* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: helvetica, sans-serif;
}

header {
    background-color: #cccccc;
    padding: 1rem;
}

h1,
h2,
h2,
h3,
h4,
h5,
h6 {
    padding: 0;
    margin: 0;
}

footer {
    background-color: #ccccff;
    padding: 1rem;
}

div.container {
    display: flex;
}


nav {
    background-color: #ffcccc;
    flex-basis: 10rem;
    flex-grow: 0;
    flex-shrink: 0;
    /* flex: 0 0 10rem; */
}

main {
    background-color: #ccffcc;
    flex-basis: 67%;
    flex-grow: 2;
    flex-shrink: 0.5;
    padding: 1rem;
}

aside {
    background-color: #cfffff;
    flex-basis: 33%;
    flex-grow: 1;
    flex-shrink: 1;
    padding: 1rem;
}