.page-about {
  --ab-bronze: #B07B4A;
  --ab-silver: #A9A49A;
  --ab-gold-tone: #D8A94A;
}

/* ============ 首屏 ============ */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background: var(--red);
  color: var(--jade-white);
}
.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: -6%;
  bottom: 0;
  width: min(860px, 88%);
  background: var(--red-deep);
  clip-path: polygon(32% 0, 100% 0, 100% 100%, 0 100%);
  opacity: .62;
  pointer-events: none;
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: clamp(38px, 6vw, 66px);
  background: var(--jade-white);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}
.page-about .ab-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 5vw, 48px);
  align-items: center;
  padding-block: clamp(38px, 6vw, 76px) clamp(84px, 13vw, 138px);
}
.page-about .ab-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--gold);
}
.page-about .ab-hero__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.85rem, 4.6vw, 3.2rem);
  line-height: 1.2;
  letter-spacing: .01em;
  color: var(--jade-white);
}
.page-about .ab-hero__lead {
  margin: 0 0 24px;
  max-width: 34em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: rgba(246, 241, 231, .9);
}
.page-about .ab-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-hero__tags .tag {
  color: var(--jade-white);
  border-bottom-color: rgba(216, 169, 74, .85);
}
.page-about .ab-hero__seal {
  margin: 0;
  justify-self: center;
  width: min(230px, 58vw);
  border-radius: var(--r-organic);
  overflow: hidden;
  border: 1px solid rgba(216, 169, 74, .5);
  background: rgba(22, 17, 15, .24);
}
.page-about .ab-hero__seal img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}
.page-about .ab-hero__note {
  position: absolute;
  z-index: 2;
  right: clamp(8px, 1.8vw, 22px);
  top: 44%;
  transform: translateY(-50%);
  writing-mode: vertical-rl;
  margin: 0;
  font-size: 12px;
  letter-spacing: .32em;
  color: var(--gold);
  display: none;
}

/* ============ 章节锚点 ============ */
.page-about .ab-nav {
  position: sticky;
  top: calc(var(--topbar-h) + 56px);
  z-index: 12;
  background: rgba(246, 241, 231, .96);
  border-bottom: 1px solid var(--line);
}
.page-about .ab-nav__inner {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-block: 10px;
  scrollbar-width: none;
}
.page-about .ab-nav__inner::-webkit-scrollbar {
  display: none;
}
.page-about .ab-nav__inner .anchor-nav__link {
  flex: 0 0 auto;
  padding: 7px 14px;
  border-radius: var(--r-chip);
  border: 1px solid transparent;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  transition: color .16s var(--ease), border-color .16s var(--ease), background-color .16s var(--ease);
}
.page-about .ab-nav__inner .anchor-nav__link:hover,
.page-about .ab-nav__inner .anchor-nav__link:focus-visible {
  border-color: var(--gold);
}
.page-about .ab-nav__inner .anchor-nav__link[aria-current="true"] {
  color: var(--red);
  border-color: var(--gold);
  background: rgba(216, 169, 74, .16);
}

/* ============ 章节骨架 ============ */
.page-about .ab-sec {
  padding-block: clamp(48px, 7vw, 92px);
}
.page-about .ab-sec--paper {
  background: var(--paper);
}
.page-about .ab-sec--ink {
  background: var(--ink-2);
  color: var(--jade-white);
}
.page-about .ab-sec__head {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 16px;
  align-items: center;
  margin-bottom: clamp(24px, 4vw, 44px);
}
.page-about .ab-sec__head .section-head__index {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  line-height: 1;
  color: var(--red);
}
.page-about .ab-sec--ink .ab-sec__head .section-head__index {
  color: var(--gold);
}
.page-about .ab-sec__head .section-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.6vw, 1.95rem);
  line-height: 1.42;
  color: inherit;
}
.page-about .ab-sec__note {
  grid-column: 2;
  margin: 0;
  font-size: 12px;
  letter-spacing: .24em;
  color: var(--jade);
}
.page-about .ab-sec--ink .ab-sec__note {
  color: var(--gold);
}

/* ============ 壹 四条主线 ============ */
.page-about .ab-axis {
  display: grid;
  gap: clamp(14px, 2.2vw, 22px);
}
.page-about .ab-axis__item {
  padding: 24px 22px 24px 26px;
  background: var(--paper);
  border-left: 3px solid var(--gold);
  border-radius: var(--r-organic);
  transition: transform .16s var(--ease), box-shadow .16s var(--ease);
}
.page-about .ab-axis__item:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-2);
}
.page-about .ab-axis__num {
  display: block;
  margin-bottom: 8px;
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--red);
}
.page-about .ab-axis__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.14rem;
  color: var(--ink);
}
.page-about .ab-axis__text {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}
.page-about .ab-axis__scene {
  margin: 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13.5px;
  line-height: 1.78;
  color: rgba(22, 17, 15, .72);
}
.page-about .ab-axis__label {
  display: inline-block;
  margin-right: 8px;
  padding: 1px 9px;
  border-radius: var(--r-chip);
  background: rgba(179, 18, 43, .1);
  color: var(--red);
  font-size: 11.5px;
  letter-spacing: .1em;
}

