* {
    box-sizing: border-box;
}
 
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
 
header {
    background-color: #333;
    color: #fff;
    padding: 1em;
    text-align: center;
}
 
main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    min-height: 100vh;
    padding: 2em;
}
 
section {
    margin: 2em 0;
}
 
h1, h2 {
    font-weight: bold;
    text-align: center;
}
 
p {
    line-height: 1.5;
}
 
ul {
    list-style: none;
    margin: 0;
    padding: 0;
}
 
li {
    display: inline-block;
    margin: 0 1em;
}