Good attempt! Your preparation time section needs to have its own background colour, you are missing the thin lines between each section and in the table and your mobile design should have no margins.
Overall, quite a good design here. The background colour should not be pure black though and should instead be the off black provided in the style guide. You also need some more margins to make the main section here a bit taller to be closer to the design. Also consider using more semantic tags like 'main' for your main content in the page. Your mobile design also doesn't change here, a simple media query would fix this problem. Finally, try not to use rem instead of pixels when possible as this is a responsive measurement.
Overall, the solution here looks quite close to the design! Only real notes I have are that you could make the mobile design closer to the challenge by making your text smaller and putting in a bit of space between your main section and the borders of the page. Also try to use more semantic tags in your html. For example, instead of 'article-content', use the 'article' tag.
Pretty clean and well done solution! The usage of line breaks especially is nice and what you've created here is very close to the design. Only things to improve would be to use "rem" for sizing with fonts as this is responsive and to have more descriptive class names rather than "txt1". Other than that, great job!