.page-about {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  overflow-x: hidden;
}

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

/* ===== Hero ===== */
.page-about .about-hero {
  position: relative;
  padding: 3rem 0 3.5rem;
  color: #fff;
  background:
    linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255,255,255,.04) 1px, transparent 1px),
    radial-gradient(ellipse at 75% 10%, rgba(124,58,237,.35), transparent 55%),
    radial-gradient(ellipse at 20% 90%, rgba(37,99,235,.3), transparent 55%),
    radial-gradient(ellipse at 90% 70%, rgba(249,115,22,.12), transparent 45%),
    linear-gradient(135deg, #0B1120 0%, #111827 55%, #1e1b4b 100%);
  background-size: 24px 24px, 24px 24px, auto, auto, auto, auto;
  border-bottom: 4px solid var(--color-border);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 2rem;
  align-items: end;
}

.page-about .about-hero__eyebrow {
  color: var(--color-accent);
}

.page-about .about-hero__title {
  margin: .5rem 0 1rem;
  font-family: var(--font-head);
  font-size: clamp(2rem, 4.6vw, 3.5rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: #fff;
}

.page-about .about-hero__lead {
  max-width: 42rem;
  margin: 0;
  font-size: 1rem;
  line-height: 1.7;
  color: rgba(255,255,255,.8);
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__coordinate {
  display: none;
  flex-direction: column;
  align-items: flex-end;
  gap: .35rem;
  padding-left: 1.5rem;
  border-left: 1px solid rgba(255,255,255,.2);
  font-family: var(--font-mono);
  font-size: .75rem;
  line-height: 1.4;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: rgba(255,255,255,.65);
}

.page-about .about-hero__coordinate .coordinate-label {
  color: inherit;
}

.page-about .about-hero__coordinate .coordinate-index {
  margin-top: 1rem;
  font-size: .7rem;
  color: var(--color-accent);
}

/* ===== 跨页主体 ===== */
.page-about .about-spread {
  padding-top: 2.5rem;
  padding-bottom: 3.5rem;
}

.page-about .about-spread__rail {
  width: 100%;
  margin-bottom: 2rem;
  padding: 1.25rem;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  box-shadow: var(--shadow-strong);
}

.page-about .about-rail__img {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: 1.5rem;
  border: 2px solid var(--color-border);
  object-fit: cover;
  border-radius: var(--radius);
}

/* ===== 时间线 ===== */
.page-about .about-timeline {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 2px;
  bottom: 2px;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-purple), var(--color-accent));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 1.5rem 1.75rem;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: .2rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 3px solid var(--color-primary);
  transition: background .2s, border-color .2s, transform .2s;
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus::before,
.page-about .about-timeline__item:focus-within::before {
  background: var(--color-accent);
  border-color: var(--color-accent);
  transform: scale(1.2);
}

.page-about .about-timeline__version {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-primary);
}

.page-about .about-timeline__title {
  display: inline-block;
  margin-left: .5rem;
  font-weight: 700;
}

.page-about .about-timeline__detail {
  margin: .35rem 0 0;
  font-size: .875rem;
  line-height: 1.6;
  color: var(--color-text-soft);
}

@media (hover: hover) {
  .page-about .about-timeline__detail {
    max-height: 0;
    margin: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .3s ease, opacity .3s ease, margin .3s ease;
  }

  .page-about .about-timeline__item:hover .about-timeline__detail,
  .page-about .about-timeline__item:focus .about-timeline__detail,
  .page-about .about-timeline__item:focus-within .about-timeline__detail {
    max-height: 8rem;
    margin-top: .35rem;
    opacity: 1;
  }
}

/* ===== 宽区章节 ===== */
.page-about .about-spread__main {
  min-width: 0;
}

.page-about .about-section {
  padding: 2.5rem 0;
  border-bottom: 1px solid var(--color-line);
}

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

.page-about .about-section__title {
  margin: .25rem 0 1rem;
  font-family: var(--font-head);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.page-about .about-section__head {
  display: flex;
  flex-direction: column;
  gap: .25rem;
}

.page-about .about-section__body {
  max-width: 65ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text-soft);
}

.page-about .about-section__body p {
  margin: 0 0 1rem;
}

.page-about .about-story__quote {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  border-left: 4px solid var(--color-accent);
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--color-text);
}

/* ===== 数据里程碑 ===== */
.page-about .about-section--data {
  margin: .5rem 0 0;
  padding: 2rem 1.5rem;
  color: #fff;
  background:
    radial-gradient(ellipse at 10% 20%, rgba(37,99,235,.45), transparent 50%),
    radial-gradient(ellipse at 90% 80%, rgba(124,58,237,.4), transparent 50%),
    var(--color-dark);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-strong);
}

.page-about .about-section--data .about-section__title {
  color: #fff;
}

.page-about .about-section--data .eyebrow {
  color: rgba(255,255,255,.6);
}

.page-about .about-metrics {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about .about-metrics__item {
  display: flex;
  flex-direction: column;
  padding: 1.25rem;
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: var(--radius);
  transition: transform .2s ease, background .2s ease;
}

