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

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

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

#ui-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 20px 30px;
    z-index: 100;
    pointer-events: none;
}

#score {
    color: #00ff88;
    font-size: 28px;
    font-weight: bold;
    text-shadow: 0 0 10px #00ff88, 0 0 20px #00ff88;
    letter-spacing: 3px;
}

#high-score {
    color: #ffaa00;
    font-size: 24px;
    font-weight: bold;
    text-shadow: 0 0 10px #ffaa00;
    text-align: right;
}

#health-bar {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    width: 300px;
    pointer-events: none;
}

.health-label {
    color: #00ffff;
    font-size: 14px;
    font-weight: bold;
    text-shadow: 0 0 5px #00ffff;
    margin-bottom: 5px;
    text-align: center;
    letter-spacing: 2px;
}

#health-fill {
    height: 12px;
    background: linear-gradient(90deg, #00ffff, #00ff88);
    border-radius: 6px;
    box-shadow: 0 0 15px #00ffff, 0 0 30px #00ffff;
    transition: width 0.3s ease, background 0.3s ease;
}

#health-fill.critical {
    background: linear-gradient(90deg, #ff0000, #ff6600);
    box-shadow: 0 0 15px #ff0000, 0 0 30px #ff0000;
    animation: pulse 0.5s ease-in-out infinite alternate;
}

@keyframes pulse {
    from { opacity: 0.7; }
    to { opacity: 1; }
}

#start-screen, #game-over-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: radial-gradient(ellipse at center, rgba(0,20,40,0.9) 0%, rgba(0,0,0,0.95) 100%);
    z-index: 200;
    cursor: default;
}

#start-screen h1, #game-over-screen h1 {
    font-size: 48px;
    color: #00ff88;
    text-shadow: 0 0 20px #00ff88, 0 0 40px #00ff88, 0 0 60px #00ff88;
    margin-bottom: 20px;
    letter-spacing: 5px;
    animation: title-glow 3s ease-in-out infinite alternate;
}

@keyframes title-glow {
    from {
        text-shadow: 0 0 20px #00ff88, 0 0 40px #00ff88, 0 0 60px #00ff88;
    }
    to {
        text-shadow: 0 0 30px #00ff88, 0 0 60px #00ff88, 0 0 90px #00ff88, 0 0 120px #00ff88;
    }
}

#game-over-screen h1 {
    color: #ff3333;
    animation: title-glow-danger 3s ease-in-out infinite alternate;
}

@keyframes title-glow-danger {
    from {
        text-shadow: 0 0 20px #ff3333, 0 0 40px #ff3333, 0 0 60px #ff3333;
    }
    to {
        text-shadow: 0 0 30px #ff3333, 0 0 60px #ff3333, 0 0 90px #ff3333, 0 0 120px #ff3333;
    }
}

#start-screen p, #game-over-screen p {
    color: #88ccff;
    font-size: 16px;
    margin: 8px 0;
    text-shadow: 0 0 5px rgba(136, 204, 255, 0.5);
}

#final-score {
    font-size: 36px !important;
    color: #00ff88 !important;
    text-shadow: 0 0 15px #00ff88, 0 0 30px #00ff88;
    margin: 15px 0 !important;
}

#enemies-destroyed {
    font-size: 20px !important;
    color: #ffaa00 !important;
    margin: 10px 0 !important;
}

button {
    margin-top: 25px;
    padding: 15px 50px;
    font-size: 18px;
    font-weight: bold;
    color: #000;
    background: linear-gradient(135deg, #00ff88, #00cccc);
    border: none;
    border-radius: 3px;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 3px;
    font-family: 'Courier New', monospace;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px rgba(0, 255, 136, 0.5);
}

button:hover {
    transform: scale(1.1);
    box-shadow: 0 0 30px rgba(0, 255, 136, 0.8), 0 0 60px rgba(0, 255, 136, 0.5);
}

button:active {
    transform: scale(0.95);
}

#crosshair {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 30px;
    height: 30px;
    pointer-events: none;
    z-index: 150;
}

#crosshair::before,
#crosshair::after {
    content: '';
    position: absolute;
    background: #00ff88;
    box-shadow: 0 0 10px #00ff88;
}

#crosshair::before {
    width: 2px;
    height: 100%;
    left: 50%;
    transform: translateX(-50%);
}

#crosshair::after {
    width: 100%;
    height: 2px;
    top: 50%;
    transform: translateY(-50%);
}

/* Hit marker */
.hit-marker {
    position: absolute;
    width: 50px;
    height: 50px;
    pointer-events: none;
    animation: hit-expand 0.3s ease-out forwards;
}

.hit-marker::before,
.hit-marker::after {
    content: '';
    position: absolute;
    background: #ff3333;
    box-shadow: 0 0 10px #ff3333;
}

.hit-marker::before {
    width: 3px;
    height: 100%;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
}

.hit-marker::after {
    width: 100%;
    height: 3px;
    top: 50%;
    transform: translateY(-50%) rotate(45deg);
}

@keyframes hit-expand {
    0% { transform: scale(0.5); opacity: 1; }
    100% { transform: scale(2); opacity: 0; }
}

@media (max-width: 768px) {
    #start-screen h1, #game-over-screen h1 {
        font-size: 28px;
    }

    #score {
        font-size: 18px;
    }

    #health-bar {
        width: 200px;
    }
}