.page-about {
  --ab-rail-w: 192px;
  --ab-sec-pad-inline: clamp(1.15rem, 3vw, 2rem);
  background: var(--ink);
  color: var(--cold);
}

/* ---------- 顶部与开篇 ---------- */

.page-about .about-top {
  padding-top: clamp(1.25rem, 3.5vw, 2rem);
}

.page-about .about-hero {
  padding: clamp(1.75rem, 4.5vw, 3rem) 0 clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .about-hero__title {
  margin: 0 0 1.15rem;
  font-family: var(--font-display);
  font-size: var(--step-display);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 14em;
  color: var(--cold);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 38rem;
  font-size: clamp(1.02rem, 1.4vw, 1.16rem);
  line-height: 1.78;
  color: rgba(244, 247, 243, 0.82);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  padding: 0;
  list-style: none;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1rem 1.1rem 1.15rem;
  background: var(--tier);
}

.page-about .fact__num {
  font-family: var(--font-num);
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1;
  color: var(--neon);
  font-variant-numeric: tabular-nums;
}

.page-about .fact__label {
  font-size: var(--step-label);
  letter-spacing: 0.16em;
  color: var(--paper-dim);
}

.page-about .about-hero__figure {
  margin: clamp(2rem, 5vw, 3rem) 0 0;
}

/* ---------- 通用图形容器 ---------- */

.page-about .figure__frame {
  position: relative;
  overflow: hidden;
  background: var(--tier);
}

.page-about .figure__frame--wide {
  aspect-ratio: 16 / 9;
}

.page-about .figure__frame--tall {
  aspect-ratio: 5 / 7;
}

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

.page-about .about-figure {
  margin: clamp(2rem, 5vw, 3rem) 0 0;
}

/* ---------- 左右分屏骨架 ---------- */

.page-about .about-shell {
  display: block;
}

.page-about .about-stream {
  min-width: 0;
}

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

/* ---------- 分区骨架 ---------- */

.page-about .ab-sec {
  padding: clamp(2.5rem, 6vw, 4.5rem) var(--ab-sec-pad-inline);
  border-top: 1px solid var(--rule);
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .ab-sec__title {
  margin: 0.5rem 0 1.1rem;
  font-family: var(--font-display);
  font-size: var(--step-h1);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.015em;
  max-width: 18em;
  color: var(--cold);
}

.page-about .ab-sec__lead {
  margin: 0 0 1.75rem;
  max-width: 42rem;
  font-size: clamp(1rem, 1.25vw, 1.08rem);
  line-height: 1.76;
  color: rgba(244, 247, 243, 0.78);
}

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

.page-about .prose p {
  margin: 0 0 1.15rem;
  font-size: var(--step-body);
  line-height: 1.78;
  color: rgba(244, 247, 243, 0.86);
}

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

/* ---------- 四组分工 ---------- */

.page-about .crew {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .crew__item {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: clamp(1.1rem, 2.4vw, 1.5rem) clamp(1rem, 2vw, 1.35rem) clamp(1.3rem, 2.6vw, 1.7rem);
  background: var(--tier);
  transition: background-color 0.24s ease;
}

.page-about .crew__item:hover,
.page-about .crew__item:focus-within {
  background: var(--grass);
}

.page-about .crew__num {
  font-family: var(--font-num);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .crew__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cold);
}

.page-about .crew__desc {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.7;
  color: rgba(244, 247, 243, 0.74);
}

.page-about .crew__out {
  margin: 0.2rem 0 0;
  padding-top: 0.85rem;
  border-top: 1px solid var(--rule);
  font-size: 0.875rem;
  line-height: 1.66;
  color: rgba(244, 247, 243, 0.5);
  transition: color 0.24s ease, border-color 0.24s ease;
}

.page-about .crew__item:hover .crew__out,
.page-about .crew__item:focus-within .crew__out {
  color: rgba(244, 247, 243, 0.95);
  border-top-color: rgba(91, 227, 122, 0.5);
}

/* ---------- 版本引子 ---------- */

.page-about .vintro {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  margin: 1.5rem 0 0;
}

.page-about .vintro__figure {
  margin: 0;
  max-width: 22rem;
}

/* ---------- 横向版本时间线 ---------- */

.page-about .tl-scroll {
  margin-top: clamp(2rem, 4.5vw, 3rem);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
  padding-bottom: 1rem;
  scrollbar-width: thin;
  scrollbar-color: var(--rule) transparent;
}

.page-about .tl-scroll::-webkit-scrollbar {
  height: 6px;
}

.page-about .tl-scroll::-webkit-scrollbar-thumb {
  background: var(--rule);
}

.page-about .tl {
  display: flex;
  align-items: stretch;
  min-width: max-content;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__item {
  flex: 0 0 254px;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 1.35rem 1.15rem 1.5rem;
  background: var(--tier);
  border-left: 1px solid var(--rule);
  scroll-snap-align: start;
}

.page-about .tl__item:first-child {
  border-left: 0;
}

.page-about .tl__node {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding-top: 0.85rem;
  border-top: 2px solid var(--rule);
}

