body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0;
    font-family: Arial, sans-serif;
}

header {
    background: #4CAF50;
    color: white;
    padding: 10px 0;
    text-align: center;
}

main {
    flex: 1;
    padding: 20px;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 10px 0;
    position: relative;
}

img {
    max-width: 100%;
    height: auto;
}