.page-about {
  --about-rail: 272px;
  --about-inner: 1240px;
  --about-edge: clamp(16px, 3vw, 40px);
  --about-body: rgba(232, 245, 240, 0.84);
  position: relative;
  overflow-x: hidden;
  padding-top: clamp(14px, 2.4vw, 26px);
  background-color: var(--phx-night);
  color: var(--phx-white);
  font-family: var(--phx-font-body);
  font-size: 16px;
  line-height: 1.75;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image:
    repeating-linear-gradient(to right, rgba(29, 46, 41, 0.85) 0, rgba(29, 46, 41, 0.85) 1px, transparent 1px, transparent 88px),
    repeating-linear-gradient(to bottom, rgba(29, 46, 41, 0.85) 0, rgba(29, 46, 41, 0.85) 1px, transparent 1px, transparent 88px);
}

.page-about > * {
  position: relative;
  z-index: 1;
}

.page-about__inner {
  width: 100%;
  max-width: var(--about-inner);
  margin: 0 auto;
  padding-left: var(--about-edge);
  padding-right: var(--about-edge);
}

/* ---------- 面包屑 ---------- */
.page-about__top {
  padding-bottom: clamp(16px, 2.6vw, 28px);
}

.page-about__crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--phx-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--phx-mist);
}

.page-about__crumbs a {
  color: var(--phx-mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--phx-ease), border-color 0.18s var(--phx-ease);
}

.page-about__crumbs a:hover,
.page-about__crumbs a:focus-visible {
  color: var(--phx-neon);
  border-bottom-color: var(--phx-neon);
  outline: none;
}

.page-about__crumbs-sep {
  color: var(--phx-line);
}

/* ---------- 首屏 ---------- */
.page-about__hero {
  padding-bottom: clamp(30px, 5vw, 52px);
}

.page-about__eyebrow {
  margin: 0 0 14px;
  font-family: var(--phx-font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--phx-violet);
}

.page-about__h1 {
  margin: 0 0 22px;
  max-width: 20em;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: clamp(29px, 5.6vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.02em;
}

.page-about__h1-mark {
  font-style: normal;
  color: var(--phx-neon);
}

.page-about__lede {
  margin: 0;
  max-width: 46em;
  font-size: clamp(16px, 2.1vw, 19px);
  line-height: 1.8;
  color: var(--about-body);
}

.page-about__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0;
  background: var(--phx-line);
  border: 1px solid var(--phx-line);
}

.page-about__fact {
  margin: 0;
  padding: 15px 16px 17px;
  background: var(--phx-night);
}

.page-about__fact dt {
  font-family: var(--phx-font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--phx-mist);
}

.page-about__fact dd {
  margin: 9px 0 0;
  font-family: var(--phx-font-mono);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--phx-neon);
}

.page-about__fact dd small {
  margin-left: 5px;
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--phx-mist);
}

.page-about__hero-figure {
  max-width: var(--about-inner);
  margin: clamp(30px, 5vw, 48px) auto 0;
  padding: 0 var(--about-edge);
}

.page-about__hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--phx-line);
  object-fit: cover;
}

.page-about__figcaption {
  margin-top: 10px;
  font-family: var(--phx-font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--phx-mist);
  text-align: right;
}

/* ---------- 目录 + 正文 ---------- */
.page-about__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 46px);
  width: 100%;
  max-width: var(--about-inner);
  margin: 0 auto;
  padding: clamp(34px, 5vw, 62px) var(--about-edge) clamp(48px, 7vw, 96px);
}

.page-about__toc {
  border-top: 2px solid var(--phx-neon);
  padding-top: 14px;
}

.page-about__toc-head {
  margin: 0 0 12px;
  font-family: var(--phx-font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--phx-mist);
}

.page-about__toc-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about__toc-link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 10px;
  border-left: 1px solid var(--phx-line);
  color: var(--phx-mist);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.18s var(--phx-ease), border-color 0.18s var(--phx-ease), background-color 0.18s var(--phx-ease);
}

.page-about__toc-link:hover,
.page-about__toc-link:focus-visible {
  color: var(--phx-white);
  border-left-color: var(--phx-neon);
  background: var(--phx-glass);
  outline: none;
}

.page-about__toc-num {
  font-size: 11px;
  color: var(--phx-violet);
}

.page-about__body {
  min-width: 0;
}

.page-about__section {
  scroll-margin-top: 96px;
  padding: clamp(26px, 3.8vw, 44px) 0;
  border-top: 1px solid var(--phx-line);
}

