.page-about {
  --ab-line: rgba(156, 198, 196, .5);
  --ab-line-soft: rgba(28, 78, 90, .16);
  --ab-dark-line: rgba(245, 240, 230, .16);
  background: var(--jn-paper);
  color: var(--jn-text);
}

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

.page-about .jn-breadcrumb {
  padding-top: 1.1rem;
}

/* ---------- 首屏 ---------- */

.ab-hero {
  position: relative;
  padding: clamp(1.6rem, 4vw, 3rem) 0 clamp(2.25rem, 5vw, 4rem);
  border-bottom: 1px solid var(--ab-line);
  overflow: hidden;
}

.ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(90deg, var(--ab-line-soft) 0 1px, transparent 1px 88px);
  opacity: .8;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .75), transparent 88%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .75), transparent 88%);
}

.ab-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(1.25rem, 4vw, 3rem);
}

.ab-hero__title {
  margin: .7rem 0 0;
  font-family: var(--jn-font-display);
  font-weight: 200;
  font-size: clamp(2.35rem, 8.4vw, 6rem);
  line-height: 1.05;
  letter-spacing: -.03em;
  color: var(--jn-night);
}

.ab-hero__title span {
  position: relative;
  color: var(--jn-ink);
}

.ab-hero__title span::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: .06em;
  height: 6px;
  background: var(--jn-green);
  opacity: .5;
  border-radius: 2px;
}

.ab-hero__lead {
  margin: 0;
  font-size: clamp(1rem, 1.5vw, 1.12rem);
  line-height: 1.9;
  color: var(--jn-text);
  max-width: 34em;
}

.ab-hero__note {
  margin: 1.1rem 0 0;
  padding-left: .9rem;
  border-left: 2px solid var(--jn-orange);
  font-size: .88rem;
  letter-spacing: .02em;
  color: var(--jn-muted);
}

.ab-hero__index {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--jn-radius);
  overflow: hidden;
}

.ab-hero__index > div {
  background: var(--jn-paper);
  padding: .95rem 1.05rem 1.05rem;
}

.ab-hero__index dt {
  font-size: .74rem;
  letter-spacing: .09em;
  color: var(--jn-muted);
  margin-bottom: .4rem;
}

.ab-hero__index dd {
  margin: 0;
  font-family: var(--jn-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.7rem;
  font-weight: 600;
  line-height: 1;
  color: var(--jn-ink);
}

.ab-hero__index dd small {
  font-family: var(--jn-font-body);
  font-size: .8rem;
  font-weight: 400;
  color: var(--jn-muted);
  margin-left: .2em;
}

/* ---------- 章节骨架 ---------- */

.ab-section {
  padding: clamp(2.5rem, 6vw, 5rem) 0;
  border-bottom: 1px solid var(--ab-line);
}

.ab-head {
  display: grid;
  gap: .75rem;
  margin-bottom: clamp(1.6rem, 4vw, 2.75rem);
}

.ab-head__tag {
  margin: 0;
  font-family: var(--jn-font-mono);
  font-size: .73rem;
  letter-spacing: .12em;
  color: var(--jn-gold-ink);
}

.ab-head__title {
  margin: 0;
  font-size: clamp(1.55rem, 3.6vw, 2.5rem);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: -.015em;
  color: var(--jn-night);
}

.ab-head__sub {
  margin: .85rem 0 0;
  font-size: .98rem;
  line-height: 1.9;
  color: var(--jn-muted);
  max-width: 42em;
}

.ab-prose {
  max-width: 40em;
  font-size: 1rem;
  line-height: 1.95;
}

.ab-prose--wide {
  max-width: 46em;
}

.ab-prose--tight p {
  margin-top: 0;
}

.ab-prose p {
  margin: 0 0 1.1em;
}

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

.ab-prose a {
  color: var(--jn-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--jn-green);
}

.ab-prose a:hover,
.ab-prose a:focus-visible {
  background: rgba(63, 240, 162, .22);
}

/* ---------- 编辑台 ---------- */

.ab-desk__figure {
  margin: 0 0 clamp(1.5rem, 3.5vw, 2.25rem);
  border: 1px solid var(--ab-line);
  border-radius: var(--jn-radius);
  overflow: hidden;
  background: var(--jn-night);
}

.ab-desk__figure img {
  width: 100%;
  object-fit: cover;
}

.ab-tri {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--jn-radius);
  overflow: hidden;
}

.ab-tri__item {
  background: var(--jn-card);
  padding: 1.35rem 1.25rem 1.5rem;
}

.ab-tri__num {
  display: inline-block;
  font-family: var(--jn-font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  color: var(--jn-green-deep);
  padding: .16rem .5rem;
  border: 1px solid rgba(63, 240, 162, .45);
  border-radius: 999px;
  margin-bottom: .85rem;
}

