.page-about {
  --ab-pad-y: 52px;
  --ab-edge: 26px;
  position: relative;
  overflow-x: hidden;
  background: var(--ink-900);
  color: var(--white);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  isolation: isolate;
  padding: calc(var(--hdr-h) + 44px) 0 var(--ab-pad-y);
  background:
    radial-gradient(85% 65% at 88% -5%, rgba(61, 255, 178, 0.14), transparent 68%),
    linear-gradient(158deg, var(--ink-900) 0%, var(--night) 58%, var(--ink-850) 100%);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(169, 184, 178, 0.075) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(169, 184, 178, 0.075) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(88% 78% at 74% 12%, #000 8%, transparent 82%);
  mask-image: radial-gradient(88% 78% at 74% 12%, #000 8%, transparent 82%);
  pointer-events: none;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -8%;
  top: 26%;
  width: 46%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--citeal));
  transform: rotate(-17deg);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .ab-hero__crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 26px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .ab-hero__crumbs a.crumbs__item {
  color: var(--pale);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .ab-hero__crumbs a.crumbs__item:hover,
.page-about .ab-hero__crumbs a.crumbs__item:focus-visible {
  color: var(--citeal);
  border-bottom-color: var(--citeal);
}

.page-about .ab-hero__crumbs .crumbs__sep {
  color: var(--steel);
}

.page-about .ab-hero__crumbs .crumbs__item:last-child {
  color: var(--white);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: 34px;
}

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

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

.page-about .ab-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 10.5vw, 96px);
  line-height: 0.98;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.page-about .ab-hero__title-accent {
  display: block;
  margin-top: 0.12em;
  color: var(--citeal);
}

.page-about .ab-hero__lede {
  max-width: 58ch;
  margin: 24px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--pale);
}

.page-about .ab-hero__aside {
  padding: 4px 0 4px 18px;
  border-left: 2px solid rgba(61, 255, 178, 0.45);
}

.page-about .ab-hero__aside-note {
  margin: 0 0 18px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .ab-index {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-index__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 12px;
  border-left: 2px solid var(--line);
  color: var(--mist);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.22s ease, border-color 0.22s ease, background 0.22s ease;
}

.page-about .ab-index__link:hover,
.page-about .ab-index__link:focus-visible {
  color: var(--white);
  border-left-color: var(--citeal);
  background: rgba(61, 255, 178, 0.07);
}

.page-about .ab-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--citeal);
}

/* ---------- 章节通用 ---------- */
.page-about .ab-chapter {
  position: relative;
  padding: var(--ab-pad-y) 0;
}

.page-about .ab-chapter--alt {
  background: linear-gradient(180deg, var(--ink-850) 0%, var(--ink-900) 100%);
}

.page-about .ab-chapter__head {
  display: grid;
  gap: 12px;
  max-width: 900px;
  margin-bottom: 30px;
}

.page-about .ab-chapter__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--citeal);
}

.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(27px, 5.6vw, 48px);
  line-height: 1.08;
  letter-spacing: -0.005em;
  text-wrap: balance;
}

.page-about .ab-chapter__sub {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 品牌由来 ---------- */
.page-about .ab-origin {
  display: grid;
  gap: 30px;
}

.page-about .ab-origin__lead {
  margin: 0 0 18px;
  font-size: 17px;
  line-height: 1.75;
  color: var(--white);
}

.page-about .ab-origin__text p {
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .ab-origin__text p:last-of-type {
  margin-bottom: 0;
}

.page-about .ab-origin__list {
  display: grid;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-origin__list li {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .ab-origin__list li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-origin__k {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--citeal);
}

.page-about .ab-figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: 30px 8px 30px 30px;
  background: linear-gradient(150deg, var(--grid-green) 0%, var(--night) 100%);
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-figure figcaption {
  padding: 12px 18px 14px;
  border-top: 1px solid var(--line);
  background: rgba(7, 26, 21, 0.55);
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 三条原则 ---------- */
.page-about .ab-rules {
  display: grid;
  gap: 14px;
}

.page-about .ab-rule {
  padding: 20px 20px 18px;
  border: 1px solid var(--line);
  border-radius: 4px 24px 24px 24px;
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(61, 255, 178, 0.1), transparent 62%),
    var(--grid-green);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .ab-rule:hover {
  border-color: rgba(61, 255, 178, 0.42);
}

.page-about .ab-rule[open] {
  border-color: rgba(61, 255, 178, 0.6);
  box-shadow: 0 18px 40px -28px rgba(61, 255, 178, 0.7);
}

.page-about .ab-rule__summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-rule__summary:focus-visible {
  outline: 2px solid var(--citeal);
  outline-offset: 5px;
  border-radius: 8px;
}

.page-about .ab-rule__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--amber);
}

.page-about .ab-rule__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.28;
  color: var(--white);
}

.page-about .ab-rule__sign {
  position: relative;
  width: 22px;
  height: 22px;
  flex: none;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  transition: background 0.25s ease, border-color 0.25s ease;
}

.page-about .ab-rule__sign::before,
.page-about .ab-rule__sign::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 9px;
  height: 1px;
  background: var(--citeal);
  transform: translate(-50%, -50%);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.page-about .ab-rule__sign::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.page-about .ab-rule[open] .ab-rule__sign {
  background: rgba(61, 255, 178, 0.16);
  border-color: var(--citeal);
}

.page-about .ab-rule[open] .ab-rule__sign::after {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(0deg);
}

