/* LMS Stylesheet */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #667eea;
}

/* Login Form Styles */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.login-form {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 450px;
    text-align: center;
}

.login-logo {
    margin-bottom: 2rem;
}

.logo-image {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin-bottom: 1rem;
    object-fit: cover;
}

.demo-credentials {
    background: #f8f9fa;
    border: 2px dashed #667eea;
    border-radius: 10px;
    padding: 1rem;
    margin-bottom: 1.5rem;
    text-align: left;
    font-size: 0.85rem;
}

.demo-credentials p {
    margin: 0.25rem 0;
    color: #555;
}

.demo-credentials strong {
    color: #333;
}

.demo-credentials code {
    background: #667eea;
    color: white;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.8rem;
}

.login-form h2 {
    margin-bottom: 2rem;
    color: #333;
    font-size: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #555;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    width: 100%;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

/* Dashboard Styles */
.dashboard {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.sidebar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 15px;
    height: fit-content;
    position: sticky;
    top: 100px;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li {
    margin-bottom: 1rem;
}

.sidebar-menu a {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    text-decoration: none;
    color: #333;
    border-radius: 10px;
    transition: background-color 0.3s;
}

.sidebar-menu a:hover,
.sidebar-menu a.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.main-content {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
}

/* Card Styles */
.card {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    margin-bottom: 1.5rem;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.card h3 {
    color: #333;
    margin-bottom: 1rem;
}

/* Course Grid */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.course-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
}

.course-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
}

.course-content {
    padding: 1.5rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.course-description {
    color: #666;
    margin-bottom: 1rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: #888;
}

/* Quiz Styles */
.quiz-container {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.quiz-header {
    background: #333;
    padding: 1rem 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: relative;
    z-index: 1000;
    color: white;
}

.quiz-question {
    margin-bottom: 2rem;
}

.quiz-question h3 {
    margin-bottom: 1rem;
    color: #333;
}

.quiz-options {
    list-style: none;
}

.quiz-options li {
    margin-bottom: 1rem;
}

.quiz-options label {
    display: flex;
    align-items: center;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.quiz-options label:hover {
    background: #e9ecef;
}

.quiz-options input[type="radio"] {
    margin-right: 1rem;
}

/* Video Page Styles */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.video-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.video-thumbnail {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
    cursor: pointer;
}

.video-info {
    padding: 1.5rem;
}

.video-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.video-duration {
    color: #666;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .dashboard {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: static;
    }
    
    .nav-links {
        flex-direction: column;
        gap: 1rem;
    }
    
    .course-grid,
    .video-grid {
        grid-template-columns: 1fr;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 2rem;
}

.mb-2 {
    margin-bottom: 2rem;
}

.hidden {
    display: none;
}

/* Loading Spinner */
.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

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