Testimonials Grid Section using CSS Grid, Media query and Flexbox

while the site is looking almost like the design there are some subtleties that can be improved.

Design

• too much whitespace overall (i'm blaming the over-use of grid-template-rows)
• the border-colors on the profile images is not necessarily white everywhere
• the profile images are too big (in the design they're as big as the space needed for the next to it)

HTML

• your solution does not include semantic HTML (e.g. your .container element could be a <main>)
• I feel like you used headings (<h1> to <h6> for styling). Styling should be done in CSS, heading levels should be in logical order. by that i mean: when you strip away everything else in your HTML, does it like a table of contents that makes sense?
• the image you included for the quotation mark in the background should either not be in the HTML (and can be added via a pseudo element in CSS) or it should have the aria-hidden attribute to ensure it is removed from the accessibility tree
• alt texts should have meaningful content (in my opinion: repeating the name is not meaningful, so those might be hidden as well, or you need to give them better alt texts)