/* ============================================================
   品牌与历程页 · /mission/
   作用域：.page-about
   ============================================================ */

.page-about {
  --ab-text: rgba(242, 234, 215, 0.78);
  --ab-text-strong: #F2EAD7;
  --ab-hairline: rgba(127, 154, 166, 0.24);
  --ab-rail-w: 104px;
  --ab-num-gap: 2px;

  display: block;
  margin-left: 0;
  padding: 20px 0 0;
  color: var(--ab-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  text-align: left;
}

@media (min-width: 1024px) {
  .page-about {
    margin-left: var(--rail-w);
    padding-top: 36px;
  }
}

.page-about .ab-shell {
  box-sizing: border-box;
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding-inline: var(--gutter);
}

/* ---------- 面包屑与首屏 ---------- */

.page-about .breadcrumbs {
  margin-bottom: 20px;
}

.page-about .ab-hero {
  padding-bottom: 22px;
  border-bottom: 1px solid var(--ab-hairline);
}

.page-about .ab-hero .eyebrow {
  margin: 0 0 14px;
}

.page-about .ab-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(32px, 6.4vw, 60px);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--ab-text-strong);
  text-align: left;
  text-wrap: balance;
}

.page-about .ab-hero__lede {
  max-width: 62ch;
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--ab-text);
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 34px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .ab-hero__facts .ab-num {
  font-size: 1.9rem;
  line-height: 1;
}

.page-about .ab-fact__label {
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--mist);
}

/* ---------- 行内数字 ---------- */

.page-about .ab-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--cyan);
  padding-inline: var(--ab-num-gap);
}

/* ---------- 图片 ---------- */

.page-about .media {
  margin: 0;
}

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

.page-about .ab-shot,
.page-about .ab-verify-shot,
.page-about .ab-tail-shot {
  margin: 28px 0 6px;
}

.page-about .ab-shot .media__frame,
.page-about .ab-verify-shot .media__frame,
.page-about .ab-tail-shot .media__frame {
  overflow: hidden;
  border-radius: var(--radius-lg);
}

.page-about .ab-verify-shot {
  max-width: 620px;
  margin-top: 30px;
}

/* ---------- 筛选 ---------- */

.page-about .ab-filter {
  margin: 24px 0 2px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--ab-hairline);
}

/* ---------- 双栏主体 ---------- */

.page-about .ab-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  align-items: start;
  padding-top: 8px;
}

@media (min-width: 900px) {
  .page-about .ab-body {
    grid-template-columns: minmax(0, 1fr) var(--ab-rail-w);
    gap: clamp(28px, 4vw, 56px);
  }
}

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

/* ---------- 章节 ---------- */

.page-about .ab-section {
  padding: 34px 0 8px;
  border-top: 1px solid var(--ab-hairline);
}

.page-about .ab-section:first-child {
  border-top: 0;
  padding-top: 20px;
}

.page-about .ab-section .eyebrow {
  margin: 0 0 10px;
}

.page-about .ab-section .section-title {
  margin: 0 0 18px;
  text-align: left;
}

.page-about .ab-prose p {
  margin: 0 0 16px;
  line-height: 1.85;
  color: var(--ab-text);
}

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

.page-about .ab-foot-note {
  margin: 20px 0 0;
  padding: 14px 18px;
  border-left: 2px solid var(--gold);
  background: var(--glass);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ab-text);
}

/* ---------- 夜班节奏 ---------- */

.page-about .ab-night {
  position: relative;
  margin: 24px 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .ab-night::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 14px;
  width: 2px;
  background: var(--spine);
  opacity: 0.5;
}

.page-about .ab-night__item {
  position: relative;
  margin-bottom: 22px;
}

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

.page-about .ab-night__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 3px rgba(255, 162, 31, 0.16);
}

.page-about .ab-night__time {
  display: block;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .ab-night__text {
  display: block;
  margin-top: 4px;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--ab-text);
}

/* ---------- 三道校验关卡 ---------- */

.page-about .verify-flow {
  position: relative;
  margin: 26px 0 0;
}

.page-about .verify-flow__spine {
  display: block;
  width: 100%;
  height: 8px;
  margin-bottom: 14px;
}

.page-about .verify-steps {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 760px) {
  .page-about .verify-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }
}

.page-about .verify-step {
  position: relative;
  padding: 16px 16px 18px;
  border: 1px solid var(--ab-hairline);
  border-radius: var(--radius);
  background: var(--glass);
  transition: transform 240ms var(--ease), border-color 240ms var(--ease);
}

.page-about .verify-step:hover,
.page-about .verify-step:focus-within {
  transform: translateY(-4px);
  border-color: rgba(63, 240, 208, 0.45);
}

@media (min-width: 760px) {
  .page-about .verify-step::after {
    content: "";
    position: absolute;
    top: 40px;
    right: -20px;
    width: 10px;
    height: 10px;
    border-top: 2px solid var(--gold);
    border-right: 2px solid var(--gold);
    transform: rotate(45deg);
    opacity: 0.85;
  }

  .page-about .verify-step:last-child::after {
    content: none;
  }
}

.page-about .verify-step__no {
  display: block;
  margin-bottom: 8px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .verify-step__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--ab-text-strong);
}

.page-about .verify-step__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .verify-step__list li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 8px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--ab-text);
}

.page-about .verify-step__list li:last-child {
  margin-bottom: 0;
}

.page-about .verify-step__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  opacity: 0.75;
}

