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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    padding: 30px;
    max-width: 600px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

header h1 {
    color: #333;
    font-size: 2.5em;
    margin-bottom: 10px;
}

.score-board {
    font-size: 1.5em;
    color: #764ba2;
    font-weight: bold;
}

#score {
    color: #e74c3c;
}

main {
    text-align: center;
}

.game-info {
    margin-bottom: 20px;
}

.game-controls {
    margin-top: 20px;
    margin-bottom: 15px;
    display: flex;
    justify-content: center;
    gap: 10px;
}

.btn {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
}

#startBtn {
    background: #27ae60;
    color: white;
}

#startBtn:hover {
    background: #229954;
}

#pauseBtn {
    background: #f39c12;
    color: white;
}

#pauseBtn:hover {
    background: #e67e22;
}

#pauseBtn:disabled {
    background: #ccc;
    cursor: not-allowed;
}

#resetBtn {
    background: #e74c3c;
    color: white;
}

#resetBtn:hover {
    background: #c0392b;
}

.difficulty-selector {
    margin-bottom: 20px;
    font-size: 1.1em;
    color: #333;
}

#difficulty {
    padding: 5px 10px;
    font-size: 16px;
    border: 2px solid #764ba2;
    border-radius: 5px;
    background: white;
    cursor: pointer;
}

#gameCanvas {
    background: #2c3e50;
    border: 4px solid #34495e;
    border-radius: 10px;
    display: block;
    margin: 0 auto 20px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.game-info {
    margin-top: 20px;
}

.game-info h3 {
    color: #333;
    margin-bottom: 10px;
}

.game-info ul {
    list-style: none;
    padding-left: 0;
    display: inline-block;
    text-align: left;
}

.game-info li {
    padding: 5px 0;
    color: #555;
    position: relative;
    padding-left: 20px;
}

.game-info li::before {
    content: "🎮";
    position: absolute;
    left: 0;
}

@media (max-width: 600px) {
    .container {
        padding: 20px;
    }

    header h1 {
        font-size: 1.8em;
    }

    #gameCanvas {
        width: 100%;
        height: auto;
    }

    .game-controls {
        flex-wrap: wrap;
    }

    .btn {
        flex: 1;
        min-width: 80px;
    }
}