/* ==========================================================
   品牌愿景 /mission/ · 页面专属样式（作用域 .page-about）
   ========================================================== */

.page-about {
  --ab-band: clamp(3.5rem, 9vw, 7rem);
  --ab-hair: 1px solid rgba(200, 210, 221, 0.24);
  background: var(--c-night);
  color: var(--c-ivory);
  overflow-x: clip;
}

.page-about .index-mark {
  margin: 0;
}

.page-about .ab-h2 {
  margin: 0.75rem 0 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(2rem, 5.6vw, 4rem);
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--c-ivory);
}

.page-about .ab-sub {
  margin: 1.1rem 0 0;
  max-width: 42rem;
  color: var(--c-steel);
  font-size: clamp(1rem, 1.35vw, 1.1rem);
  line-height: 1.85;
}

.page-about .ab-head {
  max-width: 48rem;
}

/* ---------- 首屏 ---------- */

.page-about .ab-open {
  position: relative;
  padding: clamp(2.5rem, 7vw, 5.5rem) 0 clamp(3.5rem, 9vw, 7rem);
  background:
    radial-gradient(115% 85% at 88% -10%, rgba(14, 58, 60, 0.9) 0%, rgba(10, 26, 47, 0) 62%),
    var(--c-night);
  overflow: hidden;
}

.page-about .ab-open::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -45%;
  width: min(60vw, 620px);
  aspect-ratio: 1 / 1;
  transform: rotate(-14deg);
  background-image: radial-gradient(rgba(200, 210, 221, 0.16) 1.2px, transparent 1.2px);
  background-size: 15px 15px;
  pointer-events: none;
}

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

.page-about .ab-open .breadcrumb {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .ab-open__mark {
  color: var(--c-orange);
}

.page-about .ab-open__title {
  margin: 0.9rem 0 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(2.85rem, 11vw, 7rem);
  line-height: 0.88;
  letter-spacing: -0.035em;
}

.page-about .ab-open__title span {
  display: block;
}

.page-about .ab-open__accent {
  color: var(--c-orange);
}

.page-about .ab-open__body {
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  display: grid;
  gap: 2rem;
}

.page-about .ab-open__lede {
  margin: 0;
  max-width: 38rem;
  color: var(--c-steel);
  font-size: clamp(1.02rem, 1.45vw, 1.15rem);
  line-height: 1.85;
}

.page-about .ab-facts {
  margin: 0;
  padding-top: 1.1rem;
  border-top: var(--ab-hair);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
}

.page-about .ab-facts > div {
  display: grid;
  gap: 0.3rem;
}

.page-about .ab-facts dt {
  font-family: var(--f-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-steel);
}

.page-about .ab-facts dd {
  margin: 0;
  font-family: var(--f-mono);
  font-size: clamp(1.05rem, 2.2vw, 1.5rem);
  font-variant-numeric: tabular-nums;
  color: var(--c-ivory);
}

@media (min-width: 900px) {
  .page-about .ab-open__body {
    grid-template-columns: minmax(0, 34rem) minmax(0, 1fr);
    gap: clamp(2rem, 6vw, 5rem);
    align-items: end;
  }
}

/* ---------- 发展脉络时间轴 ---------- */

.page-about .ab-timeline {
  padding: var(--ab-band) 0;
  background: linear-gradient(180deg, var(--c-night) 0%, var(--c-deep) 100%);
}

.page-about .ab-track {
  position: relative;
  margin: clamp(2.75rem, 6vw, 4.5rem) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: clamp(2.5rem, 6vw, 4rem);
}

.page-about .ab-track::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.9rem;
  bottom: 0.9rem;
  width: 2px;
  background: linear-gradient(180deg, var(--c-orange) 0%, var(--c-green) 52%, rgba(200, 210, 221, 0.18) 100%);
}

.page-about .ab-node {
  position: relative;
  padding-left: 1.75rem;
  display: grid;
  gap: 0.35rem;
  scroll-margin-top: 7rem;
}

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 0.75rem;
  width: 12px;
  height: 12px;
  background: var(--c-silver);
  box-shadow: 0 0 0 4px rgba(10, 26, 47, 0.9);
  transition: background 0.25s var(--ease);
}

