.page-about {
  --about-rail-w: 212px;
  --about-gap: 52px;
  --about-section-pad: 62px;
}

/* ============ 首屏框景 ============ */
.page-about .about-hero {
  padding: 32px 0 0;
}

.page-about .about-hero__frame {
  position: relative;
  margin-top: 20px;
  padding: 42px 20px 34px;
  border: 1px solid var(--line-soft);
  background: var(--grad-frame);
  overflow: hidden;
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 9px;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 20px);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--accent) 0%, rgba(58, 92, 255, 0.45) 46%, transparent 100%);
  pointer-events: none;
}

.page-about .about-hero__eyebrow {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
}

.page-about .about-hero h1 {
  margin: 20px 0 0;
  max-width: 17em;
  font-size: clamp(30px, 6vw, 62px);
  font-weight: 300;
  line-height: 1.07;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: 44em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-dim);
}

.page-about .about-hero__meta {
  margin: 26px 0 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--text-dim);
}

/* ============ 全宽数据横条 ============ */
.page-about .about-stats {
  margin-top: 44px;
  background: var(--grad-bar);
  border-top: 1px solid var(--line-hair);
  border-bottom: 1px solid var(--line-hair);
}

.page-about .about-stats__inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 18px;
  padding-block: 30px;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-stat__figure {
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.page-about .about-stat__num {
  font-size: clamp(30px, 7vw, 44px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--accent);
}

.page-about .about-stat__unit {
  font-size: 13px;
  color: var(--text-dim);
}

.page-about .about-stat:nth-child(3) .about-stat__num {
  color: var(--accent-alt);
}

.page-about .about-stat__label {
  font-size: 13px;
  color: var(--text-dim);
  letter-spacing: 0.04em;
}

/* ============ 主体骨架 ============ */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  padding-top: 40px;
  padding-bottom: 40px;
}

/* ---- 章节索引（小屏横向滚动） ---- */
.page-about .about-rail {
  padding: 14px 0;
  margin-bottom: 4px;
  border-top: 1px solid var(--line-hair);
  border-bottom: 1px solid var(--line-hair);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__cap {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--text-dim);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
}

.page-about .about-rail__list a {
  display: inline-block;
  padding: 7px 14px;
  font-size: 13px;
  color: var(--text-dim);
  text-decoration: none;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--text);
  border-color: var(--accent);
  background: rgba(47, 230, 200, 0.08);
  outline: none;
}

/* ---- 区块 ---- */
.page-about .about-section {
  position: relative;
  z-index: 0;
  padding: var(--about-section-pad) 0;
  scroll-margin-top: 120px;
}

.page-about .about-section--organic::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  border-radius: 2px;
  background:
    radial-gradient(120% 85% at 4% 0%, rgba(11, 59, 58, 0.72) 0%, rgba(11, 59, 58, 0) 60%),
    radial-gradient(85% 70% at 100% 100%, rgba(58, 92, 255, 0.13) 0%, rgba(58, 92, 255, 0) 62%);
}

/* ============ 章节标题 ============ */
.page-about .sec-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: 14px;
  align-items: baseline;
  margin-bottom: 30px;
}

.page-about .sec-head__no {
  grid-row: span 2;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.page-about .sec-head__title {
  margin: 0;
  font-size: clamp(23px, 4.6vw, 40px);
  font-weight: 300;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .sec-head__lede {
  grid-column: 2;
  margin: 14px 0 0;
  max-width: 42em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ============ 双栏叙事 ============ */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

/* ============ 团队分工 ============ */
.page-about .team-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-hair);
}

.page-about .team-item {
  padding: 18px 0;
  border-bottom: 1px solid var(--line-hair);
  transition: background var(--dur) var(--ease);
}

.page-about .team-item:hover,
.page-about .team-item:focus {
  background: linear-gradient(90deg, rgba(47, 230, 200, 0.07), transparent 70%);
}

.page-about .team-item:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.page-about .team-item__head {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 12px;
}

.page-about .team-item__num {
  font-size: 22px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: -0.01em;
}

.page-about .team-item__name {
  font-size: 17px;
  color: var(--text);
}

.page-about .team-item__tag {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--text-dim);
}

.page-about .team-item__desc {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .media-frame--team,
.page-about .media-frame--partners,
.page-about .media-frame--history {
  margin: 0;
  border: 1px solid var(--line-soft);
  background: var(--bg-panel);
}

.page-about .media-frame--history {
  margin-bottom: 34px;
}

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

/* ============ 版本演进 ============ */
.page-about .phase-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .phase {
  position: relative;
  padding: 20px 0 20px 20px;
  border-left: 1px solid var(--line-soft);
}

.page-about .phase::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 28px;
  width: 7px;
  height: 7px;
  background: var(--accent);
}

.page-about .phase:last-child::before {
  background: var(--accent-alt);
}

.page-about .phase__gen {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--accent);
}

.page-about .phase__title {
  margin: 8px 0 0;
  font-size: 19px;
  font-weight: 400;
  line-height: 1.3;
  color: var(--text);
}

.page-about .phase__body {
  margin: 8px 0 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ============ 数据来源细线表 ============ */
.page-about .ledger {
  border-top: 1px solid var(--line-hair);
}

.page-about .ledger__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line-hair);
}

.page-about .ledger__key {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--accent);
}

.page-about .ledger__val strong {
  display: block;
  font-size: 17px;
  font-weight: 400;
  line-height: 1.4;
  color: var(--text);
}

