body {
  margin:0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color:#111;
}

.app {
  max-width:1100px;
  margin:40px auto;
  background:white;
  padding:30px;
  border-radius:20px;
  box-shadow:0 20px 50px rgba(0,0,0,0.2);
}

h1 { text-align:center; margin-bottom:5px; }
.subtitle { text-align:center; color:#666; margin-bottom:20px; }

.container {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:20px;
}

.card {
  background:#f9fafb;
  padding:20px;
  border-radius:14px;
}

input {
  width:100%;
  margin:6px 0;
  padding:10px;
  border-radius:8px;
  border:1px solid #ddd;
}

.controls {
  margin-top:20px;
}

.buttons {
  display:flex;
  gap:10px;
}

button {
  flex:1;
  padding:12px;
  border:none;
  border-radius:10px;
  cursor:pointer;
  background:#6366f1;
  color:white;
  font-weight:bold;
}

button.secondary {
  background:#e5e7eb;
  color:#111;
}

button:hover { opacity:0.9; }

.results {
  text-align:center;
  margin-top:20px;
  font-weight:bold;
}

.error { color:red; }

canvas { margin-top:30px; }

@media(max-width:768px){
  .container { grid-template-columns:1fr; }
}