.page-about {
  --gold-soft: rgba(212, 175, 55, .14);
  --red-soft: rgba(230, 57, 70, .08);
  color: var(--c-text);
  background: var(--c-light);
}
.page-about .content-shell {
  max-width: 1160px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4.5rem;
}
.page-about .breadcrumb {
  margin-bottom: 1.5rem;
}

/* 首屏品牌声明 */
.page-about .about-lead {
  position: relative;
  background: linear-gradient(135deg, var(--c-dark), var(--c-deep) 85%);
  color: #fff;
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem 2.75rem;
  overflow: hidden;
  margin-bottom: 3rem;
}
.page-about .about-lead::after {
  content: "";
  position: absolute;
  right: -3rem;
  bottom: -3rem;
  width: 11rem;
  height: 11rem;
  border: 2px solid rgba(212, 175, 55, .35);
  border-radius: 24px;
  transform: rotate(12deg);
}
.page-about .about-lead__kicker {
  display: inline-flex;
  align-items: center;
  gap: .625rem;
  font-family: var(--f-mono);
  font-size: .8125rem;
  letter-spacing: .14em;
  color: var(--c-gold);
  text-transform: uppercase;
  margin-bottom: .75rem;
}
.page-about .about-lead__kicker::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--c-red);
}
.page-about .about-lead h1 {
  max-width: 820px;
  margin: 0 0 .75rem;
  font-size: 1.625rem;
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: -.01em;
}
.page-about .about-lead__desc {
  max-width: 700px;
  line-height: 1.75;
  color: rgba(255, 255, 255, .82);
}
.page-about .about-lead__deco {
  position: absolute;
  right: 1.5rem;
  bottom: 2rem;
  display: none;
  opacity: .8;
}

/* 章节容器间距 */
.page-about .section-group {
  margin-bottom: 3.5rem;
}
.page-about .section-heading {
  margin-bottom: 1.75rem;
}

/* 01 品牌定位 */
.page-about .about-position {
  padding: 0 0 .5rem;
}
.page-about .about-position__grid {
  display: grid;
  gap: 2rem;
}
.page-about .about-position__text {
  font-size: 1rem;
  line-height: 1.75;
}
.page-about .about-position__text p {
  margin-bottom: 1rem;
}
.page-about .about-position__stat-line {
  display: flex;
  flex-wrap: wrap;
  gap: .625rem;
  margin-top: 1.5rem;
}
.page-about .about-position__stat-line span {
  font-family: var(--f-mono);
  font-size: .8125rem;
  font-weight: 500;
  letter-spacing: .04em;
  color: var(--c-deep);
  background: var(--c-white);
  border: 1px solid var(--c-border);
  padding: .35rem .9rem;
  border-radius: 20px;
}
.page-about .about-position__media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
}
.page-about .about-position__media img {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .about-position__media-tag {
  position: absolute;
  left: 1rem;
  bottom: 1rem;
  font-family: var(--f-mono);
  font-size: .875rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: #fff;
  background: rgba(11, 31, 58, .82);
  padding: .35rem .8rem;
  border-radius: 4px;
}

/* 02 发展历程 */
.page-about .about-history {
  background: var(--c-white);
  border-radius: var(--radius);
  padding: 2.25rem 1.25rem;
}
.page-about .about-history__layout {
  display: grid;
  gap: 1.75rem;
}
.page-about .about-history__toc {
  display: flex;
  flex-wrap: wrap;
  gap: .25rem;
}
.page-about .about-history__toc a {
  display: block;
  font-family: var(--f-mono);
  font-size: .8125rem;
  line-height: 1.6;
  padding: .4rem .75rem;
  color: var(--c-text2);
  text-decoration: none;
  border-left: 2px solid var(--c-border);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}
.page-about .about-history__toc a:hover {
  color: var(--c-deep);
  border-left-color: var(--c-gold);
  background: var(--c-light);
}
.page-about .about-history__timeline {
  display: grid;
  gap: 0;
  position: relative;
  max-width: 640px;
}
.page-about .about-history__timeline::before {
  content: "";
  position: absolute;
  left: calc(4.5rem + .5rem - 1px);
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--c-gold);
}
.page-about .about-history__item {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1rem;
  padding-bottom: 1.75rem;
  margin: 0;
}
.page-about .about-history__item:last-child {
  padding-bottom: 0;
}
.page-about .about-history__year {
  justify-self: center;
  width: 3.5rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 3px solid var(--c-gold);
  background: var(--c-white);
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: .8125rem;
  letter-spacing: .02em;
  color: var(--c-deep);
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}
.page-about .about-history__item.is-current .about-history__year {
  border-color: var(--c-red);
  color: var(--c-red);
}
.page-about .about-history__card h3 {
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.35;
  margin: 0 0 .5rem;
}
.page-about .about-history__card p {
  margin: 0;
  line-height: 1.7;
  color: var(--c-text2);
}
.page-about .about-history__media {
  max-width: 800px;
  margin: 0 auto;
}
.page-about .about-history__media img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
}

