body {
    font-family: Arial, sans-serif;
    background-color: #2b2b2b;
    color: white;
    margin: 0;
    padding: 20px;
}

#course-network {
    width: 100%;
    height: 850px;
    border: 1px solid #444;
    background-color: #1e1e1e;
    border-radius: 8px;
    margin-bottom: 15px;
}

.controls {
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

button,
.file-upload {
    background: #444;
    color: white;
    border: 1px solid #666;
    padding: 10px 15px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

button:hover,
.file-upload:hover {
    background: #555;
}

.vis-network .vis-manipulation {
    background-color: rgba(68, 68, 68, 0.9) !important;
    border-color: #666 !important;
    color: white !important;
}

.vis-network .vis-manipulation .vis-button:hover {
    box-shadow: 0 0 5px white !important;
}

.context-menu {
    position: absolute;
    background-color: #333;
    border: 1px solid #555;
    border-radius: 4px;
    box-shadow: 2px 2px 8px rgba(0, 0, 0, 0.6);
    z-index: 10000;
    min-width: 160px;
    overflow: hidden;
}

.context-menu ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.context-menu li {
    padding: 10px 15px;
    cursor: pointer;
    color: #fff;
    font-size: 14px;
    border-bottom: 1px solid #444;
}

.context-menu li:last-child {
    border-bottom: none;
}

.context-menu li:hover {
    background-color: #2196F3;
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 20000;
}

.modal-content {
    background: #2b2b2b;
    border: 1px solid #444;
    padding: 20px 30px;
    border-radius: 8px;
    width: 320px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
}

.modal-content h3 {
    margin-top: 0;
    color: #2196F3;
    margin-bottom: 20px;
}

.modal-field {
    margin-bottom: 15px;
}

.modal-field label {
    display: block;
    margin-bottom: 5px;
    font-size: 14px;
    color: #ccc;
}

.modal-field input {
    width: 100%;
    padding: 10px;
    box-sizing: border-box;
    background: #1e1e1e;
    border: 1px solid #555;
    color: white;
    border-radius: 4px;
    font-size: 14px;
}

.modal-field input:focus {
    outline: none;
    border-color: #2196F3;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 25px;
}

.btn-save {
    background: #2196F3;
    border-color: #1976D2;
    font-weight: bold;
}

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

.btn-cancel {
    background: #555;
    border-color: #444;
}

.btn-cancel:hover {
    background: #444;
}

.map-dropdown {
    background: #444;
    color: white;
    border: 1px solid #666;
    padding: 10px 15px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    outline: none;
}

.map-dropdown:hover {
    background: #555;
}

.map-dropdown option {
    background: #333;
}