/* ****************** basic styles ****************** */

body {
    margin: 0;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
}

/* class */
.important {
    color: red;
}

/* id */
#bar {
    background: yellow;
}

/* id and pseudo-class */
#section2 a:hover {
    color: orange;
}

/* elements */

h1 {
    text-align: center;
}

main {
    background: lightblue;
}

section {
    padding: 10px;
    margin: 10px;
    border-color: red;
    border-style: dashed;
    border-width: 1px;
    color: black;
}

/* header */

header h1 {
    background-image: linear-gradient(dodgerblue, blue);
    margin: 0;
    padding: 30px;
    text-align: center;
}

header nav {
    margin: 0;
    padding: 15px;
}

/* footer */

footer {
    background-color: dodgerblue;
    padding: 10px;
    text-align: center;
}

/* ****************** navigation bar ****************** */

nav {
    background-color: dodgerblue;
}

nav a {
    color: white;
    text-align: center;
    padding: 14px;
    text-decoration: none;
    font-size: 17px;
}

nav a:hover {
    background-color: lightgrey;
    color: black;
}

/* ****************** layout ****************** */

* {
    box-sizing: border-box;
}

/* create two equal columns that floats next to each other */
.column {
    float: left;
    width: 50%;
    padding: 10px;
}

/* clear floats after the columns */
.row:after {
    content: "";
    display: table;
    clear: both;
}

/* responsive layout of column class */
@media (max-width: 600px) {
    .column {
        width: 100%;
        padding: 10px;
    }
}