/* ===================================
   COMMON CSS - Reusable Components
   =================================== */

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary: #818cf8;
    --primary-dark: #6366f1;
    --primary-light: #a78bfa;
    --secondary: #fbbf24;
    --bg-dark: #0f172a;
    --bg-darker: #0a0f1e;
    --bg-card: #1e293b;
    --bg-input: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border: #334155;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
}

/* ===================================
   TYPOGRAPHY
   =================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

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

a:hover {
    color: var(--primary-light);
}

/* ===================================
   NAVBAR
   =================================== */

.navbar {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.navbar-logo {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.navbar-menu {
    display: flex;
    gap: var(--spacing-xl);
    list-style: none;
}

.navbar-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

.navbar-link:hover {
    color: var(--text-primary);
}

.navbar-link.active {
    color: var(--primary);
}

/* Mobile Menu Toggle */
.navbar-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* ===================================
   BUTTONS
   =================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border);
}

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

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

.btn-success:hover {
    background: #059669;
}

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

.btn-danger:hover {
    background: #dc2626;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 1.125rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: var(--radius-md);
    background: var(--bg-input);
    color: var(--text-secondary);
}

.btn-icon:hover {
    background: var(--bg-card);
    color: var(--text-primary);
}

/* ===================================
   CARDS
   =================================== */

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.card:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.card-text {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================
   CONTAINER
   =================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--spacing-lg);
}

/* ===================================
   GRID SYSTEM
   =================================== */

.row {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.col {
    flex: 1;
}

.col-2 { flex: 0 0 calc(50% - var(--spacing-lg)); }
.col-3 { flex: 0 0 calc(33.333% - var(--spacing-lg)); }
.col-4 { flex: 0 0 calc(25% - var(--spacing-lg)); }

/* ===================================
   FOOTER
   =================================== */

.footer {
    background: var(--bg-darker);
    border-top: 1px solid var(--border);
    padding: var(--spacing-2xl) 0;
    margin-top: var(--spacing-2xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    text-align: center;
}

.footer-text {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
    list-style: none;
}

.footer-link {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

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

/* ===================================
   UTILITIES
   =================================== */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

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

.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   RESPONSIVE
   =================================== */

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
    
    .navbar-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-card);
        flex-direction: column;
        padding: var(--spacing-lg);
        border-top: 1px solid var(--border);
    }
    
    .navbar-menu.active {
        display: flex;
    }
    
    .navbar-toggle {
        display: block;
    }
    
    .col-2, .col-3, .col-4 {
        flex: 0 0 100%;
    }
}