.page-about {
  --about-index-w: 172px;
  --about-ease: cubic-bezier(0.2, 0.7, 0.25, 1);
  color: var(--warm);
  background: var(--ink-deep);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  margin: 0 0 clamp(1rem, 3vw, 1.75rem);
  padding: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .breadcrumb li {
  display: flex;
  align-items: center;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin: 0 0.55rem;
  color: var(--ink-soft);
}

.page-about .breadcrumb a {
  color: var(--volt);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(1.5rem, 4vw, 2.75rem);
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 5.6vw, 4.2rem);
  line-height: 1.03;
  letter-spacing: -0.015em;
  margin: 0 0 1.1rem;
  max-width: 22ch;
  color: var(--warm);
}

.page-about .about-hero__lede {
  max-width: 58ch;
  margin: 0 0 1.6rem;
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 0;
}

.page-about .about-hero__panel {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-figure {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1rem 1.15rem;
  background: linear-gradient(140deg, var(--ink-mid), var(--ink-deep));
}

.page-about .about-figure .stat {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 2.6vw, 1.7rem);
  letter-spacing: 0.03em;
  color: var(--flame);
  line-height: 1.1;
}

.page-about .about-figure .stat__label {
  font-size: 0.8rem;
  line-height: 1.55;
  color: var(--mist);
}

/* ---------- 目录 + 主栏 ---------- */
.page-about .about-wrap {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
  padding-block: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-toc {
  align-self: start;
  padding: 1rem 1.05rem 1.15rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background:
    radial-gradient(120% 90% at 0% 0%, rgba(255, 107, 26, 0.14), transparent 60%),
    linear-gradient(160deg, var(--ink-mid), var(--ink-night));
}

.page-about .about-toc__title {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--flame-mist);
}

.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.12rem;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.42rem 0.5rem;
  border-radius: var(--r-sm);
  color: var(--mist);
  font-size: 0.85rem;
  line-height: 1.4;
  text-decoration: none;
  transition: background-color 0.18s var(--about-ease), color 0.18s var(--about-ease),
    transform 0.18s var(--about-ease);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--flame);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  background: rgba(255, 107, 26, 0.14);
  color: var(--warm);
  transform: translateX(3px);
}

.page-about .about-body {
  display: grid;
  gap: clamp(2.25rem, 5vw, 3.5rem);
  min-width: 0;
}

/* ---------- 区块骨架 ---------- */
.page-about .about-block {
  scroll-margin-top: calc(var(--bar-h) + 1rem);
  min-width: 0;
}

.page-about .about-block__head {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  margin-bottom: 1.35rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--line);
}

.page-about .about-block__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--flame);
}

.page-about .about-block__head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 2.7vw, 2rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--warm);
}

.page-about .about-block__body {
  min-width: 0;
}

.page-about .about-block__intro {
  max-width: 62ch;
  margin: 0 0 1.4rem;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .prose p {
  max-width: 64ch;
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .prose p + p {
  margin-top: 0.9rem;
}

.page-about .about-note {
  margin: 1.5rem 0 0;
  padding: 0.7rem 0.95rem;
  border-left: 3px solid var(--volt);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: rgba(61, 220, 255, 0.07);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.65;
  letter-spacing: 0.04em;
  color: var(--volt);
}

.page-about .about-figure-frame {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
}

/* ---------- 四条主线 ---------- */
.page-about .about-lines {
  display: grid;
  gap: 1rem;
}

.page-about .about-line {
  padding: 1.15rem 1.2rem 1.3rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--ink-mid);
  transition: border-color 0.2s var(--about-ease), background-color 0.2s var(--about-ease),
    transform 0.2s var(--about-ease);
}

.page-about .about-line:hover,
.page-about .about-line:focus-within {
  border-color: var(--flame);
  background: var(--ink-soft);
  transform: translateY(-3px);
}

.page-about .about-line__tag {
  display: inline-block;
  margin-bottom: 0.7rem;
  padding: 0.18rem 0.62rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  color: var(--flame-mist);
}

.page-about .about-line h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.05rem, 1.8vw, 1.24rem);
  line-height: 1.25;
  color: var(--warm);
}

.page-about .about-line p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.5rem;
}

.page-about .timeline__item {
  position: relative;
  padding-left: 1.8rem;
}

.page-about .timeline__tick {
  position: absolute;
  top: 0.32rem;
  left: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink-deep);
  border: 2px solid var(--flame);
  transition: background-color 0.2s var(--about-ease), box-shadow 0.2s var(--about-ease);
}

.page-about .timeline__item:hover .timeline__tick,
.page-about .timeline__item:focus-within .timeline__tick {
  background: var(--flame);
  box-shadow: 0 0 0 5px rgba(255, 107, 26, 0.18);
}

.page-about .timeline__era {
  margin: 0 0 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.69rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--flame-mist);
}

.page-about .timeline__title {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  line-height: 1.28;
  color: var(--warm);
}

.page-about .timeline__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .timeline__keys {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.7rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__keys li {
  padding: 0.14rem 0.52rem;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--mist);
  transition: color 0.18s var(--about-ease), border-color 0.18s var(--about-ease);
}

