Introduction to Z-Index
In web design, one of the problems we sometimes encounter is how to create correct layering and display the elements on the page. This topic is especially important when using absolute positioning. To solve this issue, we use a CSS property called Z-Index.
When do we need Z-Index?
When elements on a page are registered in an overlapping manner or are placed on top of each other, we might face an issue where we need to change their layering. Here, Z-Index can help us place elements in different layers to manage their visibility.
Simple Use of Z-Index
Using Z-Index is very simple. You can easily apply the Z-Index property to your HTML elements and define its value. Generally, elements with a higher Z-Index value will be placed above other elements.
Common Pitfalls
One of the common pitfalls in using Z-Index is understanding the points that cause Z-Index not to work properly. A key point is that only elements with a position other than static will be affected by Z-Index.
<html>
<head>
<style>
.box1 {
position: absolute;
top: 50px;
left: 50px;
width: 100px;
height: 100px;
background-color: red;
z-index: 1;
}
.box2 {
position: absolute;
top: 80px;
left: 80px;
width: 100px;
height: 100px;
background-color: blue;
z-index: 2;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box2"></div>
</body>
</html>
Step-by-Step Explanation
<html> This is where our HTML code starts.
<head> This section includes the CSS styles used for the positioning of the elements.
.box1 is the first element with absolute positioning and has specific dimensions. Its background color is red, and its Z-Index is set to 1.
.box2 is the second element with absolute positioning that also has specific dimensions. Its background color is blue, and its Z-Index is set to 2. Therefore, it will be displayed above
.box1.
<body> This is the area where our elements are displayed within the page.
<div class="box1"></div> This is the red element which has a lower Z-Index and thus will be displayed below the blue element.
<div class="box2"></div> This is the blue element that will be displayed above.
