.page-about {
  --ab-pad-y: 64px;
  --ab-radius: 2px;
  --ab-line: rgba(139, 154, 179, 0.22);
  --ab-line-strong: rgba(139, 154, 179, 0.38);
  position: relative;
  overflow-x: clip;
  color: var(--mist);
}

.page-about .ab-kicker {
  margin: 18px 0 14px;
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--circuit);
}

.page-about .ab-index {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--signal);
  border-left: 2px solid var(--signal);
  background: rgba(255, 106, 43, 0.08);
}

.page-about .ab-p {
  margin: 0 0 18px;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(242, 246, 255, 0.86);
}

.page-about .ab-quote {
  margin: 0 0 22px;
  padding-left: 16px;
  border-left: 1px solid var(--circuit-line);
  font-size: 19px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .ab-lead {
  margin: 0;
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(242, 246, 255, 0.78);
}

.page-about a {
  color: var(--circuit);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 216, 208, 0.4);
  transition: color 140ms var(--ease), border-color 140ms var(--ease);
}

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

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  padding-top: 28px;
  isolation: isolate;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -22%;
  width: min(620px, 90vw);
  aspect-ratio: 1;
  background: radial-gradient(circle at 34% 34%, rgba(255, 106, 43, 0.24), transparent 68%);
  z-index: -1;
  pointer-events: none;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  bottom: -6%;
  left: -18%;
  width: min(460px, 70vw);
  aspect-ratio: 1;
  background: radial-gradient(circle at 60% 40%, rgba(47, 216, 208, 0.16), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.page-about .ab-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: 32px;
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.page-about .ab-hero__lede {
  max-width: 54ch;
  margin: 0 0 32px;
  color: rgba(242, 246, 255, 0.86);
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0 0 40px;
  padding: 0;
}

.page-about .ab-fact {
  padding: 14px 16px;
  background: var(--ink-700);
  border: 1px solid var(--ab-line);
  border-left: 2px solid var(--circuit);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}

.page-about .ab-fact__k {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--rock);
}

.page-about .ab-fact__v {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-hero__figure {
  margin: 0;
  position: relative;
}

.page-about .ab-hero__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    180deg,
    rgba(47, 216, 208, 0.05) 0 1px,
    transparent 1px 5px
  );
  pointer-events: none;
}

.page-about .ab-hero__figure img {
  display: block;
  width: 100%;
  height: 54vw;
  min-height: 220px;
  max-height: 520px;
  object-fit: cover;
}

/* ---------- 通用章节 ---------- */

.page-about .ab-section {
  padding: var(--ab-pad-y) 0;
  position: relative;
}

.page-about .ab-section--tight {
  padding-top: calc(var(--ab-pad-y) * 0.7);
}

.page-about .ab-section--deep {
  background: var(--ink-900);
  border-top: 1px solid var(--ab-line);
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-section--plate {
  background: linear-gradient(140deg, var(--ink-700) 0%, var(--ink-800) 58%, var(--ink-900) 100%);
  clip-path: polygon(0 0, 100% 2.2%, 100% 100%, 0 97.8%);
  padding-top: calc(var(--ab-pad-y) * 1.3);
  padding-bottom: calc(var(--ab-pad-y) * 1.3);
}

.page-about .ab-section--close {
  padding-bottom: calc(var(--ab-pad-y) * 1.1);
}

/* ---------- 呼号来由 ---------- */

.page-about .ab-split {
  display: grid;
  gap: 36px;
}

.page-about .ab-note-grid {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.page-about .ab-note-card {
  position: relative;
  padding: 18px 18px 18px 22px;
  background: rgba(18, 41, 74, 0.72);
  border: 1px solid var(--ab-line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .ab-note-card__no {
  display: block;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--violet);
}

.page-about .ab-note-card__t {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-note-card__d {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(242, 246, 255, 0.74);
}

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

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

/* ---------- 时间轴 ---------- */

.page-about .ab-timeline {
  list-style: none;
  margin: 34px 0 0;
  padding: 0 0 0 32px;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(
    180deg,
    var(--signal) 0%,
    var(--circuit) 42%,
    rgba(139, 154, 179, 0.26) 100%
  );
}

.page-about .ab-node {
  position: relative;
  padding: 0 0 34px;
}

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

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 4px;
  width: 19px;
  height: 19px;
  border-radius: 50%;
  background: var(--ink-800);
  border: 1px solid var(--circuit-line);
  box-shadow: 0 0 0 4px rgba(47, 216, 208, 0.08);
}

.page-about .ab-node::after {
  content: "";
  position: absolute;
  left: -28px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--circuit);
}

.page-about .ab-node--live::before {
  border-color: rgba(255, 106, 43, 0.68);
  box-shadow: 0 0 0 5px rgba(255, 106, 43, 0.12);
}

