1 files changed, 97 insertions, 66 deletions

diff --git a/src/ts/script.ts b/src/ts/script.ts
index 56c6d63..81c61f7 100644
--- a/src/ts/script.ts
+++ b/src/ts/script.ts
@@ -1,92 +1,123 @@
 import Prism from 'prismjs';
-import 'prismjs/components/prism-javascript';
 import 'prismjs/components/prism-css';
+import 'prismjs/components/prism-javascript';
 import 'prismjs/components/prism-markup';
 import { initOneko } from './oneko';
 
-// Auto-detect asset base from the bundled script's origin
-(() => {
-    window.ASSET_BASE = '';
-    const bundleScript = document.querySelector('script[src*="bundle"]');
-    if (bundleScript?.src) {
-        try {
-            const url = new URL(bundleScript.src, window.location.href);
-            window.ASSET_BASE = url.origin;
-        } catch {
-            // Fall back to empty string
-        }
-    }
-})();
+type Theme = 'light' | 'dark';
 
-(() => {
-    const toggleButton = document.getElementById('theme-toggle') as HTMLInputElement;
-    const html = document.documentElement;
+const THEME_STORAGE_KEY = 'theme';
+const DARK_THEME_ATTRIBUTE = 'data-theme';
 
-    const sessionTheme = sessionStorage.getItem('theme');
-    const systemPrefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+function detectAssetBase(): string {
+    const currentScript = document.currentScript as HTMLScriptElement | null;
+    const scriptSrc =
+        currentScript?.src ??
+        document.querySelector<HTMLScriptElement>('script[src*="bundle"]')?.src ??
+        '';
 
-    const initialTheme = sessionTheme || (systemPrefersDark ? 'dark' : 'light');
+    if (!scriptSrc) return '';
 
-    if (initialTheme === 'dark') {
-        html.setAttribute('data-theme', 'dark');
-        toggleButton.checked = true;
+    try {
+        return new URL(scriptSrc, window.location.href).origin;
+    } catch {
+        return '';
     }
+}
+
+function setAssetBase(): void {
+    window.ASSET_BASE = detectAssetBase();
+}
+
+function getSystemTheme(): Theme {
+    return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+}
+
+function applyTheme(theme: Theme): void {
+    if (theme === 'dark') {
+        document.documentElement.setAttribute(DARK_THEME_ATTRIBUTE, 'dark');
+    } else {
+        document.documentElement.removeAttribute(DARK_THEME_ATTRIBUTE);
+    }
+}
+
+function getStoredTheme(): Theme | null {
+    const theme = sessionStorage.getItem(THEME_STORAGE_KEY);
+    return theme === 'dark' || theme === 'light' ? theme : null;
+}
+
+function initThemeToggle(): void {
+    const toggleButton = document.getElementById('theme-toggle');
+    if (!(toggleButton instanceof HTMLInputElement)) return;
+
+    const initialTheme = getStoredTheme() ?? getSystemTheme();
+    applyTheme(initialTheme);
+    toggleButton.checked = initialTheme === 'dark';
 
     toggleButton.addEventListener('change', () => {
-        const theme = html.getAttribute('data-theme');
-
-        if (theme === 'dark') {
-            html.removeAttribute('data-theme');
-            sessionStorage.setItem('theme', 'light');
-            toggleButton.checked = false;
-        } else {
-            html.setAttribute('data-theme', 'dark');
-            sessionStorage.setItem('theme', 'dark');
-            toggleButton.checked = true;
-        }
+        const nextTheme: Theme = toggleButton.checked ? 'dark' : 'light';
+        applyTheme(nextTheme);
+        sessionStorage.setItem(THEME_STORAGE_KEY, nextTheme);
     });
-})();
+}
 
-(() => {
-    const colors = ['#ff69b4', '#b19cd9', '#8b6f47', '#ff85c0', '#c4b5fd', '#d4a574'];
-    const shapes = ['❀', '✿', '✽', '✾', '✻', '❊', '❋', '✼'];
+function sample<T>(items: readonly T[]): T {
+    return items[Math.floor(Math.random() * items.length)];
+}
 
-    document.addEventListener('mousemove', (e: MouseEvent) => {
-        createParticle(e.clientX, e.clientY);
-    });
+function initFairyDust(): void {
+    if (window.matchMedia('(prefers-reduced-motion: reduce)').matches) return;
 
-    const createParticle = (x: number, y: number) => {
+    const colors = ['#ff69b4', '#b19cd9', '#8b6f47', '#ff85c0', '#c4b5fd', '#d4a574'] as const;
+    const shapes = ['❀', '✿', '✽', '✾', '✻', '❊', '❋', '✼'] as const;
+
+    const particleLifetimeMs = 800;
+
+    function createParticle(x: number, y: number): void {
         const particle = document.createElement('div');
         particle.className = 'fairy-dust';
 
-        const shape = shapes[Math.floor(Math.random() * shapes.length)];
-        const size = Math.random() * 8 + 6;
-        const color = colors[Math.floor(Math.random() * colors.length)];
         const offsetX = (Math.random() - 0.5) * 20;
         const offsetY = (Math.random() - 0.5) * 20;
-        const rotation = Math.random() * 360;
-
-        particle.textContent = shape;
-        particle.style.cssText = `
-      position: fixed;
-      left: ${x + offsetX}px;
-      top: ${y + offsetY}px;
-      font-size: ${size}px;
-      color: ${color};
-      opacity: 0.4;
-      pointer-events: none;
-      z-index: 9001; /* it's over 9000 */
-      line-height: 1;
-      transform: rotate(${rotation}deg);
-      animation: fairy-float 0.8s ease-out forwards;
-    `;
+        const rotationDeg = Math.random() * 360;
+        const sizePx = Math.random() * 8 + 6;
+
+        particle.textContent = sample(shapes);
+        particle.style.left = `${x + offsetX}px`;
+        particle.style.top = `${y + offsetY}px`;
+        particle.style.fontSize = `${sizePx}px`;
+        particle.style.color = sample(colors);
+        particle.style.transform = `rotate(${rotationDeg}deg)`;
 
         document.body.appendChild(particle);
-        setTimeout(() => particle.remove(), 800);
-    };
-})();
+        window.setTimeout(() => particle.remove(), particleLifetimeMs);
+    }
+
+    // rAF throttle to avoid creating a particle per mouse event.
+    let latestX = 0;
+    let latestY = 0;
+    let scheduled = false;
 
-document.addEventListener('DOMContentLoaded', () => {
+    document.addEventListener('mousemove', (event: MouseEvent) => {
+        latestX = event.clientX;
+        latestY = event.clientY;
+
+        if (scheduled) return;
+        scheduled = true;
+
+        window.requestAnimationFrame(() => {
+            scheduled = false;
+            createParticle(latestX, latestY);
+        });
+    });
+}
+
+function init(): void {
+    setAssetBase();
+    initThemeToggle();
+    initFairyDust();
     Prism.highlightAll();
     initOneko();
-});
+}
+
+document.addEventListener('DOMContentLoaded', init);