.page-about {
  background: var(--hb-ink);
  color: var(--hb-paper);
  font-family: var(--hb-font-sans);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .ab-crumb {
  background: var(--hb-void);
  border-bottom: 1px solid var(--hb-hair);
}
.page-about .ab-crumb__inner {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-block: 12px;
  font-family: var(--hb-font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--hb-steel);
}
.page-about .ab-crumb__inner a {
  color: var(--hb-steel);
  text-decoration: none;
  transition: color .18s var(--hb-ease);
}
.page-about .ab-crumb__inner a:hover,
.page-about .ab-crumb__inner a:focus-visible {
  color: var(--hb-flame);
}
.page-about .ab-crumb__sep {
  color: var(--hb-hair);
}
.page-about .ab-crumb__now {
  color: var(--hb-amber);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding-block: 36px 48px;
  background-color: var(--hb-ink);
  background-image:
    repeating-linear-gradient(90deg, rgba(216, 210, 198, .06) 0 1px, transparent 1px 60px),
    repeating-linear-gradient(0deg, rgba(216, 210, 198, .035) 0 1px, transparent 1px 60px);
  border-bottom: 1px solid var(--hb-hair);
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -70px;
  width: 380px;
  height: 230px;
  background: linear-gradient(112deg, var(--hb-flame), var(--hb-lava));
  transform: skewY(-9deg);
  opacity: .16;
  pointer-events: none;
}
.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 30px;
}
.page-about .ab-hero__kicker {
  margin: 0 0 16px;
  font-family: var(--hb-font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--hb-steel);
}
.page-about .ab-hero__kicker .hb-mono {
  color: var(--hb-flame);
  margin-right: 10px;
}
.page-about .ab-hero__title {
  margin: 0 0 18px;
  font-size: clamp(30px, 6.4vw, 60px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--hb-paper);
  max-width: 18ch;
}
.page-about .ab-hero__lede {
  margin: 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 241, 234, .8);
}

.page-about .ab-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--hb-hair);
  border: 1px solid var(--hb-hair);
}
.page-about .ab-fact {
  background: var(--hb-ink-2);
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .ab-fact dt {
  font-family: var(--hb-font-mono);
  font-size: 10px;
  letter-spacing: .16em;
  color: var(--hb-steel);
  text-transform: uppercase;
}
.page-about .ab-fact dd {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--hb-paper);
  line-height: 1.2;
}
.page-about .ab-fact dd .hb-mono {
  font-size: 26px;
  color: var(--hb-flame);
  margin-right: 4px;
}

/* ---------- 正文骨架 ---------- */
.page-about .ab-shell {
  display: grid;
  gap: 32px;
  padding-block: 44px 72px;
}

/* ---------- 侧栏索引 ---------- */
.page-about .ab-toc {
  border-top: 2px solid var(--hb-flame);
  padding-top: 12px;
}
.page-about .ab-toc__title {
  margin: 0 0 12px;
  font-family: var(--hb-font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--hb-steel);
}
.page-about .ab-toc__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .ab-toc__list::-webkit-scrollbar {
  display: none;
}
.page-about .ab-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 11px;
  white-space: nowrap;
  font-size: 13px;
  line-height: 1.2;
  color: var(--hb-steel);
  text-decoration: none;
  border: 1px solid var(--hb-hair);
  transition: color .18s var(--hb-ease), background .18s var(--hb-ease), border-color .18s var(--hb-ease);
}
.page-about .ab-toc__link .hb-mono {
  font-size: 10px;
  color: var(--hb-amber);
}
.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--hb-paper);
  border-color: var(--hb-flame);
}
.page-about .ab-toc__link.is-active,
.page-about .ab-toc__link[aria-current] {
  color: var(--hb-ink);
  background: var(--hb-flame);
  border-color: var(--hb-flame);
}
.page-about .ab-toc__link.is-active .hb-mono,
.page-about .ab-toc__link[aria-current] .hb-mono {
  color: var(--hb-ink);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding-block: 38px;
  border-top: 1px solid var(--hb-hair);
}
.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .ab-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--hb-hair);
}
.page-about .ab-sec__head .hb-index {
  color: var(--hb-flame);
  flex: none;
}
.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(24px, 4.4vw, 34px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--hb-paper);
}
.page-about .ab-sec p {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 241, 234, .82);
}
.page-about .ab-sec p:last-child {
  margin-bottom: 0;
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  position: relative;
  margin: 22px 0 24px;
  padding: 8px;
  background: var(--hb-ink-2);
  border: 1px solid var(--hb-hair);
}
.page-about .ab-figure::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, transparent 50%, var(--hb-flame) 50%);
  opacity: .85;
  pointer-events: none;
}
.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--hb-void);
}
.page-about .ab-figure--4x3 img {
  aspect-ratio: 4 / 3;
}
.page-about .ab-figure__cap {
  padding: 9px 4px 2px;
  font-family: var(--hb-font-mono);
  font-size: 10px;
  letter-spacing: .14em;
  color: var(--hb-steel);
  text-align: right;
  line-height: 1.6;
}

/* ---------- 旁注 ---------- */
.page-about .ab-note {
  margin: 22px 0;
  padding: 16px 18px;
  background: var(--hb-ink-2);
  border-left: 3px solid var(--hb-flame);
}
.page-about .ab-note__label {
  margin: 0 0 10px !important;
  font-family: var(--hb-font-mono);
  font-size: 11px !important;
  letter-spacing: .18em;
  color: var(--hb-amber) !important;
  line-height: 1.4 !important;
}
.page-about .ab-note__list {
  margin: 0;
  padding: 0 0 0 18px;
  display: grid;
  gap: 8px;
}
.page-about .ab-note__list li {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(244, 241, 234, .78);
}
.page-about .ab-note__list li::marker {
  color: var(--hb-flame);
}

