.page-about {
  --ab-note-col: 156px;
  --ab-rail-col: 200px;
  background: var(--kt-ink);
  color: var(--kt-text);
  font-family: var(--kt-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(44px, 7vw, 92px) 0 clamp(34px, 5vw, 60px);
  border-bottom: 1px solid var(--kt-line);
}
.page-about .ab-hero__media {
  position: absolute;
  inset: 0;
  z-index: -1;
}
.page-about .ab-hero__media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 34%;
  opacity: 0.4;
}
.page-about .ab-hero__veil {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(120% 92% at 84% 10%, rgba(53, 240, 200, 0.16), transparent 58%),
    radial-gradient(90% 70% at 6% 92%, rgba(138, 124, 255, 0.12), transparent 60%),
    linear-gradient(180deg, rgba(7, 19, 15, 0.74) 0%, rgba(7, 19, 15, 0.93) 52%, var(--kt-ink) 100%);
}
.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}
.page-about .ab-title {
  margin: 14px 0 0;
  font-family: var(--kt-display);
  font-weight: 700;
  font-size: clamp(34px, 4.6vw, 60px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--kt-text);
  max-width: 15em;
}
.page-about .ab-lede {
  margin: 20px 0 0;
  max-width: 40em;
  font-size: clamp(16px, 1.6vw, 17.5px);
  line-height: 1.8;
  color: var(--kt-text-soft);
}
.page-about .ab-lede strong {
  color: var(--kt-cyan);
  font-weight: 600;
}
.page-about .ab-metas {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

/* ---------- 主体框架 ---------- */
.page-about .ab-frame {
  display: grid;
  gap: 20px;
  padding-top: clamp(26px, 4vw, 46px);
  padding-bottom: clamp(48px, 7vw, 88px);
}

/* ---------- 章节索引 ---------- */
.page-about .ab-railwrap {
  order: -1;
  min-width: 0;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--kt-line);
}
.page-about .ab-railwrap::-webkit-scrollbar {
  display: none;
}
.page-about .ab-rail .kt-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-rail .kt-rail__list li {
  flex: 0 0 auto;
  margin: 0;
}
.page-about .ab-rail__link {
  display: block;
  white-space: nowrap;
  padding: 7px 14px;
  border: 1px solid var(--kt-line);
  border-radius: 999px;
  font-size: 13px;
  line-height: 1.4;
  color: var(--kt-muted);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}
.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--kt-cyan);
  border-color: var(--kt-cyan);
  background: rgba(53, 240, 200, 0.08);
  outline: none;
}
.page-about .ab-rail__link.is-current {
  color: var(--kt-amber);
  border-color: rgba(242, 169, 59, 0.55);
  background: rgba(242, 169, 59, 0.1);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding: clamp(32px, 4.5vw, 54px) 0;
  border-top: 1px solid var(--kt-line);
}
.page-about .ab-sec__grid {
  display: grid;
  gap: 14px;
}
.page-about .ab-note {
  border-left: 2px solid var(--kt-line);
  padding-left: 12px;
}
.page-about .ab-note__label {
  margin: 0 0 6px;
  font-family: var(--kt-data);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--kt-cyan);
}
.page-about .ab-note__text {
  margin: 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--kt-muted);
}

.page-about .ab-h2 {
  margin: 0 0 18px;
  font-family: var(--kt-editorial);
  font-weight: 700;
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.36;
  letter-spacing: 0.01em;
  color: var(--kt-text);
}
.page-about .kt-prose.ab-prose {
  max-width: 40em;
}

/* ---------- 引用块 ---------- */
.page-about .ab-quote {
  margin: 26px 0;
  padding: 6px 0 6px 20px;
  border-left: 3px solid var(--kt-cyan);
  font-family: var(--kt-editorial);
  font-size: clamp(17px, 1.7vw, 20px);
  line-height: 1.72;
  color: var(--kt-text);
  max-width: 34em;
}

/* ---------- 要点列表 ---------- */
.page-about .ab-list {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  max-width: 40em;
  display: grid;
  gap: 10px;
}
.page-about .ab-list li {
  position: relative;
  padding-left: 22px;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--kt-text-soft);
}
.page-about .ab-list li::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 0.62em;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--kt-amber);
  transform: rotate(45deg);
}

