huddle-landing-page-with-single-introductory using flexbox properties

there is no for the <a> within the <button> remove that to fix the error issue and wrap the heading in <h1> to fix the accessibility issue.

Give the body the background-image and color you gave to the main.

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

Give the main a max-width of 1440px, a width of 80% and margin: 0 auto for the left and right sides of the page, you dont need to give the main a width value in the css this will work on all screen sizes.

main{
max-width:1440px;
width: 80%;
margin: 0 auto;
}

Hope am helpful.

Well done for completing this challenge. HAPPY CODING