.page-about .ab-rule__body {
  margin: 14px 0 0;
  padding-top: 14px;
  border-top: 1px dashed rgba(169, 184, 178, 0.28);
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 使用场景 ---------- */
.page-about .ab-scenes {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: 880px;
}

.page-about .ab-scene {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-scene:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-scene__num {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel);
}

.page-about .ab-scene__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.35;
  color: var(--white);
}

.page-about .ab-scene__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 32px;
}

.page-about .ab-team__stats {
  display: grid;
  align-content: start;
}

.page-about .ab-stat {
  display: grid;
  gap: 4px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-stat:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-stat__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 6.5vw, 40px);
  line-height: 1;
  color: var(--citeal);
}

.page-about .ab-stat__label {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .ab-team__text p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .ab-team__text .ab-figure {
  margin-top: 22px;
}

/* ---------- 里程碑 ---------- */
.page-about .ab-milestones {
  display: grid;
  gap: 32px;
}

.page-about .ab-timeline {
  position: relative;
  padding-left: 34px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 26px;
  bottom: 34px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--citeal) 0%, rgba(61, 255, 178, 0.12) 100%);
}

.page-about .ab-timeline__list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-milestone {
  position: relative;
  border: 1px solid var(--line);
  border-radius: 18px 4px 18px 18px;
  background: rgba(16, 41, 35, 0.55);
  transition: border-color 0.25s ease, background 0.25s ease;
}

.page-about .ab-milestone::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 24px;
  width: 10px;
  height: 10px;
  box-sizing: border-box;
  border: 2px solid var(--citeal);
  border-radius: 50%;
  background: var(--ink-900);
  transition: background 0.25s ease, box-shadow 0.25s ease;
}

.page-about .ab-milestone:hover {
  border-color: rgba(61, 255, 178, 0.35);
}

.page-about .ab-milestone[open] {
  border-color: rgba(61, 255, 178, 0.5);
  background: rgba(16, 41, 35, 0.92);
}

.page-about .ab-milestone[open]::before {
  background: var(--citeal);
  box-shadow: 0 0 0 5px rgba(61, 255, 178, 0.16);
}

.page-about .ab-milestone__summary {
  display: grid;
  gap: 4px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-milestone__summary:focus-visible {
  outline: 2px solid var(--citeal);
  outline-offset: 4px;
  border-radius: 10px;
}

.page-about .ab-milestone__season {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .ab-milestone__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.35;
  color: var(--white);
}

.page-about .ab-milestone__body {
  margin: 0;
  padding: 0 18px 16px;
  font-size: 14px;
  line-height: 1.82;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */
.page-about .ab-network {
  display: grid;
  gap: 28px;
}

.page-about .ab-network__figure {
  padding: 22px 0;
  border-top: 2px solid var(--amber);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-network__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(64px, 17vw, 104px);
  line-height: 0.9;
  color: var(--amber);
}

.page-about .ab-network__unit {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .ab-network__text p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .ab-agenda {
  display: grid;
  gap: 10px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-agenda li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .ab-agenda li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--citeal);
  opacity: 0.72;
}

.page-about .ab-award {
  display: grid;
  gap: 10px;
  justify-items: start;
  margin-top: 24px;
  padding: 18px 20px;
  border-left: 3px solid var(--amber);
  border-radius: 0 18px 18px 0;
  background: rgba(255, 194, 75, 0.07);
}

.page-about .ab-award p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--pale);
}

/* ---------- 收尾 ---------- */
.page-about .ab-next {
  position: relative;
  overflow: hidden;
  padding: var(--ab-pad-y) 0 calc(var(--ab-pad-y) + 16px);
  border-top: 1px solid var(--line);
  background: linear-gradient(142deg, var(--night) 0%, var(--ink-900) 82%);
}

.page-about .ab-next::before {
  content: "";
  position: absolute;
  right: -14%;
  top: -60%;
  width: 58%;
  height: 220%;
  background: linear-gradient(90deg, transparent, rgba(61, 255, 178, 0.1), transparent);
  transform: rotate(17deg);
  pointer-events: none;
}

.page-about .ab-next__inner {
  position: relative;
  display: grid;
  gap: 18px;
  max-width: 760px;
}

.page-about .ab-next__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 5.6vw, 42px);
  line-height: 1.12;
  text-wrap: balance;
}

.page-about .ab-next__inner p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .ab-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .page-about .ab-team__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 26px;
  }

  .page-about .ab-stat:nth-last-child(2) {
    border-bottom: 1px solid var(--line);
  }
}

@media (min-width: 760px) {
  .page-about {
    --ab-pad-y: 76px;
  }

  .page-about .ab-chapter__head {
    grid-template-columns: 64px minmax(0, 1fr);
    column-gap: 20px;
    align-items: start;
  }

  .page-about .ab-chapter__num {
    padding-top: 12px;
  }

  .page-about .ab-chapter__title,
  .page-about .ab-chapter__sub {
    grid-column: 2;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 0.85fr);
    gap: 48px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 48px;
    align-items: start;
  }
}

@media (min-width: 940px) {
  .page-about .ab-rules {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
    align-items: start;
  }

  .page-about .ab-rule:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .ab-rule:nth-child(3) {
    margin-top: 52px;
  }

  .page-about .ab-network {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-milestones {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .ab-milestones__figure {
    position: sticky;
    top: calc(var(--hdr-h) + 26px);
  }
}

@media (min-width: 1100px) {
  .page-about .ab-rail {
    display: block;
    position: absolute;
    left: -52px;
    top: 10px;
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.34em;
    color: var(--steel);
    pointer-events: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}