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

body {
    font-family: 'Courier New', monospace;
    background: #000;
    color: #0f0;
    overflow: hidden;
    cursor: none;
}

#game-container {
    width: 100vw;
    height: 100vh;
    position: relative;
}

#start-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background: linear-gradient(180deg, #1a0000 0%, #000 100%);
}

#start-screen h1 {
    font-size: 4rem;
    color: #ff0000;
    text-shadow: 0 0 20px #ff0000;
    margin-bottom: 2rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

#start-screen p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #aaa;
}

button {
    background: #ff0000;
    color: #fff;
    border: 3px solid #fff;
    padding: 15px 40px;
    font-size: 1.5rem;
    font-family: 'Courier New', monospace;
    cursor: pointer;
    transition: all 0.3s;
    text-transform: uppercase;
}

button:hover {
    background: #fff;
    color: #ff0000;
    box-shadow: 0 0 20px #ff0000;
}

#game-ui {
    width: 100%;
    height: 100%;
    position: relative;
}

#game-canvas {
    display: block;
    width: 100%;
    height: 100%;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
}

#hud {
    position: absolute;
    top: 20px;
    left: 20px;
    background: rgba(0, 0, 0, 0.7);
    padding: 15px;
    border: 2px solid #0f0;
    font-size: 1.2rem;
    z-index: 10;
}

#hud div {
    margin-bottom: 10px;
}

#hud div:last-child {
    margin-bottom: 0;
}

#health-value {
    color: #0f0;
}

#ammo-value {
    color: #ff0;
}

#enemy-count {
    color: #f00;
}

#game-over, #victory {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.9);
    padding: 50px;
    border: 5px solid #ff0000;
    text-align: center;
    z-index: 100;
}

#game-over h2 {
    color: #ff0000;
    font-size: 3rem;
    margin-bottom: 30px;
    text-shadow: 0 0 20px #ff0000;
}

#victory h2 {
    color: #0f0;
    font-size: 3rem;
    margin-bottom: 30px;
    text-shadow: 0 0 20px #0f0;
}

/* Crosshair */
#game-canvas::after {
    content: '+';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #0f0;
    font-size: 2rem;
    pointer-events: none;
    text-shadow: 0 0 5px #000;
}