.page-about {
  --ab-hair: rgba(243, 239, 230, 0.18);
  --ab-hair-soft: rgba(243, 239, 230, 0.08);
  --ab-ink-soft: rgba(18, 16, 20, 0.78);
  display: block;
  background: var(--hx-ink);
  color: var(--hx-cream);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  padding: calc(var(--header-h) + 40px) 0 var(--gap-l);
  background:
    radial-gradient(90% 80% at 88% 0%, rgba(255, 90, 31, 0.32), transparent 60%),
    radial-gradient(70% 70% at 0% 100%, rgba(31, 224, 176, 0.16), transparent 62%),
    linear-gradient(150deg, #121014 0%, #06373A 62%, #231A5C 100%);
  border-bottom: var(--bd) solid var(--hx-orange);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(243, 239, 230, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 239, 230, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}

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

.page-about .ab-crumb {
  color: var(--hx-gray);
  margin-bottom: var(--gap);
}

.page-about .ab-crumb .crumb__item,
.page-about .ab-crumb a.crumb__item {
  color: var(--hx-gray);
  text-decoration: none;
}

.page-about .ab-crumb a.crumb__item:hover {
  color: var(--hx-orange);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap-l);
}

.page-about .ab-hero__title {
  margin: 0 0 var(--gap);
  color: var(--hx-white);
  text-shadow: 0 0 0 transparent;
}

.page-about .ab-hero__lede {
  max-width: 34em;
  color: rgba(243, 239, 230, 0.86);
  margin: 0 0 var(--gap-l);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--gap-s);
}

.page-about .ab-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--gap);
  border-left: var(--bd) solid var(--hx-mint);
  display: grid;
  gap: var(--gap);
}

.page-about .ab-fact {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px;
}

.page-about .ab-fact__num {
  font-size: clamp(1.7rem, 1.2rem + 1.8vw, 2.5rem);
  font-weight: 800;
  line-height: 1;
  color: var(--hx-mint);
  font-style: italic;
}

.page-about .ab-fact__text {
  font-size: 0.94rem;
  line-height: 1.6;
  color: rgba(243, 239, 230, 0.78);
}

/* ---------- 分屏骨架 ---------- */

.page-about .ab-body {
  padding: var(--gap-l) 0 96px;
}

.page-about .ab-layout {
  align-items: start;
  gap: var(--gap-l);
}

.page-about .ab-rail {
  border: var(--bd) solid var(--ab-hair);
  border-radius: var(--radius);
  background: var(--ab-hair-soft);
  padding: var(--gap);
}

.page-about .ab-rail__eyebrow {
  color: var(--hx-orange);
  margin: 0 0 var(--gap-s);
}

.page-about .ab-toc {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .ab-toc__link {
  display: block;
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--hx-gray);
  text-decoration: none;
  border-left: var(--bd) solid transparent;
  border-radius: var(--radius);
  transition: color 0.2s ease-out, background 0.2s ease-out, border-color 0.2s ease-out;
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--hx-white);
  background: rgba(255, 90, 31, 0.12);
  border-left-color: var(--hx-orange);
}

.page-about .ab-toc__link.is-active {
  color: var(--hx-ink);
  background: var(--hx-orange);
  border-left-color: var(--hx-orange);
  font-weight: 700;
}

.page-about .ab-rail__note {
  margin: var(--gap) 0 0;
  padding-top: var(--gap-s);
  border-top: 1px dashed var(--ab-hair);
  font-size: 0.75rem;
  line-height: 1.7;
  color: var(--hx-gray);
}

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

/* ---------- 区块底色与通用块 ---------- */

.page-about .ab-block {
  position: relative;
  padding: var(--gap-l) var(--gap);
  border: var(--bd) solid var(--ab-hair);
  border-radius: var(--radius);
  margin-bottom: var(--gap-l);
}

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

.page-about .ab-block__head {
  margin-bottom: var(--gap);
}

.page-about .ab-block .eyebrow {
  color: var(--hx-mint);
  margin: 0 0 var(--gap-s);
}

.page-about .ab-block .sec-title {
  margin: 0;
  color: var(--hx-white);
  line-height: 1.25;
}

.page-about .ab-block--cream {
  background: var(--hx-cream);
  color: var(--hx-ink);
  border-color: var(--hx-ink);
  box-shadow: var(--shadow-ink);
}

.page-about .ab-block--cream .eyebrow {
  color: var(--hx-red);
}

.page-about .ab-block--cream .sec-title {
  color: var(--hx-ink);
}

.page-about .ab-block--teal {
  background: linear-gradient(168deg, #06373A 0%, #04262a 100%);
  border-color: rgba(31, 224, 176, 0.34);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-block--indigo {
  background: linear-gradient(168deg, #231A5C 0%, #14103a 100%);
  border-color: rgba(31, 224, 176, 0.28);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-block--wine {
  background: linear-gradient(168deg, #4E1220 0%, #2c0a13 100%);
  border-color: rgba(255, 90, 31, 0.42);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-prose p {
  margin: 0 0 var(--gap);
  max-width: var(--measure);
  line-height: var(--lh-body);
  color: var(--ab-ink-soft);
}

