:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --light-bg: #f5f7fa;
    --dark-text: #333;
    --light-text: #fff;
}

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

body {
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
    color: var(--dark-text);
    background-color: var(--light-bg);
}

header {
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 1rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    margin-bottom: 1rem;
    font-size: 2rem;
}

nav {
    margin-bottom: 1rem;
}

nav ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    list-style: none;
    gap: 0.5rem;
}

nav li a {
    display: block;
    padding: 0.5rem 1rem;
    color: var(--light-text);
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s;
}

nav li a:hover {
    background-color: rgba(255,255,255,0.2);
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

h2, h3 {
    color: var(--secondary-color);
    margin: 1.5rem 0 1rem 0;
}

h2 {
    text-align: center;
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

h3 {
    font-size: 1.4rem;
    border-left: 4px solid var(--primary-color);
    padding-left: 0.8rem;
}

p {
    margin-bottom: 1rem;
}

.quick-access {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin: 1.5rem 0;
}

.quick-access ul {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

.quick-access li a {
    display: block;
    padding: 0.8rem;
    background-color: var(--light-bg);
    border-radius: 6px;
    text-decoration: none;
    color: var(--dark-text);
    transition: transform 0.2s, box-shadow 0.2s;
}

.quick-access li a:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.quick-access p {
    text-align: right;
    margin-top: 1rem;
}

.quick-access p a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.group-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.group-card {
    background-color: white;
    border-radius: 8px;
    padding: 1rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: transform 0.2s;
}

.group-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.group-card a {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    font-size: 1.2rem;
}

.group-card p {
    margin-top: 0.5rem;
    font-size: 0.9rem;
}

.material-list {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.material-list ul {
    list-style: none;
}

.material-list li {
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
}

.material-list li::before {
    content: "✓";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

footer {
    background-color: var(--secondary-color);
    color: var(--light-text);
    text-align: center;
    padding: 1.5rem;
    margin-top: 2rem;
}

/* Styles spécifiques pour les pages de groupe */
.group-info {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

.group-info h2 {
    color: var(--primary-color);
    border-bottom: 2px solid var(--light-bg);
    padding-bottom: 0.5rem;
}

.homework {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

.homework-item {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--light-bg);
}

.homework-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.homework-date {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* Styles pour la page des supports de cours */
.resources-section {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.resource-card {
    background-color: var(--light-bg);
    border-radius: 8px;
    padding: 1.2rem;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.resource-card a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    display: block;
    margin-bottom: 0.5rem;
}

.resource-card p {
    font-size: 0.9rem;
    color: var(--dark-text);
}

@media (max-width: 768px) {
    nav ul {
        flex-direction: column;
        align-items: center;
    }
    
    nav li {
        width: 100%;
        text-align: center;
    }
    
    main {
        padding: 1rem;
    }
    
    .quick-access ul, .resources-grid {
        grid-template-columns: 1fr;
    }
    
    .group-cards {
        grid-template-columns: 1fr;
    }
}

/* Styles pour les pages de groupe */
.checklist {
    list-style: none;
    margin-bottom: 1.5rem;
}

.checklist li {
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
}

.checklist li::before {
    content: "✓";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    margin: 1.5rem 0;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.resources-section {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin: 1.5rem 0;
}

.resources-section p {
    margin-bottom: 1rem;
}

.resources-section a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.resources-section a:hover {
    text-decoration: underline;
}