.page-about {
  --about-space: clamp(72px, 9vw, 128px);
  --about-paper-card: #FFF9EF;
  --about-ink-soft: rgba(31, 29, 27, 0.78);
  --about-shadow-ink: 6px 6px 0 rgba(31, 29, 27, 0.18);
  --about-link-orange: #C2410C;
  background: var(--bg-deep);
  color: var(--text);
}

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

/* ===== 首屏 ===== */
.page-about .about-hero {
  position: relative;
  padding: clamp(48px, 7vw, 88px) 0 64px;
  background:
    radial-gradient(1100px 520px at 85% 8%, rgba(0, 229, 255, 0.13), transparent 60%),
    radial-gradient(800px 420px at 8% 85%, rgba(255, 107, 0, 0.1), transparent 55%),
    var(--bg-deep);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 1.25rem;
}

.page-about .about-hero__eyebrow {
  margin-bottom: 0.75rem;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.3rem, 6.5vw, 4.6rem);
  line-height: 1.06;
  letter-spacing: 0.01em;
  margin: 0 0 1.25rem;
  color: var(--text);
  text-shadow: 4px 4px 0 rgba(0, 0, 0, 0.3);
}

.page-about .about-hero__title-line {
  display: block;
  color: var(--cyan);
}

.page-about .about-hero__lead {
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--text-dim);
  max-width: 58ch;
  margin: 0;
}

.page-about .about-hero__domain {
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  color: var(--text-faint);
  margin: 0.75rem 0 0;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--line-strong);
}

.page-about .about-index a {
  font-size: 0.8125rem;
  line-height: 1.4;
  color: var(--text-dim);
  text-decoration: none;
  border: 1px solid var(--line);
  padding: 0.45em 0.8em;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-index a:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(0, 229, 255, 0.08);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  list-style: none;
  padding: 0;
  margin: 2rem 0 0;
  border: 1px solid var(--line-strong);
  background: var(--line-strong);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1.1rem 1rem;
  background: var(--bg-panel);
}

.page-about .about-hero__facts strong {
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-hero__facts span {
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
  color: var(--text-dim);
}

.page-about .about-hero__figure {
  margin: 0;
  border: 2px solid var(--line-strong);
  background: var(--bg-panel);
  box-shadow: var(--shadow-hard-cyan);
}

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

.page-about .about-hero .media-frame__caption {
  padding: 0.75rem 1rem;
  font-size: 0.8125rem;
  color: var(--text-dim);
  border-top: 1px solid var(--line);
}

/* ===== 章节公共头 ===== */
.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(0.75rem, 3vw, 2rem);
  margin-bottom: clamp(2.25rem, 5vw, 4rem);
}

.page-about .about-chapter__num {
  font-family: var(--font-display);
  font-size: clamp(4rem, 10vw, 7.5rem);
  line-height: 0.8;
  color: var(--cyan);
  flex: 0 0 auto;
}

.page-about .about-chapter__title-group {
  position: relative;
  padding-top: 0.25rem;
}

.page-about .about-chapter__title-group h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  line-height: 1.12;
  margin: 0;
}

/* ===== 01 从导航页到赛事数据中枢 ===== */
.page-about .about-origin {
  background: var(--paper);
  color: var(--ink);
  padding: var(--about-space) 0;
}

.page-about .about-origin .about-chapter__num {
  color: var(--red);
}

.page-about .about-origin h2 {
  color: var(--ink);
}

.page-about .about-chapter__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}

.page-about .about-origin__text p {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--about-ink-soft);
  margin: 0 0 1.1rem;
}

.page-about .about-origin__text a {
  color: var(--red);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
  transition: color 0.2s var(--ease);
}

.page-about .about-origin__text a:hover {
  color: var(--about-link-orange);
}

.page-about .about-origin__board {
  display: grid;
  gap: 1rem;
  align-content: start;
}

.page-about .about-origin__board-card {
  background: var(--about-paper-card);
  border: 2px solid var(--ink);
  box-shadow: var(--about-shadow-ink);
  padding: 1.5rem;
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-origin__board-card:hover {
  transform: translate(-3px, -3px);
  border-color: var(--red);
  box-shadow: 9px 9px 0 rgba(31, 29, 27, 0.22);
}

