.page-about {
  --about-gutter: clamp(18px, 4vw, 56px);
  --about-rail: 0px;
  background: var(--moon);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
}

/* ---------- 骨架：目录 + 正文 ---------- */
.page-about .about-shell {
  display: block;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--about-gutter);
}

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

/* ---------- 左侧锚点目录 ---------- */
.page-about .about-anchor {
  display: none;
}

.page-about .about-anchor__label {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--stone);
  margin: 0 0 16px;
}

.page-about .about-anchor__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-anchor__link {
  display: block;
  padding: 7px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--pill) var(--pill) 0;
  font-size: 13px;
  color: var(--stone);
  text-decoration: none;
  transition: color .16s ease, background-color .16s ease, border-color .16s ease;
}

.page-about .about-anchor__link:hover,
.page-about .about-anchor__link:focus-visible {
  color: var(--dai-ink);
  background: var(--paper);
  outline: none;
}

.page-about .about-anchor__link[aria-current="true"] {
  color: var(--dai-ink);
  border-left-color: var(--orange);
  background: rgba(255, 106, 31, .08);
  font-weight: 600;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  padding: 28px 0 40px;
  border-bottom: 1px solid var(--mountain);
}

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

.page-about .about-intro__title {
  margin: 14px 0 18px;
  font-family: var(--font-title);
  font-weight: 900;
  font-size: clamp(32px, 8vw, 62px);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--dai-ink);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 22px) 100%, 0 100%);
  padding-bottom: 10px;
  max-width: 15ch;
}

.page-about .about-intro__lede {
  max-width: 60ch;
  color: var(--ink);
  margin: 0 0 28px;
}

.page-about .about-intro__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  border-top: 1px solid var(--paper);
  padding-top: 18px;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.page-about .about-stat__num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 6vw, 38px);
  line-height: 1;
  font-weight: 700;
  color: var(--dai-ink);
}

.page-about .about-stat__plus {
  font-size: .5em;
  margin-left: 2px;
  color: var(--orange);
}

.page-about .about-stat__unit {
  font-size: 12px;
  color: var(--stone);
  line-height: 1.4;
}

.page-about .about-intro__figure {
  margin: 32px 0 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--dai-ink);
}

.page-about .about-intro__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(.6) contrast(1.05);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding-block: clamp(44px, 9vw, 88px);
  position: relative;
}

.page-about .about-sec__title {
  font-family: var(--font-title);
  font-weight: 900;
  font-size: clamp(24px, 5.6vw, 40px);
  line-height: 1.15;
  letter-spacing: -.01em;
  color: var(--dai-ink);
  margin: 10px 0 26px;
  max-width: 22ch;
}

.page-about .about-sec__lead {
  max-width: 54ch;
  color: var(--stone);
  font-size: 15px;
  margin: -14px 0 26px;
}

.page-about .about-sec__cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-sec__main p {
  margin: 0 0 18px;
  max-width: 66ch;
}

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

.page-about .about-sec__main a {
  color: var(--dai-ink);
  text-decoration: underline;
  text-decoration-color: var(--orange);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* 旁注 */
.page-about .about-sec__aside {
  align-self: start;
  background: var(--paper);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
}

.page-about .about-aside-note {
  margin: 0 0 10px;
  color: var(--dai-ink);
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  line-height: 1.6;
}

.page-about .about-aside-more {
  margin: 8px 0 0;
  color: var(--stone);
  font-size: 13px;
  line-height: 1.7;
  border-top: 1px solid rgba(31, 74, 85, .2);
  padding-top: 10px;
}

.page-about .about-toggle {
  appearance: none;
  border: 1px solid var(--mountain);
  background: transparent;
  color: var(--dai-ink);
  font-family: var(--font-body);
  font-size: 12px;
  padding: 5px 14px;
  border-radius: var(--pill);
  cursor: pointer;
  transition: background-color .16s ease, border-color .16s ease;
}

.page-about .about-toggle:hover,
.page-about .about-toggle:focus-visible {
  background: var(--dai-ink);
  border-color: var(--dai-ink);
  color: var(--moon);
  outline: none;
}

.page-about .about-toggle:focus-visible {
  box-shadow: 0 0 0 2px var(--orange);
}

/* 章节内配图 */
.page-about .about-sec__figure {
  margin: 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--rain-ink);
}

.page-about .about-sec__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(.5) brightness(.92);
}

/* ---------- 版本代际 ---------- */
.page-about .about-sec--gen {
  position: relative;
  isolation: isolate;
}

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

.page-about .about-gen__tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.page-about .about-gen__tab {
  font-family: var(--font-body);
  font-size: 13px;
  padding: 8px 16px;
  cursor: pointer;
  transition: color .16s ease, border-color .16s ease, background-color .16s ease;
}

.page-about .about-gen__tab .num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  margin-right: 6px;
}

.page-about .about-gen__tab[aria-selected="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--moon);
}

