/* Campus Learning Platform - Beautiful Modern Design */
/* Sophisticated dark theme with elegant gradients and refined aesthetics */

/* ===== CSS CUSTOM PROPERTIES ===== */
:root {
    /* Color Palette */
    --primary-bg: #0f1419;
    --secondary-bg: #1a1f2e;
    --card-bg: #252b3d;
    --surface-bg: #2a3142;
    --elevated-bg: #303749;
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #b8c5d6;
    --text-muted: #8a94a6;
    --text-accent: #64b5f6;
    
    /* Accent Colors */
    --accent-primary: #4285f4;
    --accent-secondary: #34a853;
    --accent-warning: #fbbc04;
    --accent-danger: #ea4335;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-card: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);
    --gradient-surface: linear-gradient(145deg, #2a3142 0%, #252b3d 100%);
    --gradient-hero: linear-gradient(135deg, rgba(15,20,25,0.95) 0%, rgba(26,31,46,0.85) 50%, transparent 100%);
    
    /* Shadows */
    --shadow-subtle: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-medium: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-large: 0 8px 24px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 20px rgba(66,133,244,0.3);
    
    /* Spacing System */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 0.75rem;
    --space-lg: 1rem;
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
    --space-3xl: 3rem;
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Inter', sans-serif;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

/* ===== RESET & BASE STYLES ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-primary);
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--primary-bg);
    overflow-x: hidden;
}

/* Beautiful background pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 25% 25%, rgba(66,133,244,0.1) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(52,168,83,0.08) 0%, transparent 50%),
        var(--primary-bg);
    z-index: -1;
    pointer-events: none;
}

/* Override Bootstrap backgrounds */
.bg-dark, .bg-primary, .bg-secondary, .bg-light, .navbar, .container, .container-fluid,
.card, .card-body, .card-header, .card-footer, .modal-content, .dropdown-menu,
main, footer, [data-bs-theme="dark"] {
    background-color: transparent !important;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-semibold);
    line-height: 1.3;
    letter-spacing: -0.02em;
}

h1 { 
    font-size: 2rem; 
    font-weight: var(--font-weight-bold);
    margin: 0 0 var(--space-xl) 0; 
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

h2 { 
    font-size: 1.5rem; 
    margin: 0 0 var(--space-lg) 0; 
}

h3 { 
    font-size: 1.25rem; 
    margin: 0 0 var(--space-md) 0; 
}

h4 { 
    font-size: 1.1rem; 
    margin: 0 0 var(--space-sm) 0; 
}

p { 
    margin: 0 0 var(--space-md) 0; 
    color: var(--text-secondary);
}

small { 
    color: var(--text-muted); 
    font-size: 0.85rem; 
}

/* ===== NAVIGATION ===== */
.navbar {
    background: var(--secondary-bg) !important;
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: var(--space-sm) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-subtle);
}

.navbar-brand {
    color: var(--text-primary) !important;
    font-weight: var(--font-weight-bold);
    font-size: 1.2rem;
    margin-right: var(--space-xl);
    text-decoration: none;
}

.navbar-brand:hover {
    color: var(--text-accent) !important;
}

.navbar-nav .nav-link {
    color: var(--text-secondary) !important;
    padding: var(--space-sm) var(--space-lg);
    font-size: 0.9rem;
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-sm);
    margin: 0 var(--space-xs);
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link:focus {
    color: var(--text-primary) !important;
    background: rgba(255,255,255,0.1);
}

/* ===== LAYOUT ===== */
.container, .container-fluid {
    padding-left: var(--space-lg);
    padding-right: var(--space-lg);
}

.main-content {
    padding: var(--space-xl) 0;
    min-height: calc(100vh - 120px);
}

/* ===== CARDS ===== */
.card {
    background: var(--gradient-surface) !important;
    border: 1px solid rgba(255,255,255,0.1) !important;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-medium);
    margin-bottom: var(--space-xl);
    overflow: hidden;
    position: relative;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--gradient-card);
    opacity: 0.8;
}

.card-header {
    background: rgba(255,255,255,0.05) !important;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: var(--space-lg) var(--space-xl);
    font-weight: var(--font-weight-semibold);
    font-size: 1.1rem;
}

