Вы устанавливаете top: 18em
стили по умолчанию:
aside {
position: fixed;
top: 18em;
...
}
Вы должны изменить это в медиа-запросе с top: auto;
@media all and (max-width: 500px) {
aside {
position: fixed;
border-radius: 0;
left: 0;
bottom: 0;
top: auto;
width: 100%;
height: 3em;
}
}
Пример:
* {
font-family: inherit;
font-style: inherit;
font-weight: inherit;
font-size: 100%;
box-sizing: border-box;
margin: 0;
padding: 0;
list-style: none;
}
/* Navigation */
nav {
background-color: #2A4543;
color: #FBFAF8;
box-shadow: 0 0 0.75em #4F5052;
position: fixed;
width: 100%;
height: 4em;
display: flex;
justify-content: space-around;
align-items: center;
}
nav ul {
display: flex;
flex-flow: row nowrap;
font-size: 1.625em;
}
nav a {
display: block;
padding: 0 6em;
}
.wrapper {
padding-top: 4em;
background-color: #EBF1F4;
display: flex;
width: 100%;
}
main {
width: 85%;
margin: auto;
}
header {
background-color: #FBFAF8;
box-shadow: 0 0 0.75em #4F5052;
color: #475148;
display: flex;
height: 20em;
justify-content: center;
align-items: center;
text-align: center;
}
header .about {
width: 35em;
height: 7em;
padding: 1em 0;
}
header h1 {
text-transform: uppercase;
font-size: 3.250em;
letter-spacing: 0.125em;
padding-bottom: 0.125em;
}
header hr {
width: 20em;
background-color: #475148;
margin: 0 auto;
height: 1px;
padding: 0;
border: 0;
}
header h2 {
font-size: 1.5em;
letter-spacing: 0.125em;
padding-top: 0.250em;
margin: 0 auto;
}
section {
background-color: #2D3441;
box-shadow: 0 0 0.75em #4F5052;
clear: both;
padding: 2em 4em;
display: flex;
flex-flow: row wrap;
justify-content: space-around;
}
section img {
padding: 3em 0;
}
a {
color: #FBFAF8;
text-decoration: none;
}
a:link {
text-decoration: none;
color: #FBFAF8;
}
a:visited {
text-decoration: none;
color: #FBFAF8;
}
nav a:active {
text-decoration: none;
color: #E49273;
}
nav a:hover {
text-decoration: none;
color: #E49273;
}
aside {
position: fixed;
top: 18em;
left: 0.625em;
background-color: #984447;
border-radius: 0.375em;
color: #FBFAF8;
width: 4.5em;
height: 12em;
display: flex;
align-items: center;
justify-content: center;
}
aside a:active {
text-decoration: none;
color: #CEB5A7;
}
aside a:hover {
text-decoration: none;
color: #CEB5A7;
}
i {
padding: 0.375em 0;
}
@media all and (max-width: 350px) {
nav {
font-size: 0.875em;
height: 4.5em;
}
header h1{
font-size: 3em;
}
}
@media all and (max-width: 500px) {
body {
font-size: 75%;
}
nav {
justify-content: center;
}
nav a {
padding: 0 1em;
}
.wrapper {
width: 100%;
height: 100%;
}
main {
width: 85%;
}
header {
font-size: 65%;
height: 18em;
}
section img {
padding: 1em 0;
width: 100%;
height: auto;
}
section {
padding: 2em 2.5em;
}
aside {
position: fixed;
border-radius: 0;
left: 0;
bottom: 0;
top: auto;
width: 100%;
height: 3em;
}
aside ul {
display: flex;
flex-flow: row nowrap;
}
i {
padding: 0.25em 0.5em;
}
}
<script src="https://use.fontawesome.com/95380c6d63.js"></script>
<body>
<!-- Navigation -->
<nav>
<ul>
<li><a href="#"><h1>About</h1></a></li>
<li><a href="#"><h1>Portfolio</h1></a></li>
<li><a href="#"><h1>Blog</h1></a></li>
</ul>
</nav>
<div class="wrapper">
<main>
<!-- About -->
<header>
<div class="about">
<h1>Daria Doronina</h1>
<hr>
<h2>Front-End Web Developer</h2>
</div>
</header>
<!-- Portolio -->
<section>
<a href="#">
<img src="http://placehold.it/400x300" alt="Tribute page">
</a>
<a href="#">
<img src="http://placehold.it/400x300" alt="Portfolio page">
</a>
<a href="#">
<img src="http://placehold.it/400x300" alt="Cartoon page">
</a>
<a href="#">
<img src="http://placehold.it/400x300" alt="My Portfolio">
</a>
</section>
</main>
</div><!-- close wrapper -->
<!-- Contacts -->
<aside>
<ul>
<li>
<a href="mailto:[email protected]" title="Send me an email">
<i class="fa email fa-envelope-o fa-2x" aria-hidden="true"></i>
</a>
</li>
<li>
<a href="https://github.com/Skidle/skidle.github.io/blob/master/CV.pdf?raw=true" target="_blank" title="My CV in PDF format">
<i class="fa cv fa-address-card-o fa-2x" aria-hidden="true"></i>
</a>
</li>
<li>
<a href="#" target="_blank" title="My FreeCodeCamp.com profile">
<i class="fa fcc fa-free-code-camp fa-2x" aria-hidden="true"></i>
</a>
</li>
</ul>
</aside>
</body>
OMG большое вам спасибо! Я бы никогда этого не заметил! –