From 471f1c54b891ba45bf29cf0b0ae9b687e9d87f79 Mon Sep 17 00:00:00 2001
From: kinou-p <alexpomms@gmail.com>
Date: Thu, 2 Oct 2025 19:12:25 +0200
Subject: [PATCH] optimisation critical css

---
 index.html                      |  11 ++-
 package.json                    |   3 +-
 scripts/extract-critical-css.js |  83 ++++++++++++++++++++++
 src/critical.css                |  63 +++++++++++++++++
 vite-plugin-critical-css.ts     | 121 ++++++++++++++++++++++++++++++++
 vite.config.ts                  |   7 +-
 6 files changed, 285 insertions(+), 3 deletions(-)
 create mode 100644 scripts/extract-critical-css.js
 create mode 100644 src/critical.css
 create mode 100644 vite-plugin-critical-css.ts

diff --git a/index.html b/index.html
index 30c90af..5e776a5 100644
--- a/index.html
+++ b/index.html
@@ -26,7 +26,16 @@
     <meta name="twitter:site" content="@lovable_dev" />
     <meta name="twitter:image" content="https://lovable.dev/opengraph-image-p98pqg.png" />
 
-    <!-- Google Fonts - Optimisé avec display=swap -->
+    <!-- Critical CSS inliné pour éviter le blocage du rendu -->
+    <style>
+      :root{--background:0 0% 100%;--foreground:222 47% 11%;--primary:217 91% 60%;--border:214 32% 91%}.dark{--background:0 0% 4%;--foreground:0 0% 98%;--primary:217 91% 60%;--border:0 0% 15%}*{margin:0;padding:0;box-sizing:border-box}html{scroll-behavior:smooth}body{background-color:hsl(var(--background));color:hsl(var(--foreground));font-family:-apple-system,BlinkMacSystemFont,'Segoe UI','Roboto',sans-serif;line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{min-height:100vh}.wf-loading body{visibility:hidden}.loading-skeleton{background:linear-gradient(90deg,hsl(var(--background)) 25%,hsl(var(--border)) 50%,hsl(var(--background)) 75%);background-size:200% 100%;animation:loading 1.5s ease-in-out infinite}@keyframes loading{0%{background-position:200% 0}100%{background-position:-200% 0}}
+    </style>
+
+    <!-- Preload critical fonts -->
+    <link rel="preload" as="font" type="font/woff2" href="https://fonts.gstatic.com/s/inter/v13/UcCO3FwrK3iLTeHuS_fvQtMwCp50KnMw2boKoduKmMEVuLyfAZ9hjp-Ek-_EeA.woff2" crossorigin>
+    <link rel="preload" as="font" type="font/woff2" href="https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WRhyyTh89ZNpQ.woff2" crossorigin>
+
+    <!-- Google Fonts - Chargement asynchrone pour ne pas bloquer le rendu -->
     <link rel="preload" as="style" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Montserrat:wght@400;500;600;700&display=swap">
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Montserrat:wght@400;500;600;700&display=swap" rel="stylesheet" media="print" onload="this.media='all'">
     <noscript>
diff --git a/package.json b/package.json
index 178db69..83877c0 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,8 @@
     "preview": "vite preview",
     "optimize-images": "node scripts/optimize-images.js",
     "create-thumbnails": "node scripts/create-thumbnails.js",
-    "analyze": "node scripts/analyze-bundle.js"
+    "analyze": "node scripts/analyze-bundle.js",
+    "extract-critical-css": "npm run build && node scripts/extract-critical-css.js"
   },
   "dependencies": {
     "@hookform/resolvers": "^3.10.0",
diff --git a/scripts/extract-critical-css.js b/scripts/extract-critical-css.js
new file mode 100644
index 0000000..c193a9c
--- /dev/null
+++ b/scripts/extract-critical-css.js
@@ -0,0 +1,83 @@
+/**
+ * Script pour extraire le CSS critique
+ * Utilise Puppeteer pour analyser la page et extraire uniquement le CSS nécessaire au rendu initial
+ * 
+ * Installation requise:
+ * npm install --save-dev puppeteer critical
+ * 
+ * Utilisation:
+ * node scripts/extract-critical-css.js
+ */
+
+import { generate } from 'critical';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+async function extractCriticalCSS() {
+  try {
+    console.log('🔍 Extraction du CSS critique...');
+    
+    const { css, html } = await generate({
+      // Chemin vers le fichier HTML de build
+      base: path.join(__dirname, '../dist/'),
