/* ============================================================
   品牌文化页 — page-about
   骨架：纵向时间线 + 团队色块分区 + 横向流程条
   节奏：慢（开篇）— 密（团队 / 流程）— 慢（收束）
   ============================================================ */

.page-about {
  --about-y: clamp(44px, 7vw, 86px);
  --about-line: rgba(13, 17, 23, .10);
  background: var(--snow);
  color: var(--ink);
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(18px, 3vw, 30px);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--grey);
}

.page-about .crumbs a {
  color: var(--teal);
  text-decoration: none;
}

.page-about .crumbs a:hover {
  color: var(--crimson);
  text-decoration: underline;
}

.page-about .crumbs__sep {
  color: rgba(13, 17, 23, .28);
}

/* ---------- 通用栏目标签与标题 ---------- */
.page-about .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--crimson);
}

.page-about .eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

.page-about .on-dark .eyebrow {
  color: var(--gold);
}

.page-about h2 {
  margin: 0 0 14px;
  font-size: clamp(23px, 3.4vw, 36px);
  line-height: 1.24;
  letter-spacing: -.02em;
  font-weight: 900;
}

.page-about .on-dark h2,
.page-about .on-dark .section-head__title {
  color: var(--snow);
}

.page-about .on-dark .section-head__link {
  color: var(--gold);
}

.page-about .on-dark .section-head__link:hover {
  color: var(--gold-soft);
}

/* ---------- 首屏 ---------- */
.page-about .section-hero {
  padding: clamp(26px, 5vw, 56px) 0 clamp(30px, 5vw, 54px);
  background:
    radial-gradient(110% 120% at 100% 0%, rgba(227, 168, 46, .20), rgba(227, 168, 46, 0) 58%),
    radial-gradient(80% 100% at 0% 100%, rgba(14, 95, 92, .10), rgba(14, 95, 92, 0) 62%),
    var(--snow);
  border-bottom: 1px solid rgba(13, 17, 23, .08);
}

.page-about .hero-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

@media (min-width: 920px) {
  .page-about .hero-grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
}

.page-about h1 {
  margin: 8px 0 18px;
  font-size: clamp(29px, 5.4vw, 52px);
  line-height: 1.16;
  letter-spacing: -.02em;
  font-weight: 900;
  max-width: 15em;
}

.page-about .hero-copy__lead {
  margin: 0;
  max-width: 58ch;
  font-size: clamp(15.5px, 1.6vw, 17px);
  line-height: 1.82;
  color: #2b2f36;
}

.page-about .hero-copy__tail {
  margin: 14px 0 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--grey);
}

/* 首屏概览面板 */
.page-about .hero-board {
  padding: 22px 22px 10px;
  background:
    radial-gradient(120% 130% at 100% 0%, rgba(28, 138, 133, .22), rgba(28, 138, 133, 0) 70%),
    var(--ink);
  border: 1px solid var(--teal);
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-1);
}

.page-about .hero-board__title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--teal-light);
}

.page-about .hero-board__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .hero-board__list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-top: 1px solid rgba(28, 138, 133, .30);
}

.page-about .hero-board__num {
  min-width: 4.6em;
  font-size: 23px;
  font-weight: 700;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .hero-board__label {
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(250, 247, 241, .86);
}

/* ---------- 发展历程时间线 ---------- */
.page-about .section-timeline {
  padding: var(--about-y) 0 0;
}

.page-about .tl-media {
  margin: 0 0 clamp(30px, 5vw, 52px);
}

.page-about .tl {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 51px;
  top: 12px;
  bottom: 14px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--crimson) 0%, var(--gold) 48%, var(--teal-light) 100%);
  opacity: .7;
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 24px 78px;
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
}

.page-about .tl__year {
  position: absolute;
  left: 0;
  top: 3px;
  width: 40px;
  text-align: right;
  font-size: 14px;
  font-weight: 700;
  color: var(--crimson);
  letter-spacing: .02em;
}

.page-about .tl__dot {
  position: absolute;
  left: 45px;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--snow);
  border: 3px solid var(--crimson);
  box-shadow: 0 0 0 4px rgba(183, 39, 31, .10);
}

