:root {
  --bpv-bg: #f5f7fb;
  --bpv-panel: #ffffff;
  --bpv-text: #1f2937;
  --bpv-muted: #5b6475;
  --bpv-primary: #2563eb;
  --bpv-secondary: #10b981;
  --bpv-danger: #ef4444;
  --bpv-border: #dbe2ee;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: radial-gradient(circle at 10% 0%, #ffffff, var(--bpv-bg) 38%);
  color: var(--bpv-text);
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.5;
}

.bpv-container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 20px;
}

.bpv-header {
  background: linear-gradient(135deg, #e9f0ff, #f9fbff);
  border: 1px solid var(--bpv-border);
  border-radius: 14px;
  padding: 22px;
  margin-bottom: 18px;
}

.bpv-header h1 {
  margin: 0 0 8px;
  font-size: clamp(1.45rem, 2.8vw, 2rem);
  color: #1e40af;
}

.bpv-header p {
  margin: 0;
  color: #3f4a5f;
}

.bpv-main {
  display: grid;
  gap: 14px;
}

.bpv-grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.bpv-panel {
  background: var(--bpv-panel);
  border: 1px solid var(--bpv-border);
  border-radius: 14px;
  padding: 16px;
}

.bpv-panel h2 {
  margin: 0 0 8px;
  color: #1e3a8a;
  font-size: 1.08rem;
}

.bpv-cards {
  margin-top: 10px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.bpv-card {
  background: #f8fbff;
  border: 1px solid #d8e4ff;
  border-radius: 10px;
  padding: 10px;
}

.bpv-card h3 {
  margin: 0 0 6px;
  font-size: 0.95rem;
  color: #1d4ed8;
}

.bpv-card p,
.bpv-panel p,
.bpv-panel li {
  color: var(--bpv-muted);
}

.bpv-formula-list {
  display: grid;
  gap: 6px;
  margin: 0;
}

.bpv-formula-item {
  background: #f1f5ff;
  border: 1px solid #d7e1ff;
  border-radius: 6px;
  padding: 5px 8px;
  min-height: 28px;
}

.bpv-control {
  margin: 8px 0;
}

.bpv-control label {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.92rem;
  color: #374151;
  margin-bottom: 4px;
}

.bpv-control input[type="range"] {
  width: 100%;
}

.bpv-equation {
  margin-top: 10px;
  border-radius: 10px;
  border: 1px solid #dbe6ff;
  background: #f8fbff;
  padding: 10px;
  color: #1f3f85;
  font-family: "Consolas", "SFMono-Regular", monospace;
  font-size: 0.92rem;
}

.bpv-canvas {
  width: 100%;
  min-height: 240px;
  border: 1px solid #dbe2ee;
  background: #fff;
  border-radius: 10px;
}

.bpv-actions {
  display: flex;
  gap: 8px;
  margin: 10px 0 6px;
}

.bpv-actions button {
  border: 0;
  border-radius: 8px;
  padding: 8px 12px;
  color: #fff;
  background: var(--bpv-primary);
  cursor: pointer;
}

.bpv-actions button:nth-child(2) {
  background: var(--bpv-secondary);
}

.bpv-actions button:nth-child(3) {
  background: #64748b;
}

.bpv-status {
  border: 1px solid #d9e7ff;
  background: #f7fbff;
  border-radius: 8px;
  padding: 8px 10px;
  color: #1e3a8a;
  font-size: 0.92rem;
}

.bpv-note {
  margin-top: 8px;
  font-size: 0.92rem;
  color: #4b5563;
}

.bpv-steps,
.bpv-list {
  margin: 0;
  padding-left: 18px;
}

.bpv-quote {
  margin-top: 10px;
  border-left: 3px solid #2563eb;
  padding-left: 10px;
  color: #334155;
}

@media (max-width: 920px) {
  .bpv-grid-2,
  .bpv-cards {
    grid-template-columns: 1fr;
  }

  .bpv-canvas {
    min-height: 220px;
  }
}