.page-about {
  --about-track-w: 172px;
  --about-shadow: 14px 14px 0 rgba(18, 51, 43, .72);
  display: block;
  padding-bottom: clamp(56px, 8vw, 120px);
  background: var(--pitch-ink);
  color: var(--chalk);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: clamp(18px, 3vw, 34px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  margin-top: clamp(12px, 2vw, 22px);
  padding-block: clamp(30px, 6vw, 76px) clamp(30px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -12%;
  width: min(820px, 96%);
  height: 150%;
  background: linear-gradient(148deg, var(--deep-moss) 0%, var(--night-blue) 52%, rgba(7, 17, 15, 0) 100%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 74%);
  opacity: .92;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -6%;
  bottom: 6%;
  width: 46%;
  height: 1px;
  background: linear-gradient(90deg, var(--lime), rgba(200, 255, 61, 0));
  opacity: .55;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: center;
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
}

.page-about .about-kicker__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--score-gray);
}

.page-about .about-hero__title {
  margin: 18px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(36px, 7.6vw, 78px);
  line-height: .95;
  letter-spacing: -.025em;
  color: var(--chalk);
}

.page-about .about-hero__title em {
  font-style: normal;
  display: inline-block;
  color: var(--lime);
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__meta {
  margin: 20px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--amber);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .06em;
  color: var(--score-gray);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line-strong);
  background: var(--night-blue);
  padding: 10px;
}

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

.page-about .about-figure--hero {
  box-shadow: var(--about-shadow);
}

.page-about .about-figure--plate,
.page-about .about-figure--archive {
  margin-top: clamp(22px, 3vw, 36px);
  background: var(--stand-gray);
  padding: 8px;
}

.page-about .about-caption {
  display: block;
  margin-top: 10px;
  padding: 0 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: .08em;
  color: var(--score-gray);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  padding-top: clamp(34px, 5vw, 68px);
}

.page-about .about-layout {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
}

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

/* ---------- 节点轨道 ---------- */
.page-about .about-track {
  display: flex;
  align-items: stretch;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 10px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-track__label {
  flex: 0 0 auto;
  align-self: center;
  margin: 0;
  padding-right: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--score-gray);
}

.page-about .about-track__item {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 116px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  background: var(--night-blue);
  text-decoration: none;
  color: var(--chalk);
  transition: border-color .22s var(--ease), background-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .about-track__item:hover,
.page-about .about-track__item:focus-visible {
  border-color: rgba(200, 255, 61, .55);
  background: var(--deep-moss);
  transform: translateY(-3px);
}

.page-about .about-track__year {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--lime);
}

.page-about .about-track__name {
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-top: clamp(30px, 4.4vw, 54px);
  border-top: 1px solid var(--line);
}

.page-about .about-section + .about-section {
  margin-top: clamp(34px, 5vw, 64px);
}

.page-about .about-section__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2.4vw, 26px);
  margin-bottom: clamp(16px, 2.4vw, 28px);
}

.page-about .about-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 5.4vw, 54px);
  line-height: .88;
  letter-spacing: -.05em;
  color: rgba(240, 247, 243, .16);
  font-variant-numeric: tabular-nums;
}

.page-about .about-section__titles {
  min-width: 0;
  padding-top: 2px;
}

.page-about .about-section__title {
  margin: 6px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(22px, 3.3vw, 34px);
  line-height: 1.06;
  letter-spacing: -.015em;
  color: var(--chalk);
}

/* ---------- 正文 ---------- */
.page-about .about-prose {
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-prose p {
  margin: 0 0 1.05em;
}

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

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

.page-about .about-prose--after {
  margin-top: clamp(20px, 2.6vw, 32px);
}

.page-about .about-prose--flush p:first-child {
  margin-top: 0;
}

/* ---------- 两条主线 ---------- */
.page-about .about-lines {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 2.8vw, 30px);
}

.page-about .about-line-card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  background: linear-gradient(168deg, var(--night-blue) 0%, rgba(7, 17, 15, .72) 100%);
  transition: transform .25s var(--ease), border-color .25s var(--ease);
}

