:root {
  --bg: #0b1020;
  --panel: #111827;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --primary: #2563eb;
  --primary-600: #1d4ed8;
  --border: rgba(255,255,255,0.08);
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

.app { display: flex; flex-direction: column; min-height: 100vh; }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: rgba(17,24,39,0.8);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand { font-weight: 700; letter-spacing: 0.2px; }

.tag { color: var(--muted); font-size: 14px; }

.wrap { max-width: 960px; width: 100%; margin: 0 auto; padding: 24px; }

.hero { padding: 28px 0; }

.hero h1 { margin: 0 0 10px; font-size: 28px; }

.hero p { margin: 0 0 18px; color: var(--muted); }

.actions { display: flex; gap: 10px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text);
  text-decoration: none;
}

.btn.primary { background: var(--primary); border-color: var(--primary); color: white; }
.btn.primary:hover { background: var(--primary-600); }

.foot { margin-top: auto; padding: 14px 18px; color: var(--muted); border-top: 1px solid var(--border); }

.builder {
  display: grid;
  grid-template-columns: 260px 1fr 280px;
  gap: 14px;
  padding: 14px;
  flex: 1;
}

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

.blocks { list-style: none; padding: 0; margin: 10px 0 0; display: grid; gap: 8px; }

.blocks li {
  padding: 10px;
  border-radius: 10px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  cursor: grab;
}

.canvas {
  min-height: 320px;
  background: var(--panel);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 18px;
}

.preview { flex: 1; padding: 14px; }

@media (max-width: 900px) {
  .builder { grid-template-columns: 1fr; }
}