body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

h1 {
    background-color: #f5f5f5;
    margin: 0;
    padding: 20px;
    text-align: center;
}

form {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 20px;
}

label, input, select, button {
    margin: 5px;
}

button {
    background-color: #4CAF50;
    border: none;
    color: white;
    cursor: pointer;
    padding: 5px 10px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    transition-duration: 0.4s;
    border-radius: 12px;
    border: 2px solid #4CAF50;
}

button:hover {
    background-color: white;
    color: black;
}

hr {
    border: 0;
    border-top: 1px solid #ccc;
}

h2 {
    margin-left: 20px;
}

div {
    margin: 20px;
    padding: 20px;
    background-color: #f5f5f5;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.tip {
    margin-top: 20px;
    padding: 20px;
    background-color: #e6fff6;
    border: 1px solid #66ffcc;
    border-radius: 4px;
}

.tip h3 {
    margin-top: 0;
    color: #00802b;
}