.page-about {
  --ab-axis-col: 16px;
  --ab-col-gap: 14px;
  position: relative;
  padding: clamp(26px, 5vw, 62px) 0 clamp(60px, 9vw, 118px);
  color: var(--text);
  font-family: var(--font-cn);
  background:
    radial-gradient(880px 520px at 84% -8%, rgba(106, 61, 255, .22), transparent 62%),
    radial-gradient(640px 420px at 2% 34%, rgba(47, 243, 224, .07), transparent 66%),
    var(--ink);
  overflow-x: clip;
}

.page-about .ab-wrap {
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 clamp(18px, 4.2vw, 44px);
}

/* ---------- 面包屑 ---------- */
.page-about .ab-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: clamp(18px, 3vw, 32px);
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--dim);
}

.page-about .ab-crumb a {
  color: var(--dim);
  text-decoration: none;
  transition: color .2s var(--ease);
}

.page-about .ab-crumb a:hover {
  color: var(--cyan);
}

.page-about .ab-crumb span[aria-hidden="true"] {
  color: var(--line);
}

.page-about .ab-crumb span:last-child {
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero__eyebrow {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .24em;
  color: var(--cyan);
}

.page-about .ab-hero__title {
  margin: 0;
  font-size: clamp(34px, 7vw, 84px);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--text);
  max-width: 18ch;
}

.page-about .ab-hero__title-soft {
  display: block;
  margin-top: clamp(12px, 1.8vw, 20px);
  font-size: clamp(15px, 2.1vw, 26px);
  font-weight: 300;
  line-height: 1.55;
  letter-spacing: .01em;
  color: var(--dim);
  max-width: 26ch;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
  margin-top: clamp(26px, 4vw, 46px);
  padding-top: clamp(22px, 3.4vw, 38px);
  border-top: 1px solid var(--line);
}

.page-about .ab-hero__lead {
  margin: 0;
  font-size: clamp(15.5px, 1.2vw, 17.5px);
  line-height: 1.9;
  color: var(--dim);
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.page-about .ab-facts li {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 15px 16px;
  background: rgba(12, 16, 34, .92);
}

.page-about .ab-facts__n {
  font-size: clamp(23px, 3vw, 31px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold);
}

.page-about .ab-facts__t {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--dim);
}

/* ---------- 首图 ---------- */
.page-about .ab-anchor {
  margin: clamp(38px, 6vw, 74px) 0 0;
}

.page-about .ab-anchor img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  object-fit: cover;
}

.page-about .ab-anchor figcaption {
  margin-top: 12px;
  padding-left: 14px;
  border-left: 2px solid var(--violet);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: .03em;
  color: var(--dim);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-chrono {
  position: relative;
  margin-top: clamp(48px, 8vw, 92px);
}

.page-about .ab-chrono::before {
  content: "";
  position: absolute;
  left: calc(var(--ab-axis-col) / 2);
  top: 10px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--violet) 0%, var(--violet-deep) 36%, var(--line) 100%);
}

.page-about .ab-entry {
  position: relative;
  display: grid;
  grid-template-columns: var(--ab-axis-col) minmax(0, 1fr);
  column-gap: var(--ab-col-gap);
  padding-bottom: clamp(40px, 6vw, 80px);
}

.page-about .ab-entry:last-of-type {
  padding-bottom: 0;
}

.page-about .ab-entry:nth-of-type(1) { --node: var(--violet); }
.page-about .ab-entry:nth-of-type(2) { --node: var(--r-green); }
.page-about .ab-entry:nth-of-type(3) { --node: var(--cyan); }
.page-about .ab-entry:nth-of-type(4) { --node: var(--gold); }
.page-about .ab-entry:nth-of-type(5) { --node: var(--r-blue); }

.page-about .ab-entry__no {
  position: relative;
  grid-column: 1;
  margin: 0;
  padding-top: 20px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: .22em;
  white-space: nowrap;
  color: var(--dim);
}

.page-about .ab-entry__no::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 5px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  transform: translateX(-50%);
  background: var(--node, var(--violet));
  box-shadow: 0 0 0 4px rgba(106, 61, 255, .14), 0 0 12px rgba(106, 61, 255, .55);
}

