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

body {
    font-family: 'Orbitron', monospace;
    background: #000011;
    color: #00aaff;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

#game-container {
    position: relative;
    width: 900px;
    height: 600px;
    border: 3px solid #00aaff;
    box-shadow: 0 0 30px rgba(0, 170, 255, 0.5);
    background: #000011;
}

#gameCanvas {
    display: block;
    width: 100%;
    height: 100%;
}

#ui-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    padding: 20px;
    pointer-events: none;
    z-index: 10;
}

#score {
    font-size: 24px;
    font-weight: 700;
    color: #00ffff;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.8);
    margin-bottom: 10px;
}

#high-score {
    font-size: 18px;
    font-weight: 400;
    color: #00aaff;
    text-shadow: 0 0 5px rgba(0, 170, 255, 0.5);
    margin-bottom: 15px;
}

#health-bar {
    width: 200px;
    height: 20px;
    border: 2px solid #00aaff;
    background: rgba(0, 0, 0, 0.5);
    position: relative;
    box-shadow: 0 0 10px rgba(0, 170, 255, 0.3);
}

#health-fill {
    height: 100%;
    width: 100%;
    background: #00ff00;
    transition: width 0.3s ease, background-color 0.3s ease;
    box-shadow: 0 0 10px rgba(0, 255, 0, 0.5);
}

#boss-health-container {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
}

#boss-health-label {
    font-size: 20px;
    font-weight: 700;
    color: #ff0000;
    text-shadow: 0 0 15px rgba(255, 0, 0, 0.8);
    margin-bottom: 8px;
    letter-spacing: 3px;
}

#boss-health-bar {
    width: 400px;
    height: 30px;
    border: 3px solid #ff0000;
    background: rgba(0, 0, 0, 0.7);
    position: relative;
    box-shadow: 0 0 20px rgba(255, 0, 0, 0.5);
    border-radius: 5px;
    overflow: hidden;
}

#boss-health-fill {
    height: 100%;
    width: 100%;
    background: linear-gradient(90deg, #ff0000, #ff6600);
    transition: width 0.3s ease;
    box-shadow: 0 0 20px rgba(255, 0, 0, 0.8);
}

#start-screen,
#game-over-screen {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 17, 0.95);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 20;
    border: 3px solid #00aaff;
}

#start-screen h1,
#game-over-screen h2 {
    font-size: 48px;
    font-weight: 900;
    color: #00ffff;
    text-shadow: 0 0 20px rgba(0, 255, 255, 0.8);
    margin-bottom: 20px;
    letter-spacing: 4px;
}

.subtitle {
    font-size: 18px;
    color: #00aaff;
    margin-bottom: 30px;
    text-align: center;
}

.instructions {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 40px;
    font-size: 16px;
    color: #88aaff;
}

.instructions div {
    text-align: center;
}

.key {
    display: inline-block;
    padding: 5px 12px;
    background: rgba(0, 170, 255, 0.2);
    border: 2px solid #00aaff;
    border-radius: 4px;
    font-weight: 700;
    color: #00ffff;
    margin: 0 5px;
    box-shadow: 0 0 10px rgba(0, 170, 255, 0.3);
}

button {
    font-family: 'Orbitron', monospace;
    font-size: 20px;
    font-weight: 700;
    padding: 15px 40px;
    background: transparent;
    border: 3px solid #00aaff;
    color: #00ffff;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 2px;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px rgba(0, 170, 255, 0.3);
}

button:hover {
    background: rgba(0, 170, 255, 0.2);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.6);
    transform: scale(1.05);
}

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

.final-score {
    font-size: 24px;
    color: #00aaff;
    margin-bottom: 30px;
}

#final-score-value {
    color: #00ffff;
    font-weight: 700;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.8);
}

.hidden {
    display: none !important;
}

#powerup-status {
    position: absolute;
    bottom: 20px;
    left: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
}

.powerup-indicator {
    font-size: 16px;
    font-weight: 700;
    padding: 8px 15px;
    background: rgba(0, 170, 255, 0.2);
    border: 2px solid #00aaff;
    border-radius: 5px;
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
    animation: powerup-pulse 1s infinite;
}

#rapidfire-indicator {
    color: #ffff00;
    border-color: #ffff00;
    box-shadow: 0 0 15px rgba(255, 255, 0, 0.5);
}

#shield-indicator {
    color: #00ddff;
    border-color: #00ddff;
    box-shadow: 0 0 15px rgba(0, 221, 255, 0.5);
}

#speedboost-indicator {
    color: #ff8800;
    border-color: #ff8800;
    box-shadow: 0 0 15px rgba(255, 136, 0, 0.5);
}

@keyframes powerup-pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.7;
        transform: scale(1.05);
    }
}