A student asked me what I mean by “decent CSS.”
In my mind, “decent” looks like you gave it some thought, care and attention. You have specified a nice font stack (no need to use Google Fonts, but you could), and you have spec’d some margins (and possibly also padding) to give the page a pleasing appearance. Any professional website has these characteristics. No professional uses the defaults for fonts, margins or padding.
Also, a professional will specify at least the body background color and the text (foreground) color, even when the background is white and the foreground is black. Why? You can never be sure that a user has not changed the browser’s default colors.
So, more precisely, decent CSS for a basic page includes:
- A good font stack, including a suitable font generic
- Changes to margins and padding as appropriate (for example, the text should NEVER sprawl full width across a wide screen)
- Values specified for both background and color for the BODY element, even if the background is white and the text is black
- Media queries as needed to make the page responsive, especially for mobile
Numbers 2 and 4 together mean that you are very likely to need at least one media query, because the way you specify left and right margins for a big screen are going to be bad on sizes more narrow than about 800px.
Do not forget to include the viewport meta tag at the correct location in your HEAD element.
I hope this is helpful.