/* CSS Custom Properties for easy maintenance */
:root {
    --color-primary: #00ff00;
    --color-accent: #ff0000;
    --color-bg: #0a0a0a;
    --color-bg-gradient-1: #0f1f0f;
    --color-bg-gradient-2: #0a1a0a;
    --font-primary: 'Courier New', Courier, monospace, -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui;
    --animation-duration: 3s;
    --border-glow-size: 20px;
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Accessibility: Skip link for keyboard navigation */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: var(--color-bg);
    padding: 8px;
    text-decoration: none;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Visually hidden but accessible to screen readers */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Body styles */
body {
    background: var(--color-bg);
    background-image: 
        radial-gradient(circle at 20% 50%, var(--color-bg-gradient-1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, var(--color-bg-gradient-2) 0%, transparent 50%);
    color: var(--color-primary);
    font-family: var(--font-primary);
    min-height: 100vh;
    display: -webkit-flex;
    display: -ms-flexbox;
    display: flex;
    -webkit-align-items: center;
    -ms-flex-align: center;
    align-items: center;
    -webkit-justify-content: center;
    -ms-flex-pack: center;
    justify-content: center;
    position: relative;
    flex-direction: column;
}

/* Animated border */
body::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    bottom: 10px;
    border: 1px solid var(--color-primary);
    border-radius: 4px;
    pointer-events: none;
    box-shadow: 
        0 0 var(--border-glow-size) var(--color-primary),
        inset 0 0 var(--border-glow-size) rgba(0, 255, 0, 0.1);
    animation: pulse var(--animation-duration) ease-in-out infinite;
}

/* Optimized pulse animation using transform */
@keyframes pulse {
    0%, 100% {
        opacity: 0.8;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.005);
    }
}

/* Main container */
.container {
    text-align: center;
    z-index: 1;
    padding: 20px;
    width: 100%;
    max-width: 600px;
}

/* Typography */
h1 {
    font-size: 3.5rem; /* Fallback for browsers that don't support clamp */
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 300;
    letter-spacing: 0.2em;
    margin-bottom: 1rem;
    white-space: nowrap;
    text-shadow: 
        0 0 5px var(--color-accent),
        0 0 10px var(--color-accent),
        0 0 20px var(--color-accent),
        0 0 40px var(--color-accent),
        0 0 80px var(--color-accent),
        0 0 120px var(--color-accent),
        0 0 160px var(--color-accent);
    animation: flicker var(--animation-duration) ease-in-out infinite;
}

/* Optimized flicker animation */
@keyframes flicker {
    0%, 100% {
        text-shadow: 
            0 0 5px var(--color-accent),
            0 0 10px var(--color-accent),
            0 0 20px var(--color-accent),
            0 0 40px var(--color-accent),
            0 0 80px var(--color-accent),
            0 0 120px var(--color-accent),
            0 0 160px var(--color-accent);
    }
    50% {
        text-shadow: 
            0 0 2px var(--color-accent),
            0 0 5px var(--color-accent),
            0 0 10px var(--color-accent),
            0 0 20px var(--color-accent),
            0 0 40px var(--color-accent),
            0 0 60px var(--color-accent),
            0 0 80px var(--color-accent);
    }
}

.tagline {
    font-size: 1.25rem; /* Fallback */
    font-size: clamp(1.25rem, 4vw, 1.5rem);
    letter-spacing: 0.1em;
    opacity: 0.8;
    text-transform: uppercase;
    margin-bottom: 3rem;
}

/* Email signup form */
.signup-form {
    margin: 3rem 0;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.signup-form input[type="email"] {
    flex: 1;
    min-width: 250px;
    padding: 12px 20px;
    background: rgba(0, 255, 0, 0.1);
    border: 1px solid var(--color-primary);
    color: var(--color-primary);
    font-family: inherit;
    font-size: 1rem;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.signup-form input[type="email"]:focus {
    outline: none;
    background: rgba(0, 255, 0, 0.15);
    box-shadow: 0 0 10px rgba(0, 255, 0, 0.5);
}

.signup-form input[type="email"]::placeholder {
    color: rgba(0, 255, 0, 0.6);
}

.signup-form button {
    padding: 12px 30px;
    background: var(--color-primary);
    color: var(--color-bg);
    border: none;
    font-family: inherit;
    font-size: 1rem;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.signup-form button:hover {
    background: #00cc00;
    box-shadow: 0 0 20px rgba(0, 255, 0, 0.8);
}

.signup-form button:active {
    transform: scale(0.98);
}

/* Success message */
.success-message {
    color: var(--color-primary);
    margin-top: 1rem;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.success-message.show {
    opacity: 1;
}

/* Social links */
.social-links {
    margin-top: 2rem;
    display: flex;
    gap: 2rem;
    justify-content: center;
}

.social-links a {
    color: var(--color-primary);
    text-decoration: none;
    opacity: 0.7;
    transition: opacity 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.social-links a svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.social-links a:hover {
    opacity: 1;
    text-shadow: 0 0 10px var(--color-primary);
}

.social-links a:hover svg {
    filter: drop-shadow(0 0 5px var(--color-primary));
}

/* Footer */
footer {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    font-size: 0.875rem;
    opacity: 0.6;
    z-index: 1;
}

/* Mobile responsiveness */
@media (max-width: 768px) {
    h1 {
        letter-spacing: 0.1em;
        font-size: 2.5rem; /* Ensure minimum readable size */
    }
    
    .tagline {
        font-size: 1.25rem; /* Match minimum clamp size */
    }
    
    .signup-form {
        flex-direction: column;
        align-items: stretch;
    }
    
    .signup-form input[type="email"] {
        min-width: auto;
    }
}

/* Extra small devices */
@media (max-width: 480px) {
    h1 {
        font-size: 2.5rem; /* Keep consistent minimum size */
        letter-spacing: 0.05em;
    }
    
    .tagline {
        font-size: 1.25rem; /* Keep consistent minimum size */
    }
}

/* Reduced motion support for accessibility */
@media (prefers-reduced-motion: reduce) {
    *, 
    *::before, 
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    /* Keep static glow effects without animation */
    body::before {
        opacity: 0.9;
        box-shadow: 
            0 0 20px var(--color-primary),
            inset 0 0 20px rgba(0, 255, 0, 0.1);
    }
    
    h1 {
        text-shadow: 
            0 0 10px var(--color-accent),
            0 0 40px var(--color-accent);
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #00ff00;
        --color-accent: #ff0000;
        --color-bg: #000000;
    }
    
    .signup-form input[type="email"] {
        border-width: 2px;
    }
    
    .signup-form button {
        border: 2px solid var(--color-bg);
    }
}

/* Print styles */
@media print {
    body::before {
        display: none;
    }
    
    h1 {
        animation: none;
        text-shadow: none;
    }
    
    .signup-form,
    .social-links,
    footer {
        display: none;
    }
}