.page-about .ab-node--live::after {
  background: var(--signal);
  animation: ab-pulse 3s ease-in-out infinite;
}

.page-about .ab-node__era {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--rock);
}

.page-about .ab-node__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 21px;
  line-height: 1.35;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-node__text {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 255, 0.76);
}

@keyframes ab-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

/* ---------- 团队 ---------- */

.page-about .ab-team {
  position: relative;
  margin-top: 30px;
}

.page-about .ab-team__radio {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .ab-team__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.page-about .ab-team__tab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 15px;
  font-size: 14px;
  color: rgba(242, 246, 255, 0.72);
  background: rgba(18, 41, 74, 0.7);
  border: 1px solid var(--ab-line);
  cursor: pointer;
  transition: color 140ms var(--ease), border-color 140ms var(--ease), background 140ms var(--ease);
}

.page-about .ab-team__tab:hover {
  color: var(--mist);
  border-color: var(--ab-line-strong);
}

.page-about .ab-team__num {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.page-about .ab-team__panels {
  border-top: 1px solid var(--ab-line);
  padding-top: 24px;
}

.page-about .ab-team__panel {
  display: none;
}

.page-about #ab-team-1:checked ~ .ab-team__panels .ab-team__panel[data-team="1"],
.page-about #ab-team-2:checked ~ .ab-team__panels .ab-team__panel[data-team="2"],
.page-about #ab-team-3:checked ~ .ab-team__panels .ab-team__panel[data-team="3"] {
  display: block;
}

.page-about #ab-team-1:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-1"],
.page-about #ab-team-2:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-2"],
.page-about #ab-team-3:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-3"] {
  color: var(--ink-900);
  background: var(--signal);
  border-color: var(--signal);
}

.page-about #ab-team-1:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-1"] .ab-team__num,
.page-about #ab-team-2:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-2"] .ab-team__num,
.page-about #ab-team-3:checked ~ .ab-team__tabs .ab-team__tab[for="ab-team-3"] .ab-team__num {
  color: rgba(6, 14, 26, 0.72);
}

.page-about .ab-team__panel-t {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-team__panel p {
  margin: 0 0 16px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 255, 0.76);
}

.page-about .ab-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .ab-team__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(242, 246, 255, 0.72);
}

.page-about .ab-team__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--circuit);
}

.page-about .ab-band {
  margin: 40px 0 0;
  position: relative;
}

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

/* ---------- 内容生态 ---------- */

.page-about .ab-eco {
  margin-top: 30px;
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-eco__row {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 12px;
  padding: 22px 0;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-eco__no {
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--violet);
}

.page-about .ab-eco__t {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-eco__body p {
  margin: 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 255, 0.76);
}

.page-about .ab-inline-link {
  margin: 26px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 255, 0.78);
}

/* ---------- 技术底座 ---------- */

.page-about .ab-tech__lead {
  margin-bottom: 30px;
}

.page-about .ab-tech__lead h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: 24px;
  line-height: 1.35;
  font-weight: 800;
  color: var(--mist);
}

.page-about .ab-tech__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .ab-tech__item {
  padding: 20px;
  background: rgba(6, 14, 26, 0.55);
  border: 1px solid var(--ab-line);
  border-top: 2px solid var(--circuit);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .ab-tech__t {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--mist);
}

.page-about .ab-tech__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(242, 246, 255, 0.74);
}

.page-about .ab-tech__cta {
  margin: 28px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 255, 0.8);
}

/* ---------- 社群收束 ---------- */

.page-about .ab-close {
  position: relative;
}

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

.page-about .ab-close h2 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: 25px;
  line-height: 1.32;
  font-weight: 800;
  color: var(--mist);
}

.page-about .ab-terraces {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 32px;
  fill: none;
  stroke: var(--ochre);
  stroke-width: 1;
  opacity: 0.38;
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about {
    --ab-pad-y: 84px;
  }

  .page-about .ab-hero__title {
    font-size: 42px;
  }

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

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

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

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

  .page-about .ab-node::after {
    left: -36px;
  }

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

  .page-about .ab-tech__lead h2 {
    font-size: 30px;
  }

  .page-about .ab-close h2 {
    font-size: 30px;
  }
}

@media (min-width: 980px) {
  .page-about .ab-hero__title {
    font-size: 50px;
  }

  .page-about .ab-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .ab-split__side {
    margin-top: 46px;
  }

  .page-about .ab-eco__row {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 24px;
    padding: 28px 0;
  }

  .page-about .ab-tech {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .ab-tech__lead {
    margin-bottom: 0;
    padding-top: 12px;
  }

  .page-about .ab-tech__cta {
    grid-column: 2;
  }

  .page-about .ab-close {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: end;
  }

  .page-about .ab-terraces {
    margin-top: 0;
    margin-bottom: 8px;
  }
}

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

  .page-about a {
    transition: none;
  }
}