/* ==========================================================================
   ModelLink 3D - Global Styles
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Variables
   -------------------------------------------------------------------------- */
:root {
    /* Colors - Core */
    --color-bg: #0f2027;
    --color-bg-gradient: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);

    /* Colors - Transparency (for cards, nav, inputs) */
    --color-glass: rgba(0, 0, 0, 0.3);
    --color-glass-light: rgba(255, 255, 255, 0.1);
    --color-glass-border: rgba(255, 255, 255, 0.1);
    --color-glass-border-hover: rgba(255, 255, 255, 0.2);

    /* Colors - Brand */
    --color-primary: #00b4db;
    --color-primary-dark: #0083b0;
    --color-primary-gradient: linear-gradient(135deg, #00b4db 0%, #0083b0 100%);
    --color-accent: #22d3ee;

    /* Colors - Text */
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-text-subtle: #64748b;

    /* Colors - State */
    --color-success: #10b981;
    --color-error: #ef4444;
    --color-warning: #f59e0b;

    /* Typography */
    --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
    --transition-slow: 0.3s ease;
}

/* --------------------------------------------------------------------------
   Base Styles
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--color-bg-gradient);
    background-attachment: fixed;
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.3;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.25rem; }

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent);
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--color-glass);
    z-index: 1000;
}

.navbar-brand {
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-text);
    text-decoration: none;
}

.navbar-brand span {
    background: var(--color-primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: var(--space-xl);
    align-items: center;
}

.nav-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
}

.nav-links a:hover {
    color: var(--color-text);
}

/* --------------------------------------------------------------------------
   Layout
   -------------------------------------------------------------------------- */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.container-wide {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

main {
    padding-top: 80px;
    padding-bottom: var(--space-3xl);
}

/* --------------------------------------------------------------------------
   Page Header
   -------------------------------------------------------------------------- */
.page-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
    padding-top: var(--space-2xl);
}

.page-header h1 {
    margin-bottom: var(--space-sm);
}

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

.page-header .last-updated {
    font-size: 0.9rem;
    color: var(--color-text-subtle);
}

/* --------------------------------------------------------------------------
   Cards & Glass Elements
   -------------------------------------------------------------------------- */
.card {
    background: var(--color-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.card-interactive {
    transition: transform var(--transition-normal), border-color var(--transition-normal);
}

.card-interactive:hover {
    transform: translateY(-2px);
    border-color: var(--color-glass-border-hover);
}

/* --------------------------------------------------------------------------
   Forms
   -------------------------------------------------------------------------- */
.form-card {
    background: var(--color-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.form-group {
    margin-bottom: var(--space-lg);
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--space-sm);
    font-size: 0.95rem;
}

.form-group .hint {
    display: block;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    margin-bottom: var(--space-sm);
}

.form-input,
.form-textarea,
.form-select,
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--color-glass-light);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-family: var(--font-body);
    font-size: 1rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus,
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(0, 180, 219, 0.15);
}

.form-input::placeholder,
.form-textarea::placeholder,
.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-subtle);
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
}

.btn-primary {
    background: var(--color-primary-gradient);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 180, 219, 0.4);
    color: white;
}

.btn-secondary {
    background: var(--color-glass-light);
    border: 1px solid var(--color-glass-border);
    color: var(--color-text);
}

.btn-secondary:hover {
    background: var(--color-glass);
    border-color: var(--color-glass-border-hover);
}

.btn-block {
    width: 100%;
}

/* --------------------------------------------------------------------------
   Alerts & Messages
   -------------------------------------------------------------------------- */
.alert {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-lg);
}

.alert-success {
    background: rgba(16, 185, 129, 0.15);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: #6ee7b7;
}

.alert-error {
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #fca5a5;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.15);
    border: 1px solid rgba(245, 158, 11, 0.3);
    color: #fcd34d;
}

/* --------------------------------------------------------------------------
   Highlight Box (for important info)
   -------------------------------------------------------------------------- */
.highlight-box {
    background: rgba(0, 180, 219, 0.1);
    border-left: 3px solid var(--color-primary);
    padding: var(--space-md) var(--space-lg);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: var(--space-lg) 0;
}

.highlight-box p {
    margin: 0;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    text-align: center;
    padding: var(--space-2xl) var(--space-xl);
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-md);
}

.footer-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-text);
}

.footer-copyright {
    color: var(--color-text-subtle);
    font-size: 0.85rem;
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */
.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.text-subtle { color: var(--color-text-subtle); }
.text-primary { color: var(--color-primary); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }

    .navbar {
        padding: 10px 15px;
    }

    .nav-links {
        gap: var(--space-md);
    }

    .nav-links a {
        font-size: 0.85rem;
    }

    .container,
    .container-wide {
        padding: 0 var(--space-md);
    }

    .footer-links {
        gap: var(--space-md);
    }
}

@media (max-width: 480px) {
    .nav-links {
        display: none; /* Consider hamburger menu for mobile */
    }

    .footer-links {
        flex-direction: column;
        gap: var(--space-sm);
    }
}