body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    margin: 40px;
}

.container {
    width: 60%;
    margin: auto;
    padding: 20px;
    background-color: #ffffff;
    border: 1px solid #e0e0e0;
    text-align: center;
    box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.1);
}

.groups {
    display: flex;
    justify-content: space-between;
}

.group {
    width: 45%;
}

.label {
    font-weight: bold;
}

.error-text {
    color: red;
    font-size: 12px;
    display: none; /* Initially hidden */
}

.input-group {
    margin: 20px 0;
}

label {
    display: block;
    margin-bottom: 8px;
}

input[type="number"], select {
    margin: 5px;
    padding: 10px;
    width: 60%;
    border: 1px solid #ccc;
    border-radius: 4px;
    outline: none;
}

input[type="number"]:focus, select:focus {
    border-color: #007bff;
}

button {
    padding: 10px 20px;
    font-size: 18px;
    cursor: pointer;
    background-color: #007bff;
    color: #ffffff;
    border: none;
    transition: background-color 0.3s ease; /* Smooth transition on hover */
}

button:hover {
    background-color: #0056b3;
}

#results {
    margin-top: 20px;
    font-size: 18px;
}

#abTestChart {
    max-width: 400px;
    margin: 20px auto;
}

@media only screen and (max-width: 768px) {
    .container {
        width: 100%;
    }

    .groups {
        flex-direction: column;
    }

    .group {
        width: 100%;
    }
}