.page-about {
  --ab-rule: rgba(159, 179, 200, 0.16);
  --ab-berry-soft: rgba(122, 46, 87, 0.26);
  --ab-indigo-soft: rgba(15, 32, 67, 0.66);
  --ab-axis-glow: 0 0 0 6px rgba(0, 229, 255, 0.12);
  padding-bottom: clamp(3rem, 8vw, 6rem);
}

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

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-top: clamp(1rem, 3vw, 1.75rem);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

.page-about .crumbs a {
  color: var(--c-cyan);
  text-decoration: none;
}

.page-about .crumbs a:hover {
  text-decoration: underline;
}

.page-about .crumbs__sep {
  opacity: 0.4;
}

/* ---------- 开场 ---------- */
.page-about .ab-open {
  padding-top: clamp(1.25rem, 4vw, 2.5rem);
}

.page-about .ab-open__bar {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.75rem;
  padding: 0.55rem 1rem;
  border: 1px solid var(--glass-line);
  border-radius: var(--r-pill);
  background: var(--glass);
  backdrop-filter: blur(10px);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

.page-about .ab-open__dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--c-orange);
  opacity: 0.75;
}

.page-about .ab-open h1 {
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  max-width: 19ch;
  font-size: clamp(2.05rem, 7.4vw, 4.25rem);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.03em;
  color: var(--c-white);
}

.page-about .ab-open__mark {
  color: var(--c-cyan);
  border-bottom: 4px solid var(--c-orange);
  padding-bottom: 2px;
}

.page-about .ab-open__lead {
  max-width: 68ch;
  margin-top: clamp(1rem, 2.5vw, 1.5rem);
  color: var(--ink-dim);
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.1rem 1.5rem;
  margin-top: clamp(2rem, 5vw, 3rem);
  padding-top: clamp(1.25rem, 3vw, 2rem);
  border-top: 1px solid var(--ab-rule);
}

.page-about .ab-stats .stat__value {
  display: block;
  font-size: clamp(1.85rem, 5.5vw, 3.25rem);
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .ab-stats .stat:nth-child(3) .stat__value {
  color: var(--c-sand);
}

.page-about .ab-stats .stat:nth-child(5) .stat__value {
  color: var(--c-orange);
}

.page-about .ab-stats__plus {
  font-size: 0.6em;
  vertical-align: super;
  opacity: 0.8;
}

/* ---------- 章节通用 ---------- */
.page-about .section {
  margin-top: clamp(3.5rem, 9vw, 7rem);
}

.page-about .section__index {
  color: var(--c-orange);
}

.page-about .section__title {
  max-width: 22ch;
}

.page-about .section__sub {
  max-width: 62ch;
}

.page-about .prose p {
  max-width: 68ch;
}

/* ---------- 01 起点 ---------- */
.page-about .ab-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.5rem, 4vw, 2.75rem);
}

.page-about .ab-origin__figure {
  margin: 0;
}

.page-about .ab-origin__body .prose p + p {
  margin-top: 1rem;
}

.page-about .ab-origin__figure .media {
  border-radius: var(--r-md);
  box-shadow: var(--shadow-1);
}

/* ---------- 02 数据流程 ---------- */
.page-about .ab-steps {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ab-rule);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .ab-step {
  background: linear-gradient(160deg, var(--c-indigo), rgba(15, 32, 67, 0.55));
  padding: clamp(1.25rem, 3.5vw, 2rem);
}

.page-about .ab-step__no {
  display: inline-block;
  font-size: var(--fs-14);
  letter-spacing: 0.14em;
  color: var(--c-cyan);
  border-bottom: 1px solid var(--glass-line);
  padding-bottom: 0.35rem;
}

.page-about .ab-step__title {
  margin: 0.75rem 0 0.5rem;
  font-size: var(--fs-22);
  font-weight: 800;
  color: var(--c-white);
}

.page-about .ab-step p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
  max-width: 46ch;
}