+      src: 'index.html',
+      
+      // Dimensions pour le CSS critique (above the fold)
+      dimensions: [
+        {
+          width: 375,
+          height: 667
+        }, // Mobile
+        {
+          width: 1920,
+          height: 1080
+        }, // Desktop
+      ],
+      
+      // Options d'extraction
+      inline: false, // Ne pas inliner automatiquement
+      extract: true,
+      
+      // Ignorer les erreurs de ressources externes
+      ignore: {
+        atrule: ['@font-face', '@import'],
+        rule: [/^\.tsparticles/],
+      },
+      
+      // Pourcentage de couverture CSS
+      penthouse: {
+        timeout: 60000,
+        maxEmbeddedBase64Length: 1000,
+        renderWaitTime: 500,
+      }
+    });
+    
+    console.log('✅ CSS critique extrait avec succès!');
+    console.log(`📊 Taille: ${(css.length / 1024).toFixed(2)} KB`);
+    
+    // Sauvegarder le CSS critique
+    const fs = await import('fs');
+    const criticalPath = path.join(__dirname, '../src/critical.css');
+    
+    // Ajouter un commentaire en haut du fichier
+    const header = `/* Critical CSS - Généré automatiquement le ${new Date().toISOString()} */\n/* Ne pas modifier manuellement - Utiliser npm run extract-critical-css */\n\n`;
+    
+    fs.writeFileSync(criticalPath, header + css);
+    console.log(`💾 Sauvegardé dans: ${criticalPath}`);
+    
+    return css;
+  } catch (error) {
+    console.error('❌ Erreur lors de l\'extraction du CSS critique:', error);
+    process.exit(1);
+  }
+}
+
+// Exécuter si appelé directement
+if (import.meta.url === `file://${process.argv[1]}`) {
+  extractCriticalCSS();
+}
+
+export { extractCriticalCSS };
diff --git a/src/critical.css b/src/critical.css
new file mode 100644
index 0000000..fb8b128
--- /dev/null
+++ b/src/critical.css
@@ -0,0 +1,63 @@
+/* Critical CSS - Above the fold content */
+/* This CSS should be inlined in the HTML head to prevent render-blocking */
+
+:root {
+  --background: 0 0% 100%;
+  --foreground: 222 47% 11%;
+  --primary: 217 91% 60%;
+  --border: 214 32% 91%;
+}
+
+.dark {
+  --background: 0 0% 4%;
+  --foreground: 0 0% 98%;
+  --primary: 217 91% 60%;
+  --border: 0 0% 15%;
+}
+
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+html {
+  scroll-behavior: smooth;
+}
+
+body {
+  background-color: hsl(var(--background));
+  color: hsl(var(--foreground));
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
+  line-height: 1.6;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+#root {
+  min-height: 100vh;
+}
+
+/* Hide content until fonts load to prevent FOUT */
+.wf-loading body {
+  visibility: hidden;
+}
+
+/* Skeleton loader for initial render */
+.loading-skeleton {
+  background: linear-gradient(90deg, 
+    hsl(var(--background)) 25%, 
+    hsl(var(--border)) 50%, 
+    hsl(var(--background)) 75%);
+  background-size: 200% 100%;
+  animation: loading 1.5s ease-in-out infinite;
+}
+
+@keyframes loading {
+  0% {
+    background-position: 200% 0;
+  }
+  100% {
+    background-position: -200% 0;
+  }
+}
diff --git a/vite-plugin-critical-css.ts b/vite-plugin-critical-css.ts
new file mode 100644
index 0000000..7777493
--- /dev/null
+++ b/vite-plugin-critical-css.ts
@@ -0,0 +1,121 @@
+import { Plugin } from 'vite';
+import fs from 'fs';
+import path from 'path';
+
+/**
+ * Plugin Vite pour inliner le CSS critique dans le HTML
+ * Cela réduit le temps de First Contentful Paint (FCP) et Largest Contentful Paint (LCP)
+ */
+export function inlineCriticalCSS(): Plugin {
+  return {
+    name: 'inline-critical-css',
+    apply: 'build', // Appliqué uniquement en mode build
+    
+    transformIndexHtml: {
+      order: 'post',
+      handler(html) {
+        // Lire le CSS critique
+        const criticalCSSPath = path.resolve(__dirname, 'src/critical.css');
+        
+        if (!fs.existsSync(criticalCSSPath)) {
+          console.warn('⚠️ Fichier critical.css introuvable. Ignoré.');
+          return html;
+        }
+        
