.page-about {
  --pa-rail-left: 6px;
  --pa-indent: 44px;
  --pa-indent-wide: 124px;
  background: var(--night);
  color: var(--snow);
  display: block;
  overflow-x: hidden;
}

.page-about img {
  display: block;
  max-width: 100%;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: calc(var(--header-h) + 64px) 0 72px;
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(20, 48, 79, 0.85) 0%, rgba(11, 27, 51, 0) 62%),
    var(--night);
  border-bottom: 1px solid var(--star);
}

.page-about .hero-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-top: 24px;
}

.page-about .hero-tag {
  color: var(--amber);
  margin: 0 0 18px;
}

.page-about .about-hero h1 {
  margin: 0;
  font-size: clamp(2rem, 7vw, 4.15rem);
  line-height: 1.08;
  letter-spacing: 0.03em;
  font-weight: 900;
  max-width: 16em;
}

.page-about .about-hero h1 .hl {
  color: var(--orange);
}

.page-about .hero-lead {
  margin: 0 0 18px;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--snow);
  max-width: 40em;
}

.page-about .hero-note {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--mist);
  border-left: 2px solid var(--star);
  padding-left: 16px;
  max-width: 40em;
}

.page-about .hero-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 56px 0 0;
  background: var(--star);
  border-top: 1px solid var(--star);
  border-bottom: 1px solid var(--star);
}

.page-about .hero-figures > div {
  background: var(--night);
  padding: 18px 18px 20px;
}

.page-about .hero-figures dt {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--mist);
  text-transform: uppercase;
}

.page-about .hero-figures dd {
  margin: 8px 0 0;
  font-size: 1.625rem;
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--snow);
}

.page-about .hero-figures dd.num {
  font-variant-numeric: tabular-nums;
}

/* ---------- 章节通用 ---------- */

.page-about .sec {
  padding: 72px 0;
  border-bottom: 1px solid var(--star);
}

.page-about .sec--team,
.page-about .sec--visual {
  background: var(--lake);
}

.page-about .sec--scale {
  background: var(--night);
}

.page-about .sec--next {
  background: var(--night);
  border-bottom: 0;
}

.page-about .sec-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .sec-aside {
  display: flex;
  align-items: center;
  gap: 16px;
}

.page-about .aside-label {
  color: var(--mist);
  margin: 0;
}

.page-about .section-num {
  display: block;
  font-family: var(--mono);
  font-size: 2.25rem;
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--star);
  transition: color 240ms var(--ease), -webkit-text-stroke-color 240ms var(--ease);
}

.page-about .section-num.is-filled {
  color: var(--orange);
  -webkit-text-stroke-color: var(--orange);
}

.page-about .section-title {
  margin: 0 0 16px;
  font-size: clamp(1.5rem, 4vw, 2.4rem);
  line-height: 1.22;
  letter-spacing: 0.045em;
  font-weight: 800;
  color: var(--snow);
}

.page-about .section-lead {
  margin: 0 0 36px;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--mist);
  max-width: 44em;
}

.page-about .mono-label {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ---------- 01 时间轴 ---------- */

.page-about .stage-figure {
  margin: 0 0 44px;
}

.page-about .stage-figure .mono-label,
.page-about .team-figure .mono-label,
.page-about .visual-figure .mono-label,
.page-about .proj-figure .mono-label {
  display: block;
  margin-top: 12px;
  color: var(--mist);
}

.page-about .media-frame {
  overflow: hidden;
  background: var(--lake);
}

.page-about .media-frame img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .stages {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .stages::before {
  content: "";
  position: absolute;
  left: var(--pa-rail-left);
  top: 28px;
  bottom: 28px;
  width: 1px;
  background: linear-gradient(180deg, var(--orange) 0%, var(--star) 18%, var(--star) 82%, rgba(42, 74, 112, 0) 100%);
}

.page-about .stage {
  position: relative;
}

.page-about .stage + .stage {
  border-top: 1px solid var(--star);
}

.page-about .stage-head {
  position: relative;
  display: block;
  width: 100%;
  padding: 26px 40px 26px var(--pa-indent);
  background: none;
  border: 0;
  text-align: left;
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.page-about .stage-dot {
  position: absolute;
  left: 0;
  top: 34px;
  width: 13px;
  height: 13px;
  background: var(--orange);
  transition: transform 180ms var(--ease), background-color 180ms var(--ease);
}

.page-about .stage-tag {
  display: block;
  color: var(--amber);
  margin-bottom: 10px;
}

.page-about .stage-title {
  display: block;
  font-size: clamp(1.125rem, 2.6vw, 1.5rem);
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.03em;
  color: var(--snow);
}

.page-about .stage-head .expand-sign {
  position: absolute;
  right: 4px;
  top: 30px;
}

.page-about .stage-head:hover .stage-dot {
  transform: scale(1.25);
}

.page-about .stage-head:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .stage-body {
  padding: 0 40px 30px var(--pa-indent);
}

.page-about .stage-body p {
  margin: 0;
  max-width: 42em;
  line-height: 1.85;
  color: var(--mist);
  font-size: 1rem;
}

/* ---------- 项目扩展图 ---------- */

.page-about .proj-figure {
  margin: 52px 0 0;
}

.page-about .proj-chart {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .proj-label {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  fill: var(--mist);
}

