basics

Replace <h2> with <h1> and <div class="attribution"> with the footer tag to make the page accessible. click here for more on web-accessibility and semantic html

Add the alt attribute alt=" " to the img tag and give it a value. The value of the alt attribute is the description of the image. For decorative images like icons, there is no need to give it an alt value, for more on alt attribute Click here.

Every html must have <h1> to make it accessible. Always begin the heading of the html with <h1> tag wrap the sub-heading of <h1> in <h2> tag, wrap the sub-heading of <h2> in <h3> this continues until <h6>, never skip a level of a heading.

To center the main on the page using flexbox or grid instead of margin:

• USING FLEXBOX: add min-height:100vh; display: flex; align-items: center: justify-content: center; to the body

body{
min-height: 100vh;
display: flex;
align-items: center;
justify-content: center;
}

• USING GRID: add min-height:100vh; display: grid place-items: center to the body

body{
min-height: 100vh;
display: grid;
place-items: center;
}

Use relative units like rem or em as unit for the padding, margin, width values and preferably rem for the font-size values, instead of using px which is an absolute unit. For more on CSS units Click here and here

For a responsive content,

• Reduce the max-width value of the main , increase the padding value for all the sides max-width: 320px which is 20rem/em padding:16px which is 1rem/em, give the main a border-radius value a d a background-color of white, the rest are not needed.
• Give the img a max-width of 100% and a border-radius value, the rest are not needed.

Give h1 and p the same font-size of 15px which is 0.9375rem, text-align: center,the same margin-left, margin-right and margin-top values. Give p a margin bottom value.

Hope am helpful.

Well done for completing this challenge. HAPPY CODING