#problem{background:#fff;}
      #problem .bs-lead{max-width:780px;margin:14px auto 44px;text-align:center;font-size:18px;line-height:1.6;color:var(--gray-700);font-family:system-ui,sans-serif;}
      #problem .bs-lead strong{color:var(--feroot-navy);font-weight:700;}
      #problem .bs-flow{display:grid;grid-template-columns:1fr auto 1fr;gap:28px;align-items:center;max-width:1040px;margin:0 auto;}
      #problem .bs-stack{display:flex;flex-direction:column;gap:12px;}
      #problem .bs-tool{display:flex;align-items:center;gap:14px;background:#fff;border:1px solid var(--gray-300);border-radius:14px;padding:16px 18px;opacity:.94;}
      #problem .bs-tool-ic{width:40px;height:40px;border-radius:10px;background:var(--gray-200);color:var(--gray-600);display:flex;align-items:center;justify-content:center;font-size:17px;flex-shrink:0;}
      #problem .bs-tool h4{font-size:15px;font-weight:700;color:var(--feroot-navy);margin:0;font-family:'Open Sans','Open Sans Fallback','Open Sans Fallback Roboto',system-ui;line-height:1.2;}
      #problem .bs-tool span{font-size:12px;color:var(--gray-600);font-family:system-ui;display:flex;align-items:center;gap:5px;margin-top:3px;}
      #problem .bs-tool span i{color:#EB0028;font-size:11px;}
      #problem .bs-divider{display:flex;flex-direction:column;align-items:center;gap:8px;text-align:center;}
      #problem .bs-line{width:1px;height:54px;background:linear-gradient(to bottom,transparent,var(--gray-300));}
      #problem .bs-perimeter{writing-mode:vertical-rl;font-size:11px;font-weight:800;letter-spacing:.14em;text-transform:uppercase;color:var(--gray-500);font-family:'Open Sans','Open Sans Fallback','Open Sans Fallback Roboto',system-ui;}
      #problem .bs-hero{background:linear-gradient(150deg,#191c54,#382785);border-radius:18px;padding:28px;color:#fff;box-shadow:0 18px 48px rgba(0,2,71,.22);}
      #problem .bs-hero-ic{width:46px;height:46px;border-radius:12px;background:rgba(255,255,255,.12);display:flex;align-items:center;justify-content:center;font-size:20px;color:#fff;margin-bottom:14px;}
      #problem .bs-hero h3{font-size:19px;font-weight:800;margin:0 0 8px;font-family:'Open Sans','Open Sans Fallback','Open Sans Fallback Roboto',system-ui;line-height:1.25;color:#fff;}
      #problem .bs-hero p{font-size:14px;line-height:1.6;margin:0;color:rgba(255,255,255,.82);font-family:system-ui;}
      #problem .bs-hero .bs-live{display:inline-flex;align-items:center;gap:6px;margin-top:14px;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:#7CF5D2;}
      #problem .bs-hero .bs-live::before{content:'';width:7px;height:7px;border-radius:50%;background:#34D399;box-shadow:0 0 0 3px rgba(52,211,153,.25);}
      #problem .bs-foot{max-width:820px;margin:36px auto 0;text-align:center;font-size:13px;color:var(--gray-600);font-family:system-ui;}
      #problem .bs-foot strong{color:var(--feroot-navy);}
      @media(max-width:820px){#problem .bs-flow{grid-template-columns:1fr;gap:20px;}#problem .bs-divider{flex-direction:row;}#problem .bs-line{width:54px;height:1px;background:linear-gradient(to right,transparent,var(--gray-300));}#problem .bs-perimeter{writing-mode:horizontal-tb;}}