.page-about .timeline__item:hover .timeline__keys li,
.page-about .timeline__item:focus-within .timeline__keys li {
  color: var(--warm);
  border-color: var(--flame-mist);
}

.page-about .timeline__link {
  display: inline-block;
  margin-top: 0.7rem;
  font-size: 0.82rem;
  color: var(--volt);
  text-decoration: none;
  border-bottom: 1px solid var(--line-volt);
  padding-bottom: 1px;
}

.page-about .timeline__link:hover,
.page-about .timeline__link:focus-visible {
  color: var(--flame-mist);
  border-bottom-color: var(--flame-mist);
}

/* ---------- 生产工序 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .about-flow__step {
  position: relative;
  padding: 1.1rem 1.15rem 1.25rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: linear-gradient(150deg, var(--ink-mid) 0%, var(--ink-deep) 100%);
}

.page-about .about-flow__num {
  display: block;
  margin-bottom: 0.55rem;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 1;
  letter-spacing: 0.06em;
  color: rgba(255, 107, 26, 0.85);
}

.page-about .about-flow__step h3 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.08rem;
  color: var(--warm);
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 团队与岗位 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--line-soft);
}

.page-about .about-roles__row {
  display: grid;
  gap: 0.45rem;
  padding: 1.05rem 1.15rem;
  background: var(--ink-deep);
  transition: background-color 0.2s var(--about-ease);
}

.page-about .about-roles__row:hover {
  background: var(--ink-mid);
}

.page-about .about-roles__key {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  color: var(--flame);
}

.page-about .about-roles__val {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 覆盖与合作 ---------- */
.page-about .about-coverage {
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
  align-content: start;
}

.page-about .about-legend__item {
  display: flex;
  gap: 0.65rem;
  align-items: flex-start;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-legend__item strong {
  color: var(--warm);
  font-weight: 600;
}

.page-about .about-dot {
  flex: none;
  width: 10px;
  height: 10px;
  margin-top: 0.6rem;
  border-radius: 3px;
}

.page-about .about-dot--flame {
  background: var(--flame);
}

.page-about .about-dot--volt {
  background: var(--volt);
}

.page-about .about-dot--mist {
  background: var(--mist);
}

.page-about .about-subhead {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0.9rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  color: var(--warm);
}

.page-about .about-coop {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--line-soft);
}

.page-about .about-coop__item {
  padding: 1rem 1.15rem 1.15rem;
  background: var(--ink-mid);
  transition: background-color 0.2s var(--about-ease);
}

.page-about .about-coop__item:hover {
  background: var(--ink-soft);
}

.page-about .about-coop__item h4 {
  margin: 0 0 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--flame-mist);
}

.page-about .about-coop__item p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 1.35rem;
  padding: clamp(1.35rem, 4vw, 2.25rem);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background:
    radial-gradient(110% 120% at 100% 0%, rgba(255, 107, 26, 0.2), transparent 58%),
    linear-gradient(150deg, var(--ink-mid), var(--ink-night));
}

.page-about .about-cta h2 {
  margin: 0 0 0.6rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.25rem, 2.6vw, 1.85rem);
  line-height: 1.2;
  color: var(--warm);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.94rem;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 0;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .page-about .about-lines {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding-bottom: 1.1rem;
  }

  .page-about .about-lines > .about-line:nth-child(even) {
    transform: translateY(1.1rem);
  }

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.35rem;
  }

  .page-about .about-flow__step + .about-flow__step::before {
    content: "→";
    position: absolute;
    top: 1.5rem;
    left: -1rem;
    color: var(--flame);
    font-size: 0.9rem;
    line-height: 1;
  }

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

  .page-about .about-roles__row {
    grid-template-columns: 12rem minmax(0, 1fr);
    gap: 1.25rem;
    align-items: start;
    padding: 1.15rem 1.35rem;
  }
}

@media (min-width: 860px) {
  .page-about .timeline {
    grid-auto-flow: column;
    grid-auto-columns: minmax(210px, 1fr);
    gap: 1.35rem;
    overflow-x: auto;
    padding-bottom: 1.35rem;
  }

  .page-about .timeline::before {
    content: "";
    position: absolute;
    top: 1.74rem;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, var(--flame) 0%, var(--line) 45%, var(--line-soft) 100%);
    pointer-events: none;
  }

  .page-about .timeline__item {
    padding-left: 0;
    padding-top: 2.3rem;
  }

  .page-about .timeline__tick {
    top: 1.15rem;
    left: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-wrap {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: clamp(1rem, 3vw, 2rem);
  }

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

@media (min-width: 980px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 0.85fr);
    align-items: end;
  }

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line,
  .page-about .about-toc__link,
  .page-about .timeline__tick,
  .page-about .timeline__keys li {
    transition-duration: 0.01ms;
  }

  .page-about .about-line:hover,
  .page-about .about-line:focus-within,
  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    transform: none;
  }

  .page-about .about-lines > .about-line:nth-child(even) {
    transform: none;
  }
}