.page-about {
  --ab-pad: clamp(48px, 8vw, 96px);
  --ab-mark: 200px;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-top: calc(var(--head-h) + 56px);
  padding-bottom: 56px;
  overflow: hidden;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--line-60) 0 1px, transparent 1px 92px);
  opacity: 0.35;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 78%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 78%);
}

.page-about .ab-hero .shell {
  position: relative;
  z-index: 1;
}

.page-about .crumbs {
  margin-bottom: 40px;
}

.page-about .crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .crumbs__list li + li::before {
  content: "/";
  margin: 0 8px;
  color: var(--line);
}

.page-about .crumbs__list a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--track), border-color var(--track);
}

.page-about .crumbs__list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .ab-hero__split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

.page-about .ab-hero__title {
  margin: 18px 0 0;
  font-size: clamp(38px, 7.6vw, 86px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.025em;
  color: var(--ink);
  max-width: 15ch;
}

.page-about .ab-hero__lede {
  margin: 26px 0 0;
  max-width: 46ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 36px;
}

.page-about .ab-hero__visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.page-about .ab-dial {
  position: relative;
  width: min(100%, 400px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  border: 1.5px solid var(--line);
  box-shadow: 6px 6px 0 var(--line);
  background:
    conic-gradient(from -90deg, var(--cyan-30) 0 92deg, transparent 92deg 360deg),
    conic-gradient(from 150deg, var(--orange-40) 0 40deg, transparent 40deg 360deg),
    conic-gradient(from 250deg, rgba(138, 92, 255, 0.35) 0 56deg, transparent 56deg 360deg),
    radial-gradient(circle at 50% 50%, var(--hull) 0 62%, var(--void) 62% 100%);
}

.page-about .ab-dial::before {
  content: "";
  position: absolute;
  inset: 17%;
  border-radius: 50%;
  border: 1.5px dashed var(--cyan-30);
}

.page-about .ab-dial::after {
  content: "";
  position: absolute;
  inset: 43%;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 34px var(--cyan-50);
  animation: ab-pulse 2.8s ease-in-out infinite;
}

@keyframes ab-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.86); }
}

.page-about .ab-hero__pulse {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .ab-hero__pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 12px var(--orange-40);
}

/* ---------- 通栏图 ---------- */
.page-about .ab-banner {
  padding-bottom: 8px;
}

.page-about .ab-shot {
  aspect-ratio: 3 / 2;
}

.page-about .ab-shot img,
.page-about .ab-yearbook__fig img,
.page-about .ab-tl__shot img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  display: block;
}

/* ---------- 章节通用 ---------- */
.page-about .ab-chapter {
  padding-block: var(--ab-pad);
}

.page-about .ab-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .ab-chapter__mark {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .ab-chapter__mark .marker {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(42px, 6.4vw, 72px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--mist);
  opacity: 0.42;
  transition: color 320ms ease, opacity 320ms ease;
}

.page-about .ab-chapter.is-active .ab-chapter__mark .marker {
  color: var(--cyan);
  opacity: 1;
}

.page-about .ab-chapter__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

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

.page-about .ab-chapter__body p {
  margin: 18px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .ab-chapter__body p:first-of-type {
  margin-top: 22px;
}

/* ---------- 区块标题 ---------- */
.page-about .ab-head {
  max-width: 62ch;
  margin-bottom: 40px;
}

.page-about .ab-head__lede {
  margin: 16px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 四道手 ---------- */
.page-about .ab-crew {
  padding-block: var(--ab-pad);
}

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

.page-about .ab-crew__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 26px 0;
  border-top: 1.5px solid var(--line);
  transition: background-color var(--track);
}

.page-about .ab-crew__row:last-child {
  border-bottom: 1.5px solid var(--line);
}

.page-about .ab-crew__idx {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .ab-crew__name {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .ab-crew__desc {
  margin: 0;
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl-section {
  padding-block: var(--ab-pad);
  background: var(--hull);
  border-top: 1.5px solid var(--line);
  border-bottom: 1.5px solid var(--line);
}

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

.page-about .ab-tl__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding-bottom: 44px;
}

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

.page-about .ab-tl__year {
  font-family: var(--font-mono);
  font-size: clamp(36px, 5.6vw, 72px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.035em;
  font-variant-numeric: tabular-nums;
  color: var(--mist);
  transition: color 320ms ease;
}

