.page-about {
  --about-rail: 176px;
  --about-measure: 38em;
  display: block;
  background: var(--bg-deep);
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(40px, 7vw, 92px) 0 clamp(30px, 4vw, 52px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(79, 174, 99, 0.055) 0 1px, transparent 1px 54px),
    radial-gradient(90% 70% at 6% 0%, rgba(63, 224, 208, 0.10), transparent 62%),
    radial-gradient(72% 66% at 100% 104%, rgba(43, 15, 26, 0.9), transparent 72%);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  max-width: 13em;
  font-size: clamp(34px, 6.4vw, 76px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--title);
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: var(--about-measure);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.78;
  color: var(--text);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
  margin: 34px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column-reverse;
  gap: 9px;
  min-width: 0;
}

.page-about .about-fact dt,
.page-about .about-fact dd {
  margin: 0;
}

.page-about .about-fact__value {
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-family: var(--mono);
  font-size: clamp(27px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-fact__unit {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0;
  color: var(--gold);
}

.page-about .about-fact__label {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text);
  opacity: 0.78;
}

/* ---------- 主体框架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  padding-top: clamp(28px, 4vw, 54px);
  padding-bottom: clamp(48px, 7vw, 92px);
}

/* ---------- 左栏刻度索引 ---------- */
.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0 0 10px;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line-soft);
  color: var(--text);
  text-decoration: none;
  font-size: 12.5px;
  white-space: nowrap;
  transition: border-color 200ms var(--ease), color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--gold);
  color: var(--title);
  background: rgba(255, 255, 255, 0.05);
}

.page-about .about-rail__num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--gold);
}

/* ---------- 章节 ---------- */
.page-about .about-track {
  min-width: 0;
}

.page-about .about-chapter {
  padding: clamp(34px, 5vw, 70px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(24px, 3vw, 38px);
}

.page-about .about-chapter__claim {
  margin: 12px 0 22px;
  max-width: 21em;
  font-size: clamp(23px, 3.3vw, 37px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--title);
}

.page-about .about-prose {
  max-width: var(--about-measure);
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text);
}

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

.page-about .about-prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 224, 208, 0.42);
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-prose a:hover {
  color: var(--title);
  border-bottom-color: var(--gold);
}

.page-about .about-track::after {
  content: "";
  display: block;
  height: 1px;
  margin-top: clamp(36px, 5vw, 66px);
  background: linear-gradient(90deg, var(--gold), rgba(63, 224, 208, 0.34) 44%, transparent);
  opacity: 0.5;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
}

.page-about .about-figure--wide {
  margin-top: 34px;
}

.page-about .about-figure--narrow {
  max-width: 420px;
  margin-top: 34px;
}

.page-about .about-figure img,
.page-about .about-split__aside img {
  max-width: 100%;
  height: auto;
}

/* ---------- 数据规模 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 28px 0 24px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 22px 18px 24px;
  background: var(--bg-panel);
  min-width: 0;
}

.page-about .about-stat__value {
  font-family: var(--mono);
  font-size: clamp(25px, 4vw, 38px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-stat:nth-child(3n + 2) .about-stat__value {
  color: var(--cyan);
}

.page-about .about-stat:nth-child(3n) .about-stat__value {
  color: var(--title);
}

.page-about .about-stat__label {
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--text);
  opacity: 0.86;
}

/* ---------- 团队分工 ---------- */
.page-about .about-teams {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 30px 0 0;
  background: var(--line-soft);
  border-top: 1px solid var(--line);
}

.page-about .about-team {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 20px 30px;
  min-width: 0;
  background-image:
    linear-gradient(180deg, rgba(12, 16, 18, 0.93), rgba(6, 24, 18, 0.93)),
    repeating-linear-gradient(90deg, rgba(79, 174, 99, 0.10) 0 2px, transparent 2px 44px);
  transition: background-image 240ms var(--ease), box-shadow 240ms var(--ease);
  box-shadow: inset 0 0 0 0 rgba(63, 224, 208, 0);
}

.page-about .about-team:hover,
.page-about .about-team:focus-within {
  background-image:
    linear-gradient(180deg, rgba(255, 255, 255, 0.10), rgba(255, 255, 255, 0.035)),
    repeating-linear-gradient(90deg, rgba(79, 174, 99, 0.17) 0 2px, transparent 2px 44px);
  box-shadow: inset 0 0 0 1px rgba(63, 224, 208, 0.34);
}

.page-about .about-team__code {
  margin: 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-team__name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--title);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.74;
  color: var(--text);
  opacity: 0.9;
}

/* ---------- 数据流程 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .about-split__main,
.page-about .about-split__aside {
  min-width: 0;
}

.page-about .about-split__aside {
  margin: 0;
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

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

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 5px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gold);
}

.page-about .about-flow__code {
  margin: 0 0 7px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-flow__name {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--title);
}

.page-about .about-flow__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.74;
  color: var(--text);
  opacity: 0.88;
}

/* ---------- 里程碑时间轴 ---------- */
.page-about .about-milestones {
  margin: 30px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-mile {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-mile__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 18px 2px;
  cursor: pointer;
  list-style: none;
  transition: background-color 200ms var(--ease);
}

.page-about .about-mile__head::-webkit-details-marker {
  display: none;
}

.page-about .about-mile__head:hover {
  background: rgba(255, 255, 255, 0.045);
}

.page-about .about-mile__code {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-mile__title {
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--title);
}

.page-about .about-mile__head::after {
  content: "+";
  margin-left: auto;
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1;
  color: var(--gold);
  transition: transform 240ms var(--ease);
}

.page-about .about-mile[open] .about-mile__head::after {
  transform: rotate(45deg);
}

.page-about .about-mile__body {
  max-width: var(--about-measure);
  padding: 0 2px 24px;
}

.page-about .about-mile__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text);
  opacity: 0.92;
}

/* ---------- 联系区块 ---------- */
.page-about .about-contact {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin-top: 4px;
}

.page-about .about-contact__main {
  min-width: 0;
}

.page-about .about-contact__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-contact__card {
  min-width: 0;
  padding: 26px 22px 28px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.055), rgba(255, 255, 255, 0.015)),
    var(--bg-indigo);
  border: 1px solid var(--line);
  box-shadow: inset 0 1px 0 rgba(63, 224, 208, 0.14);
}

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

.page-about .about-contact__item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding-bottom: 13px;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-contact__key {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-contact__val {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--title);
  overflow-wrap: anywhere;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px 26px;
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 680px) {
  .page-about .about-teams {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(28px, 4vw, 62px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 28px;
    padding-bottom: 40px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    margin: 0;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-rail__item {
    flex: none;
  }

  .page-about .about-rail__link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    width: 100%;
    padding: 11px 0 11px 16px;
    border: 0;
    border-left: 2px solid rgba(195, 204, 198, 0.14);
    font-size: 13px;
    white-space: normal;
    transition: border-color 200ms var(--ease), color 200ms var(--ease), background-color 200ms var(--ease);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--gold);
    color: var(--title);
    background: linear-gradient(90deg, rgba(217, 180, 81, 0.10), transparent 82%);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: clamp(28px, 4vw, 52px);
    align-items: start;
  }

  .page-about .about-mile:nth-child(even) .about-mile__head,
  .page-about .about-mile:nth-child(even) .about-mile__body {
    padding-left: 48px;
  }

  .page-about .about-contact {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.74fr);
    gap: clamp(28px, 4vw, 54px);
    align-items: start;
  }
}

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

  .page-about .about-rail {
    --about-rail: 196px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}