*{
    margin: 0 auto;
}

body {
    font-family: Calibri;
    background-color: aliceblue;
}

header {
    background-color: DodgerBlue;
    color: white;
    text-align: center;
    font-size: 150%;
    padding: 5px;
}

main {
    width: 70%;
    float: left;
}

button {
    background-color: LightBlue;
    color: white;
    padding: 15px;
    margin: 20px;
    width: 100%;
}

#artykul_1,
#artykul_2,
#artykul_3,
#artykul_4 {
    display: none;
}

footer {
    background-color: DodgerBlue;
    color: white;
    width: 20%;
    padding: 5px;
    margin: 10px;
    box-shadow: 15px 15px 12px dimgray;
    float: right;
}

h5,
blockquote {
    font-style: italic;
    text-align: center;
    margin: 0;
}

img {
    width: 100%;
    height: 100%;
}
table {
    margin: auto;
    width: 95%;
    border: 1px solid aliceblue;
}