.page-about {
  --about-donut-size: 240px;
  --about-line-x: 14px;
  --about-line-w: 6px;
  background: var(--bg-mist);
  color: var(--ink);
  overflow-x: clip;
}

/* ===== 面包屑 ===== */
.page-about .crumb {
  padding: 1.25rem var(--gutter) 0;
  font-size: 0.875rem;
}
.page-about .crumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .crumb__item {
  color: var(--muted);
}
.page-about .crumb__item a {
  color: var(--navy);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease);
}
.page-about .crumb__item a:hover {
  color: var(--gold-deep);
}
.page-about .crumb__sep {
  color: var(--muted);
  opacity: 0.5;
}

/* ===== Hero ===== */
.page-about .about-hero {
  position: relative;
  padding: 3rem 0 4rem;
  background: linear-gradient(135deg, var(--navy), var(--navy-light));
  color: var(--white);
  overflow: hidden;
}
.page-about .about-hero::before,
.page-about .about-hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}
.page-about .about-hero::before {
  width: 440px;
  height: 440px;
  right: -140px;
  top: -140px;
  background: radial-gradient(circle, rgba(255, 215, 0, 0.3), transparent 70%);
}
.page-about .about-hero::after {
  width: 300px;
  height: 300px;
  left: -100px;
  bottom: -120px;
  background: radial-gradient(circle, rgba(255, 107, 53, 0.22), transparent 70%);
}
.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 2.25rem;
  align-items: end;
}
.page-about .about-hero__kicker {
  display: inline-block;
  margin-bottom: 1rem;
}
.page-about .about-hero__title {
  font-family: var(--font-disp);
  font-size: clamp(2.75rem, 8vw, 4.5rem);
  line-height: 1.08;
  margin: 0 0 1rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  max-width: 13ch;
  transform: rotate(-2deg);
  transform-origin: left bottom;
}
.page-about .about-hero__lead {
  max-width: 34rem;
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.82);
}
.page-about .about-hero__stats {
  margin: 0;
  padding: 0.375rem 1.25rem 0.75rem;
  background: var(--navy-glass);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-m);
  backdrop-filter: blur(8px);
}
.page-about .about-hero .spec-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--line-dark);
}
.page-about .about-hero .spec-row:last-child {
  border-bottom: none;
}
.page-about .about-hero .spec-row__key {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.65);
}
.page-about .about-hero .spec-row__val {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gold);
}

/* ===== 品牌使命 ===== */
.page-about .about-mission {
  padding: 3rem 0 2.5rem;
}
.page-about .about-mission__grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}
.page-about .about-mission__copy .section-title {
  margin-bottom: 1.25rem;
}
.page-about .about-mission__copy p {
  margin: 0 0 1.125rem;
  line-height: 1.75;
  color: var(--muted);
  max-width: 36rem;
}
.page-about .about-mission__copy .btn {
  margin-top: 0.375rem;
}
.page-about .about-mission__figure {
  box-shadow: 0 18px 40px rgba(11, 30, 58, 0.16);
}

/* ===== 时间线 ===== */
.page-about .about-timeline {
  padding: 3rem 0;
  background: var(--white);
}
.page-about .about-timeline .section-title {
  margin-bottom: 0.5rem;
}
.page-about .about-timeline__list {
  list-style: none;
  margin: 0;
  padding: 2rem 0 0;
  position: relative;
}
.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: var(--about-line-x);
  top: 2.25rem;
  bottom: 0.5rem;
  width: var(--about-line-w);
  border-radius: 999px;
  background: linear-gradient(to bottom, var(--gold), var(--orange));
  opacity: 0.8;
}
.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 2.5rem 3.25rem;
}
.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 0.5rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--white);
  border: 4px solid var(--gold);
  box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.25);
}
.page-about .about-timeline__year {
  display: inline-block;
  margin-bottom: 0.5rem;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.875rem;
  line-height: 1;
  padding: 0.375rem 0.625rem;
  color: var(--navy);
  background: var(--gold);
  border-radius: var(--radius-s);
}
.page-about .about-timeline__card h3 {
  font-family: var(--font-disp);
  font-size: 1.3125rem;
  line-height: 1.35;
  margin: 0 0 0.5rem;
  color: var(--navy);
  letter-spacing: 0.01em;
}
.page-about .about-timeline__card p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--muted);
  max-width: 30rem;
}