.page-about .about-line-card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 48px;
  height: 3px;
  background: var(--amber);
}

.page-about .about-line-card--data::before {
  background: var(--lime);
}

.page-about .about-line-card:hover {
  transform: translateY(-4px);
  border-color: rgba(240, 247, 243, .28);
}

.page-about .about-line-card__tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-line-card__tag--lime {
  color: var(--lime);
}

.page-about .about-line-card__title {
  margin: 12px 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(19px, 2.2vw, 23px);
  line-height: 1.15;
  color: var(--chalk);
}

.page-about .about-line-card__text {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 10px;
  height: 1px;
  background: var(--lime);
}

/* ---------- 更新节奏 ---------- */
.page-about .about-rhythm {
  list-style: none;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
}

.page-about .about-rhythm__item {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .about-rhythm__item:first-child {
  border-top: 1px dashed var(--line);
}

.page-about .about-rhythm__when {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--lime);
}

.page-about .about-rhythm__what h3 {
  margin: 0 0 5px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.3;
  color: var(--chalk);
}

.page-about .about-rhythm__what p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 数据口径 ---------- */
.page-about .about-gauge {
  display: grid;
  gap: clamp(18px, 3vw, 34px);
  align-items: start;
}

.page-about .about-gauge__figure {
  border-top: 2px solid var(--lime);
  padding-top: 14px;
}

.page-about .about-gauge__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 5.6vw, 44px);
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-gauge__unit {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--score-gray);
}

.page-about .about-fold {
  margin-top: clamp(20px, 2.6vw, 30px);
  border: 1px solid var(--line);
  background: rgba(11, 27, 43, .6);
}

.page-about .about-fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--chalk);
}

.page-about .about-fold > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-fold > summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-fold[open] > summary::after {
  content: "–";
}

.page-about .about-fold__body {
  padding: 0 18px 18px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-fold__body p {
  margin: 0;
}

/* ---------- 栏目版图 ---------- */
.page-about .about-index {
  list-style: none;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-index__link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 2px 14px;
  height: 100%;
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--night-blue);
  text-decoration: none;
  color: inherit;
  transition: transform .24s var(--ease), border-color .24s var(--ease), background-color .24s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  transform: translateY(-4px);
  border-color: rgba(200, 255, 61, .5);
  background: var(--deep-moss);
}

.page-about .about-index__num {
  grid-row: span 2;
  align-self: start;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-index__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.3;
  color: var(--chalk);
}

.page-about .about-index__desc {
  font-size: 14px;
  line-height: 1.68;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-lines {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

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

@media (min-width: 720px) {
  .page-about .about-rhythm__item {
    grid-template-columns: 152px minmax(0, 1fr);
    gap: clamp(16px, 3vw, 34px);
    align-items: baseline;
  }

  .page-about .about-gauge {
    grid-template-columns: minmax(0, 208px) minmax(0, 1fr);
  }
}

@media (min-width: 880px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    gap: clamp(32px, 5vw, 72px);
  }
}

@media (min-width: 1080px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-track-w) minmax(0, 1fr);
    gap: clamp(36px, 4.5vw, 72px);
  }

  .page-about .about-track {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    position: sticky;
    top: 96px;
    align-self: start;
    padding-bottom: 0;
    margin-left: 1px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-track__label {
    align-self: flex-start;
    padding: 0 0 14px 16px;
  }

  .page-about .about-track__item {
    min-width: 0;
    padding: 12px 0 12px 16px;
    margin-left: -1px;
    border: 0;
    border-left: 2px solid transparent;
    background: transparent;
  }

  .page-about .about-track__item:hover,
  .page-about .about-track__item:focus-visible {
    transform: none;
    border-left-color: var(--lime);
    background: linear-gradient(90deg, rgba(200, 255, 61, .1), rgba(200, 255, 61, 0));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line-card,
  .page-about .about-index__link,
  .page-about .about-track__item {
    transition: none;
  }

  .page-about .about-line-card:hover,
  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible,
  .page-about .about-track__item:hover,
  .page-about .about-track__item:focus-visible {
    transform: none;
  }
}