.page-about {
  --about-gap: clamp(1.5rem, 3.2vw, 2.75rem);
  --about-glaze: rgba(123, 224, 211, .32);
  display: block;
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: 1.75rem;
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -12rem;
  left: -12%;
  right: -12%;
  height: 30rem;
  background:
    radial-gradient(38% 58% at 20% 24%, rgba(31, 191, 166, .22), transparent 70%),
    radial-gradient(34% 52% at 78% 6%, rgba(107, 75, 224, .30), transparent 72%),
    radial-gradient(24% 40% at 52% 0%, rgba(255, 179, 71, .12), transparent 70%);
  filter: blur(4px);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero__inner {
  display: grid;
  gap: .85rem;
  max-width: 46rem;
}

.page-about .about-hero h1 {
  margin: 0;
  font-size: clamp(1.95rem, 5.6vw, 3.35rem);
  line-height: 1.06;
  letter-spacing: -.02em;
  font-weight: 900;
}

.page-about .about-hero .yh-lead {
  margin: 0;
  max-width: 40rem;
}

.page-about .about-hero__media {
  margin: 2.25rem 0 0;
  border-radius: calc(var(--radius) + 6px);
  border: 1px solid var(--line);
  overflow: hidden;
  background: rgba(5, 8, 24, .55);
  box-shadow: 0 40px 80px -50px rgba(5, 8, 24, .95);
}

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

/* ---------- 章节轨道 + 内容流 ---------- */
.page-about .about-layout {
  margin-top: var(--about-gap);
  padding-bottom: 3rem;
}

.page-about .about-rail {
  margin-bottom: 1.5rem;
}

.page-about .about-rail__label {
  margin: 0 0 .5rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-rail__list {
  display: flex;
  gap: .5rem;
  margin: 0;
  padding: 0 0 .4rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  flex: 0 0 auto;
  padding: .45rem .8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: .85rem;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 200ms var(--ease), border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  border-color: var(--aurora);
  background: rgba(123, 224, 211, .10);
}

.page-about .about-rail__no {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--amber);
}

.page-about .about-flow {
  display: grid;
  gap: var(--about-gap);
  min-width: 0;
}

/* ---------- 堆叠画板 ---------- */
.page-about .about-board {
  position: relative;
  min-width: 0;
}

.page-about .about-board .yh-panel {
  padding: clamp(1.25rem, 3vw, 2.1rem);
}

.page-about .about-board .yh-panel p {
  margin-top: 0;
}

/* 三个要点 */
.page-about .about-points {
  display: grid;
  gap: .8rem;
  margin: 1.4rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-points li {
  padding: .85rem 1rem .9rem 1.1rem;
  border-left: 2px solid var(--lake);
  border-radius: 0 calc(var(--radius) - 8px) calc(var(--radius) - 8px) 0;
  background: linear-gradient(90deg, rgba(31, 191, 166, .12), rgba(31, 191, 166, 0) 72%);
}

.page-about .about-points__k {
  display: block;
  margin-bottom: .25rem;
  font-weight: 800;
  font-size: .95rem;
  color: var(--aurora);
}

.page-about .about-points p {
  margin: 0;
  color: var(--muted);
  font-size: .93rem;
  line-height: 1.7;
}

/* ---------- 三组分工 ---------- */
.page-about .about-crew {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

.page-about .about-crew__item {
  display: grid;
  align-content: start;
  gap: .5rem;
  padding: 1.15rem 1.1rem 1.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(155deg, rgba(107, 75, 224, .20), rgba(11, 16, 48, .30) 68%);
  transition: border-color 260ms var(--ease), box-shadow 260ms var(--ease), transform 260ms var(--ease);
}

.page-about .about-crew__item:hover {
  border-color: var(--aurora);
  transform: translateY(-3px);
  box-shadow: 0 0 0 1px rgba(123, 224, 211, .28), 0 22px 46px -32px var(--about-glaze);
}

.page-about .about-crew__no {
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .16em;
  color: var(--amber);
}

.page-about .about-crew__title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-crew__item p {
  margin: 0;
  color: var(--muted);
  font-size: .92rem;
  line-height: 1.75;
}

/* ---------- 目录结构 ---------- */
.page-about .about-catalog {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.page-about .about-catalog__figure {
  margin: 0;
}

.page-about .about-catalog__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border-radius: calc(var(--radius) - 4px);
}

.page-about .about-layers {
  display: grid;
  gap: .6rem;
  align-content: start;
}

.page-about .about-layer {
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) - 6px);
  background: var(--glass);
  transition: border-color 220ms var(--ease);
}

