/* =========================================================
   page-about · 品牌使命
   非对称双栏 + 纵向时间刻度 + 数字条
   ========================================================= */

.page-about {
  --about-rail: 132px;
  --about-gap: clamp(20px, 3.2vw, 44px);
  --about-cut: 8deg;
  display: block;
}

/* ---------- 通用小部件 ---------- */

.page-about .tlink {
  display: inline-block;
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 224, 184, .45);
  padding-bottom: 2px;
  font-size: var(--fs-3);
  transition: border-color .2s ease, color .2s ease;
}

.page-about .tlink:hover,
.page-about .tlink:focus-visible {
  color: var(--orange-hi);
  border-bottom-color: var(--orange-hi);
}

.page-about .about-sec-head {
  max-width: 64ch;
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .about-sec-head__lede {
  margin: 14px 0 0;
  color: var(--steel);
  font-size: var(--fs-3);
  line-height: 1.85;
}

/* ---------- 首屏 ---------- */

.page-about .about-mast {
  padding: clamp(24px, 4vw, 48px) 0 clamp(36px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(160deg, rgba(18, 58, 50, .55) 0%, rgba(7, 26, 22, 0) 58%),
    var(--ink);
}

.page-about .about-mast__grid {
  display: grid;
  gap: clamp(26px, 4vw, 52px);
  margin-top: clamp(22px, 3.5vw, 40px);
}

.page-about .about-mast__lede > .lede {
  margin-top: 20px;
}

.page-about .about-mast__facts {
  margin: clamp(26px, 4vw, 40px) 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-mast__facts > div {
  background: var(--ink);
  padding: 14px 16px 16px;
}

.page-about .about-mast__facts dt {
  margin: 0;
  font-family: var(--mono);
  font-size: var(--fs-1);
  letter-spacing: .1em;
  color: var(--steel);
}

.page-about .about-mast__facts dd {
  margin: 8px 0 0;
  font-family: var(--mono);
  font-size: clamp(26px, 5vw, var(--fs-6));
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .about-mast__media {
  margin: 0;
  border-left: 3px solid var(--orange);
}

@media (min-width: 880px) {
  .page-about .about-mast__grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    align-items: end;
  }
  .page-about .about-mast__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 发展脉络（纵向时间刻度） ---------- */

.page-about .about-stage {
  padding: clamp(44px, 6vw, 84px) 0 clamp(36px, 5vw, 64px);
  background: var(--ink);
}

.page-about .about-axis {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: axis;
}

.page-about .about-axis__item {
  position: relative;
  display: grid;
  gap: 12px;
  padding: 24px 0 26px;
  border-top: 1px solid var(--line);
}

.page-about .about-axis__item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-axis__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: -1px;
  width: 0;
  height: 1px;
  background: var(--orange);
  transition: width .45s cubic-bezier(.22, .61, .36, 1);
}

.page-about .about-axis__item.is-active::after {
  width: 84px;
}

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

.page-about .about-axis__year {
  font-family: var(--mono);
  font-size: clamp(26px, 6vw, 38px);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1;
  color: var(--steel);
  font-variant-numeric: tabular-nums;
  transition: color .3s ease;
}

.page-about .about-axis__item.is-active .about-axis__year {
  color: var(--orange);
}

.page-about .about-axis__tag {
  font-family: var(--mono);
  font-size: var(--fs-1);
  letter-spacing: .14em;
  color: var(--teal);
  border: 1px solid rgba(0, 224, 184, .4);
  padding: 3px 8px;
  white-space: nowrap;
}

.page-about .about-axis__body h3 {
  margin: 0 0 10px;
}

.page-about .about-axis__body p {
  margin: 0;
  color: var(--text);
  max-width: 62ch;
}

@media (min-width: 880px) {
  .page-about .about-axis__item {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    padding: 34px 0 38px;
  }
  .page-about .about-axis__head {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    position: sticky;
    top: calc(var(--bar-h) + 20px);
  }
}

/* ---------- 团队与质检 ---------- */

.page-about .about-team {
  padding: clamp(44px, 6vw, 84px) 0;
}

.page-about .about-team__grid {
  align-items: start;
}

.page-about .about-team__lede {
  color: var(--text);
  font-size: var(--fs-4);
  line-height: 1.85;
  max-width: 46ch;
  margin: 16px 0 0;
}

.page-about .about-mix {
  list-style: none;
  margin: clamp(28px, 4vw, 40px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-mix__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 56px;
  align-items: center;
  gap: 10px 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-mix__label {
  grid-column: 1 / 2;
  font-size: var(--fs-3);
  color: var(--text);
}

.page-about .about-mix__track {
  grid-column: 1 / 2;
  grid-row: 2;
  display: block;
  height: 3px;
  background: rgba(143, 166, 184, .18);
  overflow: hidden;
}

.page-about .about-mix__fill {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--teal), var(--orange));
}

.page-about .about-mix__row:nth-child(1) .about-mix__fill { width: 43%; }
.page-about .about-mix__row:nth-child(2) .about-mix__fill { width: 21%; }
.page-about .about-mix__row:nth-child(3) .about-mix__fill { width: 19%; }
.page-about .about-mix__row:nth-child(4) .about-mix__fill { width: 17%; }

.page-about .about-mix__val {
  grid-column: 2 / 3;
  grid-row: 1 / 3;
  align-self: center;
  text-align: right;
  font-family: var(--mono);
  font-size: clamp(22px, 4vw, var(--fs-5));
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team__aside {
  margin: clamp(30px, 4vw, 0px) 0 0;
  padding-left: 0;
}

.page-about .about-team__aside .annot {
  margin-top: 16px;
  display: block;
  border-left: 2px solid var(--teal);
  padding-left: 14px;
}

