.page-about {
  background:
    radial-gradient(120% 70% at 82% -6%, rgba(31, 138, 76, 0.22), transparent 62%),
    radial-gradient(90% 60% at 4% 8%, rgba(18, 48, 92, 0.55), transparent 68%),
    var(--ink);
  color: var(--white);
  overflow-x: clip;
}

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

.page-about h1,
.page-about h2,
.page-about h3,
.page-about h4 {
  font-family: var(--font-display);
  letter-spacing: -0.02em;
  line-height: 1.06;
  margin: 0;
}

.page-about h2 {
  font-size: clamp(26px, 5.4vw, 42px);
  font-weight: 900;
}

.page-about h3 {
  font-size: clamp(19px, 3vw, 25px);
  font-weight: 800;
}

.page-about h4 {
  font-size: clamp(17px, 2.4vw, 20px);
  font-weight: 800;
}

.page-about p {
  margin: 0;
}

/* 首屏 */
.page-about .ab-hero {
  padding-bottom: clamp(36px, 6vw, 76px);
}

.page-about .ab-hero > .kx-shell {
  padding-top: 18px;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  margin-top: clamp(20px, 3vw, 34px);
}

.page-about .kx-label {
  color: var(--grass-lt);
  margin-bottom: 14px;
}

.page-about .ab-hero h1 {
  font-size: clamp(32px, 8vw, 74px);
  font-weight: 900;
  max-width: 14em;
}

.page-about .ab-hero__lead {
  margin-top: 18px;
  max-width: 40em;
  font-size: clamp(15px, 2vw, 18px);
  line-height: 1.78;
  color: var(--paper);
  opacity: 0.86;
}

.page-about .ab-facts {
  list-style: none;
  margin: clamp(24px, 4vw, 36px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-facts__item {
  background: var(--panel);
  padding: 14px 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .ab-facts__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 4.4vw, 32px);
  font-weight: 700;
  color: var(--score);
  line-height: 1;
}

.page-about .ab-facts__txt {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  line-height: 1.5;
}

.page-about .ab-hero__figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  border-bottom: 3px solid var(--grass);
  background: var(--panel);
  padding: 10px;
}

.page-about .ab-hero__figure img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.05);
}

.page-about .ab-hero__figure figcaption,
.page-about .ab-widefig figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.7;
  color: var(--muted);
}

/* 通用章节 */
.page-about .ab-section {
  padding-block: clamp(40px, 7vw, 92px);
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-origin__grid {
  display: grid;
  gap: 24px;
}

.page-about .ab-origin__body {
  min-width: 0;
}

.page-about .ab-origin__body p {
  margin-top: 16px;
  max-width: 46em;
  font-size: clamp(15px, 1.9vw, 17px);
  line-height: 1.82;
  color: var(--paper);
  opacity: 0.84;
}

.page-about .ab-quote {
  margin: clamp(24px, 4vw, 34px) 0 0;
  padding: 18px 20px 18px 22px;
  border-left: 3px solid var(--cyan);
  background: linear-gradient(90deg, rgba(47, 224, 208, 0.12), transparent 78%);
}

.page-about .ab-quote p {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(16px, 2.4vw, 21px);
  font-weight: 700;
  line-height: 1.6;
  color: var(--white);
  opacity: 1;
}

.page-about .ab-origin__note {
  display: none;
  color: var(--grass-lt);
  letter-spacing: 0.28em;
  align-self: start;
  justify-self: end;
}

/* 版本时间轴 */
.page-about .ab-sechead {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: clamp(28px, 4vw, 44px);
}

.page-about .ab-sechead p {
  max-width: 42em;
  font-size: clamp(14px, 1.8vw, 16px);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.page-about .ab-jump a {
  display: inline-block;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--grass-lt);
  text-decoration: none;
  background: var(--panel);
  transition: color var(--dur) ease, border-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .ab-jump a:hover,
.page-about .ab-jump a:focus-visible {
  color: var(--cyan-dark);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-timeline {
  --ab-node: 40px;
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: calc(var(--ab-node) / 2 - 1px);
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--grass) 0%, var(--grass-lt) 45%, var(--score) 100%);
  opacity: 0.7;
}

.page-about .ab-timeline__item {
  position: relative;
  padding-left: calc(var(--ab-node) + 18px);
  margin-bottom: clamp(18px, 3vw, 26px);
}

