diff --git a/_includes/components/theme-switcher.webc b/_includes/components/theme-switcher.webc
new file mode 100644
index 0000000..c0e713f
--- /dev/null
+++ b/_includes/components/theme-switcher.webc
@@ -0,0 +1,167 @@
+<label class="switch-input">
+  <span class="visually-hidden">Enable setting</span>
+  <input type="checkbox" role="switch" class="visually-hidden" />
+  <span class="switch-input__decor" data-switch-input-state="on" aria-hidden="true" style="--switch-input-font-size: 65cqw;--switch-input-decor-space: var(--switch-input-gutter) 0.25ch;line-height: 0.63;">☼</span>
+  <span class="switch-input__decor" data-switch-input-state="off" aria-hidden="true" style="--switch-input-font-size: 50cqw; line-height: 1.03">☾</span>
+  <span class="switch-input__thumb" aria-hidden="true"></span>
+</label>
+
+
+<script type="module">
+customElements.define('theme-switcher', class extends HTMLElement {
+  currentTheme
+  preferDark
+
+  constructor() {
+    super()
+
+    this.preferDark = window.matchMedia("(prefers-color-scheme: dark)")
+  }
+
+  connectedCallback() {
+    const checkbox = this.querySelector('input[type="checkbox"]')
+    this.currentTheme = localStorage.getItem('theme')
+
+    if (this.currentTheme == 'dark') {
+      checkbox.checked = true
+      document.body.classList.toggle('dark')
+    } else if (this.currentTheme == 'light') {
+      checkbox.checked = false
+      document.body.classList.toggle('light')
+    }
+
+    checkbox.addEventListener('click', () => {
+      let theme
+      if (this.preferDark.matches) {
+        document.body.classList.toggle("light")
+        theme = document.body.classList.contains("light")
+          ? "light"
+          : "dark"
+      } else {
+        document.body.classList.toggle("dark")
+        theme = document.body.classList.contains("dark")
+          ? "dark"
+          : "light"
+      }
+
+      localStorage.setItem("theme", theme)
+    })
+  }
+})
+</script>
+
+<style webc:scoped>
+/* Styles */
+:host {
+  --switch-input-thumb-size: 0.88em;
+  --switch-input-thumb-bg: var(--bg-colour);
+  --switch-input-thumb-stroke: 1px solid var(--primary-colour-25);
+  --switch-input-off-bg: var(--neutral-100);
+  --switch-input-off-text: var(--neutral-900);
+  --switch-input-on-bg: var(--neutral-100-25);
+  --switch-input-on-text: var(--neutral-100);
+  --switch-input-gutter: 1px;
+  --switch-input-decor-space: var(--switch-input-gutter) 0.5ch;
+  --switch-input-focus-stroke: 2px solid #ff6978;
+  --switch-input-font-weight: bold;
+  /* --switch-input-font-family: sans-serif; */
+  --switch-input-font-size: 50cqw;
+  --switch-input-transition: inset 50ms linear;
+
+  display: grid;
+}
+
+.visually-hidden {
+  border: 0;
+  clip: rect(0 0 0 0);
+  height: auto;
+  margin: 0;
+  overflow: hidden;
+  padding: 0;
+  position: absolute;
+  width: 1px;
+  white-space: nowrap;
+}
+
+.switch-input {
+  width: calc(
+    (var(--switch-input-thumb-size) * 2) + (var(--switch-input-gutter) * 3)
+  );
+  height: calc(
+    var(--switch-input-thumb-size) + (var(--switch-input-gutter) * 2)
+  );
+  border-radius: calc(
+    var(--switch-input-thumb-size) + var(--switch-input-gutter)
+  );
+  padding: var(--switch-input-gutter);
+  background: var(--switch-input-off-bg);
+  color: var(--switch-input-off-text);
+  text-align: left;
+  text-transform: uppercase;
+  font-family: var(--switch-input-font-family);
+  font-weight: var(--switch-input-font-weight);
+  position: relative;
+  cursor: pointer;
+  container-type: inline-size;
+}
+
+.switch-input__decor {
+  position: absolute;
+  inset-block: 0;
+  inset-inline-start: 0;
+  padding: var(--switch-input-decor-space);
+
+  /* Font size lives here because we wanna use container units */
+  font-size: var(--switch-input-font-size);
+
+  /* Legacy */
+  display: flex;
+  width: 100%;
+  /* align-items: center; */
+
+  /* Future */
+  /* align-content: center; */
+  /* display: block;
+  block-size: 100%; */
+  user-select: none;
+}
+
+.switch-input__decor[data-switch-input-state="off"] {
+  justify-content: flex-end;
+}
+
+.switch-input__thumb {
+  display: block;
+  width: var(--switch-input-thumb-size);
+  height: var(--switch-input-thumb-size);
+  border-radius: var(--switch-input-thumb-size);
+  background: var(--switch-input-thumb-bg);
+  border: var(--switch-input-thumb-stroke);
+  z-index: 1;
+  position: absolute;
+  inset-block-start: var(--switch-input-gutter);
+  inset-inline-start: var(--switch-input-gutter);
+  transition: var(--switch-input-transition);
+}
+
+/* Could do this */
+/* .switch-input:has(:focus) .switch-input__thumb {
+  outline: var(--switch-input-focus-stroke);
+} */
+
+/* Better pointer experience. Still uses has because focus visible would have to be put direct on the checkbox */
+.switch-input:has(:focus-visible) .switch-input__thumb {
+  outline: var(--switch-input-focus-stroke);
+}
+
+.switch-input:has(:checked) {
+  background: var(--switch-input-on-bg);
+  color: var(--switch-input-on-text);
+}
+
+.switch-input:has(:checked) .switch-input__thumb {
+  inset-inline-start: calc(
+    var(--switch-input-thumb-size) + (var(--switch-input-gutter) * 2)
+  );
+}
+</style>