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

body {
    min-height: 100vh;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a2e 100%);
    overflow: hidden;
    font-family: 'Courier New', Consolas, monospace;
    display: flex;
    justify-content: center;
    align-items: center;
}

#game-container {
    position: relative;
    width: 800px;
    height: 600px;
    box-shadow: 0 0 50px rgba(97, 255, 181, 0.3);
    border-radius: 8px;
    overflow: hidden;
}

canvas {
    background-color: #000;
    display: block;
    border: 2px solid #333;
}

.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
}

.hidden {
    display: none;
}

h1 {
    font-size: 4em;
    margin: 0 0 20px 0;
    color: #4CAF50;
    text-shadow: 0 0 10px #4CAF50;
}

button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    margin: 10px;
    cursor: pointer;
    border-radius: 5px;
    transition: all 0.3s;
}

button:hover {
    background-color: #45a049;
    transform: scale(1.05);
}

p {
    font-size: 1.2em;
    margin: 10px 0;
}

#score-display {
    position: absolute;
    top: 20px;
    left: 20px;
    color: white;
    font-size: 1.5em;
}

#lives-display {
    position: absolute;
    top: 20px;
    right: 20px;
    color: white;
    font-size: 1em;
    text-align: right;
}

#high-score-display {
    position: absolute;
    top: 50px;
    left: 20px;
    color: #ffd700;
    font-size: 1em;
}

#controls-hint {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.8em;
    text-align: center;
}

#pause-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
}

#pause-overlay h2 {
    color: #61ffb5;
    font-size: 3em;
    text-shadow: 0 0 20px #61ffb5;
}

.mute-btn {
    position: absolute;
    bottom: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    padding: 8px 12px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9em;
    transition: all 0.3s;
}

.mute-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* Level up animation */
@keyframes levelUp {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.5); opacity: 0.8; }
    100% { transform: scale(1); opacity: 1; }
}

.level-up-flash {
    animation: levelUp 0.5s ease-out;
}