.page-about {
  --rail-w: 236px;
  --about-gap: clamp(18px, 3vw, 32px);
  background: var(--ink-900);
  color: var(--mist-200);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  overflow-x: clip;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(22px, 4vw, 40px) 0 clamp(28px, 5vw, 52px);
  border-bottom: 1px solid var(--ink-700);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 96px;
  height: 3px;
  background: var(--amber-500);
}

.page-about .about-hero__inner {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 14px 0 14px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--amber-300);
}

.page-about .about-hero__eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--celadon-400);
}

.page-about h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(28px, 6.4vw, 52px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--cream-100);
  max-width: 17em;
}

.page-about .about-hero__lede {
  margin: 0 0 24px;
  max-width: 48ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist-200);
}

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

.page-about .about-hero__figure .figure__frame {
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .figure__caption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist-200);
  opacity: 0.82;
}

/* ---------- 主体与索引轨道 ---------- */
.page-about .about-body {
  padding-top: clamp(24px, 4vw, 44px);
  padding-bottom: clamp(40px, 6vw, 72px);
}

.page-about .about-rail {
  margin-bottom: clamp(20px, 4vw, 32px);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber-300);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 8px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--ink-700);
  border-radius: 999px;
  color: var(--mist-200);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--cream-100);
  border-color: var(--amber-500);
  background: rgba(232, 163, 61, 0.09);
}

.page-about .about-rail__num {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--amber-500);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: clamp(24px, 4vw, 40px) 0;
  border-top: 1px solid var(--ink-700);
  scroll-margin-top: calc(var(--header-top-h) + 20px);
}

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

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(12px, 2.5vw, 20px);
  margin-bottom: 16px;
}

.page-about .about-chapter__num {
  flex: 0 0 auto;
  padding-top: 2px;
  font-size: clamp(26px, 5vw, 44px);
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--amber-500);
}

.page-about .about-chapter__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(20px, 3.6vw, 30px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--cream-100);
}

.page-about .about-chapter__kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist-200);
  opacity: 0.72;
}

.page-about .about-chapter p {
  margin: 0 0 14px;
  max-width: 68ch;
  color: var(--mist-200);
}

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

.page-about .about-chapter a:not(.btn) {
  color: var(--amber-300);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 引用条 ---------- */
.page-about .about-note {
  margin: 20px 0;
  padding: 16px 18px;
  max-width: 68ch;
  background: var(--cream-100);
  color: var(--brown-900);
  border-left: 4px solid var(--amber-500);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-note p {
  margin: 0;
  max-width: none;
  color: var(--brown-900);
}

/* ---------- 数据条 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .about-stat {
  padding: 14px 14px 12px;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-top: 3px solid var(--amber-500);
  border-radius: var(--radius-md);
}

.page-about .about-stat--t2 { border-top-color: var(--t2); }
.page-about .about-stat--t4 { border-top-color: var(--t4); }
.page-about .about-stat--t5 { border-top-color: var(--t5); }

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 4vw, 28px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--cream-100);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist-200);
}

/* ---------- 七类标签 ---------- */
.page-about .about-tags {
  list-style: none;
  margin: 20px 0 18px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-tag {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
}

.page-about .about-tag__name {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.01em;
  color: var(--cream-100);
}

.page-about .about-tag p {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist-200);
}

/* ---------- 岗位抽屉 ---------- */
.page-about .about-drawers {
  display: grid;
  gap: 12px;
  margin: 20px 0 0;
}

.page-about .about-drawer {
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-drawer[open] {
  border-color: var(--amber-500);
}

.page-about .about-drawer__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 13px 14px;
  cursor: pointer;
  list-style: none;
  border-top: 3px solid var(--t1);
}

.page-about .about-drawer--front .about-drawer__summary { border-top-color: var(--t2); }
.page-about .about-drawer--care .about-drawer__summary { border-top-color: var(--t7); }

