.page-about {
  --about-hair: rgba(154, 165, 177, .35);
  --about-gold-soft: rgba(201, 162, 39, .5);
  --about-ink-soft: rgba(244, 241, 233, .78);
  display: block;
  background: var(--paper);
  color: var(--text);
}

.page-about h1,
.page-about h2,
.page-about h3 {
  letter-spacing: .01em;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(26px, 4vw, 44px) clamp(38px, 6vw, 72px);
  background:
    radial-gradient(115% 95% at 88% 0%, rgba(201, 162, 39, .15), transparent 58%),
    linear-gradient(180deg, var(--ink-900), var(--ink-800));
  color: var(--paper);
  border-bottom: 1px solid var(--about-gold-soft);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(135deg, rgba(244, 241, 233, .04) 0 2px, transparent 2px 9px);
}

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

.page-about .about-hero .breadcrumb {
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(244, 241, 233, .6);
}

.page-about .about-hero .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-hero .breadcrumb__link {
  color: rgba(244, 241, 233, .72);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-hero .breadcrumb__link:hover {
  color: var(--gold-light);
  border-bottom-color: var(--gold-light);
}

.page-about .about-hero__eyebrow {
  margin: 22px 0 0;
  color: var(--gold-light);
  letter-spacing: .18em;
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(27px, 5vw, 50px);
  line-height: 1.2;
  margin: 16px 0 0;
  max-width: 22ch;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--about-gold-soft);
  text-shadow: 0 1px 0 rgba(0, 0, 0, .34);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 64ch;
  font-size: clamp(15.5px, 2vw, 19px);
  line-height: 1.78;
  color: var(--about-ink-soft);
}

.page-about .about-stats {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
}

.page-about .about-stat {
  border-left: 2px solid var(--gold);
  padding: 4px 0 4px 12px;
  min-width: 0;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(18px, 2.6vw, 25px);
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--gold-light);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 4px;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: rgba(244, 241, 233, .68);
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  padding-block: clamp(36px, 5vw, 64px) clamp(48px, 7vw, 88px);
}

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

.page-about .about-toc__head {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--slate);
}

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

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 9px 10px;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--text);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color .18s var(--ease), background .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-toc__link:hover {
  background: var(--paper-2);
  color: var(--ink-900);
}

.page-about .about-toc__link.is-active {
  background: var(--paper-2);
  border-left-color: var(--gold);
  color: var(--ink-900);
  font-weight: 600;
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--gold);
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: 218px minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 60px);
  }

  .page-about .about-toc {
    display: block;
    align-self: start;
    position: sticky;
    top: 104px;
    max-height: calc(100vh - 128px);
    overflow-y: auto;
  }
}

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

/* ---------- 通用章节 ---------- */

.page-about .about-block {
  padding-block: clamp(32px, 5vw, 56px);
  border-top: 1px solid var(--about-hair);
  scroll-margin-top: 100px;
}

.page-about .about-block:first-child {
  border-top: none;
  padding-top: 0;
}

.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}

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

.page-about .about-title {
  position: relative;
  margin: 0 0 20px;
  padding-bottom: 14px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(20px, 2.9vw, 29px);
  line-height: 1.36;
  color: var(--ink-900);
}

.page-about .about-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 76px;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 39, 0));
}

.page-about .about-text {
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.82;
  color: var(--text);
}

.page-about .about-text p {
  margin: 0 0 1.05em;
}

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

.page-about .about-text a {
  color: var(--red);
  text-decoration: none;
  border-bottom: 1px solid rgba(140, 28, 43, .35);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-text a:hover {
  color: var(--red-light);
  border-bottom-color: var(--red-light);
}

.page-about .about-text--lede {
  margin: -6px 0 0;
  color: var(--slate);
  font-size: 15.5px;
}

.page-about .about-text--tail {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px dashed var(--about-hair);
  font-size: 15px;
  color: var(--slate);
}

.page-about .side-note {
  border-left: 2px solid var(--gold);
  padding-left: 13px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.85;
  letter-spacing: .02em;
  color: var(--slate);
}

.page-about .side-note__row {
  display: block;
}

.page-about .side-note__key {
  color: var(--ink-900);
  letter-spacing: .08em;
}

