/* ==========================================================================
   Teacher Resource Dashboard - Core Design System & Stylesheet
   ========================================================================== */

/* Google Fonts Import - Inter & Outfit */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
    /* Fonts */
    --font-heading: 'Outfit', 'Inter', sans-serif;
    --font-body: 'Inter', sans-serif;

    /* Light Theme Variables */
    --bg-primary: #f3f4f6;
    --bg-secondary: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    
    --card-bg: rgba(255, 255, 255, 0.65);
    --card-border: rgba(255, 255, 255, 0.4);
    --glass-bg: rgba(255, 255, 255, 0.4);
    --glass-border: rgba(255, 255, 255, 0.2);
    
    --sidebar-bg: rgba(255, 255, 255, 0.9);
    --sidebar-active: #e0e7ff;
    --sidebar-active-text: #4f46e5;
    
    --primary-grad: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    --accent-indigo: #4f46e5;
    --accent-purple: #7c3aed;
    --accent-glow: rgba(79, 70, 229, 0.15);
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.06);
    
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --bg-primary: #0b0f19;
    --bg-secondary: #111827;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #6b7280;
    
    --card-bg: rgba(17, 24, 39, 0.65);
    --card-border: rgba(255, 255, 255, 0.06);
    --glass-bg: rgba(17, 24, 39, 0.4);
    --glass-border: rgba(255, 255, 255, 0.05);
    
    --sidebar-bg: rgba(17, 24, 39, 0.95);
    --sidebar-active: #1e1b4b;
    --sidebar-active-text: #818cf8;
    
    --primary-grad: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --accent-indigo: #6366f1;
    --accent-purple: #a855f7;
    --accent-glow: rgba(99, 102, 241, 0.25);
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
}

/* Base resets & styles */
body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-body);
    transition: var(--transition-smooth);
    min-height: 100vh;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
}

/* Glassmorphism Container Utility */
.glass-container {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    box-shadow: var(--glass-shadow);
    border-radius: 16px;
    transition: var(--transition-smooth);
}

/* Custom Scrollbars */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-indigo);
}

/* ==========================================================================
   Dashboard Layout Structure
   ========================================================================== */

#wrapper {
    display: flex;
    width: 100%;
    align-items: stretch;
    min-height: 100vh;
}

/* Sidebar Styling */
#sidebar {
    min-width: 260px;
    max-width: 260px;
    background: var(--sidebar-bg);
    color: var(--text-primary);
    transition: var(--transition-smooth);
    border-right: 1px solid var(--card-border);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    position: fixed;
    height: 100vh;
    left: 0;
    top: 0;
}

#sidebar.active {
    margin-left: -260px;
}

#sidebar .sidebar-header {
    padding: 24px 20px;
    border-bottom: 1px solid var(--card-border);
}

#sidebar .sidebar-brand {
    font-family: var(--font-heading);
    font-weight: 800;
    background: var(--primary-grad);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 1.25rem;
    letter-spacing: -0.5px;
}

#sidebar ul.components {
    padding: 20px 10px;
}

#sidebar ul li {
    list-style: none;
    margin-bottom: 6px;
}

#sidebar ul li a {
    padding: 12px 16px;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 10px;
    transition: var(--transition-smooth);
    font-weight: 500;
}

#sidebar ul li a i {
    margin-right: 12px;
    width: 20px;
    text-align: center;
    font-size: 1.1rem;
    transition: var(--transition-smooth);
}

#sidebar ul li a:hover {
    color: var(--accent-indigo);
    background: var(--sidebar-active);
}

#sidebar ul li.active > a {
    color: var(--sidebar-active-text);
    background: var(--sidebar-active);
    font-weight: 600;
}

#sidebar ul li.active > a i {
    color: var(--sidebar-active-text);
}

/* Page Content Space */
#content {
    width: calc(100% - 260px);
    padding: 30px;
    min-height: 100vh;
    transition: var(--transition-smooth);
    margin-left: 260px;
}

#content.active {
    width: 100%;
    margin-left: 0;
}

/* Navbar Top Styling */
.top-navbar {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    margin-bottom: 24px;
    padding: 12px 24px;
    box-shadow: var(--shadow-sm);
}

.search-box-container {
    position: relative;
    max-width: 320px;
}

.search-box-container input {
    background: var(--bg-primary);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    border-radius: 30px;
    padding-left: 40px;
    transition: var(--transition-smooth);
}

.search-box-container input:focus {
    box-shadow: 0 0 0 3px var(--accent-glow);
    border-color: var(--accent-indigo);
    background: var(--bg-secondary);
}

.search-box-container i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

/* ==========================================================================
   Dashboard Cards & UI Elements
   ========================================================================== */

/* Welcome Banner */
.welcome-banner {
    background: var(--primary-grad);
    color: #ffffff;
    border-radius: 18px;
    padding: 32px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.welcome-banner::after {
    content: '';
    position: absolute;
    right: -50px;
    top: -50px;
    width: 200px;
    height: 200px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
}

