.page-about {
  --about-gap-sm: clamp(12px, 1.6vw, 20px);
  --about-gap: clamp(20px, 3vw, 40px);
  --about-gap-lg: clamp(32px, 5vw, 72px);
  --about-line-dark: rgba(245, 242, 236, 0.16);
  --about-line-paper: rgba(43, 47, 54, 0.16);
}

/* ============ 主视觉 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(28px, 5vw, 56px) clamp(40px, 7vw, 88px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(245, 242, 236, 0.04) 0 1px, transparent 1px 5px),
    radial-gradient(circle at 84% 12%, rgba(224, 43, 60, 0.28), transparent 55%),
    radial-gradient(circle at 12% 88%, rgba(31, 168, 255, 0.22), transparent 52%);
  pointer-events: none;
}
.page-about .about-hero__wrap {
  position: relative;
  z-index: 1;
}
.page-about .about-hero .bb-crumb {
  margin-bottom: clamp(16px, 2.6vw, 30px);
}
.page-about .about-hero__title {
  margin: clamp(10px, 1.6vw, 18px) 0 0;
  font-size: clamp(2.1rem, 6vw, 4.4rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--bb-paper);
  max-width: 22ch;
}
.page-about .about-hero__lede {
  margin-top: clamp(16px, 2.2vw, 26px);
  color: rgba(245, 242, 236, 0.82);
  font-size: var(--bb-fs-18);
  line-height: 1.85;
}
.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin-top: clamp(28px, 4.4vw, 52px);
  border-top: 1px solid var(--about-line-dark);
  border-left: 1px solid var(--about-line-dark);
}
.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 2.4vw, 26px);
  border-right: 1px solid var(--about-line-dark);
  border-bottom: 1px solid var(--about-line-dark);
  position: relative;
}
.page-about .about-hero__stat::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 34px;
  height: 3px;
  background: var(--bb-red);
}
.page-about .about-hero__num {
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  line-height: 1;
}
.page-about .about-hero__tag {
  font-size: var(--bb-fs-12);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(245, 242, 236, 0.62);
}

/* ============ 通用小节标题 ============ */
.page-about .about-head {
  max-width: 62ch;
  margin-bottom: var(--about-gap);
}
.page-about .about-head__title {
  margin: clamp(10px, 1.4vw, 16px) 0 0;
  font-size: clamp(1.5rem, 3.4vw, 2.5rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.005em;
}
.page-about .about-head__text {
  margin-top: clamp(12px, 1.6vw, 18px);
  font-size: var(--bb-fs-18);
  line-height: 1.85;
  color: rgba(43, 47, 54, 0.76);
}
.page-about .about-head--light .about-head__title {
  color: var(--bb-paper);
}
.page-about .about-head--light .about-head__text {
  color: rgba(245, 242, 236, 0.76);
}

/* ============ 沿革 ============ */
.page-about .about-history {
  position: relative;
  overflow: hidden;
}
.page-about .about-history::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(0deg, rgba(43, 47, 54, 0.035) 0 1px, transparent 1px 6px);
  pointer-events: none;
}
.page-about .about-history > .bb-wrap {
  position: relative;
  z-index: 1;
}
.page-about .about-history__media {
  margin: 0 0 var(--about-gap-lg);
  border: 1px solid var(--about-line-paper);
  background: rgba(43, 47, 54, 0.04);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 8px;
  left: 7px;
  width: 2px;
  background: linear-gradient(180deg, var(--bb-red), var(--bb-gold) 55%, var(--bb-blue));
  opacity: 0.65;
}
.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: 0 0 var(--about-gap-lg) 32px;
}
.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .about-timeline__dot {
  position: absolute;
  left: 0;
  top: 8px;
  width: 16px;
  height: 16px;
  background: var(--bb-paper);
  border: 3px solid var(--bb-red);
  box-shadow: 0 0 0 4px rgba(224, 43, 60, 0.14);
}
.page-about .about-timeline__year {
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.page-about .about-timeline__num {
  font-family: var(--bb-mono);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--bb-red-dark);
  border-bottom: 3px solid var(--bb-gold-light);
  line-height: 1.1;
}
.page-about .about-timeline__body h3 {
  margin: 0 0 8px;
  font-size: var(--bb-fs-24);
  font-weight: 800;
  color: var(--bb-text);
}
.page-about .about-timeline__body p {
  margin: 0;
  font-size: var(--bb-fs-18);
  line-height: 1.85;
  color: rgba(43, 47, 54, 0.78);
  max-width: 60ch;
}

