Proportion

Proportion is how the sizes of elements relate to each other. Bigger elements look more important, so sizes should match importance.

In the example, the unbalanced card lets a huge icon crowd out the content. In the balanced card, the icon and title are sized in proportion, and the title gets the attention it needs.

Check proportions on each screen size, because a ratio that works on a laptop may feel too big or too small on a phone.