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

.page-about .ab-block--teal .lede,
.page-about .ab-block--indigo .lede,
.page-about .ab-block--wine .lede {
  color: rgba(243, 239, 230, 0.84);
  max-width: 42em;
  margin: 0 0 var(--gap);
}

.page-about .ab-media {
  margin: 0 0 var(--gap-l);
  border: var(--bd) solid var(--ab-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-block--cream .ab-media {
  border-color: var(--hx-ink);
}

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

.page-about .ab-media .media__caption {
  padding: 10px 14px;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--hx-gray);
  background: rgba(18, 16, 20, 0.35);
}

.page-about .ab-block--cream .ab-media .media__caption {
  background: rgba(18, 16, 20, 0.06);
  color: #5b5550;
}

/* ---------- 起点与定位：三类读者 ---------- */

.page-about .ab-uses {
  list-style: none;
  margin: var(--gap-l) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .ab-use {
  padding-top: var(--gap-s);
  border-top: var(--bd) solid var(--hx-red);
}

.page-about .ab-use__title {
  margin: 0 0 8px;
  font-size: var(--fs-m);
  font-weight: 800;
  color: var(--hx-ink);
}

.page-about .ab-use p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--ab-ink-soft);
}

/* ---------- 团队 ---------- */

.page-about .ab-team__lede {
  margin-bottom: var(--gap);
}

.page-about .ab-team {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .ab-team__card {
  padding: var(--gap);
  background: rgba(243, 239, 230, 0.06);
  border: var(--bd) solid rgba(31, 224, 176, 0.35);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-team__num {
  display: block;
  font-size: 2.6rem;
  font-weight: 700;
  line-height: 1;
  color: var(--hx-mint);
  margin-bottom: 10px;
}

.page-about .ab-team__role {
  margin: 0 0 8px;
  font-size: var(--fs-m);
  font-weight: 800;
  color: var(--hx-white);
}

.page-about .ab-team__card p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.75;
  color: rgba(243, 239, 230, 0.8);
}

.page-about .ab-zones {
  list-style: none;
  margin: var(--gap-l) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap-s);
}

.page-about .ab-zones li {
  padding-left: 12px;
  border-left: 3px solid var(--hx-orange);
  font-size: 0.93rem;
  line-height: 1.72;
  color: rgba(243, 239, 230, 0.86);
}

/* ---------- 归档流程 ---------- */

.page-about .ab-flow__lede {
  color: var(--ab-ink-soft);
}

.page-about .ab-block--cream .ab-flow__lede {
  color: var(--ab-ink-soft);
}

.page-about .ab-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .ab-flow__step {
  position: relative;
  padding: var(--gap);
  background: var(--hx-white);
  border: var(--bd) solid var(--hx-ink);
  border-radius: var(--radius);
  box-shadow: var(--shadow-ink);
  transition: transform 0.24s ease-out, box-shadow 0.24s ease-out;
}

.page-about .ab-flow__step:hover,
.page-about .ab-flow__step:focus-visible {
  transform: translateY(-4px);
  outline: none;
}

.page-about .ab-flow__no {
  display: inline-block;
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1;
  color: var(--hx-orange);
  margin-bottom: 10px;
}

.page-about .ab-flow__title {
  margin: 0 0 8px;
  font-size: var(--fs-m);
  font-weight: 800;
  color: var(--hx-ink);
}

.page-about .ab-flow__step > p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
  color: var(--ab-ink-soft);
}

.page-about .ab-flow__detail {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-flow__detail li {
  position: relative;
  padding-left: 16px;
  font-size: 0.84rem;
  line-height: 1.7;
  color: #55four;
  color: #57514c;
}

.page-about .ab-flow__detail li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 7px;
  height: 7px;
  background: var(--hx-mint);
  transform: rotate(45deg);
}

/* ---------- 四档读法 ---------- */

.page-about .ab-scale__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap-l);
}

.page-about .ab-media--scale {
  margin: 0;
  border-color: rgba(31, 224, 176, 0.3);
}

.page-about .ab-scale__lede {
  margin-bottom: var(--gap-l);
}

.page-about .ab-scale__group {
  margin-bottom: var(--gap);
}

.page-about .ab-scale__label {
  margin: 0 0 10px;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--hx-mint);
}

.page-about .ab-slots {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.page-about .ab-slot {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 9px 12px;
  border-left: 6px solid var(--hx-gray);
  border-radius: var(--radius);
  background: rgba(243, 239, 230, 0.07);
}

