.page-about {
  --about-hero-bg: var(--c-dark, #121212);
  --about-hero-text: var(--c-text, #E0E0E0);
  --about-body-bg: var(--c-light, #FAFAFA);
  --about-body-text: var(--c-dark, #121212);
  --about-accent-line: var(--c-red, #E53935);
  --about-accent-line2: var(--c-blue, #1E88E5);
  --about-sidebar-w: 220px;
  --about-content-gap: 2rem;
  --about-section-space: 3rem;
  font-family: var(--font-body, 'Noto Sans SC', sans-serif);
  color: var(--about-body-text);
  background: var(--about-body-bg);
}

/* ===== 首屏区域 ===== */
.about-hero {
  background: var(--about-hero-bg);
  color: var(--about-hero-text);
  padding: 1.5rem 1rem 2rem;
  position: relative;
  overflow: hidden;
}
.about-hero::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 45%;
  height: 100%;
  background: linear-gradient(135deg, rgba(229,57,53,0.08) 0%, rgba(30,136,229,0.06) 100%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0% 100%);
  pointer-events: none;
}
.about-hero__inner {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.about-hero__label-wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}
.about-breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.about-breadcrumb__link {
  color: var(--c-silver, #B0BEC5);
  text-decoration: none;
  transition: color 0.2s;
}
.about-breadcrumb__link:hover {
  color: var(--c-red, #E53935);
}
.about-breadcrumb__sep {
  color: var(--c-silver, #B0BEC5);
  opacity: 0.5;
}
.about-breadcrumb__current {
  color: var(--c-accent, #FF6F00);
  font-weight: 700;
}
.about-hero__tag {
  display: inline-block;
  background: var(--c-red, #E53935);
  color: #fff;
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-xl, 24px);
  margin-left: auto;
}
.about-hero__main {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  align-items: flex-start;
}
.about-hero__text {
  flex: 1;
}
.about-hero__title {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: clamp(2.4rem, 10vw, 4.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: #fff;
  margin: 0 0 0.5rem;
  text-transform: uppercase;
}
.about-hero__title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--c-red, #E53935);
  margin-top: 0.75rem;
  border-radius: 2px;
}
.about-hero__subtitle {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: clamp(1rem, 3vw, 1.4rem);
  font-weight: 400;
  color: var(--c-silver, #B0BEC5);
  letter-spacing: 0.15em;
  margin: 0 0 1rem;
  text-transform: uppercase;
}
.about-hero__desc {
  font-size: clamp(0.9rem, 2.5vw, 1.1rem);
  line-height: 1.6;
  color: var(--c-silver, #B0BEC5);
  max-width: 520px;
  margin: 0;
}
.about-hero__visual {
  flex-shrink: 0;
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
}
.about-hero__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  border-radius: var(--radius-lg, 16px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.4);
  object-fit: cover;
  aspect-ratio: 1/1;
}

/* ===== 杂志双栏布局 ===== */
.about-layout {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  flex-direction: column;
  gap: var(--about-content-gap);
}

/* ===== 侧边栏（移动端顶部水平导航） ===== */
.about-sidebar {
  padding: 1.5rem 0 0;
  border-bottom: 2px solid var(--c-red-dim, rgba(229,57,53,0.12));
  margin-bottom: 0.5rem;
}
.about-sidebar__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}
.about-sidebar__link {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  text-decoration: none;
  color: var(--about-body-text);
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius-sm, 8px);
  transition: background 0.2s, color 0.2s;
  letter-spacing: 0.02em;
}
.about-sidebar__link:hover {
  background: var(--c-red-dim, rgba(229,57,53,0.12));
  color: var(--c-red, #E53935);
}
.about-sidebar__num {
  font-family: var(--font-num, 'JetBrains Mono', monospace);
  font-size: 0.7rem;
  color: var(--c-red, #E53935);
  opacity: 0.7;
}
.about-sidebar__label {
  font-size: 0.85rem;
}
.about-sidebar__cta {
  display: none;
  margin-top: 1.5rem;
}
.about-sidebar__btn {
  display: inline-block;
  width: 100%;
  text-align: center;
}

/* ===== 右侧内容区 ===== */
.about-content {
  flex: 1;
  min-width: 0;
  padding-bottom: 3rem;
}

