demo.css

::selection { background: var(--tape-black, black); color: var(--tape-green, lime) }
:focus { outline-color: var(--tape-green, black) }
html { font-family: sans-serif; background: papayawhip }
body { margin: 0 auto }
.font-lax { font: inherit }
.pad-0 { padding: 0 }
.pad-1 { padding: 1rem }
.pad-2 { padding: 2rem }
.pad-3 { padding: 3rem }
.hold-left { margin-left: 1rem }
.m-zero { margin: 0 }
.m-auto { margin: auto }
.m-up { margin-top: 1rem }
.m-drop { margin-bottom: 1rem }
.m-down { margin-bottom: 4rem }
.maxw-2ch { max-width: 1em; max-width: 2ch; }
.maxw-25em { max-width: 25em }
.list-none { list-style: none }
.flex-down { display: flex; flex-flow: column }
.flex-up { display: flex; flex-flow: column-reverse }
.order-before { order: -1 }
.order-after { order: 1 }
.tx-end { text-align: end }