/* 第二屏与全站共用 section-shell 的内容宽度；深色背景独立延展至页面边缘。 */
.business-intro {
  position: relative;
  isolation: isolate;
  padding-block: 120px;
  color: #f5f6f8;
  font-family: Arial, "PingFang SC", "HarmonyOS Sans SC", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  scroll-margin-top: 118px;
}
.business-intro::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset-block: 0;
  left: 50%;
  width: var(--layout-width);
  transform: translateX(-50%);
  background: #171b22;
}
.business-intro h2, .business-intro h3, .business-intro h4, .business-intro p { margin: 0; }
.business-intro-heading { margin-bottom: 44px; }
/* 与第一组的两张图使用同一列比，保证右侧总述左边缘准确对齐右上图片。 */
.business-intro-title-row { display: grid; grid-template-columns: minmax(0, 1.56fr) minmax(0, 1fr); align-items: end; gap: 24px; }
.business-intro-title-row h2 { font-size: clamp(43px, calc(3.8 * var(--layout-unit)), 58px); font-weight: 620; line-height: 1.08; letter-spacing: -.055em; text-wrap: balance; }
.business-intro-title-row > p { min-width: 0; padding-bottom: 3px; color: #d4d8df; font-size: 22px; line-height: 1.5; text-align: left; }
.business-intro-groups { display: grid; gap: 52px; }
.business-intro-group { min-width: 0; }
/* 阶段只用标题、间距和一道分隔线区分，不增加外框或独立底板。 */
.business-intro-group + .business-intro-group { padding-top: 28px; border-top: 1px solid #3d424b; }
.business-intro-label { display: flex; align-items: baseline; gap: 18px; margin-bottom: 18px; }
.business-intro-label > span { flex: none; color: #adb8f2; font-size: 16px; font-weight: 650; }
.business-intro-label h3 { font-size: 28px; font-weight: 650; line-height: 1.2; letter-spacing: -.035em; }
.business-intro-cards { display: grid; grid-template-columns: minmax(0, 1.56fr) minmax(0, 1fr); gap: 24px; min-width: 0; }
.business-intro-application .business-intro-cards { grid-template-columns: minmax(0, 1fr) minmax(0, 1.56fr); }
.business-intro-card { position: relative; isolation: isolate; overflow: hidden; min-width: 0; height: clamp(244px, calc(20 * var(--layout-unit)), 360px); color: #fff; background: #11161d; }
/* 直接复用原素材 WebP，保持等比；遮罩只承接下方文字，不另设文案底板。 */
.business-intro-card img { position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; object-fit: cover; }
.business-intro-card::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(0deg, rgba(5,8,13,.94), rgba(5,8,13,.42) 24%, rgba(5,8,13,0) 64%); }
.business-intro-application .business-intro-card:first-child img { object-position: 66% 50%; }
.business-intro-copy { position: absolute; inset: auto 28px 22px; }
.business-intro-copy h4 { font-size: clamp(26px, calc(2.2 * var(--layout-unit)), 33px); font-weight: 620; line-height: 1.2; letter-spacing: -.035em; }
.business-intro .business-intro-copy p { margin-top: 8px; color: #e0e4ea; font-size: 22px; line-height: 1.4; text-wrap: balance; }
@media (max-width: 680px) {
  .business-intro { padding-block: 90px; }
  .business-intro-heading { margin-bottom: 32px; }
  .business-intro-title-row { grid-template-columns: 1fr; gap: 16px; }
  .business-intro-title-row h2 { font-size: clamp(30px, 9.7vw, 38px); }
  /* 手机取消桌面固定断行，由均衡换行避免长标题末尾落单一个字。 */
  .business-intro-title-row h2 br { display: none; }
  .business-title-asset { white-space: nowrap; }
  .business-intro-title-row > p { padding-bottom: 0; }
  .business-intro-groups { gap: 36px; }
  .business-intro-group + .business-intro-group { padding-top: 24px; }
  .business-intro-label { gap: 12px; margin-bottom: 16px; }
  .business-intro-label h3 { font-size: 24px; }
  .business-intro-cards, .business-intro-application .business-intro-cards { grid-template-columns: 1fr; gap: 16px; }
  .business-intro-card { height: auto; aspect-ratio: 1.5 / 1; }
  .business-intro-copy { inset: auto 18px 20px; }
  .business-intro-copy h4 { font-size: 26px; }
  .business-intro .business-intro-copy p { font-size: 18px; }
}