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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #0a0a1f 0%, #1a0a2e 50%, #0f0a1f 100%);
    font-family: 'Courier New', monospace;
    overflow: hidden;
}

#gameContainer {
    text-align: center;
    position: relative;
}

canvas {
    border: 3px solid #4a0e78;
    border-radius: 10px;
    background: radial-gradient(circle at center, #0d0520, #050210);
    box-shadow: 0 0 40px rgba(138, 43, 226, 0.4);
    cursor: crosshair;
    /* ensure canvas sits below overlays */
    position: relative;
    z-index: 0;
}

#ui {
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    color: #fff;
    font-size: 18px;
    text-shadow: 0 0 10px rgba(138, 43, 226, 0.8);
    pointer-events: none;
}

#score {
    float: left;
    background: rgba(74, 14, 120, 0.3);
    padding: 10px 20px;
    border-radius: 5px;
}

#timer {
    float: right;
    background: rgba(74, 14, 120, 0.3);
    padding: 10px 20px;
    border-radius: 5px;
}

#instructions {
    clear: both;
    margin-top: 80px;
    background: rgba(74, 14, 120, 0.3);
    padding: 10px;
    border-radius: 5px;
    font-size: 14px;
}

#gameOver {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(10, 5, 20, 0.95);
    padding: 40px;
    border-radius: 15px;
    border: 3px solid #8a2be2;
    display: none;
    box-shadow: 0 0 50px rgba(138, 43, 226, 0.6);
    z-index: 10; /* keep game-over on top so buttons are clickable */
}

#gameOver h2 {
    color: #8a2be2;
    font-size: 36px;
    margin-bottom: 20px;
}

#gameOver p {
    color: #fff;
    font-size: 24px;
    margin: 10px 0;
}

#restartBtn {
    margin-top: 20px;
    padding: 15px 40px;
    font-size: 20px;
    background: linear-gradient(135deg, #8a2be2, #4a0e78);
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-family: 'Courier New', monospace;
    pointer-events: all;
    transition: all 0.3s;
}

#restartBtn:hover {
    transform: scale(1.1);
    box-shadow: 0 0 20px rgba(138, 43, 226, 0.8);
}