.tubelist-container {
    max-width: 1200px;
    margin: 0 auto;
    margin-top: 20px;
    background-color: white;
    border: 2px solid #ccc;
    display: flex;
    flex-direction: column;
}

.tubelist-container .top-section {
    display: flex;
    flex: 1;
    min-height: 400px;
}

.tubelist-container .main-content {
    flex: 1;
    border: 1px solid #ddd;
    margin: 10px;
    padding: 20px;
    display: flex;
    align-items: start;
    justify-content: center;
    background-color: #fafafa;
}

.tubelist-container .sidebar {
    width: 300px;
    height: 400px;
    border: 1px solid #ddd;
    margin: 10px 10px 10px 0;
    padding: 10px;
    overflow-y: auto;
}

.tubelist-container .sidebar-item {
    display: flex;
    margin-bottom: 15px;
    border: 1px solid #eee;
    padding: 10px;
    cursor: pointer;
}

.tubelist-container .sidebar-item:last-child {
    margin-bottom: 0;
}

.tubelist-container .sidebar-image {
    width: 120px;
    height: 90px;
    background-color: #e0e0e0;
    border: 1px solid #ccc;
    margin-right: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: #666;
}

.tubelist-container .sidebar-text {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.tubelist-container .sidebar-text h4 {
    margin-bottom: 5px;
    font-size: 12px;
    color: #333;
}

.tubelist-container .sidebar-text p {
    font-size: 10px;
    color: #666;
    line-height: 1.3;
}

.tubelist-container .bottom-section {
    height: 150px;
    border: 1px solid #ddd;
    margin: 0 10px 10px 10px;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fafafa;
}

.tubelist-container .placeholder-text {
    color: #888;
    font-size: 16px;
    text-align: center;
}

@media (max-width: 768px) {
    .top-section {
        flex-direction: column;
    }

    .tubelist-container .top-section {
        flex-direction: column;
    }

    .tubelist-container .sidebar {
        width: auto;
        margin: 0 10px 10px 10px;
    }

    .tubelist-container .sidebar-item {
        flex-direction: column;
        text-align: center;
    }

    .tubelist-container .sidebar-image {
        margin: 0 auto 10px auto;
    }
}