/* ===== 团队构成 ===== */
.page-about .about-team {
  padding: 3rem 0;
}
.page-about .about-team .section-title {
  margin-bottom: 2rem;
}
.page-about .about-team__grid {
  display: grid;
  gap: 1.75rem;
  align-items: start;
}
.page-about .about-team__chart-wrap {
  text-align: center;
}
.page-about .about-team__donut {
  position: relative;
  width: min(var(--about-donut-size), 68vw);
  height: min(var(--about-donut-size), 68vw);
  margin: 0 auto 1.5rem;
  border-radius: 50%;
  background: conic-gradient(
    var(--gold) 0 56.7%,
    var(--orange) 56.7% 83.3%,
    var(--navy) 83.3% 100%
  );
  box-shadow: 0 14px 32px rgba(11, 30, 58, 0.18);
}
.page-about .about-team__donut::before {
  content: "";
  position: absolute;
  inset: 22%;
  background: var(--bg-mist);
  border-radius: 50%;
  box-shadow: inset 0 2px 12px rgba(11, 30, 58, 0.08);
}
.page-about .about-team__donut::after {
  content: "150";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--navy);
}
.page-about .about-team__legend {
  list-style: none;
  display: grid;
  gap: 0.625rem;
  margin: 0;
  padding: 0;
  font-size: 0.9375rem;
  color: var(--ink);
}
.page-about .about-team__legend li {
  display: flex;
  align-items: center;
  gap: 0.625rem;
}
.page-about .about-team__dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}
.page-about .about-team__dot--tech {
  background: var(--gold);
}
.page-about .about-team__dot--data {
  background: var(--orange);
}
.page-about .about-team__dot--edit {
  background: var(--navy);
}
.page-about .about-team__roles {
  display: grid;
  gap: 1rem;
}
.page-about .about-team__role {
  background: var(--white);
  border: 1px solid var(--line-light);
  border-radius: var(--radius-m);
  padding: 1.25rem 1.5rem;
  transition: border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}
.page-about .about-team__role:hover,
.page-about .about-team__role:focus-within {
  border-color: rgba(255, 215, 0, 0.9);
  transform: translateX(4px);
}
.page-about .about-team__role-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1;
  color: var(--gold-deep);
  margin-right: 0.625rem;
}
.page-about .about-team__role-label {
  font-family: var(--font-disp);
  font-size: 1.125rem;
  letter-spacing: 0.02em;
  color: var(--navy);
}
.page-about .about-team__role-desc {
  margin: 0.5rem 0 0;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--muted);
}
.page-about .about-team__figure {
  box-shadow: 0 14px 30px rgba(11, 30, 58, 0.12);
}
.page-about .about-team__desc p {
  margin: 0 0 1rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--muted);
}
.page-about .about-team__desc p:last-child {
  margin-bottom: 0;
}

/* ===== 资质认证 ===== */
.page-about .about-credentials {
  padding: 3rem 0;
  background: var(--white);
}
.page-about .about-credentials__grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}
.page-about .about-credentials__copy .section-title {
  margin-bottom: 1.25rem;
}
.page-about .about-credentials__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}
.page-about .about-credentials__list li {
  padding: 1.25rem 1.5rem;
  border-left: 4px solid var(--gold);
  background: linear-gradient(90deg, rgba(255, 215, 0, 0.1), transparent 70%);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
}
.page-about .about-credentials__list strong {
  display: block;
  font-family: var(--font-disp);
  font-size: 1.125rem;
  line-height: 1.4;
  color: var(--navy);
  margin-bottom: 0.375rem;
}
.page-about .about-credentials__list span {
  display: block;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--muted);
}
.page-about .about-credentials__figure {
  box-shadow: 0 14px 30px rgba(11, 30, 58, 0.12);
}