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

.page-about .about-drawer__summary:hover .about-drawer__code {
  color: var(--amber-300);
}

.page-about .about-drawer__code {
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cream-100);
  transition: color 0.18s ease;
}

.page-about .about-drawer__count {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--amber-300);
}

.page-about .about-drawer__body {
  padding: 12px 14px 14px;
  border-top: 1px solid var(--ink-700);
}

.page-about .about-drawer__body p {
  margin: 0 0 8px;
  max-width: none;
  font-size: 14px;
  color: var(--cream-100);
}

.page-about .about-drawer__body ul {
  margin: 0;
  padding-left: 1.05em;
}

.page-about .about-drawer__body li {
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 6px;
  color: var(--mist-200);
}

.page-about .about-drawer__body li:last-child {
  margin-bottom: 0;
}

/* ---------- 流程图与步骤 ---------- */
.page-about .about-flow {
  margin: 24px 0 0;
}

.page-about .about-flow .figure__frame {
  background: var(--cream-100);
  border: 1px solid var(--cream-300);
  border-radius: var(--radius-md);
  padding: 14px;
  overflow: hidden;
}

.page-about .about-steps {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-step {
  padding: 2px 0 2px 12px;
  border-left: 2px solid var(--ink-700);
}

.page-about .about-step__num {
  display: block;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--vermilion-500);
}

.page-about .about-step__title {
  margin: 2px 0 4px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  color: var(--cream-100);
}

.page-about .about-step p {
  margin: 0;
  max-width: none;
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-200);
}

/* ---------- 维护节奏 ---------- */
.page-about .about-rhythm {
  margin: 22px 0 18px;
  display: grid;
  gap: clamp(16px, 3vw, 28px);
}

.page-about .about-rhythm__figure .figure__frame {
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
  padding: 12px;
  overflow: hidden;
}

.page-about .about-rhythm__legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-rhythm__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  padding: 13px 14px;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-left: 3px solid var(--t2);
  border-radius: var(--radius-md);
}

.page-about .about-rhythm__item--quarter { border-left-color: var(--t1); }
.page-about .about-rhythm__item--month { border-left-color: var(--t3); }

.page-about .about-rhythm__key {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber-300);
  white-space: nowrap;
}

.page-about .about-rhythm__val {
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist-200);
}

/* ---------- 版本演进 ---------- */
.page-about .about-phases {
  list-style: none;
  margin: 20px 0 18px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-phase {
  padding: 16px;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
}

.page-about .about-phase--now {
  border-color: var(--amber-500);
}

.page-about .about-phase__code {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--ink-700);
  color: var(--amber-300);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.page-about .about-phase--now .about-phase__code {
  background: var(--amber-500);
  color: var(--ink-900);
}

.page-about .about-phase__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.35;
  color: var(--cream-100);
}

.page-about .about-phase p {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist-200);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  margin-top: clamp(28px, 5vw, 48px);
  padding: clamp(20px, 4vw, 32px);
  background: var(--cream-100);
  border-top: 4px solid var(--amber-500);
  border-radius: var(--radius-lg);
  color: var(--brown-900);
}

.page-about .about-cta__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(20px, 3.4vw, 28px);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--brown-900);
}

.page-about .about-cta p {
  margin: 0 0 16px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--brown-900);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta .btn--ghost {
  color: var(--brown-900);
  border: 1px solid var(--brown-900);
}

.page-about .about-cta__meta {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--cream-300);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--brown-900);
  opacity: 0.85;
}

/* ---------- 窄屏到宽屏 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-tags {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 820px) {
  .page-about .about-drawers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .about-rhythm {
    grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr);
    align-items: start;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: end;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-top-h) + 20px);
    margin-bottom: 0;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
  }

  .page-about .about-rail__link {
    display: flex;
    border: 0;
    border-left: 2px solid var(--ink-700);
    border-radius: 0;
    padding: 11px 0 11px 14px;
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--amber-500);
    background: transparent;
  }
}
<<<END>>>