diff --git a/DISCOVER/404.html b/DISCOVER/404.html
index 543b5734..1d9901c7 100644
--- a/DISCOVER/404.html
+++ b/DISCOVER/404.html
@@ -3,168 +3,589 @@
 <head>
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
-  <title>404 - Not Found</title>
+  <title>404 - Page Not Found | DISCOVER Cookbook</title>
+  <link rel="preconnect" href="https://fonts.googleapis.com">
+  <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
+  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
   <style>
+    :root {
+      --primary-blue: #0066cc;
+      --primary-purple: #6366f1;
+      --primary-orange: #f97316;
+      --dark-bg: #0f172a;
+      --dark-card: #1e293b;
+      --light-text: #f1f5f9;
+      --medium-text: #cbd5e1;
+      --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+      --numfocus-blue: #1e40af;
+      --success-green: #10b981;
+    }
+
     * {
       box-sizing: border-box;
       margin: 0;
       padding: 0;
     }
+    
     body {
-      height: 100vh;
-      background: linear-gradient(135deg, black, #e4f0ff);
+      min-height: 100vh;
+      background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
       display: flex;
       align-items: center;
       justify-content: center;
-      font-family: 'Segoe UI', sans-serif;
-      overflow: hidden;
+      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
       position: relative;
+      overflow-x: hidden;
+      padding: 1rem;
     }
 
-    .light-blur {
+    /* Animated background elements */
+    .bg-decoration {
       position: absolute;
+      border-radius: 50%;
+      filter: blur(100px);
+      opacity: 0.15;
+      animation: float 20s ease-in-out infinite;
+      pointer-events: none;
+    }
+
+    .decoration-1 {
+      width: 600px;
+      height: 600px;
+      background: radial-gradient(circle, var(--primary-purple), transparent);
+      top: -200px;
+      left: -100px;
+      animation-delay: 0s;
+    }
+
+    .decoration-2 {
       width: 500px;
       height: 500px;
-      background: radial-gradient(circle at center, transparent);
-      border-radius: 50%;
-      filter: blur(80px);
-      top: 20%;
-      left: 10%;
-      animation: drift 10s ease-in-out infinite alternate;
-      z-index: 0;
-    }
-
-    @keyframes drift {
-      0%   { transform: translate(0, 0); }
-      100% { transform: translate(60px, 30px); }
-    }
-
-    .glass-card {
-      background: rgba(255, 255, 255, 0.25);
-      backdrop-filter: blur(12px);
-      -webkit-backdrop-filter: blur(12px);
-      padding: 2.5rem 3rem;
-      border-radius: 20px;
-      border: 1px solid rgba(255, 255, 255, 0.3);
-      max-width: 500px;
-      text-align: center;
+      background: radial-gradient(circle, var(--primary-blue), transparent);
+      bottom: -150px;
+      right: -100px;
+      animation-delay: 5s;
+    }
+
+    .decoration-3 {
+      width: 400px;
+      height: 400px;
+      background: radial-gradient(circle, var(--primary-orange), transparent);
+      top: 50%;
+      right: 10%;
+      animation-delay: 10s;
+    }
+
+    @keyframes float {
+      0%, 100% { transform: translate(0, 0) scale(1); }
+      33% { transform: translate(30px, -30px) scale(1.1); }
+      66% { transform: translate(-20px, 20px) scale(0.9); }
+    }
+
+    /* Main container */
+    .container {
+      background: rgba(30, 41, 59, 0.7);
+      backdrop-filter: blur(20px);
+      -webkit-backdrop-filter: blur(20px);
+      border: 1px solid rgba(255, 255, 255, 0.1);
+      border-radius: 24px;
+      padding: 3rem 2.5rem;
+      max-width: 600px;
+      width: 100%;
+      position: relative;
       z-index: 1;
-      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
+      box-shadow: 
+        0 20px 50px rgba(0, 0, 0, 0.5),
+        0 0 0 1px rgba(255, 255, 255, 0.05) inset;
+      animation: slideUp 0.6s ease-out;
+    }
+
+    @keyframes slideUp {
+      from {
+        opacity: 0;
+        transform: translateY(30px);
+      }
+      to {
+        opacity: 1;
+        transform: translateY(0);
+      }
+    }
+
+    /* 404 Number */
+    .error-code {
+      font-size: 8rem;
+      font-weight: 700;
+      background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f97316 100%);
+      -webkit-background-clip: text;
+      -webkit-text-fill-color: transparent;
+      background-clip: text;
+      text-align: center;
+      line-height: 1;
+      margin-bottom: 1rem;
+      animation: glow 3s ease-in-out infinite;
+      letter-spacing: -0.05em;
+    }
+
+    @keyframes glow {
+      0%, 100% { filter: drop-shadow(0 0 20px rgba(102, 126, 234, 0.5)); }
+      50% { filter: drop-shadow(0 0 40px rgba(102, 126, 234, 0.8)); }
+    }
+
+    /* Title and text */
+    .title {
+      font-size: 2rem;
+      font-weight: 700;
+      color: var(--light-text);
+      text-align: center;
+      margin-bottom: 0.75rem;
+      line-height: 1.3;
     }
 
