* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: #1a1a1a;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: white;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

h1 {
    color: #00ff88;
    font-size: 28px;
    margin-bottom: 10px;
}

canvas {
    background: #000;
    border: 2px solid #333;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 255, 136, 0.1);
}

.controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
}

button {
    padding: 12px 24px;
    font-size: 16px;
    cursor: pointer;
    background: #333;
    color: white;
    border: 1px solid #555;
    border-radius: 6px;
    transition: all 0.3s ease;
    font-weight: 500;
}

button:hover {
    background: #444;
    border-color: #00ff88;
    transform: translateY(-2px);
}

button:active {
    transform: translateY(0);
}

.info {
    color: #888;
    text-align: center;
    font-size: 14px;
}

.info p {
    margin: 5px 0;
}

.info span {
    color: #00ff88;
    font-weight: 600;
}

.step {
    margin: 10px 0;
    padding: 15px;
    border: 2px solid #333;
    border-radius: 8px;
    background-color: #f5f5f5;
}

#nCirclesInput {
    width: 100px;
    font-size: 14px;
    margin: 0 10px;
    padding: 12px 24px;
    font-size: 16px;
    cursor: pointer;
    background: #333;
    color: white;
    border: 1px solid #555;
    border-radius: 6px;
    transition: all 0.3s ease;
    font-weight: 500;
}

.step label {
    font-weight: bold;
    margin-right: 10px;
}
.btn-input {
    display: inline-block;
    padding: 8px 16px;
    font-size: 16px;
    border: none;
    background: #222;
    color: #fff;
    border-radius: 4px;
    cursor: pointer;
    margin-right: 8px;
    margin-bottom: 8px;
    transition: background 0.2s;
}

.btn-input:hover {
    background: #444;
}

input[type="file"].btn-input {
    padding: 8px 0;
    color-scheme: dark;
}

@media (max-width: 768px) {
    canvas {
        width: 100%;
        height: auto;
    }
}