CSS
.gui-split-button {
--theme: hsl(220 75% 50%);
--theme-hover: hsl(220 75% 45%);
--theme-active: hsl(220 75% 40%);
--theme-text: hsl(220 75% 25%);
--theme-border: hsl(220 50% 75%);
--ontheme: hsl(220 90% 98%);
--popupbg: hsl(220 0% 100%);
--border: 1px solid var(--theme-border);
--radius: 6px;
--in-speed: 500ms;
--out-speed: 100ms;
display: inline-flex;
border-radius: var(--radius);
background: var(--theme);
color: var(--ontheme);
fill: var(--ontheme);
touch-action: manipulation;
user-select: none;
-webkit-tap-highlight-color: transparent;
@media (--dark) {
--theme: hsl(220 50% 60%);
--theme-hover: hsl(220 50% 65%);
--theme-active: hsl(220 75% 70%);
--theme-text: hsl(220 10% 85%);
--theme-border: hsl(220 20% 70%);
--ontheme: hsl(220 90% 5%);
--popupbg: hsl(220 10% 30%);
}
& button {
cursor: pointer;
appearance: none;
background: none;
border: none;
display: inline-flex;
align-items: center;
gap: 1ch;
white-space: nowrap;
font-family: inherit;
font-size: inherit;
font-weight: 500;
padding-block: 1.25ch;
padding-inline: 2.5ch;
color: var(--ontheme);
outline-color: var(--theme);
outline-offset: -5px;
&:is(:hover, :focus-visible) {
background: var(--theme-hover);
color: var(--ontheme);
& > svg {
stroke: currentColor;
fill: none;
}
}
&:active {
background: var(--theme-active);
}
}
& > button {
border-radius: var(--radius) 0 0 var(--radius);
@supports (border-start-start-radius: 1px) {
border-end-start-radius: var(--radius);
border-start-start-radius: var(--radius);
}
}
@media (--light) {
& > button,
& button:is(:focus-visible, :hover) {
text-shadow: 0 1px 0 var(--theme-active);
}
& > .gui-popup-button > svg,
& button:is(:focus-visible, :hover) > svg {
filter: drop-shadow(0 1px 0 var(--theme-active));
}
}
& svg {
inline-size: 2ch;
box-sizing: content-box;
stroke-linecap: round;
stroke-linejoin: round;
stroke-width: 2px;
}
}
.gui-popup-button {
inline-size: 4ch;
cursor: pointer;
position: relative;
display: inline-flex;
align-items: center;
justify-content: center;
border-inline-start: var(--border);
border-radius: 0 var(--radius) var(--radius) 0;
@supports (border-start-start-radius: 1px) {
border-inline-start: var(--border);
border-start-end-radius: var(--radius);
border-end-end-radius: var(--radius);
}
&:is(:hover,:focus-within) {
background: var(--theme-hover);
}
/* fixes iOS trying to be helpful */
&:focus {
outline: none;
}
&:active {
background: var(--theme-active);
}
&:focus-within {
& > svg {
transition-duration: var(--in-speed);
transform: rotateZ(.5turn);
}
& > .gui-popup {
transition-duration: var(--in-speed);
opacity: 1;
transform: translateY(0);
pointer-events: auto;
}
}
@media (--motionOK) {
& > svg {
transition: transform var(--out-speed) ease;
}
& > .gui-popup {
transform: translateY(5px);
transition:
opacity var(--out-speed) ease,
transform var(--out-speed) ease;
}
}
}
.gui-popup {
--shadow: 220 70% 15%;
--shadow-strength: 1%;
opacity: 0;
pointer-events: none;
position: absolute;
inset-block-end: 80%;
inset-inline-start: -1.5ch;
list-style-type: none;
background: var(--popupbg);
color: var(--theme-text);
padding-inline: 0;
padding-block: .5ch;
border-radius: var(--radius);
overflow: hidden;
display: flex;
flex-direction: column;
font-size: .9em;
transition: opacity var(--out-speed) ease;
box-shadow:
0 -2px 5px 0 hsl(var(--shadow) / calc(var(--shadow-strength) + 5%)),
0 1px 1px -2px hsl(var(--shadow) / calc(var(--shadow-strength) + 10%)),
0 2px 2px -2px hsl(var(--shadow) / calc(var(--shadow-strength) + 12%)),
0 5px 5px -2px hsl(var(--shadow) / calc(var(--shadow-strength) + 13%)),
0 9px 9px -2px hsl(var(--shadow) / calc(var(--shadow-strength) + 14%)),
0 16px 16px -2px hsl(var(--shadow) / calc(var(--shadow-strength) + 20%))
;
/* fixes iOS trying to be helpful */
&:focus {outline: none}
@media (--dark) {
--shadow-strength: 5%;
--shadow: 220 3% 2%;
& button:not(:focus-visible, :hover) {
text-shadow: 0 1px 0 var(--ontheme);
}
& button:not(:focus-visible, :hover) > svg {
filter: drop-shadow(0 1px 0 var(--ontheme));
}
}
@media (width <= 400px) {
inset-inline-start: -200%;
}
& svg {
fill: var(--popupbg);
stroke: var(--theme);
@media (prefers-color-scheme: dark) {
stroke: var(--theme-border);
}
}
& button {
color: var(--theme-text);
width: 100%;
}
}
JS
import $ from 'blingblingjs'
import {rovingIndex} from 'roving-ux'
const splitButtons = $('.gui-split-button')
const popupButtons = $('.gui-popup-button')
// popup activating roving index for it's buttons
popupButtons.forEach(element =>
rovingIndex({
element,
target: 'button',
}))
// support escape key
popupButtons.on('keyup', e => {
if (e.code === 'Escape')
e.target.blur()
})
popupButtons.on('focusin', e => {
e.currentTarget.setAttribute('aria-expanded', true)
})
popupButtons.on('focusout', e => {
e.currentTarget.setAttribute('aria-expanded', false)
})
// respond to any button interaction
splitButtons.on('click', event => {
if (event.target.nodeName !== 'BUTTON') return
console.info(event.target.innerText)
})