:root {
    --alien-primary: #00ff00;
    --alien-secondary: #00ccff;
    --alien-dark: #0a0a0a;
    --alien-darker: #000000;
    --alien-accent: #ff00ff;
    --alien-text: #ffffff;
    --alien-border: #333333;
}

body {
    background-color: var(--alien-darker);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-height: 100vh;
    overflow: hidden;
    box-sizing: border-box;
    color: var(--alien-text);
    font-family: 'Courier New', Courier, monospace;
}

.alien-header {
    background: linear-gradient(to right, var(--alien-dark), var(--alien-darker));
    padding: 0.5rem;
    border-bottom: 2px solid var(--alien-primary);
    text-align: center;
    box-shadow: 0 0 20px var(--alien-primary);
    flex-shrink: 0;
}

.header-content h1 {
    color: var(--alien-primary);
    font-size: clamp(1.2rem, 3vw, 2rem);
    margin: 0;
    text-shadow: 0 0 10px var(--alien-primary);
    letter-spacing: 2px;
}

.tagline {
    color: var(--alien-secondary);
    font-size: clamp(0.7rem, 1.5vw, 1rem);
    margin: 0.25rem 0 0;
    text-shadow: 0 0 5px var(--alien-secondary);
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    min-height: 0;
    overflow: hidden;
}

.game-container {
    width: 75%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 0.5rem;
    box-sizing: border-box;
    overflow: hidden;
    margin: 0 auto;
}

#canvas1 {
    background: var(--alien-dark);
    position: relative;
    max-width: 100%;
    max-height: 70vh;
    width: 100%;
    height: 100%;
    border: 3px solid var(--alien-primary);
    box-shadow: 0 0 20px var(--alien-primary);
    aspect-ratio: 16/9;
    box-sizing: border-box;
    touch-action: none;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.alien-footer {
    background: linear-gradient(to right, var(--alien-darker), var(--alien-dark));
    padding: 0.5rem;
    border-top: 2px solid var(--alien-secondary);
    text-align: center;
    box-shadow: 0 0 20px var(--alien-secondary);
    flex-shrink: 0;
}

.footer-content {
    color: var(--alien-text);
    font-size: clamp(0.7rem, 1.5vw, 0.9rem);
}

.footer-content p {
    margin: 0.25rem 0;
}

.footer-content p:first-child {
    color: var(--alien-primary);
    text-shadow: 0 0 5px var(--alien-primary);
}

.footer-content p:last-child {
    color: var(--alien-secondary);
    text-shadow: 0 0 5px var(--alien-secondary);
}

#reStart {
    background: var(--alien-dark);
    color: var(--alien-primary);
    border: 2px solid var(--alien-primary);
    padding: 0.5rem 1rem;
    font-size: clamp(0.7rem, 1.5vw, 1rem);
    cursor: pointer;
    margin-top: 0.5rem;
    transition: all 0.3s ease;
    text-shadow: 0 0 5px var(--alien-primary);
}

#reStart:hover {
    background: var(--alien-primary);
    color: var(--alien-dark);
    box-shadow: 0 0 15px var(--alien-primary);
}

#playerImage, #backgroundImage, #enemy1, #start, #reStart, #fullBackground, #startImage, #gameOver, #arrowKeys, #score, #instructMessage {
    display: none;
}

#header {
    color: white;
    text-align: center;
    font-size: clamp(1rem, 3vw, 2rem);
    margin: 1rem 0;
    padding: 0 1rem;
}

h1 {
    color: white;
}

@media (max-width: 1100px) {
    .game-container {
        width: 75%;
        padding: 0 0.25rem;
    }
    
    #canvas1 {
        max-height: 65vh;
    }
}

@media (max-width: 768px) {
    .game-container {
        width: 90%;
        padding: 0 0.25rem;
    }
    
    #canvas1 {
        max-height: 60vh;
        cursor: pointer;
    }
    
    #header {
        font-size: clamp(0.8rem, 2.5vw, 1.5rem);
    }
}

@media (max-height: 600px) {
    #canvas1 {
        max-height: 55vh;
    }
    
    .alien-header {
        padding: 0.25rem;
    }
    
    .alien-footer {
        padding: 0.25rem;
    }
}