.page-about .ab-slot--1 { border-left-color: #1FE0B0; }
.page-about .ab-slot--2 { border-left-color: #57C49C; }
.page-about .ab-slot--3 { border-left-color: #8C949C; }
.page-about .ab-slot--4 { border-left-color: #B3151F; }

.page-about .ab-slot__name {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  color: var(--hx-white);
}

.page-about .ab-slot__desc {
  font-size: 0.86rem;
  line-height: 1.65;
  color: rgba(243, 239, 230, 0.74);
}

.page-about .ab-scale__note {
  margin: var(--gap) 0 0;
  padding-top: var(--gap-s);
  border-top: 1px dashed rgba(243, 239, 230, 0.22);
  font-size: 0.9rem;
  line-height: 1.78;
  color: rgba(243, 239, 230, 0.8);
}

/* ---------- 发展阶段 ---------- */

.page-about .ab-stages {
  background: var(--hx-ink);
  border-color: var(--ab-hair);
}

.page-about .ab-stage-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--gap);
  display: grid;
  gap: var(--gap-l);
  counter-reset: ab-stage;
}

.page-about .ab-stage {
  position: relative;
  padding: var(--gap);
  border: var(--bd) solid rgba(243, 239, 230, 0.18);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-stage::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--gap) - 5px);
  top: 24px;
  width: 11px;
  height: 11px;
  background: var(--hx-mint);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px rgba(31, 224, 176, 0.18);
}

.page-about .ab-stage::after {
  content: "";
  position: absolute;
  left: calc(-1 * var(--gap));
  top: 42px;
  bottom: calc(-1 * var(--gap-l) + 8px);
  width: 2px;
  background: linear-gradient(180deg, rgba(31, 224, 176, 0.75), rgba(31, 224, 176, 0.06));
}

.page-about .ab-stage:last-child::after {
  display: none;
}

.page-about .ab-stage--1 { background: #06373A; }
.page-about .ab-stage--2 { background: #231A5C; }
.page-about .ab-stage--3 { background: #4E1220; }
.page-about .ab-stage--4 {
  background: #0C0A0E;
  border-color: var(--hx-orange);
}

.page-about .ab-stage__idx {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 0.76rem;
  letter-spacing: 0.09em;
  color: var(--hx-mint);
}

.page-about .ab-stage__title {
  margin: 0 0 8px;
  font-size: var(--fs-m);
  font-weight: 800;
  color: var(--hx-white);
}

.page-about .ab-stage p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.78;
  color: rgba(243, 239, 230, 0.82);
}

/* ---------- 合作方向 ---------- */

.page-about .ab-coop {
  list-style: none;
  margin: 0 0 var(--gap-l);
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .ab-coop__item {
  padding: var(--gap);
  background: rgba(243, 239, 230, 0.07);
  border: var(--bd) solid rgba(255, 90, 31, 0.45);
  border-radius: var(--radius);
}

.page-about .ab-coop__title {
  margin: 0 0 8px;
  font-size: var(--fs-m);
  font-weight: 800;
  color: var(--hx-white);
}

.page-about .ab-coop__item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: rgba(243, 239, 230, 0.82);
}

.page-about .ab-join__text {
  max-width: 40em;
  margin: 0 0 var(--gap);
  font-size: 0.95rem;
  line-height: 1.8;
  color: rgba(243, 239, 230, 0.86);
}

.page-about .ab-join__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--gap-s);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .ab-uses {
    grid-template-columns: repeat(3, 1fr);
  }

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

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

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

  .page-about .ab-slot {
    grid-template-columns: 150px 1fr;
    align-items: baseline;
  }

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

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: 1.4fr 1fr;
    align-items: end;
  }

  .page-about .ab-scale__grid {
    grid-template-columns: 0.85fr 1.15fr;
    align-items: start;
  }
}

@media (min-width: 961px) {
  .page-about .ab-rail {
    position: sticky;
    top: var(--sticky-top);
  }

  .page-about .ab-toc {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 4px;
  }

  .page-about .ab-toc__link {
    padding: 8px 12px;
  }
}

@media (min-width: 1140px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .ab-flow__step {
    display: flex;
    flex-direction: column;
  }

  .page-about .ab-flow__detail {
    margin-top: auto;
    padding-top: var(--gap-s);
  }
}

@media (hover: hover) and (min-width: 1140px) {
  .page-about .ab-flow__detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    margin-top: 0;
    padding-top: 0;
    transition: max-height 0.28s ease-out, opacity 0.24s ease-out,
      margin-top 0.28s ease-out, padding-top 0.28s ease-out;
  }

  .page-about .ab-flow__step:hover .ab-flow__detail,
  .page-about .ab-flow__step:focus-within .ab-flow__detail {
    max-height: 220px;
    opacity: 1;
    margin-top: auto;
    padding-top: var(--gap-s);
  }
}

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

  .page-about .ab-flow__step:hover {
    transform: none;
  }
}