.page-about {
  --about-rail-w: 13rem;
  --about-stage-1: rgba(255, 255, 255, 0.36);
  --about-stage-2: rgba(255, 255, 255, 0.54);
  --about-stage-3: rgba(255, 255, 255, 0.72);
  --about-stage-4: rgba(255, 255, 255, 0.9);
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
}

.page-about .about-shell {
  max-width: var(--measure);
  margin: 0 auto;
  padding: clamp(1.25rem, 3.5vw, 2.25rem) var(--gutter) clamp(3.5rem, 9vw, 7rem);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1rem, 3vw, 2rem);
}

.page-about .about-flow {
  min-width: 0;
  position: relative;
}

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

.page-about .about-rail-note {
  margin: 1.1rem 0 0;
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin-bottom: clamp(1rem, 3vw, 1.75rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-hero-veil {
  position: absolute;
  z-index: -1;
  top: -20%;
  right: -24%;
  width: 76%;
  height: 148%;
  background: linear-gradient(
    112deg,
    rgba(240, 194, 100, 0) 36%,
    rgba(240, 194, 100, 0.26) 50%,
    rgba(240, 194, 100, 0) 64%
  );
  transform: rotate(-9deg) translateX(-8px);
  opacity: 0;
  pointer-events: none;
  animation: about-doorlight 640ms var(--ease) 120ms forwards;
}

@keyframes about-doorlight {
  to {
    opacity: 1;
    transform: rotate(-9deg) translateX(0);
  }
}

.page-about .about-kicker {
  margin: 0 0 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.28em;
  color: var(--cinnabar);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(2.05rem, 6.4vw, 3.8rem);
  line-height: 1.16;
  letter-spacing: 0.01em;
  max-width: 15em;
}

.page-about .about-lede {
  max-width: 40rem;
  margin: 1.2rem 0 0;
  font-size: 1.02rem;
  line-height: 1.9;
  color: var(--ink-soft);
}

.page-about .about-facts {
  list-style: none;
  margin: 2rem 0 0;
  padding: 1.1rem 0 0;
  border-top: 1px solid rgba(207, 198, 179, 0.8);
  display: grid;
  gap: 0.85rem 1.75rem;
  grid-template-columns: repeat(auto-fit, minmax(10.5rem, 1fr));
}

.page-about .about-fact {
  display: grid;
  gap: 0.3rem;
}

.page-about .about-fact-key {
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  color: var(--ink-soft);
}

.page-about .about-fact-val {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--ink);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-top: clamp(2.5rem, 7vw, 4.75rem);
  scroll-margin-top: calc(var(--header-h) + 2rem);
}

.page-about .section-head {
  margin-bottom: clamp(1rem, 3vw, 1.6rem);
}

.page-about .section-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  color: var(--cinnabar);
}

.page-about .section-title {
  margin: 0.45rem 0 0;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(1.4rem, 3.6vw, 2.05rem);
  line-height: 1.35;
}

.page-about .section-lede {
  max-width: 38rem;
  margin: 0.7rem 0 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-text {
  max-width: 44rem;
}

.page-about .about-text p {
  margin: 0 0 1.05rem;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--ink);
}

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

.page-about .about-text strong {
  font-weight: 600;
  color: var(--ink);
}

/* ---------- 图片 ---------- */
.page-about .figure {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
}

.page-about .figure-frame {
  display: block;
  overflow: hidden;
  border: 1px solid rgba(207, 198, 179, 0.9);
  border-radius: 2px;
  background-color: var(--paper-edge);
}

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

.page-about .figure-cap {
  margin-top: 0.7rem;
  padding-left: 0.9rem;
  border-left: 2px solid rgba(180, 69, 46, 0.45);
  font-size: 0.84rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- 阶段时间线 ---------- */
.page-about .about-section--stages {
  background: linear-gradient(
    180deg,
    rgba(232, 225, 211, 0) 0%,
    rgba(232, 225, 211, 0.42) 34%,
    rgba(232, 225, 211, 0.78) 100%
  );
  border-radius: 3px;
}

.page-about .stage-list {
  position: relative;
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0 0 0 2.75rem;
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
}

.page-about .stage-list::before {
  content: "";
  position: absolute;
  top: 0.7rem;
  bottom: 0.7rem;
  left: 0.8125rem;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(
    180deg,
    rgba(180, 69, 46, 0.68) 0%,
    rgba(217, 164, 65, 0.62) 46%,
    rgba(74, 122, 105, 0.58) 100%
  );
}

.page-about .stage-item {
  position: relative;
}

.page-about .stage-node {
  position: absolute;
  left: -2.75rem;
  top: 0.85rem;
  width: 1.75rem;
  height: 1.75rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background-color: var(--paper);
  border: 1px solid rgba(207, 198, 179, 1);
  box-shadow: 0 0 0 4px var(--paper);
  color: var(--cinnabar);
}

.page-about .stage-node svg {
  width: 1rem;
  height: 1rem;
  display: block;
}

.page-about .stage-card {
  position: relative;
  padding: clamp(1.05rem, 3vw, 1.6rem);
  border: 1px solid rgba(207, 198, 179, 0.92);
  border-radius: 2px;
  box-shadow: 6px 6px 0 rgba(232, 225, 211, 0.85);
}

