body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    background-color: #111;
    overflow: hidden;
    perspective: 1500px;
    cursor: none;
}

#gameArea {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    background: radial-gradient(circle, rgba(0, 0, 0, 0.9) 0%, rgba(0, 0, 0, 0.7) 100%);
}

#player {
    position: absolute;
    width: 40px;
    height: 40px;
    background-color: #0f0;
    text-align: center;
    line-height: 40px;
    font-size: 24px;
    border-radius: 50%;
    box-shadow: 0 0 25px rgba(0, 255, 0, 1), 0 0 40px rgba(0, 255, 0, 0.5) inset;
    transform: translateZ(0);
    animation: playerWalk 0.5s infinite alternate, playerGlow 1s infinite alternate;
}

#gun {
    position: absolute;
    width: 40px;
    height: 40px;
    font-size: 24px;
    text-align: center;
    line-height: 40px;
    color: #f00;
    box-shadow: 0 0 25px rgba(255, 0, 0, 1), 0 0 40px rgba(255, 0, 0, 0.5) inset;
    transform: translateZ(0);
    animation: gunAim 1s infinite, gunPulse 1s infinite;
}

#hpPotion {
    position: absolute;
    width: 30px;
    height: 30px;
    font-size: 24px;
    text-align: center;
    line-height: 30px;
    color: #0f0;
    display: none;
    box-shadow: 0 0 25px rgba(0, 255, 0, 1), 0 0 40px rgba(0, 255, 0, 0.5) inset;
    animation: potionGlow 1.5s infinite alternate, potionPulse 1s infinite;
}

.zombie {
    position: absolute;
    width: 40px;
    height: 40px;
    text-align: center;
    line-height: 40px;
    font-size: 24px;
    color: #f00;
    box-shadow: 0 0 25px rgba(255, 0, 0, 1), 0 0 40px rgba(255, 0, 0, 0.5) inset;
    transform: translateZ(0);
    animation: zombieWalk 1s infinite, zombiePulse 1s infinite;
}

.bullet {
    position: absolute;
    width: 10px;
    height: 10px;
    background-color: #ff0;
    text-align: center;
    line-height: 10px;
    font-size: 24px;
    box-shadow: 0 0 20px rgba(255, 255, 0, 1), 0 0 30px rgba(255, 255, 0, 0.5) inset;
    animation: bulletMove 0.1s linear;
}

#score, #stopwatch, #hp {
    position: absolute;
    top: 10px;
    color: #fff;
    font-size: 20px;
    font-weight: bold;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.8);
}

#score {
    left: 10px;
}

#stopwatch {
    right: 10px;
}

#hp {
    right: 10px;
    top: 40px;
}

#deathScreen {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: #fff;
    background: rgba(0, 0, 0, 0.8);
    padding: 20px;
    border-radius: 10px;
    display: none;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.9);
    animation: fadeIn 1s;
}

#deathScreen h1 {
    margin: 0;
    font-size: 2.5em;
}

#restartBtn {
    margin-top: 10px;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    background: #f00;
    color: #fff;
    border: none;
    border-radius: 5px;
    box-shadow: 0 0 25px rgba(255, 0, 0, 1);
    transition: background 0.3s;
}

#restartBtn:hover {
    background: #c00;
}

@keyframes playerWalk {
    from { transform: translateZ(0) rotateY(0); }
    to { transform: translateZ(0) rotateY(15deg); }
}

@keyframes playerGlow {
    from { box-shadow: 0 0 25px rgba(0, 255, 0, 1), 0 0 40px rgba(0, 255, 0, 0.5) inset; }
    to { box-shadow: 0 0 35px rgba(0, 255, 0, 1.5), 0 0 50px rgba(0, 255, 0, 0.5) inset; }
}

@keyframes gunAim {
    0% { transform: rotate(0); }
    50% { transform: rotate(15deg); }
    100% { transform: rotate(0); }
}

@keyframes gunPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

@keyframes potionGlow {
    from { box-shadow: 0 0 25px rgba(0, 255, 0, 1), 0 0 40px rgba(0, 255, 0, 0.5) inset; }
    to { box-shadow: 0 0 35px rgba(0, 255, 0, 1.5), 0 0 50px rgba(0, 255, 0, 0.5) inset; }
}

@keyframes potionPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

@keyframes zombieWalk {
    0% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0); }
}

@keyframes zombiePulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

@keyframes bulletMove {
    0% { transform: scale(1); }
    100% { transform: scale(1.5); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes explode {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(2); opacity: 0.5; }
    100% { transform: scale(5); opacity: 0; }
}

#player.explode {
    animation: explode 0.5s forwards;
    box-shadow: 0 0 50px rgba(255, 0, 0, 1), 0 0 100px rgba(255, 0, 0, 0.5) inset;
}