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

.page-about .ab-timeline__item--v1 { --ab-accent: var(--grass); }
.page-about .ab-timeline__item--v2 { --ab-accent: var(--cyan); }
.page-about .ab-timeline__item--v3 { --ab-accent: var(--grass-lt); }
.page-about .ab-timeline__item--v4 { --ab-accent: var(--score); }

.page-about .ab-timeline__no {
  position: absolute;
  left: 0;
  top: 4px;
  width: var(--ab-node);
  height: var(--ab-node);
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--ab-accent, var(--grass));
  color: var(--cyan-dark);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .ab-card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--ab-accent, var(--grass));
  padding: 18px 18px 20px;
  overflow: hidden;
}

.page-about .ab-card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  border-style: solid;
  border-width: 0 16px 16px 0;
  border-color: transparent var(--ink) transparent transparent;
}

.page-about .ab-card__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ab-accent, var(--grass-lt));
  margin-bottom: 8px;
}

.page-about .ab-card h3 {
  padding-right: 18px;
}

.page-about .ab-card p {
  margin-top: 10px;
  font-size: clamp(14px, 1.7vw, 16px);
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.82;
}

.page-about .ab-widefig {
  margin: clamp(26px, 4vw, 40px) 0 0;
  border: 1px solid var(--line);
  border-top: 2px solid var(--score);
  background: var(--panel-2);
  padding: 10px;
}

.page-about .ab-widefig img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* 团队与校验 */
.page-about .ab-team__grid {
  display: grid;
  gap: clamp(28px, 4vw, 40px);
}

.page-about .ab-team__body p {
  margin-top: 16px;
  max-width: 44em;
  font-size: clamp(14px, 1.8vw, 16px);
  line-height: 1.82;
  color: var(--paper);
  opacity: 0.84;
}

.page-about .ab-team__tags {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-team__tags .kx-chip {
  border: 1px solid rgba(111, 211, 154, 0.4);
  color: var(--grass-lt);
  background: rgba(31, 138, 76, 0.14);
  padding: 6px 11px;
  font-size: 12px;
  letter-spacing: 0.06em;
}

.page-about .ab-checks {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  padding: clamp(18px, 2.6vw, 26px);
}

.page-about .ab-checks h3 {
  font-size: clamp(17px, 2.4vw, 21px);
  color: var(--white);
  margin-bottom: 14px;
}

.page-about .ab-step {
  border: 1px solid var(--line);
  background: var(--panel-2);
  margin-bottom: 10px;
}

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

.page-about .ab-step summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--white);
}

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

.page-about .ab-step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--cyan);
  font-size: 16px;
}

.page-about .ab-step[open] summary::after {
  content: "−";
}

.page-about .ab-step__no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--cyan-dark);
  background: var(--cyan);
  padding: 2px 7px;
  border-radius: var(--radius);
}

.page-about .ab-step p {
  padding: 0 14px 14px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--paper);
  opacity: 0.82;
}

/* 目录规模 */
.page-about .ab-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .ab-stats__item {
  background: var(--panel);
  border: 1px solid var(--line);
  border-bottom: 3px solid var(--ab-stat, var(--grass));
  padding: 16px 14px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .ab-stats__item--a { --ab-stat: var(--grass); }
.page-about .ab-stats__item--b { --ab-stat: var(--cyan); }
.page-about .ab-stats__item--c { --ab-stat: var(--score); }
.page-about .ab-stats__item--d { --ab-stat: var(--grass-lt); }

.page-about .ab-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 6vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--white);
  letter-spacing: -0.02em;
}

.page-about .ab-stats__plus {
  color: var(--score);
  font-size: 0.6em;
  vertical-align: super;
  margin-left: 2px;
}

.page-about .ab-stats__label {
  font-size: 12px;
  letter-spacing: 0.08em;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .ab-rhythm {
  margin-top: clamp(24px, 4vw, 36px);
  padding: clamp(18px, 2.6vw, 26px);
  background: var(--paper);
  border: 1px solid var(--paper-line);
  color: #0a1526;
}

.page-about .ab-rhythm h3 {
  color: #0a1526;
  margin-bottom: 14px;
}

.page-about .ab-rhythm__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-rhythm__list li {
  padding-left: 14px;
  border-left: 2px solid var(--grass);
  font-size: 14px;
  line-height: 1.78;
  color: #1a2b3c;
}