.page-about .ab-version {
  display: grid;
  gap: 1.25rem;
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  padding: clamp(1.25rem, 3.5vw, 2rem);
  border-radius: var(--r-lg);
  background: var(--ab-berry-soft);
  border: 1px solid rgba(244, 227, 193, 0.14);
}

.page-about .ab-version__body h3 {
  margin: 0.75rem 0 0.5rem;
  font-family: var(--font-mono);
  font-size: var(--fs-22);
  letter-spacing: 0.02em;
  color: var(--c-sand);
}

.page-about .ab-version__body p {
  margin: 0;
  max-width: 68ch;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
}

.page-about .ab-version__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--c-sand);
  border-top: 1px solid rgba(244, 227, 193, 0.18);
  padding-top: 0.9rem;
}

/* ---------- 03 赛季时间轴 ---------- */
.page-about .ab-season__banner {
  margin: 0 0 clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .ab-season__banner .media {
  border-radius: var(--r-md);
  overflow: hidden;
  box-shadow: var(--shadow-1);
}

.page-about .ab-phasenav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.page-about .ab-phasenav a {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  text-decoration: none;
  color: var(--c-cyan);
  border: 1px solid var(--glass-line);
  border-radius: var(--r-pill);
  padding: 0.45rem 0.95rem;
  background: var(--glass);
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .ab-phasenav a:hover {
  border-color: var(--c-cyan);
  color: var(--c-white);
}

.page-about .ab-track {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  margin-bottom: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .ab-track__seg {
  height: 3px;
  border-radius: 3px;
  background: rgba(159, 179, 200, 0.2);
}

.page-about .ab-track__seg--done {
  background: var(--c-cyan);
}

.page-about .ab-track__seg--live {
  background: var(--c-orange);
}

.page-about .ab-track__seg--off {
  background: var(--c-berry);
}

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 2.1rem;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 0.6rem;
  bottom: 0.6rem;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-orange) 52%, var(--c-berry));
  opacity: 0.6;
}

.page-about .ab-phase {
  position: relative;
  padding-bottom: clamp(1.75rem, 4.5vw, 3rem);
}

.page-about .ab-phase:last-child {
  padding-bottom: 0;
}

.page-about .ab-dot {
  position: absolute;
  left: -2.1rem;
  top: 0.35rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-deep);
  border: 2px solid var(--c-mist);
}

.page-about .ab-dot--done {
  border-color: var(--c-cyan);
  background: var(--c-cyan);
  box-shadow: var(--ab-axis-glow);
}

.page-about .ab-dot--live {
  border-color: var(--c-orange);
  background: var(--c-orange);
  box-shadow: 0 0 0 6px rgba(255, 107, 53, 0.16);
}

.page-about .ab-dot--off {
  border-color: var(--c-berry);
  background: var(--c-berry);
}

.page-about .ab-phase__body {
  max-width: 62ch;
}

.page-about .ab-phase__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.85rem;
  margin: 0 0 0.6rem;
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--ink-dim);
}

.page-about .ab-phase__body h3 {
  margin: 0 0 0.6rem;
  font-size: clamp(1.25rem, 3.6vw, 1.75rem);
  font-weight: 800;
  line-height: 1.25;
  color: var(--c-white);
}

.page-about .ab-phase__body p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
}

.page-about .ab-phase__list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.page-about .ab-phase__list li {
  position: relative;
  padding-left: 1.1rem;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--c-white);
}

.page-about .ab-phase__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 6px;
  height: 2px;
  background: var(--c-cyan);
}

.page-about .ab-phase--narrow .ab-phase__body {
  max-width: 30rem;
  padding: 1.1rem 1.25rem;
  border-radius: var(--r-md);
  border-left: 3px solid var(--c-berry);
  background: var(--ab-berry-soft);
}

.page-about .ab-phase--narrow .ab-phase__body p {
  color: var(--c-white);
  opacity: 0.86;
}

/* ---------- 04 团队 ---------- */
.page-about .ab-crew__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.page-about .ab-crew__item {
  padding: clamp(1.25rem, 3.5vw, 1.85rem);
  border: 1px solid var(--ab-rule);
  background: var(--ab-indigo-soft);
}

