Four Card Feature Solution

Replace the <h2> in the header with p, replace the <h3> with <h2> to fic the accessibility issues.

wrap the header in a div or section , give it a class to style to center the header. in the css give this div/section display: flex; align-items center, justify-content center and give the header a width of 50%.

in the html:
<section><header></header></section>
in the css:  
section{
display: flex;
align-items: center;
justify-content: center
}
header{
width: 50%;
text-align: center;
}

Give the first p in the header a class to style , give it a lighter font weight and an increase font-size. Use the font-family that was given in the styleguide.md. there is no need to give the h2 in .card a font-color

Use relative units like rem or em as unit for the padding, margin, width values and preferably rem for the font-size values for more on CSS units Click here

Hope am helpful.

Well done for completing this challenge. HAPPY CODING