/* ===== 合作生态 ===== */
.page-about .about-partners {
  padding: 3rem 0;
  background: linear-gradient(155deg, var(--navy), var(--navy-light));
  color: var(--white);
}
.page-about .about-partners .section-title {
  margin-bottom: 1.25rem;
}
.page-about .about-partners__intro {
  max-width: 44rem;
  margin: 0 0 2rem;
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.82);
}
.page-about .about-partners__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}
.page-about .about-partners__stat {
  background: var(--navy-glass);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-m);
  padding: 1.5rem 1rem;
  text-align: center;
  backdrop-filter: blur(6px);
}
.page-about .about-partners__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--gold);
}
.page-about .about-partners__label {
  display: block;
  margin-top: 0.375rem;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.72);
}
.page-about .about-partners__note {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  align-items: flex-start;
}
.page-about .about-partners__note p {
  margin: 0;
  max-width: 42rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.78);
}
.page-about .about-partners__note a {
  color: var(--gold);
  text-decoration: underline;
  text-underline-offset: 4px;
}

/* ===== 图片容器 ===== */
.page-about .img-frame {
  overflow: hidden;
  border-radius: var(--radius-m);
  position: relative;
}
.page-about .img-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.page-about .img-frame--16x9 {
  aspect-ratio: 16 / 9;
}
.page-about .img-frame--4x3 {
  aspect-ratio: 4 / 3;
}

/* ===== 桌面端 ≥900px ===== */
@media (min-width: 900px) {
  .page-about .crumb {
    padding: 1.5rem var(--gutter) 0;
    max-width: var(--container-w);
    margin-inline: auto;
  }

  .page-about .about-hero {
    padding: 4.5rem 0 5rem;
  }
  .page-about .about-hero__grid {
    grid-template-columns: 1.35fr 0.85fr;
    gap: 3rem;
  }
  .page-about .about-hero__title {
    font-size: clamp(3rem, 5.2vw, 4.75rem);
  }
  .page-about .about-hero__lead {
    font-size: 1.125rem;
  }
  .page-about .about-hero__stats {
    padding: 0.75rem 1.5rem 1rem;
  }

  .page-about .about-mission {
    padding: 5rem 0 4rem;
  }
  .page-about .about-mission__grid {
    grid-template-columns: 1fr 1fr;
    gap: 3.5rem;
  }
  .page-about .about-mission__figure {
    order: 2;
    transform: translateY(1.5rem);
  }
  .page-about .about-mission__copy {
    order: 1;
  }

  .page-about .about-timeline {
    padding: 5rem 0;
  }
  .page-about .about-timeline__list {
    max-width: 820px;
    margin-inline: auto;
    padding-top: 2.5rem;
  }
  .page-about .about-timeline__item {
    padding-left: 3.5rem;
  }
  .page-about .about-timeline__item:nth-child(even) {
    transform: translateX(2.5rem);
  }
  .page-about .about-timeline__item:nth-child(even) .about-timeline__card {
    padding-right: 2rem;
  }

  .page-about .about-team {
    padding: 5rem 0;
  }
  .page-about .about-team__grid {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 2.5rem 3rem;
  }
  .page-about .about-team__chart-wrap {
    grid-column: 2;
    grid-row: 1;
    text-align: center;
  }
  .page-about .about-team__roles {
    grid-column: 1;
    grid-row: 1 / span 2;
  }
  .page-about .about-team__figure {
    grid-column: 2;
    grid-row: 2;
  }
  .page-about .about-team__desc {
    grid-column: 1;
    grid-row: 3;
  }
  .page-about .about-team__role-desc {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: opacity var(--t-fast) var(--ease), max-height var(--t-slow) var(--ease);
  }
  .page-about .about-team__role:hover .about-team__role-desc,
  .page-about .about-team__role:focus-within .about-team__role-desc {
    max-height: 90px;
    opacity: 1;
  }

  .page-about .about-credentials {
    padding: 5rem 0;
  }
  .page-about .about-credentials__grid {
    grid-template-columns: 1fr 0.9fr;
    gap: 3.5rem;
  }
  .page-about .about-credentials__figure {
    order: 2;
  }

  .page-about .about-partners {
    padding: 5rem 0;
  }
  .page-about .about-partners__stats {
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
  }
  .page-about .about-partners__note {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}