/* ---------- 里程碑时间线 ---------- */

.page-about .ab-milestones {
  position: relative;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-milestone {
  position: relative;
  display: grid;
  grid-template-columns: 60px minmax(0, 1fr);
  gap: 18px;
  padding-bottom: 28px;
}

.page-about .ab-milestone:last-child {
  padding-bottom: 4px;
}

.page-about .ab-milestone::before {
  content: "";
  position: absolute;
  left: 68px;
  top: 16px;
  bottom: -4px;
  width: 2px;
  background: var(--spine);
  opacity: 0.36;
}

.page-about .ab-milestone:last-child::before {
  content: none;
}

.page-about .ab-milestone::after {
  content: "";
  position: absolute;
  left: 64px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  box-sizing: border-box;
  background: var(--night);
  border: 2px solid var(--gold);
}

.page-about .ab-milestone__year {
  padding-top: 2px;
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.page-about .ab-milestone__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--ab-text-strong);
}

.page-about .ab-milestone__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ab-text);
}

/* ---------- 合作伙伴 ---------- */

.page-about .ab-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 760px) {
  .page-about .ab-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }
}

.page-about .ab-partner {
  position: relative;
  padding-top: 16px;
  border-top: 2px solid var(--rust);
}

.page-about .ab-partner__no {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--rust);
}

.page-about .ab-partner__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--ab-text-strong);
}

.page-about .ab-partner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ab-text);
}

/* ---------- 收束区 ---------- */

.page-about .ab-cta {
  margin: 40px 0 56px;
  padding: 30px 24px 32px;
  border: 1px solid rgba(255, 162, 31, 0.32);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(255, 162, 31, 0.12) 0%, rgba(63, 240, 208, 0.07) 58%, rgba(7, 23, 38, 0) 100%);
}

.page-about .ab-cta .section-title {
  margin: 0 0 14px;
  text-align: left;
}

.page-about .ab-cta__text {
  max-width: 56ch;
  margin: 0 0 24px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ab-text);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .ab-cta__actions .btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

/* ---------- 年份刻度轨道 ---------- */

.page-about .ab-rail {
  position: sticky;
  top: calc(var(--topbar-h) + 6px);
  z-index: 3;
  order: -1;
  margin: 0 calc(var(--gutter) * -1);
  padding: 10px var(--gutter) 8px;
  background: linear-gradient(180deg, rgba(7, 23, 38, 0.96) 0%, rgba(7, 23, 38, 0.88) 100%);
  backdrop-filter: blur(6px);
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .ab-rail__label {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .ab-rail__list {
  position: relative;
  display: flex;
  align-items: center;
  gap: 22px;
  margin: 0;
  padding: 0;
  min-width: max-content;
  list-style: none;
}

.page-about .ab-rail__list::before {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  top: 5px;
  height: 2px;
  background: var(--spine-x);
  opacity: 0.42;
}

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

.page-about .ab-rail__link {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 2px;
  text-decoration: none;
  color: var(--mist);
  transition: color 200ms var(--ease);
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--ab-text-strong);
}

.page-about .ab-rail__tick {
  flex: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  box-sizing: border-box;
  background: var(--night);
  border: 2px solid var(--gold);
  transition: background-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .ab-rail__link:hover .ab-rail__tick,
.page-about .ab-rail__link:focus-visible .ab-rail__tick {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(255, 162, 31, 0.2);
}

.page-about .ab-rail__link.is-lit .ab-rail__tick {
  background: var(--gold);
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(63, 240, 208, 0.16);
}

.page-about .ab-rail__link.is-lit .ab-rail__year {
  color: var(--gold);
}

.page-about .ab-rail__year {
  font-size: 13px;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

@media (min-width: 900px) {
  .page-about .ab-rail {
    position: sticky;
    top: 32px;
    order: 0;
    margin: 20px 0 0;
    padding: 0 0 0 16px;
    background: none;
    backdrop-filter: none;
    overflow: visible;
  }

  .page-about .ab-rail__label {
    margin-bottom: 14px;
    writing-mode: horizontal-tb;
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    min-width: 0;
  }

  .page-about .ab-rail__list::before {
    left: 5px;
    right: auto;
    top: 14px;
    bottom: 14px;
    width: 2px;
    height: auto;
    background: var(--spine);
  }

  .page-about .ab-rail__link {
    padding: 6px 0;
  }
}

/* ---------- 页尾图带 ---------- */

.page-about .ab-tail-shot {
  margin: 12px 0 64px;
}

/* ---------- 焦点可见性 ---------- */

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about [tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 窄屏收敛 ---------- */

@media (max-width: 560px) {
  .page-about {
    font-size: 15.5px;
  }

  .page-about .ab-hero__facts {
    gap: 12px 24px;
  }

  .page-about .ab-hero__facts .ab-num {
    font-size: 1.6rem;
  }

  .page-about .ab-milestone {
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 16px;
  }

  .page-about .ab-milestone::before {
    left: 60px;
  }

  .page-about .ab-milestone::after {
    left: 56px;
  }

  .page-about .ab-cta {
    padding: 24px 18px 26px;
  }

  .page-about .ab-cta__actions .btn {
    width: 100%;
    justify-content: center;
  }
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .verify-step,
  .page-about .ab-rail__link,
  .page-about .ab-rail__tick {
    transition: none;
  }

  .page-about .verify-step:hover,
  .page-about .verify-step:focus-within {
    transform: none;
  }
}