.page-about .about-gen__panel {
  background: var(--moon);
  border: 1px solid var(--paper);
  border-left: 4px solid var(--orange);
  border-radius: var(--radius-card);
  padding: 24px 22px;
  animation: about-fade .16s ease both;
}

.page-about .about-gen__panel[hidden] {
  display: none;
}

@keyframes about-fade {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-about .about-gen__kicker {
  margin: 0 0 6px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-gen__title {
  margin: 0 0 10px;
  font-family: var(--font-title);
  font-weight: 900;
  font-size: clamp(20px, 4.6vw, 28px);
  line-height: 1.2;
  color: var(--dai-ink);
}

.page-about .about-gen__panel p:last-child {
  margin: 0;
  max-width: 64ch;
}

.page-about .about-gen__panel a {
  color: var(--dai-ink);
  text-decoration: underline;
  text-decoration-color: var(--orange);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .about-gen__texture {
  margin: 28px 0 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--rain-ink);
  position: relative;
}

.page-about .about-gen__texture::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(16, 36, 43, .35), rgba(16, 36, 43, .8));
  pointer-events: none;
}

.page-about .about-gen__texture img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.35) contrast(1.1);
}

.page-about .about-gen__footnote {
  margin: 18px 0 0;
  max-width: 68ch;
}

.page-about .about-gen__footnote a {
  color: var(--dai-ink);
  text-decoration: underline;
  text-decoration-color: var(--orange);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* ---------- 栏目去处 ---------- */
.page-about .about-channels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-channel {
  display: block;
  padding: 22px 22px 20px;
  border-radius: var(--radius-card);
  background: var(--paper);
  color: var(--ink);
  text-decoration: none;
  border: 1px solid transparent;
  transition: border-color .16s ease, background-color .16s ease, transform .16s ease;
}

.page-about .about-channel:hover,
.page-about .about-channel:focus-visible {
  background: var(--moon);
  border-color: var(--mountain);
  transform: translateY(-2px);
  outline: none;
}

.page-about .about-channel:focus-visible {
  box-shadow: 0 0 0 2px var(--orange);
}

.page-about .about-channel__label {
  color: var(--orange);
  margin: 0 0 8px;
}

.page-about .about-channel__title {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-weight: 900;
  font-size: 18px;
  line-height: 1.3;
  color: var(--dai-ink);
}

.page-about .about-channel__text {
  margin: 0 0 14px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .about-channel__go {
  font-size: 13px;
  font-weight: 600;
  color: var(--dai-ink);
  border-bottom: 1px solid var(--orange);
  padding-bottom: 2px;
}

.page-about .about-cta {
  margin-top: 28px;
  padding: 24px 22px;
  background: var(--dai-ink);
  border-radius: var(--radius-card);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}

.page-about .about-cta__text {
  margin: 0;
  color: var(--moon);
  font-size: 14px;
  line-height: 1.7;
  max-width: 46ch;
}

/* ---------- 落款 ---------- */
.page-about .about-sec--sign {
  padding-block: clamp(30px, 6vw, 56px);
  border-top: 1px solid var(--mountain);
}

.page-about .about-sign {
  margin: 0;
  font-family: var(--font-data);
  font-size: clamp(15px, 3.4vw, 20px);
  letter-spacing: .06em;
  color: var(--dai-ink);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 720px) {
  .page-about .about-intro {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, .82fr);
    gap: 40px;
    align-items: center;
    padding: 44px 0 56px;
  }

  .page-about .about-intro__figure {
    margin: 0;
    align-self: stretch;
  }

  .page-about .about-intro__figure img {
    height: 100%;
    aspect-ratio: 3 / 4;
  }

  .page-about .about-sec__cols {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 40px;
  }

  .page-about .about-sec__cols--media {
    grid-template-columns: minmax(0, 1fr) 240px;
  }

  .page-about .about-sec__figure {
    grid-column: 1 / -1;
  }

  .page-about .about-channels {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

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

/* ---------- 桌面：锚点目录贴左 ---------- */
@media (min-width: 1080px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .about-anchor {
    display: block;
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
    align-self: start;
    padding-top: 56px;
    max-height: calc(100vh - var(--topbar-h) - 56px);
    overflow: auto;
  }

  .page-about .about-anchor__side {
    display: block;
    margin: 22px 0 0;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 12px;
    letter-spacing: .3em;
    color: var(--mountain);
    font-family: var(--font-data);
  }

  .page-about .about-sec {
    padding-block: clamp(56px, 7vw, 92px);
  }

  .page-about .about-sec__cols {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 56px;
  }

  .page-about .about-sec__cols--media {
    grid-template-columns: minmax(0, 1fr) 300px 220px;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-sec__cols--media .about-sec__figure {
    grid-column: auto;
    margin: 0;
  }

  .page-about .about-gen__panels {
    max-width: 720px;
  }

  .page-about .about-gen__panel {
    padding: 30px 32px;
  }
}

/* ---------- 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-gen__panel,
  .page-about .about-channel,
  .page-about .about-anchor__link {
    animation: none;
    transition: none;
    transform: none;
  }
}