ton of tiny, single purpose classes that are named based on their visual function. • Text sizes, colors, and weights • Shadows • Borders • Background colors • Flexbox utilities • Padding and margin helper • Width & Heights • Positions and alignments one class = one job .mt-0 { margin-top: 0; } .pr-1 { padding-right: var(--spacer-1); } .bg-dark { background-color: var(--bg-dark); } .text-red { color: var(--red); }