.page-about .ab-rhythm__k {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  color: #0f6b3c;
  margin-right: 8px;
}

/* 服务对象与合作 */
.page-about .ab-audience {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-audience li {
  background: var(--panel);
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--paper);
  opacity: 0.86;
}

.page-about .ab-audience strong {
  color: var(--grass-lt);
  font-weight: 700;
  margin-right: 8px;
}

.page-about .ab-matrix__title {
  margin-top: clamp(28px, 4vw, 40px);
  margin-bottom: 14px;
  color: var(--white);
}

.page-about .ab-matrix {
  display: grid;
  gap: 12px;
}

.page-about .ab-matrix__col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--ab-mx, var(--grass));
  padding: 16px 16px 18px;
}

.page-about .ab-matrix__col--media { --ab-mx: var(--score); }
.page-about .ab-matrix__col--youth { --ab-mx: var(--grass-lt); }
.page-about .ab-matrix__col--campus { --ab-mx: var(--cyan); }

.page-about .ab-matrix__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4.6vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--ab-mx, var(--grass-lt));
  margin-bottom: 8px;
}

.page-about .ab-matrix__col h4 {
  margin-bottom: 8px;
}

.page-about .ab-matrix__col p {
  font-size: 14px;
  line-height: 1.78;
  color: var(--paper);
  opacity: 0.8;
}

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

.page-about .ab-honor__item {
  background: var(--panel);
  border: 1px solid var(--line);
  transition: border-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .ab-honor__item:hover,
.page-about .ab-honor__item:focus-within {
  border-color: rgba(47, 224, 208, 0.6);
  background: var(--panel-2);
}

.page-about .ab-honor__item summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  padding: 15px 16px;
}

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

.page-about .ab-honor__year {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--score);
  letter-spacing: 0.06em;
  padding: 2px 8px;
  border: 1px solid rgba(255, 106, 42, 0.45);
  border-radius: var(--radius);
}

.page-about .ab-honor__name {
  font-size: clamp(15px, 2vw, 18px);
  font-weight: 700;
  color: var(--white);
  flex: 1 1 12em;
  min-width: 0;
}

.page-about .ab-honor__item p {
  padding: 0 16px 16px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.8;
}

/* 下一步 */
.page-about .ab-next__grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .ab-next__card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px;
  min-width: 0;
  text-decoration: none;
  background: var(--panel);
  border: 1px solid var(--line);
  color: var(--white);
  transition: transform var(--dur) ease, border-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .ab-next__card strong {
  font-family: var(--font-display);
  font-size: clamp(16px, 2.2vw, 19px);
  font-weight: 800;
  line-height: 1.4;
}

.page-about .ab-next__card .kx-label {
  color: var(--muted);
  font-size: 10px;
  margin: 0;
}

.page-about .ab-next__go {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
  margin-top: auto;
}

.page-about .ab-next__card:hover,
.page-about .ab-next__card:focus-visible {
  border-color: var(--cyan);
  background: var(--panel-2);
  transform: translateY(-3px);
}

.page-about .ab-next__card--primary {
  border-color: rgba(47, 224, 208, 0.55);
  background: linear-gradient(150deg, rgba(47, 224, 208, 0.14), rgba(11, 26, 56, 0.9) 62%);
}

.page-about .ab-next__foot {
  margin-top: clamp(20px, 3vw, 28px);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 48em;
}

.page-about .ab-next__foot a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-next__foot a:hover,
.page-about .ab-next__foot a:focus-visible {
  color: var(--grass-lt);
}

@media (min-width: 760px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

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

  .page-about .ab-matrix {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

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

  .page-about .ab-timeline {
    --ab-node: 52px;
  }
}

@media (min-width: 980px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.85fr);
    align-items: end;
  }

  .page-about .ab-origin__grid {
    grid-template-columns: minmax(0, 1fr) 96px;
    gap: 32px;
  }

  .page-about .ab-origin__note {
    display: block;
  }

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

  .page-about .ab-versions .kx-shell,
  .page-about .ab-scale .kx-shell,
  .page-about .ab-eco .kx-shell,
  .page-about .ab-honor .kx-shell,
  .page-about .ab-next .kx-shell {
    max-width: min(var(--shell), 100%);
  }

  .page-about .ab-timeline {
    max-width: 62rem;
  }
}

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

  .page-about .ab-next__card:hover,
  .page-about .ab-next__card:focus-visible {
    transform: none;
  }
}