body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    color: #000000;
    margin: 0;
    padding: 20px;
    text-align: center;
}

header {
    background-color: #243f64;
    color: white;
    padding: 10px 0;
    text-align: center;
}

main {
    margin: 20px 0;
}

.responsive-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto; 
    border: 20px solid #000000;
}

button {
    background-color: #008CBA;
    color: white;
    border: none;
    padding: 10px 15px;
    cursor: pointer;
}

button:hover {
    background-color: #005f73;
}

footer {
    text-align: center;
    margin-top: 20px;
}

#okno {
    width: 300px;
    height: 50px;
    text-align: center;
    padding: 15px;
    border: 3px solid #0000cc;
    border-radius: 10px;
    color: #0000cc;
    display: none;

}
#okno:target {display: block;}