/**
 * ========================================
 * MAIN STYLESHEET
 * ========================================
 * Global styles, variables, and reusable components
 */

/* ========================================
   CSS VARIABLES
   ======================================== */
:root {
    /* Colors */
    --primary-color: #8b5cf6;
    --primary-hover: #7c3aed;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    
    /* Dark Mode Backgrounds (Default) */
    --bg-primary: #1f2937;
    --bg-secondary: #111827;
    --bg-tertiary: #374151;
    
    /* Dark Mode Text Colors (Default) */
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-tertiary: #9ca3af;
    
    /* Dark Mode Border Colors (Default) */
    --border-color: #374151;
    --border-hover: #4b5563;
    
    /* 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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
}

/* Light Mode Override (Optional) */
body:not(.dark-mode) {
    --bg-primary: rgba(255, 255, 255, 0.95);
    --bg-secondary: rgba(249, 250, 251, 0.95);
    --bg-tertiary: rgba(243, 244, 246, 0.95);
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --border-color: rgba(229, 231, 235, 0.8);
    --border-hover: rgba(209, 213, 219, 0.8);
}

/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #1a2332 0%, #2d4356 25%, #1e3a52 50%, #2d4356 75%, #1a2332 100%);
    min-height: 100vh;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

body.dark-mode {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 25%, #0f172a 50%, #1e293b 75%, #0f172a 100%);
}

/* ========================================
   TYPOGRAPHY
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

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

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

/* ========================================
   NAVBAR STYLES
   ======================================== */
.navbar {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 4px 16px 0 rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: background-color var(--transition-base);
}

body:not(.dark-mode) .navbar {
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.navbar-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.brand-icon {
    color: var(--primary-color);
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex: 1;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.nav-link:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-link.active {
    background: var(--primary-color);
    color: white;
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    color: var(--text-secondary);
    font-weight: 500;
}

.logout-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.logout-btn:hover {
    background: #dc2626;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Mobile Menu Toggle */
.navbar-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.navbar-toggle span {
    width: 24px;
    height: 3px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

/* ========================================
   PAGE CONTAINER
   ======================================== */
.page-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.page-header {
    text-align: center;
    margin-bottom: 3rem;
    color: white;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.page-header p {
    font-size: 1.125rem;
    opacity: 0.9;
}

/* ========================================
   CARDS
   ======================================== */
.content-card,
.settings-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.content-card:hover {
    box-shadow: var(--shadow-xl);
}

/* ========================================
   BUTTONS
   ======================================== */
.btn-primary,
.btn-secondary,
.btn-danger,
.search-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
}

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

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

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

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

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

.search-btn:hover {
    background: var(--primary-hover);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ========================================
   FORM ELEMENTS
   ======================================== */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.input-group {
    display: flex;
    gap: 0.5rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

/* ========================================
   LOADING & ERROR STATES
   ======================================== */
.loading-state {
    text-align: center;
    padding: 3rem;
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    margin: 0 auto 1rem;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.error-message {
    background: #fee2e2;
    color: #991b1b;
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--danger-color);
    margin-bottom: 1.5rem;
}

body.dark-mode .error-message {
    background: rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

.hidden {
    display: none !important;
}

/* ========================================
   UTILITY CLASSES
   ======================================== */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */
@media (max-width: 768px) {
    .navbar-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition-base);
    }

    .navbar-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    .navbar-toggle {
        display: flex;
    }

    .navbar-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translateY(8px);
    }

    .navbar-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .navbar-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translateY(-8px);
    }

    .navbar-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .user-name {
        display: none;
    }

    .page-header h1 {
        font-size: 2rem;
    }

    .page-container {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .page-header h1 {
        font-size: 1.75rem;
    }

    .content-card,
    .settings-card {
        padding: 1.5rem;
    }
}