.page-about .ab-crew__no {
  display: block;
  font-size: var(--fs-32);
  line-height: 1;
  color: var(--c-orange);
}

.page-about .ab-crew__item h3 {
  margin: 0.75rem 0 0.55rem;
  font-size: var(--fs-22);
  font-weight: 800;
  color: var(--c-white);
}

.page-about .ab-crew__item p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
}

.page-about .ab-crew__figure {
  margin: clamp(1.5rem, 4vw, 2.5rem) 0 0;
}

.page-about .ab-crew__figure .media {
  border-radius: var(--r-md);
  overflow: hidden;
  box-shadow: var(--shadow-1);
}

/* ---------- 05 合作 ---------- */
.page-about .ab-coop__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.page-about .ab-coop__aside .prose {
  color: var(--ink-dim);
  font-size: var(--fs-14);
  line-height: 1.85;
}

.page-about .ab-coop__badge {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  border-radius: var(--r-md);
  background: rgba(0, 179, 154, 0.14);
  border: 1px solid rgba(0, 179, 154, 0.34);
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
}

.page-about .ab-coop__badge .num {
  font-size: var(--fs-32);
  line-height: 1;
  color: var(--c-teal);
}

.page-about .ab-coop__badge p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.6;
  color: var(--c-white);
  opacity: 0.9;
}

.page-about .ab-coop__list details {
  border-top: 1px solid var(--ab-rule);
  padding: 1rem 0;
}

.page-about .ab-coop__list details:last-child {
  border-bottom: 1px solid var(--ab-rule);
}

.page-about .ab-coop__list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  list-style: none;
  font-size: var(--fs-17);
  font-weight: 800;
  color: var(--c-white);
}

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

.page-about .ab-coop__list summary::after {
  content: "＋";
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--fs-17);
  color: var(--c-cyan);
}

.page-about .ab-coop__list details[open] summary::after {
  content: "－";
  color: var(--c-orange);
}

.page-about .ab-coop__content {
  padding-top: 0.85rem;
}

.page-about .ab-coop__content p {
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
}

/* ---------- 下一步 ---------- */
.page-about .ab-next__panel {
  display: grid;
  gap: 1.5rem;
  padding: clamp(1.5rem, 4.5vw, 2.75rem);
  border-radius: var(--r-lg);
  border: 1px solid var(--glass-line);
  background:
    radial-gradient(120% 160% at 100% 0%, rgba(0, 229, 255, 0.16), transparent 58%),
    linear-gradient(150deg, var(--c-indigo), rgba(10, 17, 40, 0.9));
}

.page-about .ab-next__body h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.4rem, 4vw, 2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--c-white);
}

.page-about .ab-next__body p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--ink-dim);
}

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

@media (min-width: 768px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-crew__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .ab-origin__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .ab-origin__figure {
    margin-left: calc(-1 * clamp(1rem, 6vw, 6rem));
  }

  .page-about .ab-version {
    grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
    align-items: center;
  }

  .page-about .ab-version__meta {
    flex-direction: column;
    align-items: flex-start;
    border-top: 0;
    border-left: 1px solid rgba(244, 227, 193, 0.22);
    padding: 0 0 0 1.25rem;
  }

  .page-about .ab-coop__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
    gap: clamp(2rem, 6vw, 4.5rem);
  }

  .page-about .ab-next__panel {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: center;
    gap: clamp(1.5rem, 5vw, 3rem);
  }

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

  .page-about .ab-timeline {
    padding-left: 2.6rem;
  }

  .page-about .ab-timeline::before {
    left: 7px;
  }

  .page-about .ab-dot {
    left: -2.6rem;
    width: 16px;
    height: 16px;
  }

  .page-about .ab-phase {
    padding-bottom: clamp(2.25rem, 5vw, 3.5rem);
  }

  .page-about .ab-phase:nth-child(even) .ab-phase__body {
    max-width: 52ch;
  }

  .page-about .ab-phase:nth-child(odd) .ab-phase__body {
    max-width: 68ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-phasenav a,
  .page-about .ab-dot {
    transition: none;
  }
}