.page-about .proj-rail {
  stroke: var(--star);
  stroke-width: 1;
}

.page-about .proj-bar {
  fill: var(--orange);
  transition: opacity 200ms var(--ease);
}

.page-about .proj-row--1 .proj-bar { opacity: 0.95; }
.page-about .proj-row--2 .proj-bar { opacity: 0.86; }
.page-about .proj-row--3 .proj-bar { opacity: 0.77; }
.page-about .proj-row--4 .proj-bar { opacity: 0.68; }
.page-about .proj-row--5 .proj-bar { opacity: 0.59; }
.page-about .proj-row--6 .proj-bar { opacity: 0.5; }

.page-about .proj-row:hover .proj-bar,
.page-about .proj-row:focus-within .proj-bar {
  opacity: 1;
}

/* ---------- 02 团队分工 ---------- */

.page-about .roles {
  list-style: none;
  margin: 0 0 48px;
  padding: 0;
}

.page-about .role {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: 28px 0;
  border-top: 1px solid var(--star);
}

.page-about .role:last-child {
  border-bottom: 1px solid var(--star);
}

.page-about .role-num {
  font-family: var(--mono);
  font-size: 1rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .role-name {
  margin: 0;
  font-size: 1.1875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--snow);
}

.page-about .role-desc {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--mist);
  max-width: 46em;
}

.page-about .team-figure {
  margin: 0;
}

/* ---------- 03 校对流程 ---------- */

.page-about .checks {
  list-style: none;
  margin: 0 0 40px;
  padding: 0;
  counter-reset: check;
}

.page-about .check {
  position: relative;
  display: grid;
  grid-template-columns: 20px minmax(0, 1fr);
  gap: 0 20px;
  padding: 24px 0;
  border-top: 1px solid var(--star);
}

.page-about .check:last-child {
  border-bottom: 1px solid var(--star);
}

.page-about .check-mark {
  width: 13px;
  height: 13px;
  margin-top: 7px;
  background: transparent;
  border: 1px solid var(--orange);
}

.page-about .check:first-child .check-mark,
.page-about .check:hover .check-mark {
  background: var(--orange);
}

.page-about .check-name {
  margin: 0 0 10px;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.035em;
  line-height: 1.45;
  color: var(--snow);
}

.page-about .check-desc {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--mist);
  max-width: 44em;
}

.page-about .review-note {
  border-left: 2px solid var(--amber);
  padding: 4px 0 4px 20px;
  max-width: 46em;
}

.page-about .note-label {
  color: var(--amber);
  margin: 0 0 10px;
}

.page-about .review-note p:last-child {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--snow);
}

/* ---------- 04 规模表 ---------- */

.page-about .scale-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 1rem;
}

.page-about .scale-table tr {
  border-bottom: 1px solid var(--star);
}

.page-about .scale-table th {
  text-align: left;
  font-weight: 400;
  color: var(--mist);
  padding: 16px 12px 16px 0;
  vertical-align: baseline;
}

.page-about .scale-table td {
  text-align: right;
  padding: 16px 0 16px 12px;
  color: var(--snow);
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  vertical-align: baseline;
}

.page-about .scale-table td.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.0625rem;
}

/* ---------- 05 视觉基调 ---------- */

.page-about .visual-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.page-about .visual-text p {
  margin: 0 0 20px;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--snow);
  max-width: 40em;
}

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

.page-about .visual-figure {
  margin: 0;
}

/* ---------- 收尾 ---------- */

.page-about .sec--next {
  padding: 64px 0 80px;
}

.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  align-items: center;
}

.page-about .next-title {
  margin: 0;
  font-size: clamp(1.375rem, 3.4vw, 2rem);
  line-height: 1.3;
  letter-spacing: 0.04em;
  font-weight: 800;
  color: var(--snow);
}

.page-about .next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 560px) {
  .page-about .hero-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .role {
    grid-template-columns: 56px 190px minmax(0, 1fr);
    align-items: baseline;
    gap: 0 28px;
  }

  .page-about .check {
    grid-template-columns: 20px minmax(0, 1fr);
  }

  .page-about .visual-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
  }

  .page-about .next-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
  }

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

@media (min-width: 900px) {
  .page-about .hero-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 0 56px;
    align-items: start;
  }

  .page-about .hero-side {
    padding-top: 76px;
  }
}

@media (min-width: 980px) {
  .page-about .sec {
    padding: 96px 0;
  }

  .page-about .sec-grid {
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 0 40px;
  }

  .page-about .sec-aside {
    position: sticky;
    top: calc(var(--header-h) + 40px);
    align-self: start;
    display: block;
  }

  .page-about .section-num {
    font-size: 2.75rem;
  }

  .page-about .aside-label {
    margin-top: 14px;
  }

  .page-about .stages::before {
    left: var(--pa-rail-left);
  }

  .page-about .stage:nth-child(even) .stage-head {
    padding-left: var(--pa-indent-wide);
  }

  .page-about .stage:nth-child(even) .stage-body {
    padding-left: var(--pa-indent-wide);
  }
}

@media (max-width: 420px) {
  .page-about .hero-figures dd {
    font-size: 1.375rem;
  }

  .page-about .scale-table th,
  .page-about .scale-table td {
    padding-top: 14px;
    padding-bottom: 14px;
  }

  .page-about .scale-table td.num {
    font-size: 0.9375rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-dot,
  .page-about .proj-bar,
  .page-about .section-num {
    transition: none;
  }
}
<<<END>>>