css first element inside div code example

Example 1: css first element

p:first-child {
  font-size: 1.5em;
}

Example 2: select first div css

#content_id div.class_name:first-child {
	/*your style*/
}

Example 3: center element in div

/* html */
<h1>Centering with CSS</h1>

<h3>Text-Align Method</h3>
<div class="blue-square-container">
  <div class="blue-square"></div>
</div>

<h3>Margin Auto Method</h3>
<div class="yellow-square"></div>

<h3>Absolute Positioning Method</h3>
<div class="green-square"></div>

/* css */
h1,
h3 {
  text-align: center;
}

.blue-square-container {
  text-align: center;
}

.blue-square {
  background-color: #0074D9;
  width: 100px;
  height: 100px;
  display: inline-block;
}

Example 4: what is a div element in html

The <div> tag is nothing more than a container unit that encapsulates other page elements and divides the HTML document into sections.
 The div can be used for reading purposes or to nest all the information inside the div then to style the div through css as a background card.