/* =========================================================
   品牌中心 /brand/ —— 页面专属样式
   作用域：.page-about
   ========================================================= */

.page-about {
  --ab-gold-ink: #8A6114;
  --ab-ink: var(--silver);
  --ab-ink-soft: var(--moon);
  --ab-gap: clamp(1rem, 2.4vw, 1.6rem);
}

.page-about .ab-sec--paper {
  --ab-ink: var(--brown);
  --ab-ink-soft: rgba(36, 28, 20, .74);
  background: var(--paper);
  color: var(--brown);
}

.page-about .reading {
  background: var(--paper);
  color: var(--brown);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  padding: clamp(1.4rem, 4vw, 2.4rem) 0 clamp(2.6rem, 7vw, 5rem);
  overflow: hidden;
}

.page-about .ab-hero .breadcrumbs {
  margin-bottom: clamp(1.6rem, 5vw, 3rem);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(2rem, 6vw, 3.4rem);
  align-items: end;
}

.page-about .ab-hero__eyebrow {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .24em;
  color: var(--gold);
}

.page-about .ab-hero__title {
  margin: 0 0 1.3rem;
  font-family: var(--font-display);
  font-stretch: condensed;
  font-weight: 900;
  font-size: clamp(2.3rem, 8.4vw, 5.4rem);
  line-height: 1.02;
  letter-spacing: -.02em;
  color: var(--silver);
}

.page-about .ab-hero__lede {
  margin: 0 0 .9rem;
  max-width: 42em;
  font-size: clamp(1rem, 1.5vw, 1.1rem);
  line-height: 1.85;
  color: var(--silver);
}

.page-about .ab-hero__sub {
  margin: 0;
  max-width: 40em;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--mist);
}

/* 首屏右侧刻度尺 */
.page-about .ab-scale {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--line-strong);
}

.page-about .ab-scale__item {
  position: relative;
  display: grid;
  grid-template-columns: 4.6rem minmax(0, 1fr);
  align-items: baseline;
  gap: .9rem;
  padding: .85rem 0 .85rem 1.1rem;
  border-bottom: 1px dashed var(--line);
}

.page-about .ab-scale__item:last-child {
  border-bottom: 0;
}

.page-about .ab-scale__item::before {
  content: "";
  position: absolute;
  left: -3px;
  top: 1.35rem;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--moon);
}

.page-about .ab-scale__item:first-child::before {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(217, 164, 65, .18);
}

.page-about .ab-scale__num {
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.4vw, 1.4rem);
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .ab-scale__txt {
  font-size: .88rem;
  line-height: 1.6;
  color: var(--moon);
}

/* ---------- 章节通用 ---------- */

.page-about .ab-sec {
  padding: clamp(2.8rem, 7vw, 5.2rem) 0;
}

.page-about .ab-sec__head {
  max-width: 48rem;
  margin-bottom: clamp(1.7rem, 4vw, 2.8rem);
}

.page-about .ab-sec__num {
  display: inline-block;
  margin-bottom: .7rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .26em;
  color: var(--ab-gold-ink, var(--gold));
}

.page-about .ab-sec--paper .ab-sec__num {
  color: var(--ab-gold-ink);
}

.page-about .ab-sec:not(.ab-sec--paper) .ab-sec__num {
  color: var(--gold);
}

.page-about .ab-sec__title {
  margin: 0 0 .85rem;
  font-family: var(--font-display);
  font-stretch: condensed;
  font-weight: 900;
  font-size: clamp(1.6rem, 4.4vw, 2.6rem);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--ab-ink);
}

.page-about .ab-sec__note {
  margin: 0;
  max-width: 44em;
  line-height: 1.85;
  color: var(--ab-ink-soft);
}

/* ---------- 01 品牌起点 ---------- */

.page-about .ab-origin {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.6rem, 4vw, 3rem);
}

.page-about .ab-origin__copy p {
  margin: 0 0 1rem;
  max-width: 40em;
  line-height: 1.85;
  color: var(--moon);
}

.page-about .ab-origin__stamp {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .7rem;
  margin: 1.4rem 0;
  padding: 1rem 1.1rem;
  border: 1px solid var(--line-strong);
  border-left: 3px solid var(--gold);
  border-radius: var(--radius-m);
  background: rgba(16, 30, 66, .6);
}