.ab-tri__title {
  margin: 0 0 .6rem;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--jn-night);
}

.ab-tri__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.85;
  color: var(--jn-muted);
}

/* ---------- 版本与时间线 ---------- */

.ab-section--versions {
  background: linear-gradient(180deg, rgba(28, 78, 90, .05), transparent 65%);
}

.page-about .jn-tabs {
  display: inline-flex;
  flex-wrap: wrap;
  gap: .25rem;
  padding: .25rem;
  border: 1px solid var(--ab-line);
  border-radius: 999px;
  background: var(--jn-card);
  margin-bottom: 2rem;
}

.page-about .jn-tabs__btn {
  appearance: none;
  border: 0;
  background: transparent;
  font-family: inherit;
  font-size: .875rem;
  line-height: 1.4;
  padding: .5rem 1.05rem;
  border-radius: 999px;
  color: var(--jn-muted);
  cursor: pointer;
  transition: background .18s var(--jn-ease), color .18s var(--jn-ease);
}

.page-about .jn-tabs__btn:hover {
  color: var(--jn-ink);
}

.page-about .jn-tabs__btn[aria-selected="true"] {
  background: var(--jn-night);
  color: var(--jn-green);
}

.page-about .jn-tabs__btn:focus-visible {
  outline: 2px solid var(--jn-green);
  outline-offset: 2px;
}

.ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.ab-timeline > li {
  position: relative;
  padding: 0 0 1.85rem 2.1rem;
}

.ab-timeline > li::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--ab-line);
}

.ab-timeline > li::after {
  content: "";
  position: absolute;
  left: 0;
  top: .3rem;
  width: 15px;
  height: 15px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--jn-paper);
  border: 2px solid var(--jn-gold);
}

.ab-timeline > li:last-child {
  padding-bottom: 0;
}

.ab-timeline > li:last-child::before {
  bottom: auto;
  height: 1.1rem;
}

.ab-timeline > li.is-current::after {
  border-color: var(--jn-green-deep);
  background: var(--jn-green);
  box-shadow: 0 0 0 4px rgba(63, 240, 162, .24);
}

.ab-ver {
  display: block;
  margin-bottom: .35rem;
  font-family: var(--jn-font-mono);
  font-size: .76rem;
  letter-spacing: .1em;
  color: var(--jn-gold-ink);
}

.ab-ver--live {
  color: var(--jn-green-deep);
}

.ab-ver__title {
  margin: 0 0 .5rem;
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--jn-night);
}

.ab-ver__text {
  margin: 0;
  font-size: .93rem;
  line-height: 1.88;
  color: var(--jn-muted);
  max-width: 38em;
}

.ab-ver-figure {
  margin: 2rem 0 0;
  border: 1px solid var(--ab-line);
  border-radius: var(--jn-radius);
  overflow: hidden;
  background: var(--jn-night);
}

.ab-ver-figure img {
  width: 100%;
  object-fit: cover;
}

/* ---------- 数据来源 ---------- */

.ab-sources {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.ab-source {
  background: var(--jn-card);
  border: 1px solid var(--ab-line);
  border-radius: var(--jn-radius);
  padding: 1.2rem 1.15rem 1.25rem;
  transition: transform .18s var(--jn-ease), border-color .18s var(--jn-ease);
}

.ab-source:hover,
.ab-source:focus-within {
  transform: translateY(-2px);
  border-color: var(--jn-green);
}

.ab-source__code {
  display: block;
  font-family: var(--jn-font-mono);
  font-size: .74rem;
  letter-spacing: .12em;
  color: var(--jn-gold-ink);
  margin-bottom: .7rem;
}

.ab-source__title {
  margin: 0 0 .5rem;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--jn-night);
}

.ab-source__text {
  margin: 0;
  font-size: .89rem;
  line-height: 1.8;
  color: var(--jn-muted);
}

.ab-source__extra {
  margin: .7rem 0 0;
  padding-top: .7rem;
  border-top: 1px dashed var(--ab-line);
  font-size: .84rem;
  line-height: 1.75;
  color: var(--jn-ink);
}

/* ---------- 深色规模区 ---------- */

.ab-section--dark {
  background: var(--jn-night);
  color: var(--jn-paper);
  border-bottom-color: transparent;
}

.ab-head--dark .ab-head__tag--dark {
  color: var(--jn-gold);
}

.ab-head--dark .ab-head__title {
  color: var(--jn-paper);
}

.ab-head--dark .ab-head__sub {
  color: var(--jn-on-dark);
}

.ab-scales {
  list-style: none;
  margin: 0 0 2.25rem;
  padding: 0;
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.ab-scale {
  border-top: 2px solid rgba(63, 240, 162, .6);
  padding-top: 1rem;
}