.page-about .about-origin__board-card h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin: 0.5rem 0;
  letter-spacing: 0.02em;
}

.page-about .about-origin__board-card p {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--about-ink-soft);
  margin: 0;
}

.page-about .about-origin .tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.25em 0.55em;
  border: 1px solid currentColor;
  color: var(--ink);
  background: transparent;
  text-transform: uppercase;
}

.page-about .about-origin .tag--cyan {
  color: #007F99;
}

.page-about .about-origin .tag--orange {
  color: #C2410C;
}

/* ===== 02 发展理念 ===== */
.page-about .about-values {
  background:
    linear-gradient(rgba(0, 229, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 229, 255, 0.05) 1px, transparent 1px),
    var(--bg-deep);
  background-size: 48px 48px;
  padding: var(--about-space) 0;
  color: var(--text);
}

.page-about .about-values .about-chapter__num {
  color: var(--lime);
  opacity: 0.9;
}

.page-about .about-values__grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-values__item {
  border: 2px solid var(--line-strong);
  background: var(--bg-panel);
  box-shadow: var(--shadow-hard);
  padding: 2rem 1.5rem;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .about-values__item:hover {
  border-color: var(--cyan);
  box-shadow: var(--shadow-hard-cyan);
  transform: translateY(-4px);
}

.page-about .about-values__index {
  display: block;
  font-family: var(--font-display);
  font-size: 2.25rem;
  line-height: 1;
  color: var(--orange);
  margin-bottom: 1.25rem;
}

.page-about .about-values__item h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  line-height: 1.2;
  margin: 0 0 0.75rem;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .about-values__item p {
  color: var(--text-dim);
  line-height: 1.65;
  font-size: 0.9375rem;
  margin: 0;
}

.page-about .about-values__race {
  display: block;
  width: 100%;
  max-width: 500px;
  height: auto;
  margin: 2.5rem auto 0;
}

.page-about .about-values__quote {
  max-width: 720px;
  margin: 2.5rem auto 0;
  padding: 2rem 2rem 2rem 3rem;
  border-left: 4px solid var(--orange);
  background: var(--bg-raised);
  color: var(--text);
}

.page-about .about-values__quote p {
  font-size: 1.0625rem;
  line-height: 1.7;
  margin: 0;
}

.page-about .about-values__quote span {
  display: block;
  margin-top: 1rem;
  color: var(--text-faint);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
}

/* ===== 03 V4版本里程碑 ===== */
.page-about .about-milestone {
  background: var(--paper);
  color: var(--ink);
  padding: var(--about-space) 0;
}

.page-about .about-milestone .about-chapter__num {
  color: var(--red);
}

.page-about .about-milestone h2 {
  color: var(--ink);
}

.page-about .about-milestone__layout {
  display: grid;
  gap: clamp(2.5rem, 5vw, 3.5rem);
  align-items: start;
}

.page-about .about-milestone__content > p {
  color: var(--about-ink-soft);
  line-height: 1.75;
  font-size: 1rem;
  margin: 0 0 1.25rem;
}

.page-about .about-milestone__image {
  margin: 1.5rem 0;
  border: 2px solid var(--ink);
  box-shadow: var(--about-shadow-ink);
  background: #fffaf1;
}

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

.page-about .about-milestone__image .media-frame__caption {
  padding: 0.75rem 1rem;
  font-size: 0.8125rem;
  color: rgba(31, 29, 27, 0.7);
  border-top: 1px solid rgba(31, 29, 27, 0.15);
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: repeating-linear-gradient(
    to bottom,
    var(--ink) 0,
    var(--ink) 6px,
    transparent 6px,
    transparent 12px
  );
  opacity: 0.35;
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 48px;
  margin-bottom: 1.25rem;
}

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

.page-about .about-timeline__dot {
  position: absolute;
  left: 7px;
  top: 1.375rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--ink);
  z-index: 1;
}