@media (min-width: 880px) {
  .page-about .about-team__aside {
    margin-top: 6px;
    padding-left: var(--about-gap);
    border-left: 1px solid var(--line);
  }
}

/* ---------- 数据底座 ---------- */

.page-about .about-sources {
  padding: clamp(44px, 6vw, 84px) 0;
  background: var(--ink);
}

.page-about .about-sources__grid {
  align-items: start;
}

.page-about .about-sources__lede {
  margin: 16px 0 0;
  color: var(--text);
  font-size: var(--fs-4);
  line-height: 1.85;
  max-width: 48ch;
}

.page-about .about-sources__text p {
  max-width: 52ch;
}

.page-about .about-sources__link {
  margin-top: 22px;
}

.page-about .about-sources__stats {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 30px;
}

.page-about .about-sources__stats .kpi {
  background: var(--board);
  padding: 20px 18px 22px;
  display: block;
}

.page-about .about-sources__stats .kpi__num {
  display: block;
  font-size: clamp(30px, 6vw, var(--fs-7));
}

.page-about .about-sources__stats .kpi__label {
  display: block;
  margin-top: 10px;
  line-height: 1.6;
}

@media (min-width: 880px) {
  .page-about .about-sources__stats {
    margin-top: 8px;
  }
}

/* ---------- 覆盖与对象 ---------- */

.page-about .about-reach {
  padding: clamp(44px, 6vw, 84px) 0;
}

.page-about .about-reach__grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-reach__card {
  background: var(--board);
  padding: clamp(20px, 3vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 12px;
  border-left: 3px solid var(--zone);
  transition: border-color .25s ease, background .25s ease;
}

.page-about .about-reach__card:hover {
  border-left-color: var(--orange);
  background: var(--zone);
}

.page-about .about-reach__card .card__title {
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.5;
}

.page-about .about-reach__card p {
  margin: 0;
  color: var(--text);
  font-size: var(--fs-3);
  line-height: 1.8;
}

.page-about .about-reach__card .card__meta {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: var(--fs-1);
  letter-spacing: .06em;
  color: var(--teal);
}

@media (min-width: 720px) {
  .page-about .about-reach__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .about-reach__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 赛场夜读 ---------- */

.page-about .about-read {
  padding: clamp(44px, 6vw, 84px) 0;
  background:
    linear-gradient(200deg, rgba(18, 58, 50, .5) 0%, rgba(7, 26, 22, 0) 62%),
    var(--ink);
}

.page-about .about-read__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-read__media {
  margin: 0;
  border-top: 3px solid var(--teal);
}

.page-about .about-read__text p {
  max-width: 54ch;
}

.page-about .about-read__link {
  margin-top: 22px;
}

@media (min-width: 940px) {
  .page-about .about-read__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    align-items: start;
  }
  .page-about .about-read__media {
    position: sticky;
    top: calc(var(--bar-h) + 32px);
  }
}

/* ---------- 合作路径 ---------- */

.page-about .about-coop {
  padding: clamp(44px, 6vw, 84px) 0;
}

.page-about .about-paths {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-paths__item {
  background: var(--board);
  padding: clamp(22px, 3vw, 30px) clamp(18px, 3vw, 28px);
  display: grid;
  gap: 10px;
  position: relative;
  transition: background .25s ease;
}

.page-about .about-paths__item:hover {
  background: var(--zone);
}

.page-about .about-paths__no {
  font-family: var(--mono);
  font-size: var(--fs-2);
  letter-spacing: .18em;
  color: var(--orange);
}

.page-about .about-paths__item h3 {
  margin: 0;
}

.page-about .about-paths__item p {
  margin: 0;
  color: var(--text);
  font-size: var(--fs-3);
  line-height: 1.8;
  max-width: 40ch;
}

.page-about .about-coop__foot {
  margin-top: clamp(28px, 4vw, 44px);
  padding-top: 24px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 18px;
  align-items: center;
}

.page-about .about-coop__foot p {
  margin: 0;
  color: var(--steel);
  font-size: var(--fs-3);
  max-width: 46ch;
}

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

@media (min-width: 720px) {
  .page-about .about-paths {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .about-coop__foot {
    grid-template-columns: minmax(0, 1fr) auto;
    justify-content: space-between;
  }
}

/* ---------- 收口 ---------- */

.page-about .about-close {
  padding: clamp(36px, 5vw, 64px) 0 clamp(48px, 7vw, 96px);
  background: var(--ink);
}

.page-about .about-close__inner {
  display: grid;
  gap: 24px;
  padding: clamp(24px, 4vw, 40px);
  border: 1px solid var(--line-strong);
  border-left: 4px solid var(--orange);
  background: var(--board);
}

.page-about .about-close__inner p {
  margin: 14px 0 0;
  color: var(--steel);
  font-size: var(--fs-3);
  line-height: 1.85;
  max-width: 50ch;
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-self: center;
}

@media (min-width: 880px) {
  .page-about .about-close__inner {
    grid-template-columns: minmax(0, 1.4fr) auto;
    align-items: center;
  }
  .page-about .about-close__actions {
    flex-direction: column;
    align-items: stretch;
    min-width: 210px;
  }
}

/* ---------- 窄屏防溢出 ---------- */

@media (max-width: 560px) {
  .page-about .about-mast__facts > div {
    padding: 12px 12px 14px;
  }
  .page-about .about-coop__actions .btn,
  .page-about .about-close__actions .btn {
    width: 100%;
    text-align: center;
  }
}

/* ---------- 动效收敛 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-axis__item::after,
  .page-about .about-axis__year,
  .page-about .about-reach__card,
  .page-about .about-paths__item {
    transition: none;
  }
}
</main>