:root {
    /* Modern Dark Theme */
    --bg-dark: #0f172a; /* Slate 900 */
    --bg-card: rgba(30, 41, 59, 0.7); /* Slate 800 */
    --bg-input: rgba(15, 23, 42, 0.5); /* Darker input */

    /* Neon Accents - Modernized */
    --primary-neon: #10b981; /* Emerald 500 - slightly softer green */
    --primary-glow: rgba(16, 185, 129, 0.4);
    --secondary-neon: #3b82f6; /* Blue 500 */
    --secondary-glow: rgba(59, 130, 246, 0.4);
    --accent-purple: #8b5cf6; /* Violet 500 */
    --error-red: #ef4444; /* Red 500 */
    --error-glow: rgba(239, 68, 68, 0.4);

    /* Text */
    --text-main: #f8fafc; /* Slate 50 */
    --text-muted: #94a3b8; /* Slate 400 */

    /* UI Elements */
    --border-color: rgba(255, 255, 255, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 24px;

    /* Typography */
    --font-heading: 'Rubik', sans-serif;
    --font-body: 'Rubik', sans-serif;
    --font-code: 'Fira Code', monospace;

    /* Effects */
    --glass-bg: rgba(30, 41, 59, 0.4);
    --glass-border: 1px solid rgba(255, 255, 255, 0.08);
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-glow: 0 0 20px var(--primary-glow);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-body);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    /* Animated Background Mesh */
    background-image:
        radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.08) 0%, transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.08) 0%, transparent 25%);
    background-attachment: fixed;
    transition: opacity 0.5s ease;
}

/* Utilities */
.container {
    max-width: 1000px; /* Tighter container for cleaner look */
    margin: 0 auto;
    padding: 2rem;
    position: relative;
    z-index: 2;
}

.flex-center { display: flex; justify-content: center; align-items: center; }
.text-center { text-align: center; }
.hidden { display: none !important; }

/* Site Identity */
.brand-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    margin-bottom: 1.5rem;
}

.brand-logo {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--secondary-neon);
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 20px;
    border: 1px solid rgba(59, 130, 246, 0.2);
    box-shadow: 0 0 10px rgba(59, 130, 246, 0.1);
}

/* Version Badge - Glowing Pill */
.version-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-purple), #ec4899);
    color: white;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 20px;
    box-shadow: 0 0 15px rgba(236, 72, 153, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.2);
    font-family: var(--font-code);
    letter-spacing: 0.5px;
    line-height: 1;
    animation: pulse 3s infinite ease-in-out;
}

@keyframes pulse {
    0% { box-shadow: 0 0 15px rgba(236, 72, 153, 0.4); }
    50% { box-shadow: 0 0 25px rgba(236, 72, 153, 0.7); }
    100% { box-shadow: 0 0 15px rgba(236, 72, 153, 0.4); }
}

/* Modern Button System */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-family: var(--font-heading);
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid transparent;
    gap: 8px;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-neon), #059669);
    color: white;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--primary-glow);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-icon {
    padding: 8px;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-muted);
}

.btn-icon:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
}

/* Glassmorphism Cards */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    overflow: hidden; /* For inner border radius */
}

/* Typography Enhancements */
h1 {
    font-size: 3rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Input Fields */
.input-modern {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    color: var(--text-main);
    font-family: var(--font-code);
    width: 100%;
    transition: all 0.2s ease;
}

.input-modern:focus {
    border-color: var(--primary-neon);
    outline: none;
    box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
}

/* Input Error State */
.input-error {
    border-color: var(--error-red) !important;
    box-shadow: 0 0 0 2px var(--error-glow) !important;
}

.validation-msg {
    color: var(--error-red);
    font-size: 0.8rem;
    margin-top: 4px;
    display: none;
    font-weight: 600;
}

.validation-msg.active {
    display: block;
}

/* Toast Notification */
.toast-container {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-color);
    padding: 12px 24px;
    border-radius: 50px;
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 100;
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
}

.toast-container.show {
    transform: translateX(-50%) translateY(0);
}

.toast-icon {
    color: var(--primary-neon);
    display: flex; /* SVG alignment */
}

/* Footer */
footer {
    padding: 2rem;
    text-align: center;
    margin-top: auto;
}

.footer-link {
    font-family: var(--font-heading);
    color: var(--text-muted);
    font-size: 0.9rem;
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-link:hover {
    color: var(--primary-neon);
}

/* Animations */
@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0px); }
}

.animate-float {
    animation: float 6s ease-in-out infinite;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.6s ease-out forwards;
}