.page-about {
  --about-rail-w: 224px;
  --about-gap: clamp(1.5rem, 4vw, 3.5rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 2.5rem) 0 clamp(2.5rem, 6vw, 4rem);
  background:
    radial-gradient(115% 85% at 92% -18%, rgba(14, 143, 143, 0.16), transparent 60%),
    linear-gradient(178deg, var(--mist) 0%, #E5ECF1 62%, #DDE6EC 100%);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -8%;
  bottom: -1px;
  width: min(46vw, 520px);
  height: min(46vw, 520px);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(232, 128, 31, 0.14), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
  grid-template-columns: 1fr;
  position: relative;
  z-index: 1;
}

.page-about .about-hero__kicker {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--amber-deep);
}

.page-about .about-hero__title {
  margin: 0 0 clamp(1.1rem, 2.5vw, 1.6rem);
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2rem, 5.4vw, 3.75rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 60ch;
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 1.25rem 1.375rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.25rem;
  background: var(--glass);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  align-self: start;
}

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding-left: 0.875rem;
  border-left: 2px solid var(--amber);
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.15;
  color: var(--ink);
}

.page-about .about-facts__label {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 主栏 + 目录 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 clamp(3rem, 7vw, 5.5rem);
}

.page-about .about-rail {
  position: relative;
  padding: 1.125rem 1.25rem;
  background: var(--glass);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  backdrop-filter: blur(8px);
}

.page-about .about-rail .rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.125rem;
}

.page-about .about-rail .rail__link {
  display: flex;
  align-items: baseline;
  gap: 0.625rem;
  padding: 0.5rem 0.625rem;
  border-radius: var(--r-sm);
  font-size: 0.9375rem;
  line-height: 1.45;
  color: var(--ink);
  text-decoration: none;
  transition: background-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-rail .rail__link:hover,
.page-about .about-rail .rail__link:focus-visible {
  background: rgba(232, 128, 31, 0.12);
  color: var(--amber-deep);
}

.page-about .about-rail .rail__link[aria-current="true"] {
  color: var(--amber-deep);
  font-weight: 700;
  background: rgba(232, 128, 31, 0.14);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--teal);
  flex: 0 0 auto;
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-top: clamp(2rem, 4.5vw, 3rem);
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-section + .about-section {
  margin-top: clamp(2.25rem, 5vw, 3.75rem);
}

.page-about .about-sec-head {
  display: flex;
  align-items: baseline;
  gap: 0.875rem;
  margin-bottom: clamp(1.25rem, 2.6vw, 1.75rem);
}

.page-about .about-sec-num {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--silver);
  background: var(--deep);
  padding: 0.25rem 0.5rem;
  border-radius: var(--r-sm);
  flex: 0 0 auto;
}

.page-about .about-sec-title {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(1.5rem, 3.2vw, 2.125rem);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.page-about .about-claim {
  margin: 0 0 clamp(1.25rem, 2.6vw, 1.75rem);
  padding: 0.25rem 0 0.25rem 1rem;
  border-left: 3px solid var(--amber);
  font-size: clamp(1.0625rem, 1.9vw, 1.3125rem);
  font-weight: 700;
  line-height: 1.62;
  color: var(--ink);
  max-width: 44ch;
}

.page-about .about-prose p {
  margin: 0 0 1.05rem;
  max-width: 66ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink);
}

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

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: clamp(1.5rem, 3.5vw, 2.5rem) 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--silver);
}

.page-about .about-figure .figure__caption {
  margin-top: 0.625rem;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 栏目地图 ---------- */
.page-about .channel-map {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .channel-map__item {
  background: var(--silver);
}

.page-about .channel-map__link {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.25rem;
  padding: 1rem 1.125rem;
  text-decoration: none;
  color: inherit;
  border-left: 3px solid transparent;
  transition: border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .channel-map__link:hover,
.page-about .channel-map__link:focus-visible {
  border-left-color: var(--amber);
  background: #FFFDFA;
}

.page-about .channel-map__name {
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .channel-map__desc {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 时间带 ---------- */
.page-about .evo-timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
  margin: clamp(1.5rem, 3.5vw, 2.5rem) 0 0;
}

.page-about .evo-node {
  position: relative;
  padding-left: 2.25rem;
}

.page-about .evo-node::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: -1.75rem;
  width: 1px;
  background: var(--line);
}

.page-about .evo-node:last-child::before {
  display: none;
}

.page-about .evo-node__dot {
  position: absolute;
  left: 0;
  top: 5px;
  box-sizing: border-box;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
  border: 3px solid var(--ink);
}

.page-about .evo-node--now .evo-node__dot {
  background: transparent;
  border-color: var(--amber);
  border-width: 3px;
}

.page-about .evo-node__stage {
  margin: 0 0 0.375rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--teal);
}

.page-about .evo-node--now .evo-node__stage {
  color: var(--amber-deep);
}

.page-about .evo-node__text {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--ink);
  max-width: 34ch;
}

/* ---------- 数据 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: clamp(1.5rem, 3.5vw, 2.25rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-stat {
  background: var(--silver);
  padding: 1.125rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.page-about .about-stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.375rem);
  font-weight: 700;
  line-height: 1.05;
  color: var(--ink);
}

.page-about .about-stat .stat__label {
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--muted);
}

/* ---------- 运营与备案 ---------- */
.page-about .about-owner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 2.75rem);
  margin-top: clamp(1.25rem, 3vw, 1.75rem);
}

.page-about .about-contact {
  margin-top: clamp(1.5rem, 3vw, 2rem);
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--silver);
  overflow: hidden;
}

.page-about .about-contact__row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 0.75rem;
  margin: 0;
  padding: 0.875rem 1.125rem;
  border-top: 1px solid var(--line);
}

.page-about .about-contact__row:first-child {
  border-top: 0;
}

.page-about .about-contact__key {
  flex: 0 0 5.5rem;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .about-contact__val {
  flex: 1 1 12rem;
  min-width: 0;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--ink);
  word-break: break-word;
}

.page-about .about-contact .copy-btn {
  flex: 0 0 auto;
}

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

.page-about .about-owner__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--silver);
}

.page-about .about-owner__figure .figure__caption {
  margin-top: 0.625rem;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .evo-timeline {
    display: flex;
    gap: 1.25rem;
    border-top: 2px solid var(--line);
    padding-top: 0;
    margin-top: clamp(2rem, 4vw, 2.75rem);
  }

  .page-about .evo-node {
    flex: 1 1 0;
    min-width: 0;
    padding: 1.5rem 0 0 0;
  }

  .page-about .evo-node::before {
    display: none;
  }

  .page-about .evo-node__dot {
    left: 0;
    top: -7px;
  }

  .page-about .evo-node__text {
    max-width: none;
  }

  .page-about .about-owner {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 1.5rem);
  }

  .page-about .about-rail .rail__list {
    grid-template-columns: 1fr;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail .rail__link,
  .page-about .channel-map__link {
    transition: none;
  }
}