.page-about {
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-sans);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: 18px;
  padding-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
}

.page-about .about-crumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--mist);
}

.page-about .about-crumb li + li::before {
  content: "/";
  margin: 0 8px;
  color: var(--line);
}

.page-about .about-crumb a {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--cyan);
}

.page-about .about-crumb [aria-current="page"] {
  color: var(--white);
}

/* ---------- 首屏封面 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 34px 0 76px;
  background:
    radial-gradient(120% 100% at 82% 0%, rgba(47, 245, 206, 0.13), transparent 60%),
    radial-gradient(90% 85% at 0% 100%, rgba(28, 27, 75, 0.9), transparent 66%),
    var(--ink-deep);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

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

.page-about .about-hero__note span {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--mist);
  writing-mode: vertical-rl;
}

.page-about .about-eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.6vw, 74px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--white);
  max-width: 18ch;
}

.page-about .about-lede {
  margin: 0;
  max-width: 40ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(238, 244, 255, 0.82);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  margin: 34px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .about-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stats__num {
  font-family: var(--font-data);
  font-size: 30px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-stats__num.is-cyan {
  color: var(--cyan);
}

.page-about .about-stats__num.is-signal {
  color: var(--signal);
}

.page-about .about-stats__lab {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-hero__pulse {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 40px;
  color: rgba(47, 245, 206, 0.42);
  pointer-events: none;
}

.page-about .about-hero__pulse svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* ---------- 章节通用结构 ---------- */
.page-about .about-sec {
  padding: 56px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sec--indigo {
  background: var(--indigo);
}

.page-about .about-sec--teal {
  background: var(--teal);
}

.page-about .about-sec__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .about-sec__side {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-data);
}

.page-about .about-sec__idx {
  font-size: 14px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-sec__kicker {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .about-sec__main h2 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(26px, 4.4vw, 46px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-sec__main > p {
  max-width: 60ch;
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(238, 244, 255, 0.8);
}

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

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
  border: 1px solid var(--line);
  background: var(--ink-deep);
  overflow: hidden;
}

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

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 版本切换 ---------- */
.page-about .about-vers {
  margin-top: 36px;
}

.page-about .about-vers .tablist {
  display: flex;
  flex-wrap: nowrap;
  gap: 0;
  overflow-x: auto;
  border-bottom: 1px solid var(--line);
  scrollbar-width: thin;
}

.page-about .about-vers .tab {
  flex: 0 0 auto;
  appearance: none;
  padding: 12px 16px;
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: var(--mist);
  font-family: var(--font-data);
  font-size: 14px;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-vers .tab:hover {
  color: var(--white);
}

.page-about .about-vers .tab[aria-selected="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-vers .tab:focus-visible {
  outline: 1px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .about-vers .tabpanel {
  padding: 22px 0 0;
}

.page-about .about-vers .tabpanel h3 {
  margin: 0 0 10px;
  font-family: var(--font-data);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--signal);
}

.page-about .about-vers .tabpanel p {
  max-width: 58ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(238, 244, 255, 0.8);
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-partners li {
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
}

.page-about .about-partners strong {
  display: block;
  margin-bottom: 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-partners span {
  display: block;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(238, 244, 255, 0.76);
}

/* ---------- 读者 ---------- */
.page-about .about-audience {
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .about-audience li {
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-audience h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--white);
}

.page-about .about-audience p {
  max-width: 46ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(238, 244, 255, 0.76);
}

/* ---------- 结尾导航 ---------- */
.page-about .about-next {
  padding: 60px 0 76px;
  border-top: 1px solid var(--line);
  background: var(--ink-deep);
}

.page-about .about-next h2 {
  margin: 0 0 26px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 4vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-next__list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-next__list a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  color: var(--white);
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  color: var(--cyan);
  padding-left: 10px;
}

.page-about .about-next__name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .about-next__hint {
  font-size: 14px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px 40px;
  }

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

  .page-about .about-audience li {
    padding: 24px 0;
  }

  .page-about .about-audience li:nth-child(odd) {
    padding-right: 32px;
    border-right: 1px solid var(--line);
  }

  .page-about .about-audience li:nth-child(even) {
    padding-left: 32px;
  }

  .page-about .about-next__list a {
    flex-direction: row;
    align-items: baseline;
    justify-content: space-between;
    gap: 24px;
  }

  .page-about .about-next__hint {
    text-align: right;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 56px 0 96px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-hero__note {
    display: flex;
    justify-content: center;
    padding-top: 8px;
  }

  .page-about .about-sec {
    padding: 76px 0;
  }

  .page-about .about-sec__grid {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 64px;
  }

  .page-about .about-sec__side {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .page-about .about-sec__kicker {
    writing-mode: vertical-rl;
    letter-spacing: 0.26em;
  }

  .page-about .about-sec__main > p {
    font-size: 17px;
  }

  .page-about .about-figure {
    margin-top: 38px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-sec__grid {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 88px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-vers .tab,
  .page-about .about-next__list a,
  .page-about .about-crumb a {
    transition: none;
  }

  .page-about .about-next__list a:hover,
  .page-about .about-next__list a:focus-visible {
    padding-left: 0;
  }
}