* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
  line-height: 1.72;
}
a { color: #38bdf8; }

.bv-head {
  background: #020617;
  border-bottom: 1px solid #334155;
  position: sticky;
  top: 0;
  z-index: 50;
}
.bv-head-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.bv-logo { font-weight: 800; color: #7dd3fc; font-size: 18px; }
.bv-nav { display: flex; flex-wrap: wrap; gap: 14px; font-size: 14px; }
.bv-nav a { color: #94a3b8; text-decoration: none; font-weight: 600; }
.bv-nav a:hover { color: #fff; }
.bv-btn {
  display: inline-block;
  background: #0284c7;
  color: #fff !important;
  text-decoration: none;
  padding: 10px 18px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 14px;
  border: none;
  cursor: pointer;
}
.bv-wrap { max-width: 1000px; margin: 0 auto; padding: 28px 20px 100px; }
.bv-hero {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  border: 1px solid #334155;
  border-radius: 16px;
  padding: 32px 26px;
  margin-bottom: 24px;
}
.bv-hero h1 { margin: 0 0 12px; font-size: clamp(24px, 4vw, 36px); color: #f1f5f9; }
.bv-lead { color: #94a3b8; font-size: 17px; margin: 0 0 16px; }
.bv-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin: 24px 0;
}
.bv-card {
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 12px;
  padding: 22px;
}
.bv-card h2 { margin: 0 0 10px; font-size: 18px; color: #7dd3fc; }
.bv-card h2 a { color: inherit; text-decoration: none; }
.bv-section {
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 12px;
  padding: 26px;
  margin: 20px 0;
}
.bv-section h2 { margin: 0 0 12px; color: #7dd3fc; }
.bv-tip {
  background: #422006;
  border-left: 4px solid #f59e0b;
  padding: 14px 18px;
  border-radius: 0 8px 8px 0;
  margin: 16px 0;
  font-size: 15px;
}
.bv-crumb { font-size: 14px; color: #64748b; margin-bottom: 8px; }
.bv-crumb a { color: #38bdf8; }
.bv-portal {
  background: #020617;
  border: 2px solid #0284c7;
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  margin: 24px 0;
}
.bv-portal a { color: #38bdf8; font-weight: 800; font-size: 20px; }
.bv-foot { text-align: center; padding: 24px; font-size: 14px; color: #64748b; border-top: 1px solid #334155; }
.bv-phone {
  background: #1e293b;
  border: 1px dashed #475569;
  border-radius: 10px;
  padding: 16px;
  text-align: center;
  margin: 20px 0;
}
.bv-phone-mask { font-size: 19px; letter-spacing: 0.08em; margin: 8px 0; }
.bv-sticky {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: #020617ee;
  border-top: 1px solid #334155;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  z-index: 60;
  backdrop-filter: blur(8px);
}
.bv-sticky span { color: #94a3b8; font-size: 14px; }