/* ============ 品牌自述 · 页面专属样式 ============ */

.page-about {
  display: block;
}

/* ---------- 首屏 ---------- */

.page-about .about-head {
  position: relative;
  overflow: hidden;
  padding: 28px 0 56px;
  border-bottom: 1px solid rgba(90, 107, 133, 0.28);
  background:
    radial-gradient(760px 380px at 92% -10%, rgba(124, 92, 255, 0.22), transparent 66%),
    radial-gradient(620px 320px at 4% 110%, rgba(45, 225, 194, 0.12), transparent 70%),
    var(--ink-900);
}

.page-about .about-head::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(90, 107, 133, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(90, 107, 133, 0.1) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(120% 88% at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(120% 88% at 50% 0%, #000 0%, transparent 78%);
}

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

.page-about .about-head__grid {
  display: grid;
  gap: 32px;
  margin-top: 28px;
}

.page-about .about-head__title {
  margin: 14px 0 20px;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: var(--fs-32);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-head__intro .lede {
  max-width: 38ch;
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .about-head__facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  align-content: end;
  padding-top: 22px;
  border-top: 1px solid rgba(90, 107, 133, 0.35);
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .fact__num {
  font-family: var(--font-mono);
  font-size: var(--fs-24);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .fact__label {
  font-size: var(--fs-12);
  line-height: 1.5;
  color: var(--text-dim);
  letter-spacing: 0.04em;
}

/* ---------- 章节骨架 ---------- */

.page-about .chapter {
  padding: 56px 0;
}

.page-about .chapter + .chapter {
  border-top: 1px solid rgba(90, 107, 133, 0.16);
}

.page-about .chapter__grid {
  display: block;
}

.page-about .chapter__num {
  display: inline-block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-24);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: transparent;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
}

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

.page-about .chapter__title {
  margin: 0 0 18px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-24);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .chapter__lede {
  max-width: 46ch;
  margin: 0 0 28px;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .chapter__split {
  display: grid;
  gap: 32px;
}

/* ---------- 引言块 ---------- */

.page-about .pull-quote {
  margin: 32px 0;
  padding: 22px 0 22px 22px;
  border-left: 3px solid var(--cyan);
  border-top: 1px solid rgba(90, 107, 133, 0.22);
  border-bottom: 1px solid rgba(90, 107, 133, 0.22);
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-24);
  line-height: 1.5;
  letter-spacing: -0.01em;
  color: var(--text);
}

/* ---------- 图片容器 ---------- */

.page-about .about-figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid rgba(90, 107, 133, 0.3);
  border-radius: var(--r-card);
  background: var(--ink-800);
}

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

.page-about .about-figure--square img {
  aspect-ratio: 1 / 1;
}

.page-about .about-figure--wide {
  margin-bottom: 32px;
}

.page-about .about-figure--wide img {
  aspect-ratio: 16 / 9;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid rgba(90, 107, 133, 0.22);
  font-size: var(--fs-12);
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: var(--text-dim);
}

/* ---------- 四条业务线 ---------- */

.page-about .biz {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 18px;
}

.page-about .biz__item {
  position: relative;
  padding: 2px 0 2px 20px;
  border-left: 2px solid rgba(90, 107, 133, 0.4);
  transition: border-color 0.24s var(--ease);
}

.page-about .biz__item:nth-child(1) { border-left-color: var(--cyan); }
.page-about .biz__item:nth-child(2) { border-left-color: var(--orange); }
.page-about .biz__item:nth-child(3) { border-left-color: var(--violet); }
.page-about .biz__item:nth-child(4) { border-left-color: var(--lime); }

.page-about .biz__item:hover {
  border-left-width: 4px;
  padding-left: 18px;
}

.page-about .biz__tag {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-16);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text);
}

.page-about .biz__desc {
  max-width: 64ch;
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 版本时间轴 ---------- */

.page-about .vtl {
  margin-top: 8px;
  padding-bottom: 12px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: rgba(90, 107, 133, 0.6) transparent;
}

.page-about .vtl::-webkit-scrollbar {
  height: 6px;
}

.page-about .vtl::-webkit-scrollbar-thumb {
  border-radius: var(--r-capsule);
  background: rgba(90, 107, 133, 0.55);
}

.page-about .vtl:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
  border-radius: var(--r-chart);
}

.page-about .vtl__track {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 64px 4px 0;
  width: max-content;
  min-width: 100%;
}

.page-about .vtl__track::before {
  content: "";
  position: absolute;
  top: 30px;
  left: 4px;
  right: 4px;
  height: 2px;
  border-radius: var(--r-capsule);
  background: linear-gradient(
    90deg,
    rgba(124, 92, 255, 0.9),
    rgba(45, 225, 194, 0.9),
    rgba(201, 242, 77, 0.55)
  );
}

.page-about .vtl__node {
  position: relative;
  flex: 0 0 264px;
  width: 264px;
  min-width: 0;
}

.page-about .vtl__node::before {
  content: "";
  position: absolute;
  top: -42px;
  left: 2px;
  box-sizing: border-box;
  width: 16px;
  height: 16px;
  border: 2px solid var(--violet);
  border-radius: 50%;
  background: var(--ink-900);
  box-shadow: 0 0 0 5px rgba(124, 92, 255, 0.14);
  transition: border-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .vtl__node:last-child::before {
  border-color: var(--lime);
  box-shadow: 0 0 0 5px rgba(201, 242, 77, 0.16);
}

