.dersler-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.ders-header {
    text-align: center;
    margin-bottom: 3rem;
}

.ders-header h1 {
    color: #2c3e50;
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.ders-header p {
    color: #666;
    font-size: 1.1rem;
}

.ders-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.ders-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.ders-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.2);
}

.ders-card-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.ders-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.ders-card:hover .ders-card-image img {
    transform: scale(1.1);
}

.ders-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.ders-card:hover .ders-overlay {
    opacity: 1;
}

.ders-overlay i {
    color: white;
    font-size: 3rem;
    transition: transform 0.3s ease;
}

.ders-card:hover .ders-overlay i {
    transform: scale(1.1);
}

.ders-card-content {
    padding: 1.5rem;
}

.ders-card-content h3 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.ders-card-content p {
    color: #666;
    margin-bottom: 1rem;
}

.ders-meta {
    display: flex;
    justify-content: space-between;
    color: #666;
    font-size: 0.9rem;
}

.ders-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.ders-meta i {
    color: #3498db;
}

/* Ders Detay Modal */
.ders-detay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0,0,0,0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.3s;
}

.ders-content {
    background: white;
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
    border-radius: 16px;
    padding: 2rem;
    position: relative;
    box-shadow: 0 8px 32px rgba(0,0,0,0.25);
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    animation: modalFadeIn 0.3s;
}

@keyframes modalFadeIn {
    from { transform: scale(0.95); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.ders-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: #666;
    cursor: pointer;
    transition: color 0.3s;
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    z-index: 10;
}

.close-btn:hover {
    color: #e74c3c;
}

.ders-bilgi, .video-dersler, .quiz-section {
    margin-bottom: 2rem;
}

.ders-bilgi h3, .video-dersler h3, .quiz-section h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.ders-bilgi h3 i, .video-dersler h3 i, .quiz-section h3 i {
    color: #3498db;
}

.video-list {
    display: grid;
    gap: 1rem;
}

.video-item {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: background-color 0.3s ease;
}

.video-item:hover {
    background: #e9ecef;
}

.video-item i {
    color: #3498db;
    font-size: 1.5rem;
}

.quiz-button {
    background: #3498db;
    color: white;
    border: none;
    padding: 0.8rem 2rem;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: background-color 0.3s ease;
}

.quiz-button:hover {
    background: #2980b9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .dersler-container {
        padding: 0 1rem;
    }

    .ders-header h1 {
        font-size: 2rem;
    }

    .ders-grid {
        grid-template-columns: 1fr;
    }

    .ders-content {
        width: 95%;
        padding: 1.5rem;
    }
}