.page-about .ab-node:target::before,
.page-about .ab-node:hover::before {
  background: var(--c-orange);
}

.page-about .ab-node__year {
  display: inline-block;
  font-family: var(--f-display);
  font-weight: 200;
  font-size: clamp(2.75rem, 9vw, 5.25rem);
  line-height: 0.85;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: rgba(143, 160, 181, 0.72);
  text-decoration: none;
  transition: color 0.25s var(--ease);
}

.page-about .ab-node__year:hover,
.page-about .ab-node__year:focus-visible,
.page-about .ab-node:target .ab-node__year {
  color: var(--c-orange);
}

.page-about .ab-node__body {
  display: grid;
  gap: 0.2rem;
}

.page-about .ab-node__title {
  margin: 0.4rem 0 0;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.25rem, 2.7vw, 1.85rem);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--c-ivory);
}

.page-about .ab-node__text {
  margin: 0.7rem 0 0;
  max-width: 38rem;
  color: var(--c-steel);
  line-height: 1.85;
}

.page-about .ab-node__media {
  margin: 1.6rem 0 0;
  max-width: 31rem;
}

@media (min-width: 820px) {
  .page-about .ab-node {
    grid-template-columns: minmax(0, 13rem) minmax(0, 1fr);
    gap: 3rem;
    padding-left: 3rem;
    align-items: start;
  }

  .page-about .ab-node::before {
    left: -6px;
    top: 0.85rem;
    width: 14px;
    height: 14px;
  }
}

/* ---------- 数据章节 ---------- */

.page-about .ab-method {
  padding: var(--ab-band) 0;
  background: var(--c-deep);
}

.page-about .ab-method__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
}

.page-about .ab-method__media {
  margin: 0;
  max-width: 40rem;
}

.page-about .ab-source {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.9rem;
}

.page-about .ab-source li {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 0.75rem;
  align-items: baseline;
  padding-top: 0.9rem;
  border-top: 1px solid rgba(200, 210, 221, 0.2);
}

.page-about .ab-source__no {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--c-orange);
}

.page-about .ab-source p {
  margin: 0;
  color: var(--c-steel);
  line-height: 1.8;
}

.page-about .ab-body {
  margin: clamp(1.5rem, 3vw, 2rem) 0 0;
  max-width: 38rem;
  color: var(--c-steel);
  line-height: 1.85;
}

.page-about .ab-quote {
  margin: clamp(2rem, 4vw, 2.75rem) 0 0;
  max-width: 26rem;
  padding: 1.3rem 1.5rem;
  background: rgba(10, 26, 47, 0.5);
  border: var(--hard-line);
  box-shadow: var(--hard-shadow);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.1rem, 2.1vw, 1.45rem);
  line-height: 1.35;
  color: var(--c-ivory);
}

@media (min-width: 900px) {
  .page-about .ab-method__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: clamp(2.5rem, 6vw, 5rem);
    align-items: start;
  }
}

/* ---------- 团队 ---------- */

.page-about .ab-team {
  padding: var(--ab-band) 0;
  background: linear-gradient(168deg, var(--c-deep) 0%, var(--c-deep) 52%, var(--c-violet) 100%);
}

.page-about .ab-team__grid {
  margin-top: clamp(2.5rem, 6vw, 4rem);
  display: grid;
  gap: clamp(2rem, 4vw, 2.5rem);
}

.page-about .ab-crew {
  padding-top: 1.15rem;
  border-top: 2px solid var(--c-orange);
}

.page-about .ab-crew:nth-child(2) {
  border-top-color: var(--c-green);
}

.page-about .ab-crew:nth-child(3) {
  border-top-color: rgba(200, 210, 221, 0.55);
}

.page-about .ab-crew__num {
  margin: 0;
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--c-steel);
}

.page-about .ab-crew h3 {
  margin: 0.6rem 0 0;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.3rem, 2.5vw, 1.65rem);
  line-height: 1.1;
  color: var(--c-ivory);
}

.page-about .ab-crew__text {
  margin: 0.7rem 0 0;
  color: var(--c-steel);
  line-height: 1.8;
}

.page-about .ab-crew__text a {
  color: var(--c-orange);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (min-width: 860px) {
  .page-about .ab-team__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(2rem, 3.5vw, 3.5rem);
  }