/* ============ 贰 频道与房间分类 ============ */
.page-about .ab-family {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
}
.page-about .ab-family__figure {
  margin: 0 0 22px;
  border-radius: var(--r-organic);
  overflow: hidden;
  border: 1px solid rgba(216, 169, 74, .3);
  background: rgba(246, 241, 231, .06);
}
.page-about .ab-family__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .ab-family__list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-family__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
  padding: 15px 16px;
  border-radius: var(--r-soft);
  border-left: 3px solid var(--ab-tone, var(--gold));
  background: rgba(246, 241, 231, .07);
  transition: background-color .16s var(--ease), transform .16s var(--ease);
}
.page-about .ab-family__row:hover {
  background: rgba(246, 241, 231, .15);
  transform: translateX(3px);
}
.page-about .ab-family__row--table { --ab-tone: #E4536A; }
.page-about .ab-family__row--arcade { --ab-tone: var(--gold); }
.page-about .ab-family__row--theme { --ab-tone: var(--jade-soft); }
.page-about .ab-family__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--jade-white);
}
.page-about .ab-family__count {
  padding: 1px 10px;
  border: 1px solid rgba(216, 169, 74, .5);
  border-radius: var(--r-chip);
  font-size: 12.5px;
  color: var(--gold);
}
.page-about .ab-family__desc {
  flex-basis: 100%;
  font-size: 13.5px;
  line-height: 1.78;
  color: rgba(246, 241, 231, .76);
}
.page-about .ab-family__side-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.12rem;
  color: var(--gold);
}
.page-about .ab-family__side-lead {
  margin: 0 0 18px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(246, 241, 231, .8);
}
.page-about .ab-long {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-long__item {
  padding: 16px 18px;
  border-radius: var(--r-soft);
  border: 1px dashed rgba(216, 169, 74, .4);
  background: rgba(22, 17, 15, .22);
}
.page-about .ab-long__name {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  color: var(--gold);
}
.page-about .ab-long__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.78;
  color: rgba(246, 241, 231, .76);
}

/* ============ 叁 会员与权益 ============ */
.page-about .ab-tier-intro {
  max-width: 42em;
  margin: 0 0 clamp(22px, 3.5vw, 36px);
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(22, 17, 15, .82);
}
.page-about .ab-tiers {
  display: grid;
  gap: 12px;
}
.page-about .ab-tier {
  display: grid;
  gap: 16px;
  padding: 20px;
  border-radius: var(--r-organic);
  border-left: 4px solid var(--ab-tone, var(--gold));
  background: var(--paper);
  transition: transform .16s var(--ease), box-shadow .16s var(--ease);
}
.page-about .ab-tier:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-1);
}
.page-about .ab-tier--bronze { --ab-tone: var(--ab-bronze); }
.page-about .ab-tier--silver { --ab-tone: var(--ab-silver); }
.page-about .ab-tier--gold { --ab-tone: var(--gold); }
.page-about .ab-tier--jade { --ab-tone: var(--jade); }
.page-about .ab-tier__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 12px;
}
.page-about .ab-tier__seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  border-radius: 4px 14px 4px 14px;
  background: var(--ab-tone, var(--gold));
  color: var(--ink);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.1rem;
}
.page-about .ab-tier--jade .ab-tier__seal {
  color: var(--jade-white);
}
.page-about .ab-tier__name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--ink);
}
.page-about .ab-tier__basis {
  flex-basis: 100%;
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: rgba(22, 17, 15, .68);
}
.page-about .ab-tier__list {
  display: grid;
  gap: 10px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-tier__list li {
  display: grid;
  gap: 3px;
  padding-left: 12px;
  border-left: 2px solid var(--line);
}
.page-about .ab-tier__key {
  font-size: 12px;
  letter-spacing: .08em;
  color: rgba(22, 17, 15, .58);
}
.page-about .ab-tier__val {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--ink);
}