-    h1 {
-      font-size: 2.5em;
-      color: rgb(52, 51, 51);
+    .description {
+      font-size: 1.125rem;
+      color: var(--medium-text);
+      text-align: center;
       margin-bottom: 0.5rem;
+      line-height: 1.6;
     }
 
-    p {
-      font-size: 1.1em;
-      color: rgb(52, 51, 51);
-      margin-bottom: 1.4rem;
+    .suggestion {
+      font-size: 1rem;
+      color: var(--medium-text);
+      text-align: center;
+      margin-bottom: 2rem;
+      opacity: 0.8;
     }
 
-    a {
-      display: inline-block;
-      margin: 0.4rem;
-      padding: 0.6rem 1rem;
-      border-radius: 8px;
+    /* Divider */
+    .divider {
+      height: 1px;
+      background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
+      margin: 2rem 0;
+    }
+
+    /* Action section */
+    .action-label {
+      font-size: 1rem;
+      font-weight: 600;
+      color: var(--light-text);
+      text-align: center;
+      margin-bottom: 1.5rem;
+    }
+
+    .action-buttons {
+      display: flex;
+      flex-direction: column;
+      gap: 0.875rem;
+      margin-bottom: 2rem;
+    }
+
+    .btn {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      gap: 0.75rem;
+      padding: 1rem 1.5rem;
+      border-radius: 12px;
       text-decoration: none;
-      background: #d0bfff;
-      color: #1f1f1f;
       font-weight: 600;
-      transition: background 0.3s ease;
+      font-size: 1rem;
+      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+      position: relative;
+      overflow: hidden;
+    }
+
+    .btn::before {
+      content: '';
+      position: absolute;
+      top: 0;
+      left: -100%;
+      width: 100%;
+      height: 100%;
+      background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
+      transition: left 0.5s;
     }
 
-    a:hover {
-      background: #c1aaff;
+    .btn:hover::before {
+      left: 100%;
+    }
+
+    .btn-primary {
+      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+      color: #ffffff;
+      box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
+    }
+
+    .btn-primary:hover {
+      transform: translateY(-2px);
+      box-shadow: 0 8px 30px rgba(102, 126, 234, 0.6);
+    }
+
+    .btn-secondary {
+      background: rgba(255, 255, 255, 0.1);
+      color: var(--light-text);
+      border: 1px solid rgba(255, 255, 255, 0.2);
+    }
+
+    .btn-secondary:hover {
+      background: rgba(255, 255, 255, 0.15);
+      border-color: rgba(255, 255, 255, 0.3);
+      transform: translateY(-2px);
+    }
+
+    .btn:active {
+      transform: translateY(0);
+    }
+
+    .icon {
+      font-size: 1.25rem;
+      display: inline-flex;
+      align-items: center;
+    }
+
+    /* Language selector */
+    .language-section {
+      margin-top: 2rem;
+      padding-top: 2rem;
+      border-top: 1px solid rgba(255, 255, 255, 0.1);
+    }
+
+    .language-label {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      gap: 0.5rem;
+      font-size: 0.95rem;
+      font-weight: 500;
+      color: var(--medium-text);
+      margin-bottom: 0.75rem;
+    }
+
+    .select-wrapper {
+      position: relative;
+      max-width: 200px;
+      margin: 0 auto;
     }
 
