Pure CSS loaders use @keyframes animations to create the illusion of motion — no JavaScript, no images. Spinners typically animate transform: rotate() on a bordered element with one transparent edge. Dot loaders stagger animation-delay across sibling elements. Use animation-timing-function: cubic-bezier() to control the feel — ease-in-out for smooth spins, steps() for mechanical ticks. All loaders here are accessible: add role="status" and a visually hidden label for screen readers.