Schalter für dunkles und helles Design

Dieses Muster zeigt, wie Sie einen Schalter für Ihre Website erstellen, mit dem zwischen hellen und dunklen Designs gewechselt werden kann, und diese Einstellung für nachfolgende Besuche speichern.

Vollständiger Artikel · Video auf YouTube · Quelle auf GitHub

HTML

<button class="theme-toggle" id="theme-toggle" title="Toggles light & dark" aria-label="auto" aria-live="polite">
  <svg class="sun-and-moon" aria-hidden="true" width="24" height="24" viewBox="0 0 24 24">
    <mask class="moon" id="moon-mask">
      <rect x="0" y="0" width="100%" height="100%" fill="white" />
      <circle cx="24" cy="10" r="6" fill="black" />
    </mask>
    <circle class="sun" cx="12" cy="12" r="6" mask="url(#moon-mask)" fill="currentColor" />
    <g class="sun-beams" stroke="currentColor">
      <line x1="12" y1="1" x2="12" y2="3" />
      <line x1="12" y1="21" x2="12" y2="23" />
      <line x1="4.22" y1="4.22" x2="5.64" y2="5.64" />
      <line x1="18.36" y1="18.36" x2="19.78" y2="19.78" />
      <line x1="1" y1="12" x2="3" y2="12" />
      <line x1="21" y1="12" x2="23" y2="12" />
      <line x1="4.22" y1="19.78" x2="5.64" y2="18.36" />
      <line x1="18.36" y1="5.64" x2="19.78" y2="4.22" />
     </g>
  </svg>
</button>

CSS


        @import "https://unpkg.com/open-props/easings.min.css";

.sun-and-moon > :is(.moon, .sun, .sun-beams) {
  transform-origin: center;
}

.sun-and-moon > :is(.moon, .sun) {
  fill: var(--icon-fill);
}

.theme-toggle:is(:hover, :focus-visible) > .sun-and-moon > :is(.moon, .sun) {
  fill: var(--icon-fill-hover);
}

.sun-and-moon > .sun-beams {
  stroke: var(--icon-fill);
  stroke-width: 2px;
}

.theme-toggle:is(:hover, :focus-visible) .sun-and-moon > .sun-beams {
  stroke: var(--icon-fill-hover);
}

[data-theme="dark"] .sun-and-moon > .sun {
  transform: scale(1.75);
}

[data-theme="dark"] .sun-and-moon > .sun-beams {
  opacity: 0;
}

[data-theme="dark"] .sun-and-moon > .moon > circle {
  transform: translateX(-7px);
}

@supports (cx: 1) {
  [data-theme="dark"] .sun-and-moon > .moon > circle {
    cx: 17;
    transform: translateX(0);
  }
}

@media (prefers-reduced-motion: no-preference) {
  .sun-and-moon > .sun {
    transition: transform .5s var(--ease-elastic-3);
  }

  .sun-and-moon > .sun-beams {
    transition: transform .5s var(--ease-elastic-4), opacity .5s var(--ease-3);
  }

  .sun-and-moon .moon > circle {
    transition: transform .25s var(--ease-out-5);
  }

  @supports (cx: 1) {
    .sun-and-moon .moon > circle {
      transition: cx .25s var(--ease-out-5);
    }
  }

  [data-theme="dark"] .sun-and-moon > .sun {
    transition-timing-function: var(--ease-3);
    transition-duration: .25s;
    transform: scale(1.75);
  }

  [data-theme="dark"] .sun-and-moon > .sun-beams {
    transition-duration: .15s;
    transform: rotateZ(-25deg);
  }

  [data-theme="dark"] .sun-and-moon > .moon > circle {
    transition-duration: .5s;
    transition-delay: .25s;
  }
}

JS


        const storageKey = 'theme-preference'

const onClick = () => {
  // flip current value
  theme.value = theme.value === 'light'
    ? 'dark'
    : 'light'

  setPreference()
}

const getColorPreference = () => {
  if (localStorage.getItem(storageKey))
    return localStorage.getItem(storageKey)
  else
    return window.matchMedia('(prefers-color-scheme: dark)').matches
      ? 'dark'
      : 'light'
}

const setPreference = () => {
  localStorage.setItem(storageKey, theme.value)
  reflectPreference()
}

const reflectPreference = () => {
  document.firstElementChild
    .setAttribute('data-theme', theme.value)

  document
    .querySelector('#theme-toggle')
    ?.setAttribute('aria-label', theme.value)
}

const theme = {
  value: getColorPreference(),
}

// set early so no page flashes / CSS is made aware
reflectPreference()

window.onload = () => {
  // set on load so screen readers can see latest value on the button
  reflectPreference()

  // now this script can find and listen for clicks on the control
  document
    .querySelector('#theme-toggle')
    .addEventListener('click', onClick)
}

// sync with system changes
window
  .matchMedia('(prefers-color-scheme: dark)')
  .addEventListener('change', ({matches:isDark}) => {
    theme.value = isDark ? 'dark' : 'light'
    setPreference()
  })