/* ============ 团队 ============ */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap-sm);
}
.page-about .about-team__card {
  position: relative;
  padding: clamp(20px, 2.8vw, 32px);
  background: rgba(14, 17, 22, 0.55);
  border: 1px solid var(--about-line-dark);
  border-top: 3px solid var(--bb-blue);
}
.page-about .about-team__card:nth-child(2) {
  border-top-color: var(--bb-gold);
}
.page-about .about-team__card:nth-child(3) {
  border-top-color: var(--bb-red);
}
.page-about .about-team__num {
  display: block;
  font-family: var(--bb-mono);
  font-size: clamp(2.6rem, 5.5vw, 3.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--bb-paper);
}
.page-about .about-team__card h3 {
  margin: 12px 0 10px;
  font-size: var(--bb-fs-24);
  font-weight: 800;
  color: var(--bb-paper);
}
.page-about .about-team__card p {
  margin: 0 0 16px;
  font-size: var(--bb-fs-18);
  line-height: 1.8;
  color: rgba(245, 242, 236, 0.76);
}
.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px dashed var(--about-line-dark);
}
.page-about .about-team__list li {
  padding: 9px 0 9px 16px;
  position: relative;
  font-size: var(--bb-fs-14);
  letter-spacing: 0.02em;
  color: rgba(245, 242, 236, 0.66);
  border-bottom: 1px dashed rgba(245, 242, 236, 0.1);
}
.page-about .about-team__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  background: var(--bb-blue-light);
}
.page-about .about-team__list li:last-child {
  border-bottom: 0;
}

/* ============ 内容生产 ============ */
.page-about .about-flow__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}
.page-about .about-flow__head {
  margin-bottom: 0;
}
.page-about .about-flow__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
}
.page-about .about-flow__step {
  position: relative;
  padding: clamp(16px, 2.2vw, 24px) 0 clamp(16px, 2.2vw, 24px) 66px;
  border-bottom: 1px solid var(--about-line-paper);
}
.page-about .about-flow__step:first-child {
  border-top: 1px solid var(--about-line-paper);
}
.page-about .about-flow__index {
  position: absolute;
  left: 0;
  top: clamp(16px, 2.2vw, 24px);
  font-family: var(--bb-mono);
  font-size: var(--bb-fs-24);
  font-weight: 700;
  color: var(--bb-red);
  letter-spacing: 0.04em;
}
.page-about .about-flow__step h3 {
  margin: 0 0 8px;
  font-size: var(--bb-fs-18);
  font-weight: 800;
  color: var(--bb-text);
}
.page-about .about-flow__step p {
  margin: 0;
  font-size: var(--bb-fs-18);
  line-height: 1.85;
  color: rgba(43, 47, 54, 0.76);
}

/* ============ 数据档案 ============ */
.page-about .about-archive__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  align-items: start;
}
.page-about .about-archive__media {
  margin: 0;
  border: 1px solid var(--about-line-dark);
}
.page-about .about-archive__body p {
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  font-size: var(--bb-fs-18);
  line-height: 1.85;
  color: rgba(245, 242, 236, 0.8);
}
.page-about .about-archive__meta {
  margin: 0;
  border-top: 1px solid var(--about-line-dark);
}
.page-about .about-archive__row {
  display: grid;
  grid-template-columns: minmax(80px, 110px) 1fr;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px dashed rgba(245, 242, 236, 0.14);
}
.page-about .about-archive__row dt {
  font-size: var(--bb-fs-12);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bb-gold-light);
  padding-top: 3px;
}
.page-about .about-archive__row dd {
  margin: 0;
  font-family: var(--bb-mono);
  font-size: var(--bb-fs-14);
  letter-spacing: 0.02em;
  color: var(--bb-paper);
}

/* ============ 覆盖范围 ============ */
.page-about .about-coverage__media {
  margin: 0 0 var(--about-gap);
  border: 1px solid var(--about-line-paper);
}
.page-about .about-coverage__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap-sm);
}
.page-about .about-coverage__cell {
  padding: clamp(18px, 2.4vw, 28px);
  background: rgba(43, 47, 54, 0.045);
  border-left: 3px solid var(--bb-gold);
}
.page-about .about-coverage__num {
  display: block;
  font-family: var(--bb-mono);
  font-size: clamp(2.2rem, 4.6vw, 3.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--bb-red);
}
.page-about .about-coverage__unit {
  font-size: 0.45em;
  margin-left: 4px;
  color: var(--bb-text);
}
.page-about .about-coverage__label {
  display: block;
  margin-top: 8px;
  font-size: var(--bb-fs-12);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(43, 47, 54, 0.6);
}
.page-about .about-coverage__cell p {
  margin: 12px 0 0;
  font-size: var(--bb-fs-14);
  line-height: 1.8;
  color: rgba(43, 47, 54, 0.72);
}

