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    <h1>h1 - Page Title</h1>
    <h2>h2 - And this is the sub heading</h2>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Explicabo ea nostrum aperiam nobis, eaque perferendis beatae cupiditate deserunt sit, voluptatibus minima suscipit deleniti at. Ipsa, rerum? Suscipit minus impedit fugit.</p>

    <h3>h3 - Section title</h3>
    <p>Habitant morbi tristique senectus et. Lorem ipsum dolor sit amet consectetur adipiscing elit. Egestas erat imperdiet sed euismod nisi. Ac tincidunt vitae semper quis lectus. Consectetur a erat nam at. Erat pellentesque adipiscing commodo elit at imperdiet.</p>

        <li>Scelerisque varius morbi enim nunc faucibus a</li>
        <li>Porttitor eget dolor morbi non arcu risus quis varius</li>
        <li>Posuere lorem ipsum dolor sit amet consectetur adipiscing elit duis</li>


                html {
    font-size: 16px; // 16px browser's default size
    line-height: 1.5;
    margin: 0 2rem;

@media only screen and (min-width: 720px) {
    html {
        font-size: 18px;
        background-color: lightgreen;

@media only screen and (min-width: 960px) {
    html {
        font-size: 20px;
        background-color: lightgoldenrodyellow;

@media only screen and (min-width: 1240px) {
    html {
        font-size: 24px;
        background-color: lightblue;    

header {
    max-width: 50rem;
    margin: 2rem auto 3rem;
    border-bottom: solid 0.2rem rgba(0,0,0,0.2);
    padding-bottom: 1rem;

main {
    max-width: 70ch;
    margin: 0 auto;

h1 {
    font-size: 3.5rem;

h2 {
    font-size: 2.5rem;

h3 {
    font-size: 2rem; 

header h1, header h2 {
    margin: 0;