/* ===== 章节通用 ===== */
.about-section {
  padding: 1.5rem 0;
  scroll-margin-top: 5rem;
}
.about-section__header {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}
.about-section__num {
  font-family: var(--font-num, 'JetBrains Mono', monospace);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--c-red, #E53935);
  letter-spacing: 0.05em;
  flex-shrink: 0;
}
.about-section__title {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: clamp(1.6rem, 5vw, 2.4rem);
  font-weight: 800;
  color: var(--about-body-text);
  margin: 0;
  line-height: 1.15;
  letter-spacing: -0.01em;
}
.about-section__title::after {
  content: '';
  display: inline-block;
  width: 40px;
  height: 3px;
  background: var(--c-red, #E53935);
  margin-left: 0.75rem;
  vertical-align: middle;
  border-radius: 2px;
}
.about-section__body {
  padding-left: 0;
}
.about-section__text {
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  line-height: 1.7;
  color: var(--about-body-text);
  margin: 0 0 1rem;
  max-width: 680px;
}
.about-section__text strong {
  color: var(--c-red, #E53935);
  font-weight: 700;
}
.about-section__quote {
  margin: 2rem 0 0;
  padding: 1.25rem 1.5rem;
  background: var(--c-red-dim, rgba(229,57,53,0.06));
  border-left: 4px solid var(--c-red, #E53935);
  border-radius: 0 var(--radius-sm, 8px) var(--radius-sm, 8px) 0;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}
.about-section__quote-mark {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 2.5rem;
  line-height: 1;
  color: var(--c-red, #E53935);
  font-weight: 900;
  flex-shrink: 0;
  margin-top: -0.2rem;
}
.about-section__quote-text {
  font-size: 1.05rem;
  font-style: italic;
  color: var(--about-body-text);
  line-height: 1.5;
}
.about-section__footnote {
  font-size: 0.9rem;
  color: var(--c-silver, #B0BEC5);
  margin: 2rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid rgba(0,0,0,0.06);
  line-height: 1.6;
}
.highlight {
  color: var(--c-red, #E53935);
  font-weight: 700;
}

/* ===== 柔和曲线分隔 ===== */
.about-divider {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 50px;
  margin: 0.5rem 0;
  overflow: hidden;
  opacity: 0.6;
}
.about-divider__svg {
  display: block;
  width: 100%;
  max-width: 600px;
  height: 100%;
}

/* ===== 服务范围 - 折叠交互 ===== */
.services-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 1rem;
}
.service-item {
  border-bottom: 1px solid rgba(0,0,0,0.06);
}
.service-item__toggle {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
  background: none;
  border: none;
  padding: 1rem 0;
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--about-body-text);
  cursor: pointer;
  text-align: left;
  transition: color 0.2s;
}
.service-item__toggle:hover {
  color: var(--c-red, #E53935);
}
.service-item__icon {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
}
.service-item__icon svg {
  display: block;
}
.service-item__name {
  flex: 1;
}
.service-item__arrow {
  flex-shrink: 0;
  color: var(--c-silver, #B0BEC5);
  transition: transform 0.3s ease;
}
.service-item__toggle[aria-expanded="true"] .service-item__arrow {
  transform: rotate(180deg);
}
.service-item__content {
  overflow: hidden;
  padding: 0 0 0.5rem 2.5rem;
  transition: max-height 0.35s ease, opacity 0.3s ease;
}
.service-item__content[hidden] {
  display: none;
}
.service-item__desc {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--about-body-text);
  margin: 0 0 0.75rem;
}
.service-item__link {
  display: inline-block;
  font-size: 0.85rem;
  margin-top: 0.25rem;
}

/* ===== 数据承诺 - 信息图与卡片 ===== */
.data-chart {
  margin: 1.5rem 0;
  border-radius: var(--radius-lg, 16px);
  overflow: hidden;
  background: var(--c-dark, #121212);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}
.data-chart__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 800/400;
}