     select {
-      margin-top: 1rem;
+      width: 100%;
+      padding: 0.75rem 2.5rem 0.75rem 1rem;
+      border-radius: 10px;
+      border: 1px solid rgba(255, 255, 255, 0.2);
+      background: rgba(255, 255, 255, 0.05);
+      color: var(--light-text);
+      font-size: 1rem;
+      font-weight: 500;
+      font-family: inherit;
+      cursor: pointer;
+      transition: all 0.3s ease;
+      appearance: none;
+    }
+
+    .select-wrapper::after {
+      content: '▼';
+      position: absolute;
+      right: 1rem;
+      top: 50%;
+      transform: translateY(-50%);
+      color: var(--medium-text);
+      pointer-events: none;
+      font-size: 0.75rem;
+    }
+
+    select:hover {
+      background: rgba(255, 255, 255, 0.08);
+      border-color: rgba(255, 255, 255, 0.3);
+    }
+
+    select:focus {
+      outline: none;
+      border-color: var(--primary-purple);
+      background: rgba(255, 255, 255, 0.1);
+      box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
+    }
+
+    option {
+      background: var(--dark-card);
+      color: var(--light-text);
       padding: 0.5rem;
-      border-radius: 6px;
-      border: 1px solid #ccc;
-      font-size: 1em;
-      background: #fff;
+    }
+
+    /* Footer */
+    .footer {
+      margin-top: 2rem;
+      padding-top: 1.5rem;
+      border-top: 1px solid rgba(255, 255, 255, 0.1);
+      font-size: 0.875rem;
+      color: var(--medium-text);
+      text-align: center;
+      opacity: 0.7;
+    }
+
+    /* Responsive Design */
+    @media (max-width: 768px) {
+      .container {
+        padding: 2.5rem 2rem;
+      }
+
+      .error-code {
+        font-size: 6rem;
+      }
+
+      .title {
+        font-size: 1.75rem;
+      }
+
+      .description {
+        font-size: 1rem;
+      }
+
+      .suggestion {
+        font-size: 0.95rem;
+      }
+
+      .bg-decoration {
+        filter: blur(80px);
+      }
+    }
+
+    @media (max-width: 480px) {
+      body {
+        padding: 0.75rem;
+      }
+
+      .container {
+        padding: 2rem 1.5rem;
+        border-radius: 20px;
+      }
+
+      .error-code {
+        font-size: 4.5rem;
+        margin-bottom: 0.75rem;
+      }
+
+      .title {
+        font-size: 1.5rem;
+        margin-bottom: 0.5rem;
+      }
+
+      .description {
+        font-size: 0.95rem;
+        margin-bottom: 0.5rem;
+      }
+
+      .suggestion {
+        font-size: 0.875rem;
+        margin-bottom: 1.5rem;
+      }
+
+      .divider {
+        margin: 1.5rem 0;
+      }
+
+      .action-label {
+        font-size: 0.95rem;
+        margin-bottom: 1rem;
+      }
+
+      .action-buttons {
+        gap: 0.75rem;
+        margin-bottom: 1.5rem;
+      }
+
+      .btn {
+        padding: 0.875rem 1.25rem;
+        font-size: 0.95rem;
+        border-radius: 10px;
+      }
+
+      .language-section {
+        margin-top: 1.5rem;
+        padding-top: 1.5rem;
+      }
+
+      .footer {
+        margin-top: 1.5rem;
+        padding-top: 1rem;
+        font-size: 0.8rem;
+      }
+