.card-body {
    padding: var(--space-xl);
    background: transparent;
}

.card-footer {
    background: rgba(0,0,0,0.2) !important;
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: var(--space-lg) var(--space-xl);
}

.card-title {
    margin: 0 0 var(--space-sm) 0;
    font-size: 1.1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
}

.card-text {
    color: var(--text-secondary);
    margin: 0 0 var(--space-lg) 0;
    line-height: 1.5;
}

/* Course Grid */
.course-grid .card {
    height: 100%;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.course-grid .card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-large);
}

.course-grid .card-body {
    display: flex;
    flex-direction: column;
}

.course-grid .card-text {
    flex-grow: 1;
}

/* ===== BUTTONS ===== */
.btn {
    border-radius: var(--radius-md);
    padding: var(--space-sm) var(--space-xl);
    font-size: 0.9rem;
    font-weight: var(--font-weight-medium);
    border: none;
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

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

.btn-primary:hover, .btn-primary:focus {
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--surface-bg);
    color: var(--text-primary);
    border: 1px solid rgba(255,255,255,0.2);
}

.btn-secondary:hover, .btn-secondary:focus {
    background: var(--elevated-bg);
    border-color: rgba(255,255,255,0.3);
}

.btn-success { 
    background: linear-gradient(135deg, var(--accent-secondary), #2e7d32);
    color: white;
}

.btn-warning { 
    background: linear-gradient(135deg, var(--accent-warning), #f57f17);
    color: white;
}

.btn-danger { 
    background: linear-gradient(135deg, var(--accent-danger), #c62828);
    color: white;
}

.btn-sm {
    padding: var(--space-xs) var(--space-lg);
    font-size: 0.8rem;
}

.btn-lg {
    padding: var(--space-lg) var(--space-2xl);
    font-size: 1rem;
}

/* ===== FORMS ===== */
.form-control, .form-select, input, textarea, select {
    background: var(--surface-bg) !important;
    color: var(--text-primary) !important;
    border: 1px solid rgba(255,255,255,0.2) !important;
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(66,133,244,0.1);
    outline: none;
    background: var(--elevated-bg) !important;
}

.form-label {
    color: var(--text-primary);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--space-sm);
    font-size: 0.9rem;
}

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

/* ===== HERO BANNER ===== */
.hero-banner {
    position: relative;
    height: 160px;
    overflow: hidden;
    background: var(--secondary-bg);
    margin-bottom: var(--space-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-large);
}

.hero-banner-media {
    position: absolute;
    top: 50%;
    left: 50%;
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    transform: translate(-50%, -50%);
    object-fit: cover;
    z-index: 1;
}

.hero-banner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient-hero);
    z-index: 2;
}

.hero-banner-content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 3;
    padding: var(--space-xl);
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    height: 100%;
}

.hero-banner h1 {
    font-size: 1.8rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--space-sm);
    text-shadow: 0 2px 8px rgba(0,0,0,0.8);
    background: linear-gradient(135deg, #ffffff 0%, #e3f2fd 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-banner p {
    font-size: 1rem;
    margin: 0;
    opacity: 0.9;
    text-shadow: 0 1px 4px rgba(0,0,0,0.6);
    color: #e3f2fd;
}

/* Sidebar styles moved to sidebar.css - loaded conditionally on course pages */

/* ===== TABLES ===== */
.table {
    background-color: transparent;
    color: var(--text-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-medium);
}

.table th {
    background: var(--gradient-surface);
    color: var(--text-primary);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: var(--space-lg);
    font-weight: var(--font-weight-semibold);
    font-size: 0.9rem;
}

.table td {
    padding: var(--space-lg);
    border-bottom: 1px solid rgba(255,255,255,0.05);
    vertical-align: middle;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(255,255,255,0.02);
}

/* ===== UTILITIES ===== */
.text-muted { color: var(--text-muted) !important; }
.text-primary { color: var(--accent-primary) !important; }
.text-success { color: var(--accent-secondary) !important; }
.text-warning { color: var(--accent-warning) !important; }
.text-danger { color: var(--accent-danger) !important; }

