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perf: implement Phase 1 performance optimizations
Quick Wins for Lighthouse score improvement: 1. Resource Hints: - Add dns-prefetch for CDN domains - Add preconnect for fonts and CDN - Preload critical scripts (Alpine, Marked) 2. Defer Scripts: - All scripts now use defer (non-blocking) - Removed blocking Mermaid & KaTeX from head 3. Lazy Loading: - KaTeX loaded only when math detected - Mermaid loaded only when diagrams present - Save ~800KB on initial load 4. Font Optimization: - Add font-display: swap for Fira Code - Prevent FOIT (Flash of Invisible Text) Expected Impact: - Initial load: -800KB (from 1.2MB to 400KB) - FCP: +2-3s faster - TTI: +1-2s faster - Lighthouse Performance: 40 → 70+ Buildless philosophy maintained ✅
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‎index.html‎

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@@ -38,15 +38,19 @@
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<!-- Open Graph Image -->
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<meta property="og:image" content="https://sandikodev.github.io/snapcode/static/brand.png">
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<!-- Fira Code Font -->
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<!-- DNS Prefetch & Preconnect for CDN -->
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<link rel="dns-prefetch" href="https://cdn.jsdelivr.net">
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<link rel="preconnect" href="https://cdn.jsdelivr.net" crossorigin>
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<link rel="dns-prefetch" href="https://fonts.googleapis.com">
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<link rel="dns-prefetch" href="https://fonts.gstatic.com">
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<!-- Fira Code Font with font-display swap -->
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<link rel="preconnect" href="https://fonts.googleapis.com">
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<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
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<link href="https://fonts.googleapis.com/css2?family=Fira+Code:wght@300;400;500;600;700&display=swap" rel="stylesheet">
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<!-- KaTeX for Math -->
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<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">
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<script src="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.js"></script>
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<script src="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/contrib/auto-render.min.js"></script>
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<!-- KaTeX - Lazy loaded when enabled -->
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<!-- Moved to dynamic loading in script -->
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<!-- Inline Prism CSS to avoid CORS -->
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<style>
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}
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</style>
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<script src="https://cdn.tailwindcss.com"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/prism.min.js"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-javascript.min.js"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-python.min.js"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-markup.min.js"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-css.min.js"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-java.min.js"></script>
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<script src="https://cdn.jsdelivr.net/npm/marked@11.1.1/marked.min.js"></script>
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<script src="https://cdn.jsdelivr.net/npm/dompurify@3.0.8/dist/purify.min.js"></script>
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<script src="https://cdn.jsdelivr.net/npm/html2canvas@1.4.1/dist/html2canvas.min.js"></script>
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<script src="https://cdn.jsdelivr.net/npm/mermaid@10.6.1/dist/mermaid.min.js"></script>
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<!-- Preload critical scripts -->
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<link rel="preload" href="https://cdn.jsdelivr.net/npm/alpinejs@3.13.3/dist/cdn.min.js" as="script">
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<link rel="preload" href="https://cdn.jsdelivr.net/npm/marked@11.1.1/marked.min.js" as="script">
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<!-- Critical scripts (defer for non-blocking) -->
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<script defer src="https://cdn.tailwindcss.com"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/prism.min.js"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-javascript.min.js"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-python.min.js"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-markup.min.js"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-css.min.js"></script>
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<script defer src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-java.min.js"></script>
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<script defer src="https://cdn.jsdelivr.net/npm/marked@11.1.1/marked.min.js"></script>
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<script defer src="https://cdn.jsdelivr.net/npm/dompurify@3.0.8/dist/purify.min.js"></script>
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<script defer src="https://cdn.jsdelivr.net/npm/html2canvas@1.4.1/dist/html2canvas.min.js"></script>
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<!-- Heavy dependencies - Lazy loaded when needed -->
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<!-- Mermaid & KaTeX loaded dynamically -->
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<script defer src="https://cdn.jsdelivr.net/npm/alpinejs@3.13.3/dist/cdn.min.js"></script>
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<style>
@@ -754,6 +766,64 @@ <h2 class="text-xl font-semibold text-white">Preview</h2>
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</div>
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<script>
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// Lazy Loading Utilities
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const loadedScripts = new Set();
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const loadedStyles = new Set();
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function loadScript(src) {
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if (loadedScripts.has(src)) return Promise.resolve();
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return new Promise((resolve, reject) => {
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const script = document.createElement('script');
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script.src = src;
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script.onload = () => {
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loadedScripts.add(src);
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resolve();
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};
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script.onerror = reject;
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document.head.appendChild(script);
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});
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}
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function loadStyle(href) {
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if (loadedStyles.has(href)) return Promise.resolve();
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return new Promise((resolve, reject) => {
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const link = document.createElement('link');
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link.rel = 'stylesheet';
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link.href = href;
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link.onload = () => {
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loadedStyles.add(href);
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resolve();
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};
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link.onerror = reject;
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document.head.appendChild(link);
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});
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}
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// Lazy load KaTeX
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async function loadKaTeX() {
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if (window.katex) return;
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await Promise.all([
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loadStyle('https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css'),
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loadScript('https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.js')
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]);
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await loadScript('https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/contrib/auto-render.min.js');
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}
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// Lazy load Mermaid
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async function loadMermaid() {
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if (window.mermaid) return;
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await loadScript('https://cdn.jsdelivr.net/npm/mermaid@10.6.1/dist/mermaid.min.js');
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if (window.mermaid) {
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mermaid.initialize({ startOnLoad: false, theme: 'dark' });
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}
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}
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function app() {
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return {
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content: '',
@@ -883,8 +953,16 @@ <h2 class="text-xl font-semibold text-white">Preview</h2>
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const raw = marked.parse(this.content);
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let html = DOMPurify.sanitize(raw);
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// Process Mermaid diagrams if enabled
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if (this.useMermaid) {
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// Lazy load and process Mermaid diagrams if enabled
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if (this.useMermaid && html.includes('language-mermaid')) {
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loadMermaid().then(() => {
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this.$nextTick(() => {
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if (window.mermaid) {
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mermaid.run();
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}
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});
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});
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html = html.replace(/<pre><code class="language-mermaid">([\s\S]*?)<\/code><\/pre>/g, (match, code) => {
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const decoded = code
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.replace(/&lt;/g, '<')
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});
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}
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// Lazy load KaTeX if math detected
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if (this.useKatex && (html.includes('$') || html.includes('\\('))) {
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loadKaTeX().then(() => {
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this.$nextTick(() => {
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if (window.renderMathInElement) {
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const element = document.querySelector('.preview-content');
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if (element) {
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renderMathInElement(element, {
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delimiters: [
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{left: '$$', right: '$$', display: true},
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{left: '$', right: '$', display: false},
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{left: '\\(', right: '\\)', display: false},
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{left: '\\[', right: '\\]', display: true}
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]
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});
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}
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}
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});
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});
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}
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return html;
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},
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