  .page-about .ab-crew:nth-child(2) {
    transform: translateY(2.5rem);
  }

  .page-about .ab-crew:nth-child(3) {
    transform: translateY(1.15rem);
  }
}

/* ---------- 天津 ---------- */

.page-about .ab-tianjin {
  padding: var(--ab-band) 0;
  background: var(--c-violet);
}

.page-about .ab-tianjin .ab-h2 {
  color: var(--c-ivory);
}

.page-about .ab-tianjin__banner {
  margin: clamp(2rem, 5vw, 3rem) 0 0;
  aspect-ratio: 16 / 9;
}

.page-about .ab-tianjin__cols {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  display: grid;
  gap: 2rem;
}

.page-about .ab-tianjin__text p {
  margin: 0 0 1.1rem;
  max-width: 42rem;
  color: rgba(244, 241, 234, 0.8);
  line-height: 1.85;
}

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

.page-about .ab-tianjin__stats {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1.1rem;
}

.page-about .ab-tianjin__stats li {
  display: grid;
  gap: 0.15rem;
  padding-top: 0.85rem;
  border-top: 1px solid rgba(244, 241, 234, 0.3);
}

.page-about .ab-stat__num {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--c-green);
}

.page-about .ab-tianjin__stats li:nth-child(2) .ab-stat__num {
  color: var(--c-orange);
}

.page-about .ab-tianjin__stats li:nth-child(3) .ab-stat__num {
  color: var(--c-silver);
}

.page-about .ab-stat__label {
  color: rgba(244, 241, 234, 0.72);
  font-size: 0.9375rem;
}

@media (min-width: 800px) {
  .page-about .ab-tianjin__banner {
    aspect-ratio: 21 / 9;
  }
}

@media (min-width: 900px) {
  .page-about .ab-tianjin__cols {
    grid-template-columns: minmax(0, 1fr) minmax(0, 22rem);
    gap: clamp(2.5rem, 6vw, 5rem);
    align-items: start;
  }
}

/* ---------- 下一步 ---------- */

.page-about .ab-next {
  padding: var(--ab-band) 0;
  background: var(--c-ivory);
  color: var(--c-night);
}

.page-about .ab-next .ab-h2 {
  color: var(--c-night);
}

.page-about .ab-next .ab-sub {
  color: rgba(10, 26, 47, 0.72);
}

.page-about .ab-next__list {
  margin: clamp(2rem, 5vw, 3rem) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-next__list li {
  display: grid;
  gap: 0.5rem;
  padding: clamp(1.25rem, 3vw, 1.75rem) 0;
  border-top: 2px solid rgba(10, 26, 47, 0.14);
}

.page-about .ab-next__list li:last-child {
  border-bottom: 2px solid rgba(10, 26, 47, 0.14);
}

.page-about .ab-next__list h3 {
  margin: 0;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  line-height: 1.15;
  color: var(--c-night);
}

.page-about .ab-next__list p {
  margin: 0;
  max-width: 42rem;
  color: rgba(10, 26, 47, 0.72);
  line-height: 1.8;
}

.page-about .ab-cta {
  margin-top: clamp(2rem, 5vw, 3rem);
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.page-about .ab-next .btn {
  color: var(--c-night);
  border-color: var(--c-night);
  box-shadow: 5px 5px 0 rgba(10, 26, 47, 0.2);
}

.page-about .ab-next .btn:hover,
.page-about .ab-next .btn:focus-visible {
  color: var(--c-orange);
  box-shadow: 5px 5px 0 rgba(255, 106, 31, 0.6);
}

.page-about .ab-next .btn--solid,
.page-about .ab-next .btn--solid:hover,
.page-about .ab-next .btn--solid:focus-visible {
  color: var(--c-night);
}

@media (min-width: 760px) {
  .page-about .ab-next__list li {
    grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
    gap: 2.5rem;
    align-items: baseline;
  }
}

/* ---------- 窄屏收尾 ---------- */

@media (max-width: 560px) {
  .page-about .ab-facts {
    gap: 0.7rem;
  }

  .page-about .ab-quote {
    padding: 1.1rem 1.2rem;
  }

  .page-about .ab-node__media {
    max-width: 100%;
  }
}