• global All property values: inherit vs initial vs unset vs revert
• Use “\^M” for line continuation; use “\A” for a real newline
• image-set() https://drafts.csswg.org/css-images-4/#image-set-notation
• absolute length units: https://ethercalc.org/zd82oa4saoto
• dpi vs dpcm vs dppx, 96 dpi = 1 dppx
• em, ex, rem, ch
• vw, vh, viewport width/height / 100
• vmin = min(vw, vh), vmax = max(vw, vh)
• calc(90% - 2em)
• attr(maxlength em) = 10em
• Named Colors https://www.w3.org/TR/css-color-4/#named-colors
• rgb(25.5%, 4200%, 98.6%) or rgb(255, 444, 255)
• rgba(25.5%, 4200%, 98.6%, 0.5) or rgb(255, 444, 255, 0.5)
• #666, #903bc0, #000000cc
• hsl(300, 0%, 25%), hsla(300, 0%, 25%, 0.8)
• currentColor, transparent
• 360deg, 400grad, 6.283rad, 1turn
• 2.4s, 2400ms, 128hz, 0.128khz
• html { –case-sensitive: #639 }, h1 { color: var(–case-sensitive) }
• calc(var(–gutter) * var(–offset))