+      .decoration-1,
+      .decoration-2,
+      .decoration-3 {
+        filter: blur(60px);
+      }
+    }
+
+    @media (max-width: 320px) {
+      .error-code {
+        font-size: 3.5rem;
+      }
+
+      .title {
+        font-size: 1.25rem;
+      }
+
+      .btn {
+        padding: 0.75rem 1rem;
+        font-size: 0.9rem;
+      }
+    }
+
+    /* Accessibility */
+    @media (prefers-reduced-motion: reduce) {
+      * {
+        animation: none !important;
+        transition: none !important;
+      }
+
+      .bg-decoration {
+        animation: none;
+      }
+    }
+
+    @media (prefers-contrast: high) {
+      .container {
+        border: 2px solid rgba(255, 255, 255, 0.4);
+      }
+
+      .btn {
+        border: 2px solid currentColor;
+      }
     }
   </style>
 </head>
 <body>
-  <div class="light-blur"></div>
-  <div class="glass-card">
-    <h1 id="title">404 - Page Not Found</h1>
-    <p id="message">This page might’ve wandered off or was never here at all.</p>
-    <p id="suggestion">Maybe it was deleted, renamed, or never existed in the first place.</p>
-    <p><strong id="what-do">What can you do?</strong></p>
-    <a href="./intro.html" id="home">⬅️ Back to Home</a>
-    <a href="https://github.com/numfocus/DISCOVER-Cookbook/issues" id="report">🐞 Report the Issue</a>
-
-    <div>
-      <label for="language-switcher" style="display:block; margin-top:1.5rem; color:#444;">🌐 Switch Language:</label>
-      <select id="language-switcher">
-        <option value="en">English</option>
-        <option value="es">Español</option>
-      </select>
+  <!-- Animated background decorations -->
+  <div class="bg-decoration decoration-1"></div>
+  <div class="bg-decoration decoration-2"></div>
+  <div class="bg-decoration decoration-3"></div>
+
+  <!-- Main container -->
+  <div class="container">
+    <!-- Error code -->
+    <div class="error-code" aria-label="Error 404">404</div>
+
+    <!-- Title and description -->
+    <h1 class="title" id="title">Page Not Found</h1>
+    <p class="description" id="message">
+      Looks like this page decided to take a coffee break and forgot to come back!
+    </p>
+    <p class="suggestion" id="suggestion">
+      The page you're looking for might have been moved, deleted, or never existed.
+    </p>
+
+    <!-- Divider -->
+    <div class="divider"></div>
+
+    <!-- Action section -->
+    <p class="action-label" id="action-label">Here's what you can do:</p>
+    
+    <div class="action-buttons">
+      <a href="./intro.html" class="btn btn-primary" id="home-btn">
+        <span class="icon" aria-hidden="true">🏠</span>
+        <span id="home-text">Go Back Home</span>
+      </a>
+      
+      <a href="https://github.com/numfocus/DISCOVER-Cookbook/issues" 
+         class="btn btn-secondary" 
+         id="report-btn"
+         target="_blank" 
+         rel="noopener noreferrer">
+        <span class="icon" aria-hidden="true">🐛</span>
+        <span id="report-text">Report This Issue</span>
+      </a>
     </div>
 
