body {
    font-family: 'Arial', sans-serif;
    background-image: linear-gradient(to right, #a1c4fd, #c2e9fb);  /* Soft blue gradient */
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    color: #333;
}

.wrapper {
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 1200px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    overflow: hidden;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; /* Updated font */
}

header {
    background-color: #3b5998; /* Darker blue */
    color: white;
    text-align: center;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

main.content {
    display: flex;
    flex-grow: 1;
}

.concept-map {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
}

.sidebar {
    width: 300px;
    background-color: #f0faff; /* Very light blue */
    color: #333;
    display: flex;
    flex-direction: column;
    padding: 20px;
    border-left: 1px solid #e0e0e0;
}

.form-controls input, .form-controls select {
    padding: 12px;
    margin: 10px 0;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 16px;
}

.action-buttons button {
    padding: 12px;
    margin-top: 10px;
    background-color: #3b5998; /* Matching header */
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    font-size: 16px;
    font-weight: bold;
    text-transform: uppercase;
}

.action-buttons button:hover {
    background-color: #334d8c; /* Darker shade */
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.action-buttons button:active {
    background-color: #2c4379;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.menu-link {
    display: block;
    margin-bottom: 20px;
    text-align: center;
    text-decoration: none;
    background-color: #3b5998;
    color: white;
    padding: 12px;
    border-radius: 6px;
    font-size: 16px;
    font-weight: bold;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.menu-link:hover {
    background-color: #334d8c;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.menu-link:active {
    background-color: #2c4379;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.credits-info {
    margin-top: auto; /* Pushes to the bottom of the sidebar */
    font-size: 14px;
}

footer {
    text-align: center;
    padding: 10px;
    background-color: #3b5998;
    color: white;
    box-shadow: 0 -4px 6px rgba(0,0,0,0.1);
}

@media screen and (max-width: 768px) {
    .content {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        border-left: none;
        border-top: 1px solid #e0e0e0;
    }
}