.page-about .ab-origin__stamp-label {
  font-size: .78rem;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .ab-origin__stamp-code {
  font-family: var(--font-mono);
  font-size: clamp(.95rem, 2.2vw, 1.1rem);
  letter-spacing: .14em;
  color: var(--gold);
}

.page-about .ab-origin__figure {
  align-self: start;
}

/* ---------- 02 沿革时间轴 ---------- */

.page-about .ab-filter {
  margin-bottom: clamp(1.6rem, 4vw, 2.4rem);
}

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

.page-about .ab-node {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .75rem;
  padding-bottom: 2.1rem;
}

.page-about .ab-node:nth-child(1) { padding-bottom: 2.6rem; }
.page-about .ab-node:nth-child(2) { padding-bottom: 2.4rem; }
.page-about .ab-node:nth-child(3) { padding-bottom: 2.2rem; }
.page-about .ab-node:nth-child(4) { padding-bottom: 2rem; }
.page-about .ab-node:nth-child(5) { padding-bottom: 1.8rem; }
.page-about .ab-node:last-child { padding-bottom: 0; }

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

.page-about .ab-node__rail {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.page-about .ab-node__dot {
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
}

.page-about .ab-node__year {
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.6vw, 1.5rem);
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--ab-gold-ink);
}

.page-about .ab-node__body {
  padding: clamp(1rem, 2.4vw, 1.5rem);
  border: 1px solid var(--line-paper);
  border-radius: var(--radius-m);
  background: rgba(255, 255, 255, .58);
}

.page-about .ab-node__title {
  margin: 0 0 .6rem;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.6vw, 1.28rem);
  font-weight: 800;
  line-height: 1.4;
  color: var(--brown);
}

.page-about .ab-node__text {
  margin: 0;
  font-size: .95rem;
  line-height: 1.85;
  color: rgba(36, 28, 20, .76);
}

.page-about .ab-node__meta {
  margin: .85rem 0 0;
  padding-top: .7rem;
  border-top: 1px dashed var(--line-paper);
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .1em;
  color: var(--ab-gold-ink);
}

/* ---------- 03 团队构成 ---------- */

.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

.page-about .ab-team__col {
  position: relative;
  padding: 1.5rem 1.25rem 1.4rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: rgba(16, 30, 66, .62);
}

.page-about .ab-team__tag {
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .3em;
  color: var(--gold);
}

.page-about .ab-team__name {
  margin: 0 0 .35rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--silver);
}

.page-about .ab-team__role {
  margin: 0 0 1.1rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .ab-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .7rem;
}

.page-about .ab-team__list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: .93rem;
  line-height: 1.75;
  color: var(--moon);
}

.page-about .ab-team__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .66em;
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: var(--gold);
  opacity: .8;
}

.page-about .ab-team__figure {
  margin-top: clamp(1.6rem, 4vw, 2.6rem);
}

/* ---------- 04 标准维护 ---------- */

.page-about .ab-keep {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
}

.page-about .ab-keep__item {
  padding: clamp(1.15rem, 2.6vw, 1.5rem);
  border: 1px solid var(--line-paper);
  border-radius: var(--radius-m);
  background: rgba(255, 255, 255, .6);
}

.page-about .ab-keep__code {
  display: inline-block;
  margin-bottom: .7rem;
  padding: .2rem .7rem;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(138, 97, 20, .35);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--ab-gold-ink);
}

.page-about .ab-keep__name {
  margin: 0 0 .6rem;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--brown);
}

.page-about .ab-keep__item p {
  margin: 0;
  font-size: .93rem;
  line-height: 1.85;
  color: rgba(36, 28, 20, .76);
}

/* ---------- 05 渠道复核（标签切换） ---------- */

.page-about .ab-tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1.3rem;
}

.page-about .ab-tab {
  font: inherit;
  font-size: .86rem;
  padding: .55rem 1.15rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--moon);
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-tab:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.page-about .ab-tab[aria-selected="true"] {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
  font-weight: 700;
}

.page-about .ab-tabs__panels {
  padding: clamp(1.2rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: rgba(16, 30, 66, .55);
}

.page-about .ab-panel__title {
  margin: 0 0 .9rem;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--silver);
}

.page-about .ab-panel__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .8rem;
}