.page-about .ledger__val p {
  margin: 8px 0 0;
  max-width: 46em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ============ 更新节奏横条 ============ */
.page-about .pulse-bar {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
  margin-top: 32px;
  padding: 24px 20px;
  border-left: 1px solid var(--line-hair);
  border-right: 1px solid var(--line-hair);
  background: var(--grad-bar);
}

.page-about .pulse-bar__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .pulse-bar__num {
  font-size: 20px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: -0.01em;
}

.page-about .pulse-bar__label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--text-dim);
}

.page-about .source-tail {
  margin: 28px 0 0;
  max-width: 46em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-dim);
}

.page-about .source-tail a,
.page-about .text-link {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 230, 200, 0.45);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .source-tail a:hover,
.page-about .text-link:hover {
  border-bottom-color: var(--accent);
  color: var(--text);
}

/* ============ 伙伴 ============ */
.page-about .partner-body {
  min-width: 0;
}

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

.page-about .partner-fact {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-hair);
}

.page-about .partner-fact__num {
  font-size: 22px;
  font-weight: 500;
  color: var(--accent-alt);
  line-height: 1.2;
}

.page-about .partner-fact__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .partner-fact__text strong {
  display: block;
  margin-bottom: 4px;
  font-size: 16px;
  font-weight: 400;
  color: var(--text);
}

.page-about .partner-note {
  margin: 22px 0 0;
  max-width: 45em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-dim);
}

.page-about .text-link {
  display: inline-block;
  margin-top: 20px;
  font-size: 15px;
}

/* ============ 资质 ============ */
.page-about .cred-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .cred {
  padding: 22px 0;
  border-top: 1px solid var(--line-hair);
}

.page-about .cred__mark {
  display: inline-block;
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--accent);
  border: 1px solid rgba(47, 230, 200, 0.4);
  border-radius: var(--radius);
}

.page-about .cred__title {
  display: block;
  margin-top: 14px;
  font-size: 18px;
  font-weight: 400;
  color: var(--text);
}

.page-about .cred__note {
  margin: 10px 0 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ============ 合作入口 ============ */
.page-about .skill-path {
  margin: 0 0 32px;
  padding: 0;
  list-style: none;
}

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

/* ============ 中等屏幕 ============ */
@media (min-width: 768px) {
  .page-about .about-hero__frame {
    padding: 56px 40px 46px;
  }

  .page-about .about-stats__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding-block: 36px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-split--reverse .media-frame {
    order: -1;
  }

  .page-about .team-item__desc {
    max-height: 0;
    margin-top: 0;
    padding-left: 60px;
    overflow: hidden;
    opacity: 0;
    transition: max-height var(--dur-slow) var(--ease), opacity var(--dur) var(--ease), margin-top var(--dur) var(--ease);
  }

  .page-about .team-item:hover .team-item__desc,
  .page-about .team-item:focus .team-item__desc {
    max-height: 280px;
    margin-top: 12px;
    opacity: 1;
  }

  .page-about .phase {
    display: grid;
    grid-template-columns: 118px minmax(0, 1fr);
    column-gap: 24px;
    padding: 24px 0 24px 26px;
  }

  .page-about .phase__gen {
    grid-row: span 2;
    padding-top: 4px;
  }

  .page-about .phase__title {
    margin-top: 0;
  }

  .page-about .phase__body {
    grid-column: 2;
  }

  .page-about .ledger__row {
    grid-template-columns: 112px minmax(0, 1fr);
    column-gap: 28px;
    gap: 0;
  }

  .page-about .ledger__key {
    padding-top: 4px;
  }

  .page-about .pulse-bar {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding: 28px 24px;
  }

  .page-about .cred-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 32px;
  }
}

/* ============ 桌面分屏 ============ */
@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: var(--about-gap);
    padding-top: 60px;
    padding-bottom: 64px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 112px;
    align-self: start;
    padding: 4px 0 4px 22px;
    margin: 0;
    border: 0;
    border-left: 1px solid var(--line-hair);
    overflow: visible;
    background: none;
  }

  .page-about .about-rail__cap {
    margin-bottom: 20px;
  }

  .page-about .about-rail__list {
    display: block;
    white-space: normal;
  }

  .page-about .about-rail__list li + li {
    margin-top: 2px;
  }

  .page-about .about-rail__list a {
    position: relative;
    display: block;
    padding: 9px 0;
    font-size: 14px;
    border: 0;
    border-radius: 0;
    background: none;
  }

  .page-about .about-rail__list a::after {
    content: "";
    position: absolute;
    left: -23px;
    top: 50%;
    width: 9px;
    height: 1px;
    background: var(--line);
    transform: translateY(-50%);
    transition: width var(--dur) var(--ease), background var(--dur) var(--ease);
  }

  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a:focus-visible {
    background: none;
    border: 0;
    color: var(--text);
  }

  .page-about .about-rail__list a:hover::after,
  .page-about .about-rail__list a:focus-visible::after {
    width: 17px;
    background: var(--accent);
  }

  .page-about .about-section:first-child {
    padding-top: 12px;
  }
}

/* ============ 大屏收口 ============ */
@media (min-width: 1200px) {
  .page-about {
    --about-section-pad: 76px;
  }

  .page-about .about-hero__frame {
    padding: 64px 56px 52px;
  }

  .page-about .about-split {
    gap: 52px;
  }
}

/* ============ 动效降级 ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .team-item__desc,
  .page-about .team-item,
  .page-about .about-rail__list a,
  .page-about .about-rail__list a::after,
  .page-about .source-tail a,
  .page-about .text-link {
    transition: none;
  }
}