@media (min-width: 760px) {
  .page-about .about-grid {
    grid-template-columns: minmax(0, 1fr) 186px;
    gap: clamp(26px, 3.6vw, 48px);
  }
}

@media (min-width: 1100px) {
  .page-about .about-grid--media {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 42px;
  }

  .page-about .about-grid--media-rev {
    grid-template-columns: 272px minmax(0, 1fr);
    gap: 42px;
  }
}

/* ---------- 图片框 ---------- */

.page-about .about-figure {
  margin: 0;
  min-width: 0;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--paper-2);
}

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

.page-about .about-figure--top {
  margin-bottom: clamp(26px, 4vw, 40px);
}

/* ---------- 版本号浮注 ---------- */

.page-about .ver-chip {
  position: relative;
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .92em;
  letter-spacing: .04em;
  color: var(--ink-900);
  background: var(--paper-2);
  border-bottom: 1px dashed var(--gold);
  padding: 0 4px;
  cursor: help;
}

.page-about .ver-chip__note {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 8px);
  transform: translateX(-50%) translateY(4px);
  white-space: nowrap;
  max-width: 70vw;
  font-family: var(--font-sans);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0;
  color: var(--paper);
  background: var(--ink-900);
  border: 1px solid var(--gold);
  border-radius: var(--radius);
  padding: 6px 10px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity .18s var(--ease), transform .18s var(--ease), visibility .18s var(--ease);
  z-index: 3;
}

.page-about .ver-chip:hover .ver-chip__note,
.page-about .ver-chip:focus-within .ver-chip__note {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* ---------- 改版前后对照条 ---------- */

.page-about .path-compare {
  margin-top: clamp(26px, 4vw, 40px);
  padding: clamp(18px, 3vw, 28px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  background:
    repeating-linear-gradient(135deg, rgba(15, 59, 50, .035) 0 2px, transparent 2px 8px),
    var(--paper-2);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
}

.page-about .path-compare__col {
  padding: 16px 18px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  min-width: 0;
}

.page-about .path-compare__col--before {
  background: rgba(107, 122, 143, .12);
  border-color: rgba(107, 122, 143, .4);
}

.page-about .path-compare__col--after {
  background: rgba(201, 162, 39, .12);
  border-color: var(--about-gold-soft);
}

.page-about .path-compare__tag {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--ink-900);
}

.page-about .path-compare__data {
  margin: 0;
  display: grid;
  gap: 8px;
}

.page-about .path-compare__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px dotted var(--about-hair);
  padding-bottom: 6px;
}

.page-about .path-compare__row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .path-compare__row dt {
  font-size: 13.5px;
  color: var(--slate);
}

.page-about .path-compare__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 18px;
  letter-spacing: .02em;
  color: var(--ink-900);
}

.page-about .path-compare__col--after .path-compare__row dd {
  color: var(--red);
}

.page-about .path-compare__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  transform: rotate(90deg);
}

.page-about .path-compare__arrow-line {
  display: block;
  width: 46px;
  height: 1px;
  background: var(--gold);
}

.page-about .path-compare__arrow-head {
  display: block;
  width: 8px;
  height: 8px;
  border-top: 1px solid var(--gold);
  border-right: 1px solid var(--gold);
  transform: rotate(45deg) translate(-3px, 3px);
}

@media (min-width: 720px) {
  .page-about .path-compare {
    grid-template-columns: minmax(0, 1fr) 72px minmax(0, 1fr);
    align-items: center;
    gap: 0;
  }

  .page-about .path-compare__arrow {
    transform: none;
  }
}

/* ---------- 资料分类 ---------- */

.page-about .tax-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.page-about .tax-chip {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  padding: 6px 13px;
  border: 1px solid var(--about-gold-soft);
  border-radius: 999px;
  color: var(--ink-900);
  text-decoration: none;
  background: rgba(201, 162, 39, .07);
  transition: background .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .tax-chip:hover,
.page-about .tax-chip:focus-visible {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink-900);
}

.page-about .tax-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .tax-item {
  padding: 15px 17px;
  background: var(--paper-2);
  border: 1px solid var(--about-hair);
  border-left: 3px solid var(--gold);
  border-radius: var(--radius);
  scroll-margin-top: 120px;
  transition: background .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .tax-item:hover,
.page-about .tax-item:target {
  background: #fff;
  border-left-color: var(--red);
  box-shadow: var(--shadow-card);
}

