# Split button

Subtle web animation sketch from [https://mighil.com/animations](https://mighil.com/animations).

- **Live demo:** https://mighil.com/animations/split-button
- **Standalone HTML:** https://mighil.com/animations/split-button?download=1
- **This file:** https://mighil.com/animations/split-button/split-button.md
- **Technique:** `menu`

## What it does

Main action is one click. Chevron hides the quieter ones.

## Instructions for AI / coding agents

Implement this micro-interaction in the user's stack (vanilla HTML, React, Vue, Svelte, etc.).

1. Use the **HTML** as the DOM structure (adapt JSX/templates as needed; keep class names and ids).
2. Include the **Theme** CSS (or map the same variables into the host design system). It switches light/dark with `prefers-color-scheme`.
3. Apply the **CSS** as-is when possible. It uses `var(--text-color)`, `var(--heading-color)`, `var(--background-color)`, etc. from the theme so both modes work.
4. Run the **JavaScript** after the markup mounts. Prefer `DOMContentLoaded` or a framework `useEffect` / `onMount`.
5. Keep motion respectful of `prefers-reduced-motion` if the snippet already checks it.
6. Do not depend on mighil.com runtime or fonts. Theme variables are enough for color.
7. If porting to a component, expose the interactive root via a ref and preserve accessibility attributes (`aria-*`, `role`, `button` types).

## Theme (auto light / dark)

```css
/* Auto light / dark — follows prefers-color-scheme */
:root{
  color-scheme: light dark;
  --text-color: hsl(0, 0%, 18%);
  --heading-color: hsl(0, 0%, 18%);
  --background-color: hsl(0, 0%, 99%);
  --bg-color: hsl(0, 0%, 99%);
  --link-color: hsl(0, 0%, 18%);
  --visited-color: hsl(0, 0%, 18%);
  --blockquote-color: hsl(0, 0%, 18%);
  --code-bg-color: hsl(0, 0%, 95%);
  --code-color: hsl(0, 0%, 18%);
  --sub-color: hsl(0, 0%, 29%);
}
@media (prefers-color-scheme: dark){
:root{
  --text-color: hsl(35, 25%, 85%);
  --heading-color: hsl(35.2, 32.6%, 82.5%);
  --background-color: hsl(60, 2.2%, 8.8%);
  --bg-color: hsl(60, 2.2%, 8.8%);
  --link-color: hsl(34.7, 55.3%, 79.8%);
  --visited-color: hsla(34.7, 55.3%, 79.8%, 0.85);
  --blockquote-color: hsl(35, 30%, 75%);
  --code-bg-color: hsl(30, 5%, 7.8%);
  --code-color: limegreen;
  --sub-color: hsla(34.7, 24.7%, 84.9%, 0.78);
}
}
```

## HTML

```html
<div class="splitbtn" id="splitbtn">
        <button type="button" class="splitbtn-main" id="splitbtn-main">Publish</button>
        <button type="button" class="splitbtn-toggle" id="splitbtn-toggle" aria-expanded="false" aria-label="More publish options">
          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M6 9l6 6 6-6"/></svg>
        </button>
        <div class="splitbtn-menu" id="splitbtn-menu" role="menu">
          <button type="button" role="menuitem" data-split="Schedule">Schedule…</button>
          <button type="button" role="menuitem" data-split="Save draft">Save draft</button>
        </div>
      </div>
```