/* ---------- 术语释义 ---------- */
.page-about .ab-term {
  position: relative;
  color: var(--kt-cyan-soft);
  border-bottom: 1px dashed rgba(143, 248, 224, 0.5);
  cursor: help;
  text-decoration: none;
  outline-offset: 3px;
}
.page-about .ab-term:focus-visible {
  outline: 1px solid var(--kt-cyan-soft);
  border-radius: 2px;
}
.page-about .ab-term__tip {
  position: absolute;
  left: 0;
  bottom: calc(100% + 10px);
  width: min(262px, 72vw);
  padding: 9px 12px;
  background: var(--kt-panel);
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius-sm);
  font-family: var(--kt-body);
  font-size: 13px;
  font-weight: 400;
  line-height: 1.58;
  color: var(--kt-text-soft);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.18s ease, visibility 0.18s ease;
  z-index: 8;
}
.page-about .ab-term:hover .ab-term__tip,
.page-about .ab-term:focus-visible .ab-term__tip {
  opacity: 1;
  visibility: visible;
}

/* ---------- 八节点环形图 ---------- */
.page-about .ab-flowfig {
  margin: 28px 0 0;
  padding: clamp(18px, 3vw, 30px);
  background: var(--kt-panel);
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius-lg);
}
.page-about .ab-flowfig svg {
  display: block;
  width: 100%;
  max-width: 400px;
  height: auto;
  margin: 0 auto;
}
.page-about .ab-flowfig__ring {
  fill: none;
  stroke: rgba(53, 240, 200, 0.18);
  stroke-width: 1;
}
.page-about .ab-flowfig__track {
  fill: none;
  stroke: rgba(28, 63, 54, 0.9);
  stroke-width: 2;
  stroke-dasharray: 94 23.81;
  stroke-linecap: round;
}
.page-about .ab-flowfig__node {
  fill: var(--kt-ink);
  stroke: var(--kt-cyan);
  stroke-width: 2.5;
}
.page-about .ab-flowfig__node--amber {
  stroke: var(--kt-amber);
}
.page-about .ab-flowfig__label {
  font-family: var(--kt-data);
  font-size: 15px;
  font-weight: 600;
  fill: var(--kt-cyan);
  text-anchor: middle;
  dominant-baseline: central;
}
.page-about .ab-flowfig__label--amber {
  fill: var(--kt-amber);
}

/* ---------- 八步列表 ---------- */
.page-about .ab-steps {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  max-width: 44em;
}
.page-about .ab-steps li {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 0 14px;
  padding: 15px 0;
  border-top: 1px solid var(--kt-line);
}
.page-about .ab-steps li:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .ab-steps__n {
  font-family: var(--kt-data);
  font-size: 14px;
  font-weight: 600;
  color: var(--kt-amber);
  padding-top: 3px;
}
.page-about .ab-steps__name {
  margin: 0 0 3px;
  font-family: var(--kt-display);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--kt-text);
}
.page-about .ab-steps__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--kt-muted);
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 30px 0 0;
}
.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius);
}
.page-about .ab-figure figcaption {
  margin-top: 10px;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 24px;
}
.page-about .ab-team__media {
  margin: 0;
}
.page-about .ab-team__media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius);
}
.page-about .ab-team__media figcaption {
  margin-top: 10px;
}
.page-about .ab-roles {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}
.page-about .ab-roles__item {
  padding: 17px 17px 19px;
  background: var(--kt-panel);
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius);
}
.page-about .ab-roles__num {
  margin: 0;
  font-family: var(--kt-data);
  font-size: clamp(26px, 3vw, 34px);
  font-weight: 600;
  line-height: 1;
  color: var(--kt-cyan);
}
.page-about .ab-roles__name {
  margin: 11px 0 6px;
  font-family: var(--kt-display);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--kt-text);
}
.page-about .ab-roles__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--kt-muted);
}