.page-about .ab-tl__item.is-in .ab-tl__year {
  color: var(--cyan);
}

.page-about .ab-tl__body {
  position: relative;
  max-width: 62ch;
}

.page-about .ab-tl__title {
  margin: 0 0 10px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .ab-tl__body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-tl__shot {
  margin-top: 48px;
  aspect-ratio: 3 / 2;
}

/* ---------- 合作方 ---------- */
.page-about .ab-partners {
  padding-block: var(--ab-pad);
}

.page-about .ab-partners__panel {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  padding: 32px 24px;
  background: var(--panel);
  border: 1.5px solid var(--line);
  box-shadow: 6px 6px 0 var(--line);
}

.page-about .ab-partners__panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 24px;
  width: 84px;
  height: 3px;
  background: var(--orange);
}

.page-about .ab-partners__lead p {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-partners__lead p:first-of-type {
  margin-top: 20px;
}

.page-about .ab-partners__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .ab-partners__facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-partners__facts li:first-child {
  border-top: none;
  padding-top: 0;
}

.page-about .ab-partners__facts strong {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .ab-partners__facts span {
  font-size: 14px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 年鉴 ---------- */
.page-about .ab-yearbook {
  padding-block: var(--ab-pad);
}

.page-about .ab-yearbook__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}

.page-about .ab-yearbook__fig {
  aspect-ratio: 4 / 3;
}

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

.page-about .ab-yearbook__body p {
  margin: 18px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-yearbook__body p:first-of-type {
  margin-top: 22px;
}

/* ---------- 底部引导 ---------- */
.page-about .ab-callout {
  padding-block: 0 clamp(56px, 9vw, 104px);
}

.page-about .ab-callout__box {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  padding: 32px 24px;
  background: var(--hull);
  border: 1.5px solid var(--line);
  border-left: 4px solid var(--cyan);
  box-shadow: 6px 6px 0 var(--line);
}

.page-about .ab-callout__title {
  margin: 0 0 12px;
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .ab-callout__text p {
  margin: 0;
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-callout__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: flex-start;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .ab-crew__row {
    grid-template-columns: 72px 190px minmax(0, 1fr);
    column-gap: 32px;
    align-items: start;
    padding: 32px 0;
  }

  .page-about .ab-partners__panel {
    padding: 44px 40px;
  }

  .page-about .ab-partners__panel::before {
    left: 40px;
  }

  .page-about .ab-partners__facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 32px;
  }

  .page-about .ab-partners__facts li:nth-child(2) {
    border-top: none;
    padding-top: 0;
  }

  .page-about .ab-callout__box {
    padding: 40px 36px;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 880px) {
  .page-about .ab-hero__split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    column-gap: 64px;
  }

  .page-about .ab-chapter__grid {
    grid-template-columns: var(--ab-mark) minmax(0, 1fr);
    column-gap: 56px;
    align-items: start;
  }

  .page-about .ab-chapter__mark {
    flex-direction: column;
    gap: 12px;
    padding-top: 6px;
  }

  .page-about .ab-tl__item {
    grid-template-columns: 168px minmax(0, 1fr);
    column-gap: 40px;
    padding-bottom: 56px;
  }

  .page-about .ab-tl__body {
    padding-left: 40px;
  }

  .page-about .ab-tl__body::before {
    content: "";
    position: absolute;
    left: 0;
    top: 12px;
    bottom: -56px;
    width: 2px;
    background: var(--line);
  }

  .page-about .ab-tl__item:last-child .ab-tl__body::before {
    bottom: auto;
    height: 40px;
  }

  .page-about .ab-tl__body::after {
    content: "";
    position: absolute;
    left: -4px;
    top: 8px;
    width: 10px;
    height: 10px;
    background: var(--mist);
    transition: background-color 320ms ease, box-shadow 320ms ease;
  }

  .page-about .ab-tl__item.is-in .ab-tl__body::after {
    background: var(--cyan);
    box-shadow: 0 0 16px var(--cyan-50);
  }

  .page-about .ab-yearbook__grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1fr);
    column-gap: 56px;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-partners__panel {
    grid-template-columns: minmax(0, 1fr) minmax(0, 420px);
    gap: 56px;
    padding: 52px 48px;
  }

  .page-about .ab-partners__panel::before {
    left: 48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-dial::after {
    animation: none;
  }

  .page-about .ab-chapter__mark .marker,
  .page-about .ab-tl__year,
  .page-about .ab-tl__body::after,
  .page-about .ab-crew__row {
    transition: none;
  }
}