/* ============ 肆 发展脉络 ============ */
.page-about .ab-era__figure {
  margin: 0 0 clamp(24px, 4vw, 40px);
  border-radius: var(--r-organic);
  overflow: hidden;
  border: 1px solid var(--line);
}
.page-about .ab-era__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .ab-era__track {
  display: grid;
  gap: 12px;
  margin: 0 0 clamp(24px, 4vw, 38px);
  padding: 0;
  list-style: none;
}
.page-about .ab-era__node {
  position: relative;
}
.page-about .ab-era__link {
  display: block;
  padding: 18px 16px 18px 22px;
  border-left: 3px solid var(--gold);
  border-radius: var(--r-soft);
  background: var(--jade-white);
  color: var(--ink);
  text-decoration: none;
  transition: background-color .16s var(--ease), transform .16s var(--ease);
}
.page-about .ab-era__link:hover,
.page-about .ab-era__link:focus-visible {
  background: rgba(216, 169, 74, .16);
  transform: translateY(-2px);
}
.page-about .ab-era__ver {
  display: block;
  margin-bottom: 6px;
  font-size: 1rem;
  color: var(--red);
}
.page-about .ab-era__cap {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  color: var(--ink);
}
.page-about .ab-era__notes {
  display: grid;
  gap: 16px;
}
.page-about .ab-era__note {
  padding: 22px 22px 22px 24px;
  border-radius: var(--r-organic);
  border-top: 3px solid var(--gold);
  background: var(--jade-white);
}
.page-about .ab-era__note-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--red);
}
.page-about .ab-era__note p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(22, 17, 15, .84);
}

/* ============ 伍 更新节奏 ============ */
.page-about .ab-cadence {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-organic);
  overflow: hidden;
}
.page-about .ab-cadence__item {
  padding: 22px 20px;
  background: var(--jade-white);
}
.page-about .ab-cadence__freq {
  display: block;
  margin-bottom: 8px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--red);
}
.page-about .ab-cadence__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink);
}
.page-about .ab-cadence__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.78;
  color: rgba(22, 17, 15, .74);
}
.page-about .ab-cadence__foot {
  max-width: 52em;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding-left: 18px;
  border-left: 3px solid var(--gold);
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(22, 17, 15, .8);
}

/* ============ 陆 规模概况 ============ */
.page-about .ab-scale {
  display: grid;
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-scale .stat {
  padding: 22px 20px;
  border-left: 3px solid var(--gold);
  border-radius: var(--r-organic);
  background: rgba(246, 241, 231, .06);
}
.page-about .ab-scale .stat__value {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.9rem, 4.4vw, 2.8rem);
  line-height: 1.08;
  color: var(--gold);
}
.page-about .ab-scale .stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.72;
  color: rgba(246, 241, 231, .78);
}

/* ============ 柒 下一步 ============ */
.page-about .ab-next {
  display: grid;
  gap: 14px;
}
.page-about .ab-next__card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 22px 20px;
  border-radius: var(--r-organic);
  border-left: 3px solid var(--gold);
  background: var(--jade-white);
  color: var(--ink);
  text-decoration: none;
  transition: transform .16s var(--ease), box-shadow .16s var(--ease), background-color .16s var(--ease);
}
.page-about .ab-next__card:hover,
.page-about .ab-next__card:focus-visible {
  transform: translateY(-3px);
  box-shadow: var(--shadow-2);
  background: #FFFBF2;
}
.page-about .ab-next__kicker {
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--red);
}
.page-about .ab-next__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ink);
}
.page-about .ab-next__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(22, 17, 15, .78);
}
.page-about .ab-next__more {
  margin-top: auto;
  padding-top: 6px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--jade);
  border-bottom: 2px solid rgba(216, 169, 74, .7);
  align-self: flex-start;
}
.page-about .ab-next__foot {
  max-width: 56em;
  margin: clamp(22px, 3.5vw, 34px) 0 0;
  padding: 18px 20px;
  border-radius: var(--r-soft);
  background: rgba(179, 18, 43, .06);
  border-left: 3px solid var(--red);
  font-size: 14px;
  line-height: 1.85;
  color: rgba(22, 17, 15, .82);
}

/* ============ 响应式 ============ */
@media (min-width: 620px) {
  .page-about .ab-long {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-tier__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-scale {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-cadence {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-next {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 780px) {
  .page-about .ab-axis {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-era__track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
  }
  .page-about .ab-era__node:not(:last-child)::after {
    content: "";
    position: absolute;
    top: 34px;
    right: -12px;
    width: 12px;
    border-top: 1px dashed var(--gold);
  }
  .page-about .ab-era__notes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, .68fr);
  }
  .page-about .ab-hero__seal {
    width: min(300px, 100%);
  }
  .page-about .ab-nav__inner {
    justify-content: center;
  }
  .page-about .ab-tier {
    grid-template-columns: 220px minmax(0, 1fr);
    align-items: center;
    gap: 24px;
    padding: 22px 24px;
  }
}

@media (min-width: 980px) {
  .page-about .ab-family {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-hero__note {
    display: block;
  }
  .page-about .ab-scale {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-cadence {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-next {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1140px) {
  .page-about .ab-tier__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-axis__item,
  .page-about .ab-tier,
  .page-about .ab-family__row,
  .page-about .ab-era__link,
  .page-about .ab-next__card {
    transition: opacity .16s linear;
  }
  .page-about .ab-axis__item:hover,
  .page-about .ab-tier:hover,
  .page-about .ab-family__row:hover,
  .page-about .ab-era__link:hover,
  .page-about .ab-next__card:hover {
    transform: none;
  }
}