/* ---------- 版本刻度 ---------- */
.page-about .ab-versions {
  position: relative;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  max-width: 44em;
}
.page-about .ab-versions::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--kt-cyan) 0%, var(--kt-violet) 58%, var(--kt-amber) 100%);
  opacity: 0.45;
}
.page-about .ab-versions__item {
  position: relative;
  padding: 0 0 26px 40px;
}
.page-about .ab-versions__item:last-child {
  padding-bottom: 0;
}
.page-about .ab-versions__item::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  box-sizing: border-box;
  background: var(--kt-ink);
  border: 2px solid var(--kt-cyan);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}
.page-about .ab-versions__item--latest::before {
  border-color: var(--kt-amber);
}
.page-about .ab-versions__item:hover::before,
.page-about .ab-versions__item:focus-within::before {
  transform: scale(1.22);
  box-shadow: 0 0 0 5px rgba(53, 240, 200, 0.12);
}
.page-about .ab-versions__tag {
  display: inline-block;
  margin-bottom: 9px;
  padding: 2px 12px;
  border-radius: 999px;
  background: rgba(53, 240, 200, 0.13);
  border: 1px solid rgba(53, 240, 200, 0.4);
  color: var(--kt-cyan);
  font-family: var(--kt-data);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
}
.page-about .ab-versions__item--latest .ab-versions__tag {
  background: rgba(242, 169, 59, 0.14);
  border-color: rgba(242, 169, 59, 0.45);
  color: var(--kt-amber);
}
.page-about .ab-versions__name {
  margin: 0 0 5px;
  font-family: var(--kt-editorial);
  font-size: 17px;
  line-height: 1.45;
  color: var(--kt-text);
}
.page-about .ab-versions__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.68;
  color: var(--kt-muted);
}
.page-about .ab-versions__more {
  max-height: 0;
  margin-top: 0;
  overflow: hidden;
  opacity: 0;
  padding-left: 12px;
  border-left: 2px solid rgba(53, 240, 200, 0.35);
  font-size: 13.5px;
  line-height: 1.62;
  color: var(--kt-text-soft);
  transition: max-height 0.28s ease, opacity 0.24s ease, margin-top 0.28s ease;
}
.page-about .ab-versions__item:hover .ab-versions__more,
.page-about .ab-versions__item:focus-within .ab-versions__more {
  max-height: 7em;
  margin-top: 10px;
  opacity: 1;
}

/* ---------- 延伸入口 ---------- */
.page-about .ab-links {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
  max-width: 40em;
}
.page-about .ab-links__link {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 15px 18px;
  background: var(--kt-panel);
  border: 1px solid var(--kt-line);
  border-radius: var(--kt-radius);
  text-decoration: none;
  color: var(--kt-text);
  font-family: var(--kt-display);
  font-size: 17px;
  letter-spacing: 0.02em;
  transition: border-color 0.18s ease, background-color 0.18s ease, transform 0.18s ease;
}
.page-about .ab-links__link span {
  font-family: var(--kt-body);
  font-size: 14px;
  letter-spacing: 0;
  line-height: 1.6;
  color: var(--kt-muted);
}
.page-about .ab-links__link:hover,
.page-about .ab-links__link:focus-visible {
  border-color: rgba(53, 240, 200, 0.5);
  background: rgba(53, 240, 200, 0.06);
  transform: translateX(3px);
  outline: none;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .ab-sec__grid {
    grid-template-columns: var(--ab-note-col) minmax(0, 1fr);
    column-gap: clamp(28px, 3.4vw, 52px);
  }
  .page-about .ab-note {
    border-left: 0;
    padding-left: 0;
    padding-top: 8px;
    text-align: right;
  }
  .page-about .ab-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .ab-team {
    grid-template-columns: minmax(0, 1fr) 220px;
    column-gap: clamp(24px, 3vw, 44px);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-frame {
    grid-template-columns: minmax(0, 1fr) var(--ab-rail-col);
    column-gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }
  .page-about .ab-railwrap {
    order: 0;
    position: sticky;
    top: 112px;
    overflow: visible;
    border-bottom: 0;
    border-left: 1px solid var(--kt-line);
    padding: 6px 0 6px 18px;
  }
  .page-about .ab-rail .kt-rail__list {
    display: block;
  }
  .page-about .ab-rail .kt-rail__list li {
    margin-bottom: 4px;
  }
  .page-about .ab-rail__link {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    padding: 6px 0 6px 12px;
    font-size: 13.5px;
    background: transparent;
  }
  .page-about .ab-rail__link:hover,
  .page-about .ab-rail__link:focus-visible {
    border-left-color: var(--kt-cyan);
    background: transparent;
  }
  .page-about .ab-rail__link.is-current {
    border-left-color: var(--kt-amber);
    color: var(--kt-amber);
    background: transparent;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}