.page-about .ab-panel__list li {
  position: relative;
  padding-left: 1.2rem;
  font-size: .94rem;
  line-height: 1.8;
  color: var(--moon);
}

.page-about .ab-panel__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .7em;
  width: 7px;
  height: 1px;
  background: var(--gold);
}

.page-about .ab-panel__list strong {
  color: var(--silver);
  font-weight: 700;
}

/* ---------- 06 合作生态与荣誉 ---------- */

.page-about .ab-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.6rem, 4vw, 3rem);
}

.page-about .ab-eco__copy p {
  margin: 0 0 1rem;
  max-width: 40em;
  font-size: .97rem;
  line-height: 1.9;
  color: rgba(36, 28, 20, .78);
}

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

/* ---------- 07 下一步 ---------- */

.page-about .ab-next-sec {
  padding-bottom: clamp(3.2rem, 8vw, 6rem);
}

.page-about .ab-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
}

.page-about .ab-next__card {
  display: flex;
  flex-direction: column;
  gap: .55rem;
  padding: clamp(1.2rem, 3vw, 1.7rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: rgba(16, 30, 66, .55);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-next__card:hover,
.page-about .ab-next__card:focus-visible {
  border-color: var(--gold);
  background: rgba(16, 30, 66, .85);
}

.page-about .ab-next__card--gold {
  border-color: rgba(217, 164, 65, .5);
}

.page-about .ab-next__code {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .18em;
  color: var(--gold);
}

.page-about .ab-next__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--silver);
}

.page-about .ab-next__card p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .ab-next__go {
  margin-top: auto;
  padding-top: .8rem;
  font-size: .86rem;
  letter-spacing: .06em;
  color: var(--moon);
}

.page-about .ab-next__card:hover .ab-next__go {
  color: var(--gold);
}

/* ---------- 图片兜底 ---------- */

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

/* ---------- 响应式 ---------- */

@media (min-width: 760px) {
  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.1rem;
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
  }

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .ab-eco {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
  }

  /* 时间轴：左刻度线 + 右节点卡 */
  .page-about .ab-timeline::before {
    content: "";
    position: absolute;
    left: calc(7.6rem + 1.2rem);
    top: .5rem;
    bottom: 1.2rem;
    width: 1px;
    background: linear-gradient(180deg, var(--gold), rgba(217, 164, 65, .18) 78%, rgba(217, 164, 65, 0));
  }

  .page-about .ab-node {
    grid-template-columns: 7.6rem minmax(0, 1fr);
    gap: 2.4rem;
    padding-bottom: 2.4rem;
  }

  .page-about .ab-node:nth-child(1) { padding-bottom: 2.8rem; }
  .page-about .ab-node:nth-child(2) { padding-bottom: 2.5rem; }
  .page-about .ab-node:nth-child(3) { padding-bottom: 2.2rem; }
  .page-about .ab-node:nth-child(4) { padding-bottom: 1.95rem; }
  .page-about .ab-node:nth-child(5) { padding-bottom: 1.7rem; }
  .page-about .ab-node:last-child { padding-bottom: 0; }

  .page-about .ab-node__rail {
    display: block;
    text-align: right;
    padding-top: .35rem;
  }

  .page-about .ab-node__dot {
    position: absolute;
    left: calc(7.6rem + 1.2rem);
    top: .75rem;
    transform: translateX(-50%);
    box-shadow: 0 0 0 4px rgba(217, 164, 65, .16);
  }

  /* 团队三栏：竖排职责标注 */
  .page-about .ab-team {
    gap: 1.4rem;
  }

  .page-about .ab-team__col {
    padding: 1.7rem 1.3rem 1.6rem 3rem;
  }

  .page-about .ab-team__tag {
    position: absolute;
    left: .85rem;
    top: 1.75rem;
    margin: 0;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    letter-spacing: .32em;
  }

  .page-about .ab-next {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (hover: hover) and (min-width: 900px) {
  .page-about .ab-node__meta {
    opacity: 0;
    transition: opacity var(--dur) var(--ease);
  }

  .page-about .ab-node:hover .ab-node__meta,
  .page-about .ab-node:focus-within .ab-node__meta {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-tab,
  .page-about .ab-next__card,
  .page-about .ab-node__meta {
    transition: none;
  }

  .page-about .ab-node__meta {
    opacity: 1;
  }
}