.page-about .tl__card {
  padding: 17px 20px 15px;
  background: #fff;
  border: 1px solid rgba(13, 17, 23, .09);
  border-radius: var(--r-lg);
  transition: transform .18s ease-out, box-shadow .18s ease-out, border-color .18s ease-out;
}

.page-about .tl__item:hover .tl__card,
.page-about .tl__item:focus-within .tl__card {
  transform: translateY(-2px);
  border-color: rgba(183, 39, 31, .34);
  box-shadow: var(--shadow-2);
}

.page-about .tl__card:focus-visible {
  outline: var(--ring);
  outline-offset: 3px;
}

.page-about .tl__title {
  margin: 0 0 8px;
  font-size: 17.5px;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .tl__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: #3a3f47;
}

.page-about .tl__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  max-height: 0;
  margin-top: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height .18s ease-out, opacity .18s ease-out, margin-top .18s ease-out;
}

.page-about .tl__item:hover .tl__tags,
.page-about .tl__item:focus-within .tl__tags {
  max-height: 92px;
  margin-top: 12px;
  opacity: 1;
}

@media (max-width: 640px) {
  .page-about .tl__tags {
    max-height: none;
    margin-top: 12px;
    opacity: 1;
  }
}

/* ---------- 团队分工（靛紫深色区） ---------- */
.page-about .section-crew {
  padding: var(--about-y) 0;
  background:
    radial-gradient(100% 130% at 100% 0%, rgba(183, 39, 31, .34), rgba(183, 39, 31, 0) 58%),
    var(--indigo);
  color: var(--snow);
}

.page-about .section-crew .section-head__title {
  color: var(--snow);
}

.page-about .section-crew .section-head__link {
  color: var(--gold);
}

.page-about .crew-grid {
  display: grid;
  gap: clamp(20px, 3.5vw, 34px);
  margin-top: clamp(22px, 4vw, 38px);
}

@media (min-width: 940px) {
  .page-about .crew-grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
}

.page-about .crew-bar {
  display: flex;
  gap: 4px;
  height: 16px;
  margin-bottom: 26px;
}

.page-about .crew-bar__seg {
  display: block;
  min-width: 16px;
  border-radius: var(--pill);
}

.page-about .crew-bar__seg--ops { background: var(--crimson); }
.page-about .crew-bar__seg--eng { background: var(--teal-light); }
.page-about .crew-bar__seg--edit { background: var(--gold); }
.page-about .crew-bar__seg--cs { background: var(--snow); }

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

.page-about .crew-list__item {
  display: grid;
  grid-template-columns: 10px 1fr;
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid rgba(250, 247, 241, .16);
}

.page-about .crew-list__dot {
  width: 10px;
  height: 10px;
  margin-top: 7px;
  border-radius: 50%;
}

.page-about .crew-list__dot--ops { background: var(--crimson); }
.page-about .crew-list__dot--eng { background: var(--teal-light); }
.page-about .crew-list__dot--edit { background: var(--gold); }
.page-about .crew-list__dot--cs { background: var(--snow); }

.page-about .crew-list__item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--snow);
}

.page-about .crew-list__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(250, 247, 241, .76);
}

.page-about .crew-media {
  border-radius: var(--r-lg);
}

/* ---------- 数据流程（横向滑动条） ---------- */
.page-about .section-flow {
  padding: var(--about-y) 0;
  background: var(--snow);
}

.page-about .flow-lead {
  max-width: 64ch;
  margin: 0 0 clamp(20px, 3.5vw, 30px);
  font-size: 15.5px;
  line-height: 1.82;
  color: #3a3f47;
}

.page-about .gates {
  display: flex;
  gap: 14px;
  padding: 6px 2px 20px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .gates__item {
  flex: 0 0 78%;
  scroll-snap-align: start;
  padding: 20px 20px 22px;
  background:
    linear-gradient(160deg, rgba(14, 95, 92, .55), rgba(13, 17, 23, 0) 62%),
    var(--ink);
  border: 1px solid rgba(28, 138, 133, .55);
  border-radius: var(--r-lg);
  color: var(--snow);
}