## CSS

```css
.splitbtn{display:inline-flex;position:relative;align-items:stretch}

.splitbtn-main,.splitbtn-toggle{
  appearance:none;-webkit-appearance:none;box-sizing:border-box;height:40px;cursor:pointer;color:inherit;
  font:inherit;font-size:.9rem;font-weight:500;line-height:1;
  border:1px solid color-mix(in srgb,var(--text-color) 14%,transparent);
  background:color-mix(in srgb,var(--text-color) 4%,transparent);
}

.splitbtn-main{
  width:118px;padding:0;border-radius:8px 0 0 8px;border-right:0;
  display:inline-flex;align-items:center;justify-content:center;
  transition:opacity .2s ease;
}

.splitbtn-toggle{
  width:36px;padding:0;border-radius:0 8px 8px 0;display:grid;place-items:center;
}

.splitbtn.is-busy .splitbtn-main,
.splitbtn.is-busy .splitbtn-toggle{opacity:.55;cursor:default;pointer-events:none}

.splitbtn-toggle svg{width:14px;height:14px;transition:transform .2s ease}

.splitbtn.is-open .splitbtn-toggle svg{transform:rotate(180deg)}

.splitbtn-menu{
  position:absolute;top:calc(100% + 6px);right:0;min-width:100%;padding:4px;border-radius:8px;z-index:2;
  border:1px solid color-mix(in srgb,var(--text-color) 12%,transparent);
  background:var(--background-color);
  box-shadow:0 8px 24px color-mix(in srgb,var(--text-color) 8%,transparent);
  opacity:0;transform:translateY(4px) scale(.96);transform-origin:top right;pointer-events:none;
  transition:opacity .16s ease, transform .18s var(--ease-out-soft);
}

.splitbtn.is-open .splitbtn-menu{opacity:1;transform:translateY(0) scale(1);pointer-events:auto}

.splitbtn-menu button{
  appearance:none;-webkit-appearance:none;width:100%;height:34px;padding:0 10px;border:0;border-radius:6px;
  background:transparent;color:inherit;font:inherit;font-size:.85rem;font-weight:500;text-align:left;cursor:pointer;
}

.splitbtn-menu button:hover{background:color-mix(in srgb,var(--text-color) 6%,transparent)}

@media (prefers-reduced-motion: reduce){
  .grow-link::after,.wipe,.wipe .b,.shuffle .card,.odo-digit > b,.flap-reel,.step-node,.step-line > i,
  .switch,.switch::after,.copy-btn .c-idle,.copy-btn .c-done,.field label,.tip-bubble,.chip,.like-btn svg,
  .disc-btn svg,.disc-panel,.snack,.save-btn,.ux-box,.seg-pill,.soft-tabs-ink,.list-actions,.success-banner,.search-clear,.pin-btn svg,.submit-ring rect,
  .hold-btn .hold-fill,.toast,.menu-btn .menu-line,.stars button,.conn,.retry-btn,.sort-item,.mute-btn .wave,.mute-btn .x-line,.wizard-dots span,.cart-badge,.range-bubble,
  .filter-list li,.upload-bar > i,.quota-track > i,.quota-tip,.splitbtn-toggle svg,.splitbtn-menu,.presence-dot,
  .draft-banner,.tag-chip,.empty-state,.empty-item,.deadline,.deadline-clock,.deadline-track > i,.edge-fade-mask,.dirty-bar,.seen-ticks path,.nudge-field,.stack-card,
  .blur-line,.xface span,.magnet-chip,.confirm-btn,.confirm-btn span,.offline-banner,.sort-flip-btn svg,.sort-flip-list li,.react-fan,.react-fan button,.sticky-cta,
  .pw-toggle .pw-eye,.pw-toggle .pw-slash,.otp input,.exp-search,.exp-search input,.ok-field input,.ok-field .ok-check,.unread-dot,.unread-check,.unread-row,.sync-label,.sync-btn .sync-arrows,.sync-btn .sync-check,
  .inline-edit .ie-title,.inline-edit .ie-rename,.inline-edit .ie-panel,.inline-edit .ie-input,.inline-edit .ie-bar,
  .ghost-wrap .ghost-hint,.ghost-wrap .ghost-key,.cmd-palette,.cmd-palette li,.cmd-stage::before,.crumb-mid,.crumb-more,.diff-add,.diff-add > .diff-add-inner,.slot > i,.zoom-thumb,.zoom-full,.zoom-caption,
  .bulk-bar,.bulk-check svg,.bulk-row,.env-switch .env-ink,.env-switch button,.invite-btn .invite-idle,.invite-btn .invite-done,.flag-row,.flag-sw,.flag-sw::after,.deploy-node,.deploy-node i,.deploy-wire > b,.ws-ink,.ws-item .ws-check,.thread,.thread-body,.thread-resolve svg,
  .unfurl-card,.unfurl-thumb,.seat,.form-prog-bar > i,.form-prog-field,.form-prog-field svg,.mention b,.glyph-tile path,.glyph-tile line,.glyph-tile circle{transition:none!important}

  .splitbtn.is-open .splitbtn-menu{opacity:1;transform:none}
}
```

## JavaScript

```js
// Split button
  const splitBtn = document.getElementById('splitbtn');
  const splitBtnMain = document.getElementById('splitbtn-main');
  const splitBtnToggle = document.getElementById('splitbtn-toggle');
  const splitBtnMenu = document.getElementById('splitbtn-menu');
  let splitTimer = null;
  function closeSplitBtn() {
    if (!splitBtn || !splitBtnToggle) return;
    splitBtn.classList.remove('is-open');
    splitBtnToggle.setAttribute('aria-expanded', 'false');
  }
  function openSplitBtn() {
    if (!splitBtn || !splitBtnToggle) return;
    splitBtn.classList.add('is-open');
    splitBtnToggle.setAttribute('aria-expanded', 'true');
  }
  function runSplitAction(busyLabel, doneLabel) {
    if (!splitBtn || !splitBtnMain || splitBtn.classList.contains('is-busy')) return;
    clearTimeout(splitTimer);
    closeSplitBtn();
    splitBtn.classList.add('is-busy');
    splitBtnMain.textContent = busyLabel;
    const wait = reduce ? 120 : 900;
    const hold = reduce ? 200 : 1100;
    splitTimer = setTimeout(() => {
      splitBtnMain.textContent = doneLabel;
      splitTimer = setTimeout(() => {
        splitBtnMain.textContent = 'Publish';
        splitBtn.classList.remove('is-busy');
      }, hold);
    }, wait);
  }
  if (splitBtnToggle) {
    splitBtnToggle.addEventListener('click', (e) => {
      e.stopPropagation();
      if (splitBtn.classList.contains('is-busy')) return;
      if (splitBtn.classList.contains('is-open')) closeSplitBtn();
      else openSplitBtn();
    });
  }
  if (splitBtnMain) {
    splitBtnMain.addEventListener('click', () => {
      runSplitAction('Publishing…', 'Published');
    });
  }
  if (splitBtnMenu) {
    splitBtnMenu.querySelectorAll('[data-split]').forEach((btn) => {
      btn.addEventListener('click', () => {
        const label = btn.getAttribute('data-split');
        if (label === 'Schedule') runSplitAction('Scheduling…', 'Scheduled');
        else runSplitAction('Saving…', 'Draft saved');
      });
    });
  }
  document.addEventListener('click', (e) => {
    if (splitBtn && !splitBtn.contains(e.target)) closeSplitBtn();
  });
```

---

_Source: https://mighil.com/animations/split-button_