/* ============ 合作生态 ============ */
.page-about .about-partners__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap-sm);
}
.page-about .about-partners__card {
  padding: clamp(20px, 2.6vw, 30px);
  background: rgba(14, 17, 22, 0.5);
  border: 1px solid var(--about-line-dark);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}
.page-about .about-partners__card h3 {
  margin: 0 0 10px;
  font-size: var(--bb-fs-18);
  font-weight: 800;
  color: var(--bb-paper);
  display: flex;
  align-items: center;
  gap: 10px;
}
.page-about .about-partners__card h3::before {
  content: "";
  width: 10px;
  height: 10px;
  background: var(--bb-red);
  flex: 0 0 auto;
}
.page-about .about-partners__card p {
  margin: 0;
  font-size: var(--bb-fs-14);
  line-height: 1.85;
  color: rgba(245, 242, 236, 0.74);
}

/* ============ 长期读者 ============ */
.page-about .about-stable__wrap {
  max-width: var(--bb-wrap);
}
.page-about .about-stable__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}
.page-about .about-stable__col h3 {
  margin: 0 0 16px;
  font-size: var(--bb-fs-24);
  font-weight: 800;
  color: var(--bb-text);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--bb-red);
  display: inline-block;
}
.page-about .about-stable__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-stable__list li {
  padding: 12px 0;
  border-bottom: 1px dashed var(--about-line-paper);
  font-size: var(--bb-fs-18);
  line-height: 1.8;
  color: rgba(43, 47, 54, 0.78);
}
.page-about .about-stable__list li:last-child {
  border-bottom: 0;
}
.page-about .about-stable__k {
  display: inline-block;
  margin-right: 10px;
  padding: 2px 8px;
  font-size: var(--bb-fs-12);
  letter-spacing: 0.1em;
  color: var(--bb-paper);
  background: var(--bb-ink);
  border-left: 3px solid var(--bb-gold);
}
.page-about .about-stable__meta {
  margin: 0;
  border-top: 1px solid var(--about-line-paper);
}
.page-about .about-stable__row {
  display: grid;
  grid-template-columns: minmax(72px, 96px) 1fr;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--about-line-paper);
  align-items: baseline;
}
.page-about .about-stable__row dt {
  font-size: var(--bb-fs-12);
  letter-spacing: 0.12em;
  color: rgba(43, 47, 54, 0.58);
}
.page-about .about-stable__row dd {
  margin: 0;
  font-family: var(--bb-mono);
  font-size: var(--bb-fs-14);
  letter-spacing: 0.02em;
  color: var(--bb-text);
  word-break: break-word;
}
.page-about .about-stable__link {
  color: var(--bb-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .about-stable__link:hover {
  color: var(--bb-red);
}
.page-about .about-stable__note {
  margin: clamp(16px, 2.2vw, 22px) 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--bb-gold);
  font-size: var(--bb-fs-14);
  line-height: 1.8;
  color: rgba(43, 47, 54, 0.68);
}

/* ============ 响应式 ============ */
@media (min-width: 640px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-team__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-coverage__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-partners__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-stable__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-timeline__item {
    grid-template-columns: 150px 1fr;
    gap: clamp(20px, 3vw, 40px);
    padding-left: 40px;
    padding-bottom: clamp(36px, 5vw, 64px);
  }
  .page-about .about-timeline__year {
    position: sticky;
    top: 96px;
    align-self: start;
  }
  .page-about .about-timeline::before {
    left: 7px;
  }
  .page-about .about-timeline__dot {
    top: 12px;
  }
  .page-about .about-flow__inner {
    grid-template-columns: minmax(240px, 4fr) minmax(0, 8fr);
    gap: var(--about-gap-lg);
    align-items: start;
  }
  .page-about .about-flow__head {
    position: sticky;
    top: 96px;
  }
  .page-about .about-flow__step {
    padding-left: 84px;
  }
  .page-about .about-flow__index {
    font-size: var(--bb-fs-32);
  }
  .page-about .about-archive__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--about-gap-lg);
  }
  .page-about .about-partners__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 639px) {
  .page-about .about-hero__title {
    font-size: clamp(1.7rem, 8vw, 2.3rem);
  }
  .page-about .about-hero__lede {
    font-size: var(--bb-fs-14);
    line-height: 1.85;
  }
  .page-about .about-head__text,
  .page-about .about-timeline__body p,
  .page-about .about-flow__step p,
  .page-about .about-stable__list li {
    font-size: var(--bb-fs-14);
  }
  .page-about .about-archive__row,
  .page-about .about-stable__row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
  .page-about .about-timeline__num {
    font-size: var(--bb-fs-24);
  }
  .page-about .about-history__media .bb-media__cap,
  .page-about .about-coverage__media .bb-media__cap,
  .page-about .about-archive__media .bb-media__cap {
    font-size: var(--bb-fs-12);
  }
}