.page-about__section:first-child {
  border-top: 2px solid var(--phx-neon);
}

.page-about__section-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about__section-num {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--phx-violet);
}

.page-about__section-title {
  margin: 0;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: clamp(20px, 3.2vw, 29px);
  line-height: 1.32;
  letter-spacing: -0.01em;
}

.page-about__section p {
  margin: 0 0 16px;
  max-width: 46em;
  font-size: 16px;
  color: var(--about-body);
}

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

/* ---------- 三种查看方式 ---------- */
.page-about__views {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about__view {
  padding: 15px 17px;
  border: 1px solid var(--phx-line);
  border-left: 2px solid var(--phx-neon);
  background: var(--phx-glass);
}

.page-about__view-name {
  margin: 0 0 6px;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--phx-neon);
}

.page-about__view-text {
  margin: 0;
  font-size: 15px;
  color: var(--about-body);
}

/* ---------- 版本时间轴 ---------- */
.page-about__timeline {
  position: relative;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about__timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--phx-neon) 0%, var(--phx-violet) 62%, rgba(123, 92, 255, 0) 100%);
}

.page-about__release {
  position: relative;
  padding: 0 0 clamp(20px, 3vw, 30px) 30px;
}

.page-about__release:last-child {
  padding-bottom: 0;
}

.page-about__release::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--phx-neon);
  background: var(--phx-night);
  transform: rotate(45deg);
}

.page-about__release-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about__release-ver {
  padding: 2px 8px;
  border: 1px solid var(--phx-line);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--phx-neon);
}

.page-about__release-year {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--phx-mist);
}

.page-about__release-title {
  margin: 10px 0 6px;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.4;
}

.page-about__release p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  color: var(--about-body);
}

/* ---------- 配图 ---------- */
.page-about__figure {
  margin: clamp(24px, 3.6vw, 36px) 0 0;
}

.page-about__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--phx-line);
  object-fit: cover;
}

/* ---------- 校对流程 ---------- */
.page-about__steps {
  display: grid;
  gap: 12px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about__step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 16px;
  padding: 16px 18px;
  border: 1px solid var(--phx-line);
  background: var(--phx-glass);
}

.page-about__step-num {
  font-size: 22px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--phx-violet);
}

.page-about__step-body h3 {
  margin: 0 0 5px;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: 16px;
}

.page-about__step-body p {
  margin: 0;
  max-width: 42em;
  font-size: 15px;
  color: var(--about-body);
}

.page-about__process-note {
  margin: 22px 0 0 !important;
  padding: 13px 16px;
  border-left: 2px solid var(--phx-yellow);
  background: var(--phx-glass);
  font-size: 15px;
}

/* ---------- 覆盖数据 ---------- */
.page-about__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 24px 0 0;
  padding: 0;
  background: var(--phx-line);
  border: 1px solid var(--phx-line);
  list-style: none;
}

.page-about__stat {
  padding: 18px 16px 20px;
  background: var(--phx-night);
}

.page-about__stat-num {
  display: block;
  font-family: var(--phx-font-mono);
  font-weight: 700;
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--phx-neon);
}

.page-about__stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--phx-mist);
}

/* ---------- 使用场景 ---------- */
.page-about__scenes {
  display: grid;
  gap: 18px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about__scene {
  padding-top: 14px;
  border-top: 2px solid var(--phx-line);
}

.page-about__scene h3 {
  margin: 0 0 8px;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: 17px;
}

.page-about__scene p {
  margin: 0;
  font-size: 15px;
  color: var(--about-body);
}

/* ---------- 尾部入口 ---------- */
.page-about__cta {
  display: grid;
  gap: 22px;
  margin-top: clamp(34px, 5vw, 56px);
  padding: clamp(22px, 3.6vw, 36px);
  border: 1px solid var(--phx-line);
  border-left: 3px solid var(--phx-neon);
  background: var(--phx-glass-strong);
}

.page-about__cta-text h2 {
  margin: 6px 0 12px;
  font-family: var(--phx-font-display);
  font-weight: 800;
  font-size: clamp(20px, 3vw, 26px);
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.page-about__cta-text p {
  margin: 0;
  max-width: 42em;
  font-size: 15px;
  color: var(--about-body);
}

.page-about__cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about__scenes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about__cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about__cta-actions {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (min-width: 1000px) {
  .page-about__layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 4.4vw, 72px);
    align-items: start;
  }

  .page-about__toc {
    position: sticky;
    top: 92px;
  }

  .page-about__toc-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about__figure--narrow {
    max-width: 620px;
  }

  .page-about__section p {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about__toc-link,
  .page-about__crumbs a {
    transition: none;
  }
}