.page-about .about-metrics__item:hover {
  transform: translateY(-3px);
  background: rgba(255,255,255,.1);
}

.page-about .about-metrics__item dt {
  order: 2;
  font-weight: 700;
  font-size: .875rem;
  margin-top: .5rem;
  color: rgba(255,255,255,.9);
}

.page-about .about-metrics__item dd {
  order: 1;
  margin: 0;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 900;
  line-height: 1;
  color: var(--color-accent);
}

.page-about .about-metrics__item span {
  order: 3;
  margin-top: .25rem;
  font-size: .75rem;
  line-height: 1.5;
  color: rgba(255,255,255,.65);
}

@media (min-width: 640px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1200px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== 资质与荣誉 ===== */
.page-about .about-credential__head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: start;
  margin-bottom: 1.5rem;
}

.page-about .about-credential__head p:not(.eyebrow) {
  max-width: 60ch;
  margin: 0;
  line-height: 1.7;
  color: var(--color-text-soft);
}

.page-about .about-credential__badge {
  width: min(200px, 100%);
  aspect-ratio: 1 / 1;
  height: auto;
  object-fit: cover;
  border-radius: 50%;
  border: 3px solid var(--color-border);
  box-shadow: var(--shadow-strong);
}

.page-about .about-credential__list {
  display: grid;
  gap: 1rem;
}

.page-about .about-credential__card {
  padding: 1.5rem;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-strong);
  transition: transform .2s ease, box-shadow .2s ease;
}

.page-about .about-credential__card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-soft);
}

.page-about .about-credential__card h3 {
  margin: 0 0 .75rem;
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 900;
  letter-spacing: -0.01em;
}

.page-about .about-credential__card p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--color-text-soft);
}

@media (min-width: 900px) {
  .page-about .about-credential__head {
    grid-template-columns: 1fr auto;
  }

  .page-about .about-credential__badge {
    justify-self: end;
  }

  .page-about .about-credential__list {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== 团队概况 ===== */
.page-about .about-section__intro {
  max-width: 60ch;
  margin-bottom: 1.5rem;
  line-height: 1.7;
  color: var(--color-text-soft);
}

.page-about .about-team {
  display: grid;
  gap: 2rem;
}

.page-about .about-team__main,
.page-about .about-team__aside {
  min-width: 0;
}

.page-about .about-team__img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 320px;
  object-fit: cover;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-strong);
  margin-bottom: 1rem;
}

.page-about .about-team__main p,
.page-about .about-team__note {
  line-height: 1.7;
  color: var(--color-text-soft);
}

.page-about .about-team__struct {
  padding: 1.5rem;
  background: var(--color-bg-alt);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
}

.page-about .about-team__bar {
  margin-bottom: 1rem;
}

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

.page-about .about-team__bar > span {
  display: block;
  margin-bottom: .4rem;
  font-size: .875rem;
  font-weight: 700;
}

.page-about .about-team__track {
  height: 1.4rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .about-team__fill {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-purple));
  font-family: var(--font-mono);
  font-size: .75rem;
  line-height: 1.4rem;
  color: #fff;
  padding-left: .75rem;
  white-space: nowrap;
}

@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: 1.1fr .9fr;
    align-items: start;
  }
}

/* ===== 底部行动区 ===== */
.page-about .about-more {
  padding: 3.5rem 0;
  color: #fff;
  background:
    radial-gradient(ellipse at 15% 100%, rgba(37,99,235,.4), transparent 55%),
    radial-gradient(ellipse at 85% 0%, rgba(124,58,237,.35), transparent 50%),
    var(--color-dark);
  border-top: 4px solid var(--color-border);
}

.page-about .about-more__inner {
  text-align: center;
}

.page-about .about-more__title {
  margin: 0 0 .75rem;
  font-family: var(--font-head);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 900;
}

.page-about .about-more__inner p {
  max-width: 52ch;
  margin: 0 auto 1.5rem;
  color: rgba(255,255,255,.7);
  line-height: 1.7;
}

.page-about .about-more__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

.page-about .about-more .btn-ghost {
  border-color: rgba(255,255,255,.4);
  color: #fff;
}

.page-about .about-more .btn-ghost:hover {
  background: rgba(255,255,255,.1);
}

/* ===== 跨页桌面布局 ===== */
@media (min-width: 980px) {
  .page-about .about-hero__inner {
    grid-template-columns: 1fr 280px;
  }

  .page-about .about-hero__coordinate {
    display: flex;
  }

  .page-about .about-spread {
    display: grid;
    grid-template-columns: 320px minmax(0, 1fr);
    gap: 4rem;
    align-items: start;
  }

  .page-about .about-spread__rail {
    position: sticky;
    top: calc(var(--header-h) + 1rem);
    max-height: calc(100vh - var(--header-h) - 2rem);
    overflow: auto;
    margin-bottom: 0;
    padding: 0 1.5rem 0 0;
    background: transparent;
    border: 0;
    box-shadow: none;
  }

  .page-about .about-spread__main {
    padding-left: 0;
  }
}