.data-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 1.5rem 0;
}
.data-card {
  position: relative;
  background: #fff;
  border-radius: var(--radius-lg, 16px);
  padding: 1.25rem;
  box-shadow: 0 4px 16px rgba(0,0,0,0.04);
  border: 1px solid rgba(0,0,0,0.04);
  transition: box-shadow 0.3s ease, transform 0.25s ease;
  cursor: default;
}
.data-card:hover {
  box-shadow: 0 8px 32px rgba(229,57,53,0.10);
  transform: translateY(-2px);
}
.data-card__front {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.data-card__num {
  font-family: var(--font-num, 'JetBrains Mono', monospace);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--c-red, #E53935);
  line-height: 1;
  letter-spacing: -0.03em;
}
.data-card__unit {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--c-silver, #B0BEC5);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.data-card__title {
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--about-body-text);
  margin: 0.25rem 0 0;
}
.data-card__detail {
  margin-top: 1rem;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(0,0,0,0.06);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--about-body-text);
  display: none;
}
.data-card[data-hover-detail]:hover .data-card__detail {
  display: block;
  animation: dataFadeIn 0.3s ease;
}
.data-card__detail strong {
  color: var(--c-red, #E53935);
}
.data-card__link {
  display: inline-block;
  font-size: 0.8rem;
  margin-top: 0.5rem;
}
@keyframes dataFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== 页尾氛围图 ===== */
.about-ambient {
  margin: 2rem -1rem -3rem;
  border-radius: var(--radius-lg, 16px) var(--radius-lg, 16px) 0 0;
  overflow: hidden;
  line-height: 0;
}
.about-ambient__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 1920/300;
  opacity: 0.75;
}

/* ===== 按钮复用 ===== */
.btn-primary {
  display: inline-block;
  background: var(--c-red, #E53935);
  color: #fff;
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 0.9rem;
  font-weight: 700;
  padding: 0.7rem 1.6rem;
  border-radius: var(--radius-xl, 24px);
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: background 0.25s, transform 0.2s;
  border: none;
  cursor: pointer;
}
.btn-primary:hover {
  background: #c62828;
  transform: scale(1.02);
}
.btn-secondary {
  display: inline-block;
  background: transparent;
  color: var(--c-blue, #1E88E5);
  font-family: var(--font-head, 'Roboto Condensed', sans-serif);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-xl, 24px);
  text-decoration: none;
  border: 1.5px solid var(--c-blue, #1E88E5);
  transition: background 0.25s, color 0.25s;
  cursor: pointer;
}
.btn-secondary:hover {
  background: var(--c-blue, #1E88E5);
  color: #fff;
}

/* ===== 媒体查询：平板及以上 ===== */
@media (min-width: 640px) {
  .about-hero {
    padding: 2rem 2rem 3rem;
  }
  .about-hero__main {
    flex-direction: row;
    align-items: center;
  }
  .about-hero__visual {
    max-width: 280px;
  }
  .about-hero__title {
    font-size: clamp(3rem, 8vw, 4.8rem);
  }
  .about-section__body {
    padding-left: 0.5rem;
  }
  .data-cards {
    grid-template-columns: repeat(2, 1fr);
  }
  .about-ambient {
    margin: 2rem -2rem -3rem;
  }
}

@media (min-width: 900px) {
  .about-hero {
    padding: 2.5rem 2rem 4rem;
  }
  .about-hero__main {
    gap: 3rem;
  }
  .about-hero__visual {
    max-width: 340px;
  }
  .about-hero__tag {
    margin-left: 0;
  }
  .about-layout {
    flex-direction: row;
    align-items: flex-start;
    padding: 0 2rem;
  }
  .about-sidebar {
    position: sticky;
    top: calc(var(--header-h, 4rem) + 1.5rem);
    width: var(--about-sidebar-w);
    flex-shrink: 0;
    border-bottom: none;
    padding: 2rem 0 0;
    margin-bottom: 0;
  }
  .about-sidebar__nav {
    flex-direction: column;
    gap: 0.35rem;
  }
  .about-sidebar__link {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    border-radius: var(--radius-sm, 8px);
  }
  .about-sidebar__cta {
    display: block;
  }
  .about-sidebar__btn {
    width: auto;
  }
  .about-content {
    padding-bottom: 4rem;
  }
  .about-section {
    padding: 2rem 0;
  }
  .about-section__body {
    padding-left: 1rem;
  }
  .about-section__title {
    font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  }
  .data-cards {
    grid-template-columns: repeat(4, 1fr);
  }
  .about-ambient {
    margin: 2rem -2rem -4rem;
    border-radius: var(--radius-xl, 24px) var(--radius-xl, 24px) 0 0;
  }
}

@media (min-width: 1200px) {
  .about-hero {
    padding: 3rem 2rem 5rem;
  }
  .about-hero__visual {
    max-width: 400px;
  }
  .about-layout {
    padding: 0 2rem;
  }
}