+        const criticalCSS = fs.readFileSync(criticalCSSPath, 'utf-8');
+        
+        // Minifier le CSS critique (simple)
+        const minifiedCSS = criticalCSS
+          .replace(/\/\*[\s\S]*?\*\//g, '') // Supprimer les commentaires
+          .replace(/\s+/g, ' ') // Réduire les espaces multiples
+          .replace(/\s*([{}:;,>+~])\s*/g, '$1') // Supprimer les espaces autour des symboles
+          .trim();
+        
+        // Injecter le CSS critique dans le <head>
+        const criticalStyle = `<style>${minifiedCSS}</style>`;
+        
+        // Insérer juste après la balise <head> ou avant la première <link>
+        const headEndIndex = html.indexOf('</head>');
+        if (headEndIndex !== -1) {
+          html = html.slice(0, headEndIndex) + criticalStyle + html.slice(headEndIndex);
+        }
+        
+        return html;
+      }
+    }
+  };
+}
+
+/**
+ * Plugin pour précharger les ressources critiques
+ */
+export function preloadCriticalAssets(): Plugin {
+  return {
+    name: 'preload-critical-assets',
+    apply: 'build',
+    
+    transformIndexHtml: {
+      order: 'post',
+      handler(html, ctx) {
+        const preloads: string[] = [];
+        
+        // Trouver les chunks CSS et JS critiques
+        if (ctx.bundle) {
+          for (const [fileName, chunk] of Object.entries(ctx.bundle)) {
+            if (chunk.type === 'chunk' && chunk.isEntry) {
+              // Précharger le JS principal
+              preloads.push(`<link rel="preload" href="/${fileName}" as="script" crossorigin>`);
+            } else if (chunk.type === 'asset' && fileName.endsWith('.css')) {
+              // Précharger le CSS principal
+              preloads.push(`<link rel="preload" href="/${fileName}" as="style">`);
+            }
+          }
+        }
+        
+        // Insérer les preloads dans le <head>
+        if (preloads.length > 0) {
+          const headEndIndex = html.indexOf('</head>');
+          if (headEndIndex !== -1) {
+            html = html.slice(0, headEndIndex) + preloads.join('') + html.slice(headEndIndex);
+          }
+        }
+        
+        return html;
+      }
+    }
+  };
+}
+
+/**
+ * Plugin pour charger les CSS non critiques de manière asynchrone
+ */
+export function asyncNonCriticalCSS(): Plugin {
+  return {
+    name: 'async-non-critical-css',
+    apply: 'build',
+    
+    transformIndexHtml: {
+      order: 'post',
+      handler(html) {
+        // Convertir les <link rel="stylesheet"> en chargement asynchrone
+        html = html.replace(
+          /<link([^>]*rel=["']stylesheet["'][^>]*)>/gi,
+          (match, attrs) => {
+            // Ne pas modifier les liens externes (Google Fonts, etc.)
+            if (attrs.includes('fonts.googleapis.com')) {
+              return match;
+            }
+            
+            // Ajouter media="print" onload="this.media='all'" pour chargement async
+            if (!attrs.includes('media=')) {
+              return `<link${attrs} media="print" onload="this.media='all'"><noscript><link${attrs}></noscript>`;
+            }
+            return match;
+          }
+        );
+        
+        return html;
+      }
+    }
+  };
+}
diff --git a/vite.config.ts b/vite.config.ts
index 6fddb7a..a3901bb 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -2,6 +2,7 @@ import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react-swc";
 import path from "path";
 import { componentTagger } from "lovable-tagger";
+import { preloadCriticalAssets } from "./vite-plugin-critical-css";
 
 // https://vitejs.dev/config/
 export default defineConfig(({ mode }) => ({
@@ -16,7 +17,11 @@ export default defineConfig(({ mode }) => ({
       "0.0.0.0"
     ]
   },
-  plugins: [react(), mode === "development" && componentTagger()].filter(Boolean),
+  plugins: [
+    react(), 
+    mode === "development" && componentTagger(),
+    mode === "production" && preloadCriticalAssets()
+  ].filter(Boolean),
   resolve: {
     alias: {
       "@": path.resolve(__dirname, "./src"),