.page-about .vtl__badge {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 12px;
  border: 1px solid rgba(124, 92, 255, 0.6);
  border-radius: var(--r-capsule);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--violet);
}

.page-about .vtl__btn {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 13px 14px;
  border: 1px solid rgba(90, 107, 133, 0.45);
  border-radius: var(--r-card);
  background: var(--ink-800);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-16);
  font-weight: 500;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
  transition:
    border-color 0.24s var(--ease),
    background-color 0.24s var(--ease),
    transform 0.24s var(--ease);
}

.page-about .vtl__btn:hover {
  border-color: var(--cyan);
  background: var(--ink-700);
  transform: translateY(-2px);
}

.page-about .vtl__btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .vtl__name {
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .vtl__sign {
  position: relative;
  flex: 0 0 18px;
  width: 18px;
  height: 18px;
  margin-top: 2px;
}

.page-about .vtl__sign::before,
.page-about .vtl__sign::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .vtl__sign::before {
  left: 2px;
  right: 2px;
  top: 8px;
  height: 2px;
}

.page-about .vtl__sign::after {
  top: 2px;
  bottom: 2px;
  left: 8px;
  width: 2px;
}

.page-about .vtl__node [aria-expanded="true"] .vtl__sign::after {
  opacity: 0;
  transform: rotate(90deg);
}

.page-about .vtl__node .disclosure__panel {
  padding: 14px 2px 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .vtl__node .disclosure__panel p {
  margin: 0;
}

/* ---------- 数据来源与校对 ---------- */

.page-about .sources {
  display: grid;
  gap: 16px;
  margin-bottom: 36px;
}

.page-about .source {
  padding: 18px 18px 20px;
  border: 1px solid rgba(90, 107, 133, 0.3);
  border-radius: var(--r-card);
  background: linear-gradient(180deg, var(--ink-800), rgba(19, 28, 48, 0.55));
}

.page-about .source__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--violet);
}

.page-about .source__name {
  margin: 0 0 8px;
  font-size: var(--fs-16);
  font-weight: 700;
  color: var(--text);
}

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

.page-about .relay {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: 1px solid rgba(90, 107, 133, 0.24);
}

.page-about .relay__step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid rgba(90, 107, 133, 0.24);
}

.page-about .relay__idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: var(--fs-24);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .relay__name {
  margin: 0 0 6px;
  font-size: var(--fs-18);
  font-weight: 700;
  color: var(--text);
}

.page-about .relay__text {
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 团队与分工 ---------- */

.page-about .roles {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .role {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  border-radius: var(--r-card);
  border: 1px solid rgba(90, 107, 133, 0.26);
  background: rgba(30, 42, 68, 0.45);
}

.page-about .role__name {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .role__desc {
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--text-dim);
}

/* ---------- 合作与产出 ---------- */

.page-about .partners {
  display: grid;
  gap: 12px;
  margin: 24px 0 28px;
  padding: 22px 0;
  border-top: 1px solid rgba(90, 107, 133, 0.24);
  border-bottom: 1px solid rgba(90, 107, 133, 0.24);
}

.page-about .partner {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .partner__num {
  flex: 0 0 auto;
  min-width: 3.2ch;
  font-family: var(--font-mono);
  font-size: var(--fs-32);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
}

.page-about .partner__label {
  font-size: var(--fs-14);
  line-height: 1.6;
  color: var(--text-dim);
}

/* ---------- 结尾行动区 ---------- */

.page-about .about-cta {
  padding: 56px 0 72px;
  border-top: 1px solid rgba(90, 107, 133, 0.24);
  background:
    radial-gradient(680px 300px at 80% 0%, rgba(255, 122, 47, 0.16), transparent 68%),
    var(--ink-900);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 28px;
}

.page-about .about-cta__title {
  margin: 12px 0 12px;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: var(--fs-24);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-cta__desc {
  max-width: 44ch;
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--text-dim);
}

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

/* ---------- 平板与桌面 ---------- */

@media (min-width: 720px) {
  .page-about .about-head {
    padding: 40px 0 72px;
  }

  .page-about .about-head__title {
    font-size: var(--fs-48);
  }

  .page-about .chapter {
    padding: 72px 0;
  }

  .page-about .chapter__title {
    font-size: var(--fs-32);
  }

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

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

  .page-about .partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .partner {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
    gap: 48px;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 960px) {
  .page-about .about-head__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: end;
    gap: 56px;
  }

  .page-about .about-head__intro .lede {
    font-size: var(--fs-18);
  }

  .page-about .about-head__facts {
    padding-top: 26px;
  }

  .page-about .chapter__grid {
    display: grid;
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .chapter__num {
    position: sticky;
    top: calc(var(--topbar-h) + 24px);
    margin-bottom: 0;
    font-size: var(--fs-48);
    line-height: 1;
  }

  .page-about .chapter__split {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-cta__title {
    font-size: var(--fs-32);
  }
}

@media (min-width: 1280px) {
  .page-about .about-head__title {
    font-size: var(--fs-64);
    max-width: 16ch;
  }

  .page-about .chapter {
    padding: 88px 0;
  }

  .page-about .chapter__title {
    font-size: var(--fs-48);
    max-width: 20ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .biz__item,
  .page-about .vtl__btn,
  .page-about .vtl__node::before,
  .page-about .vtl__sign::before,
  .page-about .vtl__sign::after {
    transition: none;
  }

  .page-about .vtl__btn:hover {
    transform: none;
  }
}