.ab-scale__value {
  display: block;
  font-family: var(--jn-font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 300;
  font-size: clamp(2.6rem, 8vw, 6.4rem);
  line-height: .95;
  letter-spacing: -.045em;
  color: var(--jn-green);
}

.ab-scale__value em {
  font-family: var(--jn-font-body);
  font-style: normal;
  font-size: .32em;
  font-weight: 500;
  letter-spacing: 0;
  margin-left: .18em;
  color: var(--jn-paper);
}

.ab-scale__label {
  display: block;
  margin-top: .75rem;
  font-size: .88rem;
  line-height: 1.7;
  color: var(--jn-on-dark);
  max-width: 20em;
}

.ab-section--dark .jn-tabs {
  background: rgba(255, 255, 255, .07);
  border-color: var(--ab-dark-line);
}

.ab-section--dark .jn-tabs__btn {
  color: var(--jn-on-dark);
}

.ab-section--dark .jn-tabs__btn:hover {
  color: var(--jn-paper);
}

.ab-section--dark .jn-tabs__btn[aria-selected="true"] {
  background: var(--jn-green);
  color: var(--jn-night);
}

.ab-scene {
  border-left: 2px solid rgba(63, 240, 162, .5);
  padding-left: 1.15rem;
}

.ab-scene__title {
  margin: 0 0 .65rem;
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--jn-paper);
}

.ab-scene__text {
  margin: 0;
  font-size: .95rem;
  line-height: 1.9;
  color: var(--jn-on-dark);
  max-width: 42em;
}

/* ---------- 更正步骤 ---------- */

.ab-steps__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.ab-step {
  background: var(--jn-card);
  border: 1px solid var(--ab-line);
  border-left: 3px solid var(--jn-ink);
  border-radius: var(--jn-radius-sm);
  padding: 1.15rem 1.2rem 1.3rem;
}

.ab-step__num {
  display: block;
  font-family: var(--jn-font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  color: var(--jn-orange);
  margin-bottom: .55rem;
}

.ab-step__title {
  margin: 0 0 .5rem;
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--jn-night);
}

.ab-step__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.85;
  color: var(--jn-muted);
}

.ab-step__text a {
  color: var(--jn-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--jn-green);
}

.ab-step__text a:hover,
.ab-step__text a:focus-visible {
  background: rgba(63, 240, 162, .22);
}

/* ---------- 收束 ---------- */

.ab-end {
  position: relative;
  isolation: isolate;
  padding: clamp(3rem, 8vw, 6rem) 0 clamp(2.75rem, 6vw, 5rem);
  background: var(--jn-night-deep);
  color: var(--jn-paper);
  overflow: hidden;
}

.ab-end__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .34;
  z-index: -1;
}

.ab-end::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, rgba(8, 24, 31, .72), rgba(8, 24, 31, .92));
}

.ab-end__eyebrow {
  margin: 0 0 1rem;
  font-family: var(--jn-font-mono);
  font-size: .74rem;
  letter-spacing: .14em;
  color: var(--jn-green);
}

.ab-end__title {
  margin: 0;
  font-family: var(--jn-font-display);
  font-weight: 300;
  font-size: clamp(1.6rem, 4.4vw, 3rem);
  line-height: 1.24;
  letter-spacing: -.02em;
  color: var(--jn-paper);
  max-width: 22em;
}

.ab-end__text {
  margin: 1.25rem 0 0;
  font-size: .98rem;
  line-height: 1.95;
  color: var(--jn-on-dark);
  max-width: 42em;
}

.ab-end__links {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin-top: 2rem;
}

.ab-end__links a {
  display: inline-block;
  padding: .55rem 1.05rem;
  border: 1px solid rgba(245, 240, 230, .28);
  border-radius: 999px;
  font-size: .87rem;
  color: var(--jn-paper);
  text-decoration: none;
  transition: border-color .18s var(--jn-ease), background .18s var(--jn-ease), color .18s var(--jn-ease);
}

.ab-end__links a:hover,
.ab-end__links a:focus-visible {
  border-color: var(--jn-green);
  background: var(--jn-green);
  color: var(--jn-night);
}

/* ---------- 响应式 ---------- */

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

  .ab-steps__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    background: var(--ab-line);
    border: 1px solid var(--ab-line);
    border-radius: var(--jn-radius);
    overflow: hidden;
  }

  .ab-step {
    border: 0;
    border-top: 3px solid var(--jn-ink);
    border-radius: 0;
  }
}

@media (min-width: 860px) {
  .ab-head {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 2.5rem;
    align-items: start;
  }

  .ab-head__tag {
    padding-top: .55rem;
  }

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

  .ab-hero {
    padding-top: clamp(2rem, 4vw, 3.5rem);
  }
}

@media (min-width: 960px) {
  .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .ab-hero__aside {
    padding-bottom: .6rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}