/* Course Discussions Styles */
:root {
    --primary-color: #4CAF50;
    --primary-hover: #45a049;
    --secondary-color: #2196F3;
    --text-color: #333;
    --bg-color: #f5f5f5;
    --white: #ffffff;
    --border-color: #ddd;
}

body {
    margin: 0;
    padding: 0;
    background: var(--bg-color);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
}

/* Header */
.discussions-header {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo img {
    height: 40px;
}

.discussions-header h1 {
    flex: 1;
    text-align: center;
    margin: 0;
    font-size: 24px;
    color: var(--text-color);
}

.close-page-btn {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

.close-page-btn:hover {
    background: #1976D2;
}

/* Container */
.discussions-container {
    max-width: 1200px;
    margin: 20px auto;
    padding: 0 20px;
    display: flex;
    gap: 20px;
}

/* Sidebar */
.discussions-sidebar {
    width: 250px;
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    height: fit-content;
}

.new-discussion-btn {
    width: 100%;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

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

.filter-section {
    margin-top: 20px;
}

.filter-section h3 {
    margin-bottom: 10px;
    font-size: 14px;
    text-transform: uppercase;
    color: #666;
}

#sortFilter {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
}

/* Main Content */
.discussions-main {
    flex: 1;
}

.discussions-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

/* Discussion Item */
.discussion-item {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    cursor: pointer;
    transition: box-shadow 0.3s;
}

.discussion-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.discussion-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.discussion-header h3 {
    margin: 0;
    color: var(--text-color);
}

.pinned-badge {
    background: #ff9800;
    color: white;
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 12px;
}

.discussion-preview {
    color: #666;
    margin-bottom: 10px;
    line-height: 1.5;
}

.discussion-meta {
    display: flex;
    align-items: center;
    gap: 15px;
    font-size: 14px;
    color: #999;
}

.discussion-meta .stats {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 10px;
}

.discussion-meta .stats i {
    margin-right: 3px;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-content {
    background: white;
    border-radius: 10px;
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #999;
}

.modal-body {
    padding: 20px;
}

#discussionTitle {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 16px;
    margin-bottom: 15px;
}

#discussionMessage {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 14px;
    resize: vertical;
    margin-bottom: 15px;
}

.submit-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}

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

/* Messages */
.error {
    color: #f44336;
    text-align: center;
    padding: 20px;
}

.no-discussions {
    text-align: center;
    color: #666;
    padding: 40px;
    background: white;
    border-radius: 8px;
}

/* Responsive */
@media (max-width: 768px) {
    .discussions-container {
        flex-direction: column;
    }
    
    .discussions-sidebar {
        width: 100%;
    }
}