/* ---------- 团队分工 ---------- */
.page-about .ab-roles {
  display: grid;
  gap: 1px;
  margin-top: 24px;
  background: var(--hb-hair);
  border: 1px solid var(--hb-hair);
}
.page-about .ab-role {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  background: var(--hb-ink-2);
}
.page-about .ab-role__num {
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  color: var(--hb-flame);
}
.page-about .ab-role__name {
  margin: 0;
  font-size: 17px;
  font-weight: 900;
  color: var(--hb-paper);
  letter-spacing: .04em;
}
.page-about .ab-role p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(244, 241, 234, .74);
}

/* ---------- 流程步骤 ---------- */
.page-about .ab-steps {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-step {
  position: relative;
  padding: 18px 18px 18px 20px;
  background: var(--hb-ink-2);
  border-left: 2px solid var(--hb-flame);
}
.page-about .ab-step__n {
  display: block;
  margin-bottom: 8px;
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--hb-amber);
}
.page-about .ab-step__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 900;
  color: var(--hb-paper);
}
.page-about .ab-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(244, 241, 234, .76);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl {
  display: flex;
  gap: 14px;
  margin: 26px 0 0;
  padding: 0 0 14px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--hb-flame) transparent;
}
.page-about .ab-tl__item {
  flex: 0 0 min(272px, 80vw);
  scroll-snap-align: start;
}
.page-about .ab-tl__card {
  height: 100%;
  padding: 20px 18px 22px;
  background: var(--hb-ink-2);
  border: 1px solid var(--hb-hair);
  border-top: 3px solid var(--hb-flame);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}
.page-about .ab-tl__year {
  display: block;
  margin-bottom: 10px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--hb-amber);
}
.page-about .ab-tl__name {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 900;
  line-height: 1.3;
  color: var(--hb-paper);
}
.page-about .ab-tl__card p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(244, 241, 234, .74);
}

/* ---------- 数据 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 24px 0;
  background: var(--hb-hair);
  border: 1px solid var(--hb-hair);
}
.page-about .ab-stat {
  padding: 20px 16px;
  background: var(--hb-ink);
}
.page-about .ab-stat__num {
  display: block;
  font-family: var(--hb-font-mono);
  font-size: clamp(26px, 4.4vw, 34px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--hb-paper);
}
.page-about .ab-stat__unit {
  font-size: .55em;
  margin-left: 3px;
  color: var(--hb-blue);
}
.page-about .ab-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--hb-steel);
}

/* ---------- 引文与原则 ---------- */
.page-about .ab-quote {
  margin: 22px 0 0;
  padding: 24px 20px;
  background: linear-gradient(118deg, rgba(244, 81, 30, .18), rgba(244, 81, 30, 0) 72%);
  border-left: 4px solid var(--hb-flame);
  font-size: clamp(17px, 2.6vw, 24px);
  font-weight: 900;
  line-height: 1.55;
  color: var(--hb-paper);
}
.page-about .ab-principles {
  display: grid;
  gap: 14px;
  margin-top: 24px;
}
.page-about .ab-principle {
  padding: 20px 18px;
  background: var(--hb-paper);
  color: var(--hb-ink);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}
.page-about .ab-principle h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 900;
  color: var(--hb-ink);
}
.page-about .ab-principle p {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.78;
  color: #3b3f45;
}

/* ---------- 结尾动作 ---------- */
.page-about .ab-cta {
  margin-top: 32px;
  padding: 24px 20px;
  background: linear-gradient(100deg, var(--hb-ink-2) 0%, rgba(27, 30, 34, .4) 100%);
  border-top: 1px solid var(--hb-hair);
  border-bottom: 1px solid var(--hb-hair);
}
.page-about .ab-cta__text {
  margin: 0 0 18px;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(244, 241, 234, .84);
}
.page-about .ab-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 返回顶部 ---------- */
.page-about .ab-totop {
  position: fixed;
  right: 16px;
  bottom: 20px;
  z-index: 20;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .ab-hero {
    padding-block: 52px 64px;
  }
  .page-about .ab-fact {
    padding: 20px 18px;
  }
  .page-about .ab-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-cta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 28px 24px;
  }
  .page-about .ab-cta__text {
    margin: 0;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__inner {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: end;
    gap: 52px;
  }
  .page-about .ab-hero__facts {
    align-self: stretch;
  }
  .page-about .ab-tl {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .ab-tl__item {
    flex: none;
  }
  .page-about .ab-sec {
    padding-block: 46px;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-shell {
    grid-template-columns: 236px minmax(0, 1fr);
    gap: 60px;
    padding-block: 56px 88px;
  }
  .page-about .ab-toc {
    position: sticky;
    top: 96px;
    align-self: start;
  }
  .page-about .ab-toc__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .ab-toc__link {
    width: 100%;
    white-space: normal;
    padding: 10px 12px;
    border: 0;
    border-left: 2px solid transparent;
    font-size: 13.5px;
    box-sizing: border-box;
  }
  .page-about .ab-toc__link:hover,
  .page-about .ab-toc__link:focus-visible {
    border-left-color: var(--hb-flame);
    background: rgba(244, 81, 30, .1);
  }
  .page-about .ab-toc__link.is-active,
  .page-about .ab-toc__link[aria-current] {
    border-left-color: var(--hb-flame);
    background: rgba(244, 81, 30, .16);
    color: var(--hb-paper);
  }
  .page-about .ab-toc__link.is-active .hb-mono,
  .page-about .ab-toc__link[aria-current] .hb-mono {
    color: var(--hb-amber);
  }
}

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