.border { border: 1px solid rgba(255,255,255,0.1) !important; }
.border-top { border-top: 1px solid rgba(255,255,255,0.1) !important; }
.border-bottom { border-bottom: 1px solid rgba(255,255,255,0.1) !important; }

.shadow-sm { box-shadow: var(--shadow-subtle); }
.shadow { box-shadow: var(--shadow-medium); }

.rounded { border-radius: var(--radius-md); }

/* Spacing utilities */
.p-0 { padding: 0 !important; }
.p-1 { padding: var(--space-xs) !important; }
.p-2 { padding: var(--space-sm) !important; }
.p-3 { padding: var(--space-md) !important; }
.p-4 { padding: var(--space-lg) !important; }
.p-5 { padding: var(--space-xl) !important; }

.m-0 { margin: 0 !important; }
.m-1 { margin: var(--space-xs) !important; }
.m-2 { margin: var(--space-sm) !important; }
.m-3 { margin: var(--space-md) !important; }
.m-4 { margin: var(--space-lg) !important; }
.m-5 { margin: var(--space-xl) !important; }

.mb-1 { margin-bottom: var(--space-xs) !important; }
.mb-2 { margin-bottom: var(--space-sm) !important; }
.mb-3 { margin-bottom: var(--space-md) !important; }
.mb-4 { margin-bottom: var(--space-lg) !important; }
.mb-5 { margin-bottom: var(--space-xl) !important; }

/* ===== SPECIAL COMPONENTS ===== */
.section-header {
    background: var(--gradient-surface);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-2xl);
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: var(--shadow-medium);
}

.section-header h2 {
    margin: 0;
    color: var(--text-primary);
    font-weight: var(--font-weight-bold);
}

.breadcrumb {
    background: transparent;
    padding: 0;
    margin-bottom: var(--space-xl);
}

.breadcrumb-item {
    color: var(--text-muted);
}

.breadcrumb-item.active {
    color: var(--text-secondary);
}

.breadcrumb-item + .breadcrumb-item::before {
    content: "›";
    color: var(--text-muted);
}

.breadcrumb-item a {
    color: var(--text-accent);
    text-decoration: none;
}

.breadcrumb-item a:hover {
    color: var(--text-primary);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
    :root {
        --space-xs: 0.2rem;
        --space-sm: 0.4rem;
        --space-md: 0.6rem;
        --space-lg: 0.8rem;
        --space-xl: 1.2rem;
        --space-2xl: 1.6rem;
    }
    
    .sidebar-toggle {
        display: flex !important;
    }
    
    .main-content {
        margin-left: 0;
    }
}
    
    .container, .container-fluid {
        padding-left: var(--space-lg);
        padding-right: var(--space-lg);
    }
    
    .hero-banner {
        height: 120px;
        margin-bottom: var(--space-xl);
        border-radius: var(--radius-lg);
    }
    
    .hero-banner h1 {
        font-size: 1.4rem;
    }
    
    .hero-banner p {
        font-size: 0.85rem;
    }
    
    .hero-banner-content {
        padding: var(--space-lg);
    }
    
/* Sidebar responsive styles moved to sidebar.css */
    
    .card-body {
        padding: var(--space-lg);
    }
    
    .btn {
        font-size: 0.8rem;
        padding: var(--space-sm) var(--space-lg);
    }
    
    h1 { font-size: 1.6rem; }
    h2 { font-size: 1.3rem; }
    h3 { font-size: 1.1rem; }
}

@media (max-width: 576px) {
    .hero-banner {
        height: 100px;
    }
    
    .hero-banner h1 {
        font-size: 1.2rem;
    }
    
    .hero-banner p {
        font-size: 0.8rem;
    }
}

/* ===== ANIMATIONS & EFFECTS ===== */
@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.loading-shimmer {
    position: relative;
    overflow: hidden;
}

.loading-shimmer::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    animation: shimmer 1.5s infinite;
}

/* ===== PRINT STYLES ===== */
@media print {
    .sidebar, .navbar, .btn, .sidebar-toggle, .sidebar-overlay {
        display: none !important;
    }
    
    body, .card, .card-body {
        background: white !important;
        color: black !important;
    }
}

/* Performance optimization */
.card, .btn {
    will-change: transform;
}

/* Cache buster */
/* Updated: 2025-08-05 Beautiful Design */