deg
The everyday degree: 360 to the turn, the dominant dialect of angles.
One deg is 1/360 of a full turn — the Babylonian division that crossed four thousand years of geometry and arrived in CSS intact. It is the working currency of the <angle> type: rotations, gradient slopes, conic-gradient slices, color hues.
It is the right choice almost always, by force of habit: 45deg reads without translation. Worth remembering the house clock: in gradients, 0deg points up and the angle grows clockwise.
.pano {
background: linear-gradient(135deg, #14b8a6, #134e4a);
}