**Give this code a shot and hopefully it solves your problem.**
**Modify button CSS styling**
.btnQuiz{
font-family: "Montserrat", sans-serif;
background-color: #ffe31c;
border-radius: 10px;
border: none;
color: black;
text-align: center;
text-decoration: none;font-size: 16px;
display: flex;
}
**New changes applied**
.btnQuiz{
font-family: "Montserrat", sans-serif;
background-color: #ffe31c;
border-radius: 10px;
border: none;
color: black;
text-align: center;
text-decoration: none;
font-size: 16px;
display: flex;
margin: 0;
position: absolute;
top: 50%;
left: 75%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
<div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code> @import url("https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700&display=swap");
/* ---- Setting up the site grid layout for responsiveness ---- */
@media (max-width: 600px) {
.left, .right{
width: 100%;
}
}
* {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}
body {
background: gray;
font-family: "Montserrat", sans-serif;
}
main{
grid-area: main;
background: #272727;
}
footer{
grid-area: footer;
background-color: black;
text-align: right;
color: white;
}
h1.titleH1 {
font-family: 'Montserrat', sans-serif;
font-size: 2.3vw;
padding-left: 150px;
margin: auto;
color: white;
/* -- Vertically centering the heading -- */
position: relative;
top: 50%;
transform: translateY(-50%);
-webkit-transform: translateY(-50%);
-ms-transform: translateY(-50%);
}
img.roundleft{
border-top-left-radius: 10px;
border-bottom-left-radius: 10px;
box-shadow: 1px 0px 10px #000;
float: left;
}
/*--- Navigation Bar ---*/
.wrapper{
display: grid;
grid-template-areas:
'headerLeft headerRight';
grid-template-columns: 600px 1fr;
}
.headerLeft{
text-align: left;
background-color: black;
}
.headerRight{
text-align: right;
background: linear-gradient(to left,#55524e, black);
}
.navMenu {
margin-top: 30px;
margin-right: 20px;
}
.navMenu a {
color: #f6f4e6;
text-decoration: none;
font-size: 1vw;
text-transform: uppercase;
font-weight: 500;
margin-left: 50px;
margin-right: 50px;
-webkit-transition: all 0.2s ease-in-out;
transition: all 0.2s ease-i n-out;
}
.navMenu a:hover {
color: #fddb3a;
}
/*---- Main Pages (Rows and Columns) ----*/
.row{
display: flex;
}
.column
{
height: 800px;
}
.left
{
background-color: black;
width: 50%;
float: left;
}
.right{
background: linear-gradient(to left,#55524e, #171716);
width: 50%;
float: left;
}
.homeImage{
max-width: 100%;
height: 800px;
}
h1.mainH1{
color: white;
font-size: 2.5vw;
display: flex;
justify-content: center;
margin-top: 1em;
}
h2.mainH2{
color: white;
font-size: 2vw;
font-family: "Montserrat", sans-serif;
display: flex;
justify-content: center;
margin-top: 20px;
}
.listItems{
color: white;
font-size: 1vw;
font-family: "Montserrat", sans-serif;
display: flex;
justify-content: center;
}
.btnQuiz{
font-family: "Montserrat", sans-serif;
background-color: #ffe31c;
border-radius: 10px;
border: none;
color: black;
text-align: center;
text-decoration: none;
font-size: 16px;
display: flex;
margin: 0;
position: absolute;
top: 50%;
left: 75%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<main>
<div class="row">
<div class="column left"> <!-- Section on the Left side -->
<img class="homeImage" src="images/barbell.jpg" alt="Man lifting barbell">
</div>
<div class="column right"> <!-- Section on the Right side -->
<h1 class="mainH1">Welcome to the Fitness project</h1>
<h2 class="mainH2">Here you can:<br></h2>
<br>
<ul>
<li class="listItems">Learn the fundamentals of fitness as well as diet</li>
<br>
<li class="listItems">Take a quiz to optimize the information for your goals</li>
<br>
<li class="listItems">Expand your knowledge with useful bodybuilding tips</li>
</ul>
<button class="btnQuiz">Take Quiz</button>
</div>
</div>
</main>