/* 03 数据与能力 */
.page-about .about-capacity {
  background: linear-gradient(135deg, var(--c-dark), var(--c-deep));
  color: #fff;
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem 3rem;
}
.page-about .about-capacity .section-title {
  color: #fff;
}
.page-about .about-capacity .section-desc {
  color: rgba(255, 255, 255, .68);
}
.page-about .about-capacity .section-index {
  color: var(--c-gold);
}
.page-about .about-capacity__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 2rem;
}
.page-about .about-capacity__stat {
  border: 1px solid rgba(255, 255, 255, .14);
  background: rgba(255, 255, 255, .05);
  border-radius: var(--radius);
  padding: 1.25rem 1rem;
  text-align: center;
  transition: background var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}
.page-about .about-capacity__stat:hover {
  background: rgba(255, 255, 255, .1);
  transform: translateY(-2px);
}
.page-about .about-capacity__num {
  display: block;
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: 1.875rem;
  line-height: 1.2;
  color: var(--c-gold);
  margin-bottom: .25rem;
}
.page-about .about-capacity__label {
  font-size: .875rem;
  color: rgba(255, 255, 255, .75);
}
.page-about .about-capacity__body {
  display: grid;
  gap: 1.75rem;
  margin-top: 2.25rem;
}
.page-about .about-capacity__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
}
.page-about .about-capacity__text p {
  margin-bottom: 1rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, .85);
}
.page-about .about-capacity__note {
  font-family: var(--f-mono);
  font-size: .875rem;
  color: var(--c-gold);
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, .12);
}

/* 04 关于改版 */
.page-about .about-redesign {
  padding: 0 0 .5rem;
}
.page-about .about-redesign__content {
  display: grid;
  gap: 2rem;
}
.page-about .about-redesign__main h3 {
  font-size: 1.0625rem;
  font-weight: 700;
  margin: 1.5rem 0 .5rem;
}
.page-about .about-redesign__main h3:first-of-type {
  margin-top: 0;
}
.page-about .about-redesign__main p {
  line-height: 1.75;
  margin-bottom: 1rem;
}
.page-about .about-redesign__main ul {
  list-style: none;
  margin: 0 0 1.5rem;
  padding: 0;
}
.page-about .about-redesign__main li {
  position: relative;
  padding: .6rem 0 .6rem 1.6rem;
  border-bottom: 1px solid var(--c-border);
  line-height: 1.65;
}
.page-about .about-redesign__main li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .95rem;
  width: 8px;
  height: 8px;
  background: var(--c-red);
  border-radius: 2px;
  transform: skewX(-12deg);
}
.page-about .about-redesign__aside {
  background: var(--c-light);
  border-left: 4px solid var(--c-gold);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.5rem;
  align-self: start;
}
.page-about .about-redesign__aside h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 .75rem;
}
.page-about .about-redesign__aside p {
  line-height: 1.7;
  color: var(--c-text2);
  margin: 0;
}
.page-about .about-redesign__tag {
  display: block;
  font-family: var(--f-mono);
  font-size: .8125rem;
  color: var(--c-gold);
  letter-spacing: .08em;
  margin-top: 1.25rem;
}

/* 返回顶部 */
.page-about .about-back-top {
  font-family: var(--f-mono);
  font-size: .875rem;
  color: var(--c-deep);
  background: none;
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: .5rem 1rem;
  margin-top: 2rem;
  cursor: pointer;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}
.page-about .about-back-top:hover {
  border-color: var(--c-gold);
  color: var(--c-gold);
}

/* 桌面端增强 */
@media (min-width: 768px) {
  .page-about .about-capacity__stats {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .about-capacity__body {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: center;
  }
  .page-about .about-redesign__content {
    grid-template-columns: 1.2fr .8fr;
    align-items: start;
  }
  .page-about .about-lead__deco {
    display: block;
  }
}

@media (min-width: 1080px) {
  .page-about .about-position__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    align-items: center;
    gap: 3rem;
  }
  .page-about .about-history {
    padding: 3rem 2.5rem;
  }
  .page-about .about-history__layout {
    grid-template-columns: 190px minmax(0, 1fr);
    grid-template-areas: "toc timeline" "media media";
    gap: 2rem 2.5rem;
    align-items: start;
  }
  .page-about .about-history__toc {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 1.5rem);
    grid-area: toc;
  }
  .page-about .about-history__timeline {
    grid-area: timeline;
  }
  .page-about .about-history__media {
    grid-area: media;
  }
}