“Child themes” are a great feature of WordPress! — I wish I knew about them the first time I looked for themes. I found then some themes I liked but I discarded them all because of a few issues I saw in each; things like too small line height, justified text in paragraphs (ugly without hyphenation), a not optimal choice of Windows fonts, or, sometimes, no Windows font specified at all!
Now, such “details” only take a few keystrokes to change. With a basic knowledge of HTML and CSS and a reference at hand, you spot the rules in the stylesheet, change a value or two, and save your changes. But I never liked this option: you have to keep track of your changes, remember about them, and reapply them every time the theme is updated. So I settled for a theme that got most of the “details” right but which I did not like that much…