.page-about .stage-item:nth-child(1) .stage-card { background-color: var(--about-stage-1); }
.page-about .stage-item:nth-child(2) .stage-card { background-color: var(--about-stage-2); }
.page-about .stage-item:nth-child(3) .stage-card { background-color: var(--about-stage-3); }
.page-about .stage-item:nth-child(4) .stage-card { background-color: var(--about-stage-4); }

.page-about .stage-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.page-about .stage-ver {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  letter-spacing: 0.1em;
  color: var(--cinnabar);
}

.page-about .stage-item:nth-child(2) .stage-ver,
.page-about .stage-item:nth-child(4) .stage-ver {
  color: var(--celadon);
}

.page-about .stage-item:nth-child(2) .stage-node,
.page-about .stage-item:nth-child(4) .stage-node {
  color: var(--celadon);
}

.page-about .stage-title {
  margin: 0.6rem 0 0.5rem;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.08rem, 2.4vw, 1.3rem);
  line-height: 1.5;
}

.page-about .stage-card > p {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .stage-points {
  list-style: none;
  margin: 0.95rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.page-about .stage-points li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .stage-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 0.45rem;
  height: 1px;
  background-color: var(--cinnabar);
  opacity: 0.85;
}

/* ---------- 门径三段 ---------- */
.page-about .doorway-set {
  display: grid;
  gap: 1rem;
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .doorway-card {
  display: block;
  padding: 1.15rem 1.15rem 1.3rem;
  border: 1px solid rgba(207, 198, 179, 0.9);
  border-top: 3px solid var(--amber);
  border-radius: 2px;
  background-color: rgba(255, 255, 255, 0.5);
  color: inherit;
  text-decoration: none;
  transition: border-color var(--fast) var(--ease), background-color var(--fast) var(--ease);
}

.page-about .doorway-card:hover,
.page-about .doorway-card:focus-visible {
  border-top-color: var(--cinnabar);
  background-color: rgba(255, 255, 255, 0.88);
}

.page-about .doorway-key {
  display: block;
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  color: var(--ink-soft);
}

.page-about .doorway-name {
  margin: 0.55rem 0 0.4rem;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 1.08rem;
  line-height: 1.45;
}

.page-about .doorway-desc {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 主体信息 ---------- */
.page-about .entity-card {
  margin-top: clamp(1.2rem, 3vw, 1.75rem);
  padding: clamp(1.1rem, 3vw, 1.6rem);
  border: 1px solid rgba(207, 198, 179, 0.9);
  border-radius: 2px;
  background-color: rgba(255, 255, 255, 0.55);
}

.page-about .entity-list {
  margin: 0;
}

.page-about .entity-row {
  display: grid;
  grid-template-columns: minmax(5.5rem, 8rem) minmax(0, 1fr);
  gap: 0.3rem 1.25rem;
  padding: 0.75rem 0;
  border-bottom: 1px dashed rgba(207, 198, 179, 0.85);
}

.page-about .entity-row:first-child {
  padding-top: 0;
}

.page-about .entity-row:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .entity-row dt {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

.page-about .entity-row dd {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.75;
  color: var(--ink);
  overflow-wrap: anywhere;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  margin-top: clamp(2.5rem, 7vw, 4.5rem);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid rgba(217, 164, 65, 0.5);
  border-radius: 2px;
  background: linear-gradient(
    135deg,
    rgba(240, 194, 100, 0.17) 0%,
    rgba(246, 241, 231, 0.22) 55%,
    rgba(232, 225, 211, 0.42) 100%
  );
}

.page-about .about-next-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(1.25rem, 3vw, 1.6rem);
  line-height: 1.4;
}

.page-about .about-next-lede {
  max-width: 38rem;
  margin: 0.65rem 0 0;
  font-size: 0.96rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.35rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .doorway-set {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4.5rem);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 2.75rem);
    align-self: start;
    max-height: calc(100vh - var(--header-h) - 5rem);
    overflow-y: auto;
  }

  .page-about .about-flow::before {
    content: "";
    position: absolute;
    left: calc(-1 * clamp(1rem, 2.5vw, 2.25rem));
    top: 0;
    bottom: 0;
    width: 1px;
    background: linear-gradient(
      180deg,
      rgba(180, 69, 46, 0.5) 0%,
      rgba(217, 164, 65, 0.35) 48%,
      rgba(207, 198, 179, 0.2) 100%
    );
  }
}

@media (max-width: 560px) {
  .page-about .stage-list {
    padding-left: 2.25rem;
  }

  .page-about .stage-list::before {
    left: 0.6875rem;
  }

  .page-about .stage-node {
    left: -2.25rem;
    width: 1.5rem;
    height: 1.5rem;
  }

  .page-about .stage-node svg {
    width: 0.85rem;
    height: 0.85rem;
  }

  .page-about .entity-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.25rem;
  }

  .page-about .about-next-actions .btn {
    flex: 1 1 auto;
    justify-content: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero-veil {
    animation: none;
    opacity: 1;
    transform: rotate(-9deg);
  }

  .page-about .doorway-card {
    transition: none;
  }
}
<<<END>>>