-    <p id="footer" style="margin-top: 1.2rem;">If you think this is an error, let us know by creating an issue.</p>
+    <!-- Language selector -->
+    <div class="language-section">
+      <label class="language-label" for="language-switcher">
+        <span aria-hidden="true">🌐</span>
+        <span id="lang-label">Select Language</span>
+      </label>
+      <div class="select-wrapper">
+        <select id="language-switcher" aria-label="Choose your preferred language">
+          <option value="en">English</option>
+          <option value="es">Español</option>
+        </select>
+      </div>
+    </div>
+
+    <!-- Footer -->
+    <p class="footer" id="footer">
+      If this seems like an error, please let us know by creating an issue on GitHub.
+    </p>
   </div>
 
   <script>
     const translations = {
       en: {
-        title: "404 - Page Not Found",
-        message: "This page might’ve wandered off or was never here at all.",
-        suggestion: "Maybe it was deleted, renamed, or never existed in the first place.",
-        whatDo: "What can you do?",
-        home: "⬅️ Back to Home",
-        report: "🐞 Report the Issue",
-        footer: "If you think this is an error, let us know by creating an issue."
+        title: "Page Not Found",
+        message: "Looks like this page decided to take a coffee break and forgot to come back!",
+        suggestion: "The page you're looking for might have been moved, deleted, or never existed.",
+        actionLabel: "Here's what you can do:",
+        homeText: "Go Back Home",
+        reportText: "Report This Issue",
+        langLabel: "Select Language",
+        footer: "If this seems like an error, please let us know by creating an issue on GitHub."
       },
       es: {
-        title: "404 - Página no encontrada",
-        message: "Esta página se ha perdido o nunca existió.",
-        suggestion: "Tal vez fue eliminada, renombrada o nunca existió.",
-        whatDo: "¿Qué puedes hacer?",
-        home: "⬅️ Volver al inicio",
-        report: "🐞 Informar del problema",
-        footer: "Si crees que esto es un error, infórmanos creando un issue."
+        title: "Página No Encontrada",
+        message: "¡Parece que esta página decidió tomar un descanso para el café y olvidó regresar!",
+        suggestion: "La página que buscas puede haber sido movida, eliminada o nunca existió.",
+        actionLabel: "Esto es lo que puedes hacer:",
+        homeText: "Volver al Inicio",
+        reportText: "Reportar Este Problema",
+        langLabel: "Seleccionar Idioma",
+        footer: "Si esto parece un error, por favor háganoslo saber creando un issue en GitHub."
       }
     };
 
     function detectLanguage() {
-      const pathLang = location.pathname.split("/")[1];
-      const refLang = new URL(document.referrer || "", location.origin).pathname.split("/")[1];
+      // Try to detect language from URL path
+      const pathLang = location.pathname.split("/").find(seg => seg === "en" || seg === "es");
+      if (pathLang && translations[pathLang]) return pathLang;
+
+      // Try to detect from referrer
+      const refLang = new URL(document.referrer || "", location.origin).pathname.split("/").find(seg => seg === "en" || seg === "es");
+      if (refLang && translations[refLang]) return refLang;
+
+      // Try localStorage
       const storedLang = localStorage.getItem("preferredLang");
-      return translations[pathLang]
-        ? pathLang
-        : translations[refLang]
-        ? refLang
-        : translations[storedLang]
-        ? storedLang
-        : "en";
+      if (storedLang && translations[storedLang]) return storedLang;
+
+      // Default to English
+      return "en";
     }
 
     function applyLanguage(lang) {
       const t = translations[lang] || translations["en"];
+      
       document.getElementById("title").textContent = t.title;
       document.getElementById("message").textContent = t.message;
       document.getElementById("suggestion").textContent = t.suggestion;
-      document.getElementById("what-do").textContent = t.whatDo;
-      document.getElementById("home").textContent = t.home;
-      document.getElementById("report").textContent = t.report;
+      document.getElementById("action-label").textContent = t.actionLabel;
+      document.getElementById("home-text").textContent = t.homeText;
+      document.getElementById("report-text").textContent = t.reportText;
+      document.getElementById("lang-label").textContent = t.langLabel;
       document.getElementById("footer").textContent = t.footer;
       document.getElementById("language-switcher").value = lang;
+      
+      // Save preference
       localStorage.setItem("preferredLang", lang);
+      
+      // Update HTML lang attribute for accessibility
+      document.documentElement.lang = lang;
     }
 
+    // Initialize
     const initialLang = detectLanguage();
     applyLanguage(initialLang);
 
-    document.getElementById("language-switcher").addEventListener("change", function () {
+    // Handle language changes
+    document.getElementById("language-switcher").addEventListener("change", function() {
       applyLanguage(this.value);
     });
   </script>
 </body>
-</html>
+</html>
\ No newline at end of file
diff --git a/README.md b/README.md
index eac4e8d1..e4853e50 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,16 @@
 # DISCOVER-Cookbook
-![All Contributors](https://img.shields.io/github/all-contributors/numfocus/DISCOVER-Cookbook?color=ee8449)
 
