body {
    margin: 0;
    overflow: hidden;
    background-color: black;
    font-family: 'Press Start 2P', cursive;
    color: #00ffcc;
    text-align: center;
    filter: contrast(1.2) brightness(1.1);
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
}

canvas {
    display: block;
    background-color: #000;
    margin: 0 auto;
    border: 2px solid #00fff6;
    box-shadow: 0 0 20px #00fff6;
}

#ui {
    position: absolute;
    top: 10px;
    left: 10px;
    color: #00ffcc;
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
}

#menu, #gameOverMenu {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #00ffcc;
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
    text-align: center;
}

button {
    font-family: 'Press Start 2P', cursive;
    color: #00ffcc;
    background: none;
    border: 2px solid #00ffcc;
    padding: 10px 20px;
    cursor: pointer;
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
}

button:hover {
    background-color: #00ffcc;
    color: black;
}

.hidden {
    display: none;
}

#redHalo {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 0, 0, 0.3), transparent);
    pointer-events: none;
    display: none;
    z-index: -1;
}

#upgradeMenu {
    position: absolute;
    background-color: rgba(0, 0, 0, 0.8);
    border: 2px solid #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
    padding: 20px;
    text-align: center;
    z-index: 10;
}

#instructionsButton {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 10px;
    background-color: rgba(0, 0, 0, 0.8);
    border: 2px solid #00ffcc;
    color: #00ffcc;
    cursor: pointer;
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
}

#instructionsButton:hover {
    background-color: #00ffcc;
    color: black;
}

#instructionsWindow {
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translate(-50%, -20%);
    background-color: rgba(0, 0, 0, 0.8);
    border: 2px solid #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
    padding: 20px;
    text-align: center;
    z-index: 10;
}

#pauseButton {
    position: absolute;
    bottom: 10px;
    right: 10px;
    padding: 10px;
    background-color: rgba(0, 0, 0, 0.8);
    border: 2px solid #00ffcc;
    color: #00ffcc;
    cursor: pointer;
    text-shadow: 0 0 5px #00ffcc, 0 0 10px #00ffcc, 0 0 15px #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
}

#pauseButton:hover {
    background-color: #00ffcc;
    color: black;
}

#musicPlayer {
    position: absolute;
    bottom: 10px;
    left: 10px;
    padding: 10px;
    background-color: rgba(0, 0, 0, 0.8);
    border: 2px solid #00ffcc;
    color: #00ffcc;
    box-shadow: 0 0 10px #00ffcc;
}

#musicToggle, #volumeControl {
    display: block;
    margin: 5px 0;
	color: #00ffcc;
}

.crt {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVQYV2NgYAAAAAMAASsJTYQAAAAASUVORK5CYII=') repeat;
    opacity: 0.2;
    pointer-events: none;
}

.tower-level-0 {
    box-shadow: 0 0 5px #ff004d;
}

.tower-level-1 {
    box-shadow: 0 0 10px #ff004d;
}

.tower-level-2 {
    box-shadow: 0 0 15px #ff004d;
}

.tower-level-3 {
    box-shadow: 0 0 20px #ff004d;
}

.tower-level-4 {
    box-shadow: 0 0 30px #ff004d;
}

.tower-level-5 {
    box-shadow: 0 0 40px #ff004d;
}

.tower-level-6 {
    box-shadow: 0 0 50px #ff004d;
}