.page-about .about-timeline__details {
  border: 2px solid var(--ink);
  background: #fffaf1;
  box-shadow: 6px 6px 0 rgba(31, 29, 27, 0.16);
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .about-timeline__details:hover {
  border-color: var(--red);
  box-shadow: 8px 8px 0 rgba(31, 29, 27, 0.2);
  transform: translate(-2px, -2px);
}

.page-about .about-timeline__details summary {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.25rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline__details summary:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .about-timeline__version {
  font-family: var(--font-display);
  font-size: 1.25rem;
  line-height: 1;
  color: var(--red);
  min-width: 2ch;
}

.page-about .about-timeline__name {
  font-size: 1rem;
  line-height: 1.35;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-timeline__body {
  padding: 0 1.25rem 1.25rem;
  border-top: 1px dashed rgba(31, 29, 27, 0.25);
}

.page-about .about-timeline__body p {
  margin: 0.85rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--about-ink-soft);
}

/* ===== 04 数据服务规范 ===== */
.page-about .about-data {
  position: relative;
  background: var(--bg-panel);
  padding: var(--about-space) 0;
  color: var(--text);
}

.page-about .about-data .about-chapter__num {
  color: var(--cyan);
}

.page-about .about-data__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.page-about .about-data__lead {
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--text);
  max-width: 58ch;
  margin: 0 0 2rem;
}

.page-about .about-data__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-data__list li {
  display: grid;
  grid-template-columns: 2.25rem 1fr;
  gap: 0.75rem;
  padding: 1.25rem 0;
  border-top: 1px solid var(--line);
}

.page-about .about-data__list li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-data__list-index {
  font-family: var(--font-display);
  font-size: 1.375rem;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-data__list strong {
  display: block;
  font-size: 1.0625rem;
  line-height: 1.3;
  margin-bottom: 0.35rem;
  color: var(--text);
}

.page-about .about-data__list p {
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--text-dim);
  margin: 0;
}

.page-about .about-data__list a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s var(--ease);
}

.page-about .about-data__list a:hover {
  color: var(--orange);
}

.page-about .about-data__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.page-about .about-data__figure {
  position: relative;
  margin: 0;
  border: 2px solid var(--line-strong);
  background: var(--bg-raised);
  box-shadow: var(--shadow-hard);
}

.page-about .about-data__figure::after {
  content: "";
  position: absolute;
  right: -8px;
  bottom: -8px;
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, transparent 50%, var(--lime) 50%);
}

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

.page-about .about-data__figure .media-frame__caption {
  padding: 0.75rem 1rem;
  font-size: 0.8125rem;
  color: var(--text-dim);
  border-top: 1px solid var(--line);
}

.page-about .about-data__note {
  margin-top: 2rem;
  font-size: 0.8125rem;
  color: var(--text-faint);
  line-height: 1.6;
}

/* ===== 尾注 ===== */
.page-about .about-outro {
  position: relative;
  background: var(--bg-deep);
  padding: calc(var(--about-space) * 1.2) 0;
  color: var(--text);
}

.page-about .about-outro::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 6px;
  background: linear-gradient(90deg, var(--cyan) 0 25%, var(--orange) 0 50%, var(--lime) 0 75%, var(--red) 0 100%);
  opacity: 0.9;
}

.page-about .about-outro .eyebrow {
  margin-bottom: 0.75rem;
}

.page-about .about-outro h2 {
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 5vw, 4rem);
  line-height: 1.1;
  max-width: 20ch;
  margin: 0 0 1.25rem;
}

.page-about .about-outro p {
  color: var(--text-dim);
  line-height: 1.7;
  max-width: 56ch;
  margin: 0 0 2rem;
}

.page-about .about-outro__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ===== 桌面端布局 ===== */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.05fr 0.95fr;
  }

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

  .page-about .about-hero__facts strong {
    font-size: 2.25rem;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 0.9fr 1.1fr;
    gap: clamp(3rem, 6vw, 6rem);
  }

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

  .page-about .about-origin__board-card--wide {
    grid-column: 1 / -1;
  }

  .page-about .about-values__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .page-about .about-milestone__layout {
    grid-template-columns: 1fr 1.05fr;
    gap: clamp(2.5rem, 5vw, 4rem);
  }

  .page-about .about-data__grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: clamp(3rem, 6vw, 5rem);
  }
}