.page-about .tl__dot {
  position: absolute;
  top: -6px;
  left: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 3px rgba(232, 181, 74, 0.18);
}

.page-about .tl__ver {
  font-family: var(--font-num);
  font-size: 0.9rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .tl__name {
  margin: 0.15rem 0 0;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.38;
  letter-spacing: -0.005em;
  color: var(--cold);
}

.page-about .tl__text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(244, 247, 243, 0.7);
}

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

.page-about .tl__list li {
  position: relative;
  padding-left: 0.9rem;
  font-size: 0.8125rem;
  line-height: 1.66;
  color: rgba(244, 247, 243, 0.74);
}

.page-about .tl__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 1px;
  background: var(--neon);
}

.page-about .disclosure {
  margin-top: auto;
  padding-top: 0.7rem;
}

.page-about .disclosure__toggle {
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
  border: 0;
  border-bottom: 1px solid rgba(91, 227, 122, 0.38);
  border-radius: 0;
  padding: 0.25rem 0;
  color: var(--neon);
  font-family: var(--font-body);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: border-color 0.2s ease;
}

.page-about .disclosure__toggle:hover,
.page-about .disclosure__toggle:focus-visible {
  border-bottom-color: var(--neon);
}

.page-about .disclosure__panel {
  padding-top: 0.7rem;
}

/* ---------- 暖纸区 ---------- */

.page-about .ab-sec--paper {
  background: var(--paper);
  color: var(--ink);
  border-top-color: var(--paper);
}

.page-about .ab-sec--paper + .ab-sec--paper {
  border-top: 1px solid rgba(11, 19, 16, 0.12);
}

.page-about .ab-sec--paper .eyebrow {
  color: rgba(11, 19, 16, 0.55);
}

.page-about .ab-sec--paper .ab-sec__title {
  color: var(--ink);
}

.page-about .ab-sec--paper .ab-sec__lead,
.page-about .ab-sec--paper .prose p {
  color: var(--grass);
}

.page-about .partner-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 1.85rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--ink-rule);
  border: 1px solid var(--ink-rule);
}

.page-about .partner-stat {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1.1rem 1.15rem 1.25rem;
  background: var(--paper);
}

.page-about .partner-stat__num {
  font-family: var(--font-num);
  font-size: clamp(1.6rem, 4vw, 2.35rem);
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-stat__label {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: rgba(11, 19, 16, 0.6);
}

.page-about .season-figures {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 1.85rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--ink-rule);
  border: 1px solid var(--ink-rule);
}

.page-about .season-figure {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.2rem 1.2rem 1.35rem;
  background: var(--paper);
}

.page-about .season-figure__num {
  font-family: var(--font-num);
  font-size: clamp(1.5rem, 3.4vw, 2.1rem);
  line-height: 1;
  color: var(--grass);
  font-variant-numeric: tabular-nums;
}

.page-about .season-figure__label {
  font-size: 0.8125rem;
  line-height: 1.6;
  color: rgba(11, 19, 16, 0.62);
}

/* ---------- 起步三步 ---------- */

.page-about .steps {
  display: grid;
  gap: 1px;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--rule);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.page-about .step {
  display: flex;
  align-items: flex-start;
  gap: clamp(0.9rem, 2.5vw, 1.5rem);
  padding: 1.35rem 0 1.4rem;
  background: var(--ink);
}

.page-about .step__num {
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: clamp(1.35rem, 3vw, 1.75rem);
  line-height: 1;
  color: var(--neon);
  font-variant-numeric: tabular-nums;
}

.page-about .step__body {
  min-width: 0;
}

.page-about .step__name {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cold);
}

.page-about .step__text {
  margin: 0;
  max-width: 42rem;
  font-size: 0.9375rem;
  line-height: 1.74;
  color: rgba(244, 247, 243, 0.74);
}

.page-about .ab-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .ab-hint {
  margin: 1.4rem 0 0;
  max-width: 44rem;
  font-size: 0.9375rem;
  line-height: 1.76;
  color: rgba(244, 247, 243, 0.62);
}

.page-about .ab-hint a {
  color: var(--neon);
  text-decoration: none;
  border-bottom: 1px solid rgba(91, 227, 122, 0.4);
}

.page-about .ab-hint a:hover,
.page-about .ab-hint a:focus-visible {
  border-bottom-color: var(--neon);
}

/* ---------- 平板 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .season-figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 780px) {
  .page-about .vintro {
    grid-template-columns: minmax(200px, 300px) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .vintro__figure {
    max-width: none;
  }
}

/* ---------- 桌面：左侧刻度轨 ---------- */

@media (min-width: 1040px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4rem);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 7.5rem;
    align-self: start;
    border-left: 1px solid var(--rule);
    padding-left: 1.1rem;
  }

  .page-about .crew {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 侧栏内部 ---------- */

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

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--rule-soft);
  color: var(--paper-dim);
  font-size: 0.875rem;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--neon);
  border-bottom-color: rgba(91, 227, 122, 0.45);
}

.page-about .about-rail__num {
  font-family: var(--font-num);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

/* ---------- 动效偏好 ---------- */

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

  .page-about .tl-scroll {
    scroll-behavior: auto;
  }
}