* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
}
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: #333;
    color: white;
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: 10px;
    z-index: 1000;
}
.navbar a {
    color: white;
    text-decoration: none;
    padding: 10px 20px;
    position: relative;
}
.navbar a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: green;
}
.section {
    padding: 100px 20px;
    border-bottom: 1px solid #ddd;
    margin-top: 60px;
}
.section h2 {
    margin-top: 0;
}