.page-about .ab-entry__box {
  grid-column: 2;
  min-width: 0;
}

.page-about .ab-entry:nth-of-type(odd) .ab-entry__box {
  padding: clamp(18px, 2.8vw, 34px) clamp(16px, 2.6vw, 32px);
  background: var(--glass);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.page-about .ab-entry:nth-of-type(even) .ab-entry__box {
  padding: clamp(18px, 2.8vw, 34px) clamp(16px, 2.6vw, 32px);
  background: linear-gradient(180deg, rgba(58, 31, 168, .17) 0%, rgba(12, 16, 34, .92) 46%);
  border-left: 2px solid var(--violet);
  border-radius: 0 10px 10px 0;
}

.page-about .ab-entry__meta {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--dim);
}

.page-about .ab-entry__meta .mono {
  margin-right: 10px;
  letter-spacing: .07em;
  color: var(--cyan);
}

.page-about .ab-entry__title {
  margin: 0 0 18px;
  font-size: clamp(21px, 3.1vw, 35px);
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .ab-entry__text {
  margin: 0 0 15px;
  max-width: 44em;
  font-size: clamp(15px, 1.15vw, 17px);
  line-height: 1.88;
  color: var(--dim);
}

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

.page-about .ab-entry__text a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 224, .38);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

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

/* ---------- 赛区标签 ---------- */
.page-about .ab-regions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 20px;
  padding: 0;
  list-style: none;
}

.page-about .ab-regions li {
  padding: 7px 15px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--c);
  border: 1px solid var(--c);
  border-radius: 999px;
  background: rgba(106, 61, 255, .1);
  background: color-mix(in srgb, var(--c) 12%, transparent);
  transition: background .18s var(--ease), transform .18s var(--ease);
}

.page-about .ab-regions li:nth-child(1) { --c: var(--violet); }
.page-about .ab-regions li:nth-child(2) { --c: var(--r-red); }
.page-about .ab-regions li:nth-child(3) { --c: var(--r-green); }
.page-about .ab-regions li:nth-child(4) { --c: var(--r-green); }
.page-about .ab-regions li:nth-child(5) { --c: var(--r-blue); }
.page-about .ab-regions li:nth-child(6) { --c: var(--r-blue); }

.page-about .ab-regions li:hover {
  background: color-mix(in srgb, var(--c) 26%, transparent);
  transform: translateY(-2px);
}

/* ---------- 图注容器 ---------- */
.page-about .ab-figure {
  margin: 22px 0 4px;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  object-fit: cover;
}

.page-about .ab-figure figcaption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--dim);
}

/* ---------- 折叠组 ---------- */
.page-about .ab-fold {
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
}

.page-about .ab-fold summary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 4px 0;
  font-size: 13.5px;
  letter-spacing: .06em;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color .2s var(--ease);
}

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

.page-about .ab-fold summary::before {
  content: "";
  flex: none;
  width: 0;
  height: 0;
  border-left: 5px solid currentColor;
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  transition: transform .22s var(--ease);
}

.page-about .ab-fold summary:hover {
  color: var(--cyan);
}

.page-about .ab-fold[open] summary::before {
  transform: rotate(90deg);
}

.page-about .ab-fold__body {
  padding: 14px 0 2px;
  animation: ab-reveal .22s var(--ease) both;
}

@keyframes ab-reveal {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: none; }
}

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

.page-about .ab-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--dim);
}

.page-about .ab-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .62em;
  width: 6px;
  height: 6px;
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 底部动作 ---------- */
.page-about .ab-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
  margin-top: clamp(42px, 6vw, 76px);
  padding-top: clamp(24px, 3vw, 34px);
  border-top: 1px solid var(--line);
}

.page-about .ab-next__t {
  margin: 0;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--text);
}

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

/* ---------- 桌面增强 ---------- */
@media (min-width: 640px) {
  .page-about {
    --ab-axis-col: 22px;
    --ab-col-gap: 22px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --ab-axis-col: 28px;
    --ab-col-gap: 30px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 68px);
    align-items: start;
  }

  .page-about .ab-facts li {
    padding: 18px 20px;
  }

  .page-about .ab-figure--square {
    max-width: 460px;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-entry__box {
    width: 82%;
  }

  .page-about .ab-entry:nth-of-type(even) .ab-entry__box {
    margin-left: auto;
  }

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

/* ---------- 动效减弱 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}