.page-about {
  --about-read: 46rem;
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
  min-height: clamp(560px, 88vh, 900px);
  padding: clamp(124px, 18vh, 196px) 0 clamp(48px, 7vw, 88px);
  background: var(--bg);
}

.page-about .about-hero__img {
  position: absolute;
  inset: 0;
  z-index: -2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.5;
}

.page-about .about-hero__veil {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(5, 7, 13, 0.9) 0%, rgba(5, 7, 13, 0.5) 40%, rgba(5, 7, 13, 0.96) 100%),
    repeating-linear-gradient(90deg, rgba(0, 240, 181, 0.08) 0 1px, rgba(0, 0, 0, 0) 1px 96px);
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(12px, 1.6vw, 20px);
  justify-items: start;
  max-width: 960px;
}

.page-about .about-hero .h-display {
  max-width: 16ch;
  margin: 0;
}

.page-about .about-hero__lede {
  max-width: 62ch;
  margin: 0;
  color: rgba(228, 251, 244, 0.82);
}

.page-about .hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(20px, 4vw, 56px);
  list-style: none;
  margin: clamp(10px, 1.6vw, 18px) 0 0;
  padding: clamp(18px, 2.6vw, 28px) 0 0;
  border-top: 1px solid var(--line);
}

.page-about .hero-fact {
  display: grid;
  gap: 4px;
}

.page-about .hero-fact__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 38px);
  line-height: 1.05;
  letter-spacing: 0.04em;
  color: var(--signal);
}

.page-about .hero-fact__label {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

/* ---------- 起点与今天（奶油长读区） ---------- */
.page-about .section--cream {
  background: var(--cream);
}

.page-about .about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 3vw, 40px);
}

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

.page-about .v-note {
  writing-mode: vertical-rl;
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--cream-ink);
  opacity: 0.6;
  border-right: 2px solid rgba(58, 42, 30, 0.25);
  padding-right: 10px;
}

.page-about .about-origin__body {
  max-width: var(--about-read);
}

.page-about .about-origin__body .eyebrow,
.page-about .about-origin__body .h-section,
.page-about .about-origin__body p {
  color: var(--cream-ink);
}

.page-about .about-origin__body .h-section {
  margin: 10px 0 22px;
}

.page-about .about-origin__body p {
  margin: 0 0 18px;
  line-height: 1.85;
}

.page-about .about-origin__body p:last-child {
  margin-bottom: 0;
  font-weight: 600;
}

@media (min-width: 900px) {
  .page-about .about-origin__grid {
    grid-template-columns: 56px minmax(0, 1fr);
  }

  .page-about .about-origin__aside {
    display: flex;
    align-items: flex-start;
  }
}

/* ---------- 四层内容体系 ---------- */
.page-about .about-layers__head {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: center;
  margin-bottom: clamp(32px, 5vw, 64px);
}

.page-about .about-layers__head .h-section {
  margin: 10px 0 16px;
}

.page-about .about-layers__head .lede {
  margin: 0;
}

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

.page-about .about-layers__body {
  display: grid;
  gap: clamp(28px, 5vw, 64px);
  align-items: center;
}

@media (min-width: 960px) {
  .page-about .about-layers__head {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-layers__body {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  }
}

.page-about .layer-map {
  position: relative;
  width: 100%;
  max-width: 520px;
  aspect-ratio: 4 / 3;
  margin-inline: auto;
}

.page-about .layer-ring {
  position: absolute;
  display: block;
  border-radius: 16px;
  border: 1px solid var(--line);
  transition: background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .layer-ring--1 {
  inset: 0;
  border-color: var(--line-signal);
}

.page-about .layer-ring--2 {
  inset: 11%;
  border-color: rgba(0, 240, 181, 0.26);
}

.page-about .layer-ring--3 {
  inset: 22%;
  border-color: rgba(0, 240, 181, 0.18);
}

.page-about .layer-ring--4 {
  inset: 33%;
  border-color: rgba(122, 92, 255, 0.4);
}

.page-about .layer-ring:hover {
  background-color: rgba(0, 240, 181, 0.1);
  border-color: var(--signal);
  box-shadow: inset 0 0 0 1px rgba(0, 240, 181, 0.28), 0 0 30px rgba(0, 240, 181, 0.14);
}

.page-about .layer-ring--4:hover {
  background-color: rgba(122, 92, 255, 0.14);
  border-color: var(--violet);
  box-shadow: inset 0 0 0 1px rgba(122, 92, 255, 0.3), 0 0 30px rgba(122, 92, 255, 0.16);
}

