theme switcher

src/components/ThemeSwitcher.astro

@@ -0,0 +1,73 @@
+---
+import Icon from '@components/Icon.astro';
+---
+
+
+<div class="theme-switcher">
+    <button id="switch-to-dark">
+        <Icon name="sun" />
+    </button>
+    <button id="switch-to-light">
+        <Icon name="moon" />
+    </button>
+</div>
+
+
+<style>
+.theme-switcher {
+    position: relative;
+    isolation: isolate;
+    width: 1.5rem;
+    height: 1.5rem;
+
+    transform: translateY(0.1rem);
+}
+
+button {
+    position: absolute;
+    inset: 0;
+
+    background-color: transparent;
+    padding: 0;
+    color: var(--nav-link-color);
+    border: none;
+
+    &:hover {
+        cursor: pointer;
+        color: var(--accent-color);
+    }
+
+    /* hide by default, i.e. if JS isn't enabled and the data-theme attribute didn't get set, */
+    visibility: hidden;
+    opacity: 0;
+    transition:
+        color 0.2s ease,
+        opacity 0.5s ease,
+        transform 0.5s ease;
+}
+
+:global(html[data-theme="light"]) button#switch-to-dark {
+    opacity: 1;
+    visibility: visible;
+    transform: rotate(360deg);
+    /* whichever one is currently active should be on top */
+    z-index: 10;
+}
+:global(html[data-theme="dark"]) button#switch-to-light {
+    opacity: 1;
+    visibility: visible;
+    transform: rotate(-360deg);
+    z-index: 10;
+}
+</style>
+
+<script>
+document.getElementById('switch-to-dark')?.addEventListener('click', () => {
+    localStorage.setItem('theme-preference', 'dark');
+    document.documentElement.dataset.theme = 'dark';
+});
+document.getElementById('switch-to-light')?.addEventListener('click', () => {
+    localStorage.setItem('theme-preference', 'light');
+    document.documentElement.dataset.theme = 'light';
+})
+</script>