left-color: var(--aqua);
}

.page-about .about-hero-stats .stat:nth-child(3) {
  border-left-color: var(--sand);
}

.page-about .about-hero-stats .stat:nth-child(4) {
  border-left-color: var(--amber);
}

.page-about .about-hero-stats .stat-value {
  font-family: var(--font-mono);
  font-size: 1.7rem;
  line-height: 1;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero-stats .stat-label {
  font-size: 0.82rem;
  color: var(--mist);
}

/* ---------- 主体布局：索引 + 时间轴 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .about-index-list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-index-list .anchor-link {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--pill);
  border: 1px solid var(--line);
  font-size: 0.84rem;
  color: var(--about-body-dim);
  text-decoration: none;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about .about-index-list .anchor-link:hover,
.page-about .about-index-list .anchor-link[aria-current="true"] {
  border-color: var(--mint);
  color: var(--mint);
  background: var(--mint-soft);
}

/* ---------- 时间轴 ---------- */
.page-about .about-stream {
  position: relative;
  padding-left: var(--about-gutter);
}

.page-about .about-stream::before {
  content: "";
  position: absolute;
  left: var(--about-rail-x);
  top: 8px;
  bottom: 40px;
  width: 2px;
  border-radius: var(--pill);
  background: linear-gradient(
    180deg,
    var(--mint) 0%,
    rgba(47, 227, 154, 0.42) 26%,
    rgba(159, 181, 172, 0.26) 68%,
    rgba(255, 154, 60, 0.5) 100%
  );
}

.page-about .about-node {
  position: relative;
  padding-bottom: 46px;
}

.page-about .about-node:last-child {
  padding-bottom: 8px;
}

.page-about .about-node-dot {
  position: absolute;
  left: -28px;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--deep);
  border: 2px solid var(--mint);
  box-shadow: 0 0 0 4px rgba(47, 227, 154, 0.1);
  transition: background 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
  z-index: 1;
}

.page-about .about-node:hover .about-node-dot {
  background: var(--mint);
  box-shadow: 0 0 0 7px rgba(47, 227, 154, 0.18);
}

.page-about .about-node--next .about-node-dot {
  border-color: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 154, 60, 0.14);
  border-style: dashed;
}

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

.page-about .about-node-aside {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 12px;
}

.page-about .about-node-num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--mint);
  font-variant-numeric: tabular-nums;
}

.page-about .about-node--next .about-node-num {
  color: var(--amber);
}

.page-about .about-node-meta {
  margin: 0;
  flex-basis: 100%;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-node-main h2 {
  margin: 0 0 14px;
  font-size: clamp(1.3rem, 3.4vw, 1.85rem);
  line-height: 1.26;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-node-main p {
  margin: 0 0 14px;
  max-width: 34em;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--about-body);
}

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

.page-about .about-inline-link {
  color: var(--aqua);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 217, 198, 0.42);
  padding-bottom: 1px;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-inline-link:hover {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

/* ---------- 展开组 ---------- */
.page-about .about-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
  padding: 9px 18px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: transparent;
  color: var(--aqua);
  font-family: inherit;
  font-size: 0.88rem;
  line-height: 1;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about .about-toggle::after {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 0.95rem;
}

.page-about .about-toggle[aria-expanded="true"]::after {
  content: "－";
}

.page-about .about-toggle:hover {
  border-color: var(--mint);
  color: var(--mint);
  background: var(--mint-soft);
}

.page-about .about-detail {
  margin-top: 18px;
  padding: 18px 20px;
  border-left: 3px solid var(--sand);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
  background: var(--panel);
}

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

.page-about .about-detail-list li {
  display: grid;
  gap: 4px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-detail-list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-detail-list strong {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--sand);
}

.page-about .about-detail-list span {
  font-size: 0.94rem;
  line-height: 1.72;
  color: var(--about-body-dim);
}

/* ---------- 图组 ---------- */
.page-about .about-figure {
  margin: 24px 0 0;
}

.page-about .about-figure .media-frame {
  border-radius: var(--radius-m);
  overflow: hidden;
  border: 1px solid var(--line-soft);
}

/* ---------- 下一步动作 ---------- */
.page-about .about-next-actions {
  margin-top: 22px;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-node-grid {
    grid-template-columns: minmax(150px, 215px) minmax(0, 1fr);
    gap: 6px 48px;
    align-items: start;
  }

  .page-about .about-node:nth-of-type(even) .about-node-grid {
    grid-template-columns: minmax(0, 1fr) minmax(150px, 215px);
  }

  .page-about .about-node:nth-of-type(even) .about-node-aside {
    order: 2;
  }

  .page-about .about-node-aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .page-about .about-node-meta {
    flex-basis: auto;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 188px minmax(0, 1fr);
    gap: 60px;
    align-items: start;
  }

  .page-about .about-index-sticky {
    position: sticky;
    top: 96px;
  }

  .page-about .about-index-list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 6px;
  }

  .page-about .about-index-list .anchor-link {
    width: 100%;
    border-color: transparent;
    border-left: 2px solid var(--line);
    border-radius: 0 var(--radius-s) var(--radius-s) 0;
    padding: 7px 12px;
  }
}

/* ---------- 窄屏收紧 ---------- */
@media (max-width: 560px) {
  .page-about {
    --about-gutter: 26px;
    --about-rail-x: 8px;
  }

  .page-about .about-node-dot {
    left: -22px;
    width: 10px;
    height: 10px;
  }

  .page-about .about-hero-frame {
    padding: 22px 18px 24px;
  }

  .page-about .about-detail {
    padding: 16px 15px;
  }

  .page-about .about-hero-stats .stat {
    padding: 12px 13px;
  }
}