.page-about .layer-ring__idx {
  position: absolute;
  top: 8px;
  left: 12px;
  pointer-events: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .layer-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about .layer-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 12px;
  padding-bottom: clamp(18px, 2.6vw, 26px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .layer-item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .layer-item__idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--signal);
}

.page-about .layer-item__title {
  margin: 0 0 7px;
  font-size: clamp(17px, 1.6vw, 20px);
  color: var(--ink);
}

.page-about .layer-item__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 覆盖范围数字墙 ---------- */
.page-about .about-reach {
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(0, 240, 181, 0.1) 0%, rgba(0, 0, 0, 0) 58%),
    var(--bg);
}

.page-about .about-reach__lede {
  max-width: 62ch;
}

.page-about .num-wall {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(168px, 1fr));
  gap: clamp(22px, 3vw, 40px);
  list-style: none;
  margin: clamp(28px, 4vw, 48px) 0 0;
  padding: 0;
}

.page-about .num-wall__item {
  padding-top: 18px;
  border-top: 2px solid rgba(0, 240, 181, 0.45);
}

.page-about .num-wall__item:nth-child(2) {
  border-top-color: rgba(255, 180, 60, 0.55);
}

.page-about .num-wall__item:nth-child(3) {
  border-top-color: rgba(255, 77, 46, 0.55);
}

.page-about .num-wall__item:nth-child(4) {
  border-top-color: rgba(122, 92, 255, 0.55);
}

.page-about .num-wall__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(34px, 5vw, 60px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .num-wall__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  color: var(--ink);
}

.page-about .num-wall__desc {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-reach__more {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  font-size: 14.5px;
  color: var(--muted);
}

.page-about .about-reach__more a {
  color: var(--signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 240, 181, 0.35);
  padding-bottom: 2px;
}

.page-about .about-reach__more a:hover {
  border-bottom-color: var(--signal);
}

/* ---------- 更新节奏 ---------- */
.page-about .about-refresh__grid {
  display: grid;
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

@media (min-width: 1024px) {
  .page-about .about-refresh__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .page-about .about-refresh__figure {
    position: sticky;
    top: 96px;
  }
}

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

.page-about .flow {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
}

.page-about .flow__step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  padding: clamp(16px, 2.2vw, 22px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .flow__step:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .flow__idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--signal);
}

.page-about .flow__title {
  margin: 0 0 6px;
  font-size: clamp(16px, 1.5vw, 19px);
  color: var(--ink);
}

.page-about .flow__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-versions__head {
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .about-versions__head .h-section {
  margin: 10px 0 14px;
}

.page-about .about-versions__head .lede {
  margin: 0;
  max-width: 58ch;
}

.page-about .v-rail {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 14px var(--pad-x) 26px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .v-rail:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: -4px;
}

.page-about .v-line {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 1.8vw, 22px);
  list-style: none;
  margin: 0;
  padding: 0;
  min-width: max-content;
}

.page-about .v-item {
  position: relative;
  flex: 0 0 auto;
  width: clamp(232px, 25vw, 296px);
  padding-top: 20px;
  border-top: 2px solid var(--line);
  scroll-snap-align: start;
}

.page-about .v-item::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 4px rgba(0, 240, 181, 0.14);
}

.page-about .v-ver {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--signal);
}

.page-about .v-name {
  margin: 8px 0 6px;
  font-size: clamp(18px, 1.7vw, 22px);
  color: var(--ink);
}

.page-about .v-sum {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .v-fold .fold__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 遇到问题 ---------- */
.page-about .about-help__grid {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}

@media (min-width: 960px) {
  .page-about .about-help__grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  }
}

.page-about .about-help__body .h-section {
  margin: 10px 0 16px;
}

.page-about .about-help__body p {
  margin: 0 0 16px;
  max-width: 62ch;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-help__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin-top: 6px;
}

.page-about .about-help__links a {
  font-size: 14.5px;
  color: var(--signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 240, 181, 0.35);
  padding-bottom: 2px;
}

.page-about .about-help__links a:hover {
  border-bottom-color: var(--signal);
}

.page-about .about-help__card {
  display: grid;
  gap: 12px;
  justify-items: start;
  padding: clamp(22px, 3vw, 32px);
  border-radius: var(--radius-lg);
}

.page-about .about-help__mail {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(14px, 1.3vw, 16px);
  letter-spacing: 0.02em;
  color: var(--signal);
  word-break: break-all;
}

.page-about .about-help__note {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

@media (max-width: 600px) {
  .page-about .hero-facts {
    gap: 18px 28px;
  }

  .page-about .about-help__card {
    border-radius: var(--radius);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .layer-ring {
    transition: none;
  }
}