.page-about .about-layer[open] {
  border-color: rgba(123, 224, 211, .45);
}

.page-about .about-layer > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 1rem;
  cursor: pointer;
  font-weight: 700;
  font-size: .96rem;
  color: var(--ink);
  list-style: none;
}

.page-about .about-layer > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-layer > summary::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--amber);
  font-weight: 400;
}

.page-about .about-layer[open] > summary::after {
  content: "–";
}

.page-about .about-layer > summary:focus-visible {
  outline: 2px solid var(--aurora);
  outline-offset: 2px;
}

.page-about .about-layer__body {
  padding: 0 1rem 1rem;
}

.page-about .about-layer__body p {
  margin: 0;
  color: var(--muted);
  font-size: .92rem;
  line-height: 1.75;
}

/* ---------- 巡检节奏 ---------- */
.page-about .about-rhythm {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

.page-about .about-rhythm__cell {
  padding: 1.1rem 1.15rem 1.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(5, 8, 24, .45);
}

.page-about .about-rhythm__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4.2vw, 2rem);
  line-height: 1.05;
  color: var(--amber);
  letter-spacing: -.01em;
}

.page-about .about-rhythm__label {
  display: block;
  margin-top: .5rem;
  font-weight: 800;
  font-size: .95rem;
}

.page-about .about-rhythm__cell p {
  margin: .4rem 0 0;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.7;
}

.page-about .about-rhythm__foot {
  margin: 1.25rem 0 0;
  font-size: .9rem;
  line-height: 1.75;
}

/* ---------- 版本 ---------- */
.page-about .about-versions__intro {
  display: grid;
  gap: 1.25rem;
  margin-top: 1.5rem;
  align-items: center;
}

.page-about .about-versions__intro .yh-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border-radius: calc(var(--radius) - 4px);
}

.page-about .about-versions__intro p {
  margin: 0;
  color: var(--muted);
  font-size: .96rem;
  line-height: 1.8;
}

.page-about .about-versionband {
  display: flex;
  gap: 1rem;
  margin: 1.75rem 0 0;
  padding: .4rem .2rem 1.1rem;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-ver {
  position: relative;
  flex: 0 0 min(16.5rem, 76vw);
  scroll-snap-align: start;
  padding: 1.15rem 1.1rem 1.25rem 2.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(150deg, rgba(11, 16, 48, .92), rgba(107, 75, 224, .18));
  transition: border-color 280ms var(--ease), box-shadow 280ms var(--ease), transform 280ms var(--ease);
}

.page-about .about-ver:hover,
.page-about .about-ver:focus-within,
.page-about .about-ver:focus-visible {
  border-color: var(--amber);
  transform: translateY(-3px);
  outline: none;
  box-shadow: 0 0 0 1px rgba(255, 179, 71, .30), 0 24px 52px -32px rgba(255, 179, 71, .45);
}

.page-about .about-ver__node {
  position: absolute;
  top: 1.45rem;
  left: 1rem;
  width: .68rem;
  height: .68rem;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 179, 71, .16), 0 0 18px rgba(255, 179, 71, .55);
}

.page-about .about-ver__tag {
  display: block;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .16em;
  color: var(--aurora);
}

.page-about .about-ver__title {
  margin: .4rem 0 .55rem;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.35;
}

.page-about .about-ver__more {
  margin: 0;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.72;
}

/* ---------- 下一步 ---------- */
.page-about .about-next__panel {
  padding: clamp(1.35rem, 3vw, 2rem);
}

.page-about .about-next__panel .yh-btnrow {
  margin-top: 1.25rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-rhythm {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .about-crew {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-catalog {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr);
    align-items: start;
    gap: 2rem;
  }

  .page-about .about-versions__intro {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 2rem;
  }

  .page-about .about-board:nth-child(odd) {
    margin-right: 2rem;
  }

  .page-about .about-board:nth-child(even) {
    margin-left: 2rem;
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 196px minmax(0, 1fr);
    gap: 3rem;
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 6.5rem;
    margin-bottom: 0;
  }

  .page-about .about-rail__list {
    display: grid;
    gap: .3rem;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    width: 100%;
    border-radius: calc(var(--radius) - 6px);
    padding: .55rem .7rem;
    white-space: normal;
    line-height: 1.4;
  }
}

@media (hover: hover) and (min-width: 900px) {
  .page-about .about-ver__more {
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 2;
    overflow: hidden;
  }

  .page-about .about-ver:hover .about-ver__more,
  .page-about .about-ver:focus-within .about-ver__more,
  .page-about .about-ver:focus-visible .about-ver__more {
    display: block;
    overflow: visible;
    -webkit-line-clamp: unset;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-crew__item,
  .page-about .about-ver,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .about-ver:hover,
  .page-about .about-ver:focus-within,
  .page-about .about-crew__item:hover {
    transform: none;
  }
}