.page-about .tax-item__name {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 6px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink-900);
}

.page-about .tax-item__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--gold);
}

.page-about .tax-item__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text);
}

@media (min-width: 620px) {
  .page-about .tax-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 使用场景 ---------- */

.page-about .scene-grid {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .scene {
  position: relative;
  padding: 18px 18px 18px 20px;
  background: var(--paper-2);
  border-radius: 0 0 var(--radius) var(--radius);
  border-top: 2px solid var(--ink-900);
  min-width: 0;
  transition: border-top-color .2s var(--ease), background .2s var(--ease);
}

.page-about .scene:hover {
  border-top-color: var(--gold);
  background: #fff;
}

.page-about .scene__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--slate);
  margin-bottom: 9px;
}

.page-about .scene__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.45;
  color: var(--ink-900);
}

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

.page-about .scene__desc a {
  color: var(--red);
  text-decoration: none;
  border-bottom: 1px solid rgba(140, 28, 43, .35);
}

.page-about .scene__desc a:hover {
  color: var(--red-light);
  border-bottom-color: var(--red-light);
}

@media (min-width: 620px) {
  .page-about .scene-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .scene-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 里程碑（深色面板） ---------- */

.page-about .about-block--ink {
  margin-block: 8px;
  padding: clamp(24px, 4vw, 46px) clamp(20px, 3.4vw, 42px);
  background:
    radial-gradient(120% 100% at 10% 0%, rgba(201, 162, 39, .12), transparent 55%),
    linear-gradient(180deg, var(--ink-900), var(--ink-800));
  border-top: none;
  border-radius: var(--radius);
  color: var(--paper);
  overflow: hidden;
}

.page-about .about-title--ink {
  color: var(--paper);
  margin-bottom: 26px;
}

.page-about .about-title--ink::after {
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 39, 0));
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, rgba(201, 162, 39, .75), rgba(201, 162, 39, .12));
}

.page-about .era {
  position: relative;
  padding: 0 0 28px 28px;
  min-width: 0;
}

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

.page-about .era__dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--ink-900);
  box-shadow: 0 0 0 3px rgba(201, 162, 39, .2);
  transition: box-shadow .22s var(--ease), background .22s var(--ease);
}

.page-about .era:hover .era__dot {
  background: var(--gold-light);
  box-shadow: 0 0 0 6px rgba(201, 162, 39, .26);
}

.page-about .era__date {
  margin: 0 0 7px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--gold-light);
}

.page-about .era__title {
  margin: 0 0 9px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .era__text {
  margin: 0 0 10px;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-ink-soft);
}

.page-about .era__range {
  margin: 0;
  display: inline-block;
  max-width: 100%;
  padding: 5px 11px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  line-height: 1.6;
  color: rgba(244, 241, 233, .9);
  border-left: 2px solid rgba(201, 162, 39, .55);
  background: rgba(244, 241, 233, .05);
  transition: border-color .22s var(--ease), color .22s var(--ease), background .22s var(--ease);
}

.page-about .era:hover .era__range {
  border-left-color: var(--gold-light);
  color: var(--gold-light);
  background: rgba(201, 162, 39, .1);
}

/* ---------- 下一步入口 ---------- */

.page-about .about-next {
  background: var(--paper-2);
  border-top: 1px solid var(--about-hair);
  padding-block: clamp(34px, 5vw, 60px);
}

.page-about .about-next__title {
  margin: 0 0 22px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(19px, 2.6vw, 26px);
  color: var(--ink-900);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-next__item {
  padding: 16px 18px;
  background: var(--paper);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  min-width: 0;
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .about-next__item:hover {
  border-color: var(--about-gold-soft);
  box-shadow: var(--shadow-card);
}

.page-about .about-next__link {
  display: inline-block;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink-900);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  padding-bottom: 2px;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-next__link:hover {
  color: var(--red);
  border-bottom-color: var(--red);
}

.page-about .about-next__desc {
  margin: 9px 0 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--slate);
}

@media (min-width: 640px) {
  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1020px) {
  .page-about .about-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 动效收敛 ---------- */

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