/* Statistics Cards */
.stat-card {
    border-radius: 16px;
    padding: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: var(--transition-smooth);
    border: 1px solid var(--card-border);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    width: 52px;
    height: 52px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #ffffff;
    background: var(--primary-grad);
}

.stat-card .value {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 2px;
    color: var(--text-primary);
}

.stat-card .label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Resource Card Grid */
.resource-card {
    border-radius: 16px;
    overflow: hidden;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: var(--transition-smooth);
    position: relative;
}

.resource-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-indigo);
}

.resource-card-image {
    height: 160px;
    background: #e2e8f0;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.resource-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.resource-type-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    padding: 6px 12px;
    border-radius: 30px;
    font-size: 0.75rem;
    font-weight: 600;
    color: #ffffff;
    background: var(--primary-grad);
    box-shadow: var(--shadow-sm);
    z-index: 5;
}

.favorite-btn-overlay {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition-smooth);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    z-index: 5;
}

.favorite-btn-overlay:hover {
    transform: scale(1.1);
    color: #ef4444;
}

.favorite-btn-overlay.active {
    color: #ef4444;
    background: #ffffff;
}

.resource-card-body {
    padding: 20px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.resource-card-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
    line-height: 1.4;
    color: var(--text-primary);
}

.resource-card-metadata {
    font-size: 0.78rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.resource-card-metadata span {
    display: inline-flex;
    align-items: center;
    margin-right: 12px;
}

.resource-card-metadata i {
    margin-right: 4px;
    color: var(--text-muted);
}

.resource-card-description {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
    flex-grow: 1;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.resource-card-footer {
    border-top: 1px solid var(--card-border);
    padding-top: 15px;
    display: flex;
    gap: 8px;
}

/* Buttons */
.btn-primary-grad {
    background: var(--primary-grad);
    border: none;
    color: #ffffff;
    font-weight: 500;
    border-radius: 10px;
    padding: 8px 16px;
    transition: var(--transition-smooth);
}

.btn-primary-grad:hover {
    opacity: 0.9;
    transform: translateY(-2px);
    color: #ffffff;
    box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-glass {
    background: var(--glass-bg);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    font-weight: 500;
    border-radius: 10px;
    padding: 8px 16px;
    transition: var(--transition-smooth);
}

.btn-glass:hover {
    background: var(--sidebar-active);
    color: var(--accent-indigo);
    border-color: var(--accent-indigo);
}

/* Authentication Page Styles */
.auth-bg {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(circle at 10% 20%, rgba(99, 102, 241, 0.08) 0%, rgba(168, 85, 247, 0.05) 90.2%), var(--bg-primary);
    padding: 20px;
}

.auth-card {
    width: 100%;
    max-width: 440px;
    padding: 40px;
}

/* Form Controls styling */
.form-control, .form-select {
    background: var(--bg-primary);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    border-radius: 10px;
    padding: 10px 14px;
    transition: var(--transition-smooth);
}

.form-control:focus, .form-select:focus {
    box-shadow: 0 0 0 3px var(--accent-glow);
    border-color: var(--accent-indigo);
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Dark Mode Form Select Fix */
[data-theme="dark"] .form-select {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23f9fafb' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e");
}

/* Drag and Drop Upload Area */
.upload-zone {
    border: 2px dashed var(--text-muted);
    border-radius: 16px;
    padding: 40px 20px;
    text-align: center;
    background: var(--glass-bg);
    cursor: pointer;
    transition: var(--transition-smooth);
}

.upload-zone:hover, .upload-zone.dragover {
    border-color: var(--accent-indigo);
    background: var(--sidebar-active);
    color: var(--accent-indigo);
}

.upload-zone i {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: 15px;
    transition: var(--transition-smooth);
}

.upload-zone:hover i, .upload-zone.dragover i {
    color: var(--accent-indigo);
    transform: translateY(-5px);
}

/* Media Previews */
.video-preview-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.video-preview-container iframe, .video-preview-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

.pdf-viewer-container {
    height: 600px;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--card-border);
    box-shadow: var(--shadow-md);
}

.pdf-viewer-container iframe {
    width: 100%;
    height: 100%;
    border: 0;
}

/* ==========================================================================
   Responsive & Collapse Rules (Mobile First)
   ========================================================================== */

@media (max-width: 991.98px) {
    #sidebar {
        margin-left: -260px;
    }
    #sidebar.active {
        margin-left: 0;
    }
    #content {
        width: 100%;
        margin-left: 0;
        padding: 15px;
    }
    #content.active {
        margin-left: 260px;
        width: calc(100% - 260px);
    }
    
    .search-box-container {
        max-width: 100%;
        margin-bottom: 12px;
    }
}

/* Loader Styles */
.loader-spinner {
    width: 50px;
    height: 50px;
    border: 5px solid var(--card-border);
    border-top: 5px solid var(--accent-indigo);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 30px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}