-The NumFOCUS DISCOVER Cookbook (Diverse &amp; Inclusive Spaces and Conferences: Overall Vision and Essential Resources). A guide for organizing more diverse and inclusive events and conferences, produced by the NumFOCUS Diversity &amp; Inclusion in Scientific Computing (DISC) Program, with support from the Moore Foundation. 
+[![Documentation Build](https://github.com/numfocus/DISCOVER-Cookbook/actions/workflows/build-gh-pages.yml/badge.svg)](https://github.com/numfocus/DISCOVER-Cookbook/actions/workflows/build-gh-pages.yml)
+[![All Contributors](https://img.shields.io/github/all-contributors/numfocus/DISCOVER-Cookbook?color=ee8449)](#contributors-)
+
+The NumFOCUS DISCOVER Cookbook (Diverse & Inclusive Spaces and Conferences: Overall Vision and Essential Resources). A guide for organizing more diverse and inclusive events and conferences, produced by the NumFOCUS Diversity & Inclusion in Scientific Computing (DISC) Program, with support from the Moore Foundation. 
 
 If you are looking to read the book please visit https://discover-cookbook.numfocus.org/ for a live version of the book. This is the code that powers that website and is intended for maintainers and contributors.
 
 
-## Ways to contribute to this repository
+## Ways to Contribute to this Repository
 
-The original body of work took place at a series of unconferences and various spurts of energy, today the DISCOVER-cookbook is a living project with numerous contributors. Because it is code to produce a book rather than code for a software library or application, it has different needs than typical open source software systems. Because of these unique needs, we separate various types of contributions:
+The original body of work took place at a series of unconferences and various spurts of energy. Today, the DISCOVER-Cookbook is a living project with numerous contributors. Because it is code to produce a book rather than code for a software library or application, it has different needs than typical open source software systems. Because of these unique needs, we separate various types of contributions:
 
 ### Ideas, Questions, and Discussions
 
@@ -20,9 +22,9 @@ Please add issues on [the GitHub issue tracker](https://github.com/numfocus/DISC
 
 ### Content and Design
 
-While content is the heart of the project, the quality of the content needs to remain high. Due to a high volume of generated text being submitted for review, content takes longer to review and approve. We value these contributions but just understand that it will take time to add. Please start an idea in the discussions, then move to making an issue once there is approval for the content to be added to the book. After that issue is made we feel free to open [a pull request](https://github.com/numfocus/DISCOVER-Cookbook/pulls) against the repository to begin the review process.
+While content is the heart of the project, the quality of the content needs to remain high. Due to a high volume of generated text being submitted for review, content takes longer to review and approve. We value these contributions but just understand that it will take time to add. Please start an idea in the discussions, then move to making an issue once there is approval for the content to be added to the book. After that issue is created, feel free to open [a pull request](https://github.com/numfocus/DISCOVER-Cookbook/pulls) against the repository to begin the review process.
 
-### Bug fixes
+### Bug Fixes
 
 For issues with other elements of the book, first make sure an issue is open and tracking can occur on the issue. Then open a [pull request](https://github.com/numfocus/DISCOVER-Cookbook/pulls).
 
@@ -85,7 +87,7 @@ conda env create -f environment.yml
 ```sh
 conda activate DISCOVER-Cookbook
 ```
-3. Finally, to build the Jupyter Book
+3. Finally, to build the Jupyter Book:
 ``` sh
 sphinx-build -b html DISCOVER/ DISCOVER/_build/html
 ```
@@ -108,7 +110,7 @@ source .venv/bin/activate
 ```sh
 pip install -r requirements.txt
 ```
-4. Finally, to build the Jupyter Book
+4. Finally, to build the Jupyter Book:
 ``` sh
 sphinx-build -b html DISCOVER/ DISCOVER/_build/html
 ```