@media (min-width: 700px) {
  .page-about .gates__item {
    flex: 0 0 300px;
  }
}

.page-about .gates__idx {
  display: inline-block;
  margin-bottom: 14px;
  padding: 3px 10px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--gold);
  border: 1px solid rgba(227, 168, 46, .5);
  border-radius: var(--pill);
}

.page-about .gates__item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 800;
}

.page-about .gates__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(250, 247, 241, .78);
}

.page-about .flow-media {
  margin: clamp(22px, 4vw, 36px) 0 0;
}

/* ---------- 用户规模与使用习惯 ---------- */
.page-about .section-users {
  padding: var(--about-y) 0;
  background:
    linear-gradient(180deg, rgba(247, 223, 163, .40), rgba(247, 223, 163, 0) 72%),
    var(--snow);
  border-top: 1px solid rgba(13, 17, 23, .06);
  border-bottom: 1px solid rgba(13, 17, 23, .06);
}

.page-about .users-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

@media (min-width: 940px) {
  .page-about .users-grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }
}

.page-about .users-copy__title {
  margin-bottom: 14px;
}

.page-about .users-copy p {
  margin: 0 0 12px;
  max-width: 52ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: #3a3f47;
}

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

.page-about .users-list li {
  padding: 18px 20px;
  background: #fff;
  border: 1px solid rgba(13, 17, 23, .08);
  border-left: 4px solid var(--gold);
  border-radius: var(--r-lg);
  transition: transform .18s ease-out, box-shadow .18s ease-out;
}

.page-about .users-list li:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-1);
}

.page-about .users-list h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
}

.page-about .users-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: #3a3f47;
}

/* ---------- 合作生态 ---------- */
.page-about .section-partner {
  padding: var(--about-y) 0;
}

.page-about .partner-lead {
  max-width: 64ch;
  margin: 0 0 clamp(20px, 3.5vw, 30px);
  font-size: 15.5px;
  line-height: 1.82;
  color: #3a3f47;
}

.page-about .partner-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .partner-stats li {
  display: grid;
  grid-template-columns: 4.4em 1fr;
  gap: 14px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .partner-stats__num {
  font-size: 26px;
  font-weight: 700;
  color: var(--crimson);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-stats__text {
  font-size: 15px;
  line-height: 1.74;
  color: #2b2f36;
}

/* ---------- 长期维护（靛紫收束） ---------- */
.page-about .section-ethos {
  padding: clamp(46px, 7vw, 90px) 0;
  background:
    radial-gradient(85% 120% at 0% 0%, rgba(14, 95, 92, .42), rgba(14, 95, 92, 0) 62%),
    var(--indigo);
  color: var(--snow);
}

.page-about .ethos-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

@media (min-width: 940px) {
  .page-about .ethos-grid {
    grid-template-columns: 8fr 4fr;
    align-items: end;
  }
}

.page-about .ethos-copy p {
  margin: 0 0 14px;
  max-width: 64ch;
  font-size: 15.5px;
  line-height: 1.84;
  color: rgba(250, 247, 241, .80);
}

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

.page-about .ethos-actions .btn--quiet {
  color: var(--snow);
  background: transparent;
  border: 1px solid rgba(250, 247, 241, .38);
}

.page-about .ethos-actions .btn--quiet:hover {
  color: var(--gold);
  border-color: var(--gold);
}

/* ---------- 窄屏微调 ---------- */
@media (max-width: 520px) {
  .page-about .tl::before {
    left: 39px;
  }

  .page-about .tl__item {
    padding-left: 62px;
    padding-bottom: 20px;
  }

  .page-about .tl__year {
    width: 30px;
    font-size: 12.5px;
  }

  .page-about .tl__dot {
    left: 33px;
    top: 5px;
  }

  .page-about .hero-board__num {
    min-width: 4em;
    font-size: 20px;
  }

  .page-about .partner-stats li {
    grid-template-columns: 3.4em 1fr;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tl__card,
  .page-about .tl__tags,
  .page-about .users-list li {
    transition: none;
  }

  .page-about .tl__item:hover .tl__card,
  .page-about .users-list li:hover {
    transform: none;
  }
}