CSS Problém

body {
    background-image: url(background.jpg);;
}

#hlavicka {
    margin: auto;
    padding: 30px;
    background: #333;
    color: white;
    display: block;
    opacity: 0.7;
    border-top-left-radius: 40;
    border-top-right-radius: 40;
    text-align: center;
    font-family: Impact, Charcoal, sans-serif;
}

#hr {
    margin: auto;
    padding: 4px;
}

#menu {
    margin: auto;
    padding: 10px;
    background: #333;
    color: white;
    display: block;
    opacity: 0.7;
    border-top-style: solid;
    border-top-color: black;
    border-bottom-left-radius: 40;
    border-bottom-right-radius: 40;
    text-align: center;
    font-family: Impact, Charcoal, sans-serif;
}

#menu a:hover {
    color: #111;
}

#menu a {
    color: white;
    text-decoration: none;
    text-transform: uppercase;
}

#obsah {
    padding: 200px 30;
    background: #333;
    color: white;
    opacity: 0.7;
    font-family: Arial;
    border-top-left-radius: 40;
    border-top-right-radius: 40;
}

#footer {
    margin: auto;
    padding: 20px;
    background: #333;
    color: white;
    display: block;
    opacity: 0.7;
    text-align: center;
    font-family: Impact, Charcoal, sans-serif;
    border-bottom-left-radius: 40;
    border-bottom-right-radius: 40;
    border-top-style: solid;
    border-top-color: black;
}