404 Page Example in HTML

<script type="module" src="https://unpkg.com/ionicons@7.1.0/dist/ionicons/ionicons.esm.js"></script>
<script nomodule src="https://unpkg.com/ionicons@7.1.0/dist/ionicons/ionicons.js"></script>

<div class="shape shape-1"></div>
<div class="shape shape-2"></div>
<div class="shape shape-3"></div>

<div class="container">
  <div class="error-container">
    <div class="content">
      <div class="error-icon">
        <ion-icon name="alert-circle-outline"></ion-icon>
      </div>

      <div class="error-code">404</div>

      <h1>Oops! Page Not Found</h1>

      <p>The page you're looking for seems to have wandered off into the digital void. Don't worry, it happens to the best of us!</p>

      <div class="button-group">
        <a href="/" class="btn">
          <ion-icon name="home-outline"></ion-icon>
          Back to Home
        </a>
        <button class="btn btn-secondary" onclick="window.history.back()">
          <ion-icon name="arrow-back-outline"></ion-icon>
          Go Back
        </button>
      </div>

      <div class="search-box">
        <input type="text" placeholder="Search for what you need..." id="searchInput">
        <button type="submit">
          <ion-icon name="search-outline"></ion-icon>
        </button>
      </div>

      <div class="suggestions">
        <a href="/" class="suggestion-card">
          <ion-icon name="home-outline"></ion-icon>
          <h3>Home</h3>
          <p>Go to homepage</p>
        </a>
        <a href="/about" class="suggestion-card">
          <ion-icon name="information-circle-outline"></ion-icon>
          <h3>About</h3>
          <p>Learn about us</p>
        </a>
        <a href="/contact" class="suggestion-card">
          <ion-icon name="mail-outline"></ion-icon>
          <h3>Contact</h3>
          <p>Get in touch</p>
        </a>
        <a href="/help" class="suggestion-card">
          <ion-icon name="help-circle-outline"></ion-icon>
          <h3>Help</h3>
          <p>Need support?</p>
        </a>
      </div>

      <div class="footer-text">
        Lost? Contact our <a href="/support">support team</a> for assistance
      </div>
    </div>
  </div>
</div>

<script>

   * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
            overflow-x: hidden;
        }

        .container {
            text-align: center;
            max-width: 700px;
            width: 100%;
        }

        .error-container {
            background: white;
            border-radius: 30px;
            padding: 60px 40px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
            position: relative;
            overflow: hidden;
        }

        .error-container::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(102, 126, 234, 0.1) 0%, transparent 70%);
            animation: rotate 20s linear infinite;
        }

        @keyframes rotate {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        .content {
            position: relative;
            z-index: 1;
        }

        .error-icon {
            font-size: 120px;
            color: #667eea;
            margin-bottom: 20px;
            animation: float 3s ease-in-out infinite;
        }

        @keyframes float {
            0%, 100% { transform: translateY(0px); }
            50% { transform: translateY(-20px); }
        }

        .error-code {
            font-size: 120px;
            font-weight: 900;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            line-height: 1;
            margin-bottom: 20px;
            animation: glitch 5s infinite;
        }

        @keyframes glitch {
            0%, 90%, 100% { transform: translate(0); }
            91% { transform: translate(-2px, 2px); }
            92% { transform: translate(2px, -2px); }
            93% { transform: translate(-2px, 2px); }
            94% { transform: translate(2px, -2px); }
        }

        h1 {
            font-size: 36px;
            color: #333;
            margin-bottom: 15px;
            font-weight: 700;
        }

        p {
            font-size: 18px;
            color: #666;
            margin-bottom: 30px;
            line-height: 1.6;
        }

        .button-group {
            display: flex;
            gap: 15px;
            justify-content: center;
            flex-wrap: wrap;
            margin-bottom: 30px;
        }

        .btn {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 50px;
            padding: 14px 32px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            text-decoration: none;
        }

        .btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
        }

        .btn:active {
            transform: translateY(-1px);
        }

        .btn-secondary {
            background: white;
            color: #667eea;
            border: 2px solid #667eea;
        }

        .btn-secondary:hover {
            background: #f8f9ff;
        }

        .search-box {
            max-width: 400px;
            margin: 0 auto 30px;
            position: relative;
        }

        .search-box input {
            width: 100%;
            padding: 14px 50px 14px 20px;
            border: 2px solid #e0e0e0;
            border-radius: 50px;
            font-size: 15px;
            transition: border-color 0.3s;
        }

        .search-box input:focus {
            outline: none;
            border-color: #667eea;
        }

        .search-box button {
            position: absolute;
            right: 5px;
            top: 50%;
            transform: translateY(-50%);
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border: none;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            color: white;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: transform 0.2s;
        }

        .search-box button:hover {
            transform: translateY(-50%) scale(1.1);
        }

        .suggestions {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
            gap: 15px;
            margin-top: 30px;
        }

        .suggestion-card {
            background: #f8f9ff;
            padding: 20px;
            border-radius: 15px;
            transition: all 0.3s ease;
            cursor: pointer;
            text-decoration: none;
            color: #333;
        }

        .suggestion-card:hover {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
        }

        .suggestion-card ion-icon {
            font-size: 32px;
            margin-bottom: 10px;
            display: block;
        }

        .suggestion-card h3 {
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 5px;
        }

        .suggestion-card p {
            font-size: 12px;
            margin: 0;
            opacity: 0.8;
        }

        .footer-text {
            margin-top: 40px;
            font-size: 14px;
            color: #999;
        }

        .footer-text a {
            color: #667eea;
            text-decoration: none;
            font-weight: 600;
        }

        .footer-text a:hover {
            text-decoration: underline;
        }

        /* Floating shapes */
        .shape {
            position: absolute;
            opacity: 0.1;
            z-index: 0;
        }

        .shape-1 {
            width: 100px;
            height: 100px;
            background: #667eea;
            border-radius: 50%;
            top: 10%;
            left: 5%;
            animation: float 6s ease-in-out infinite;
        }

        .shape-2 {
            width: 80px;
            height: 80px;
            background: #764ba2;
            border-radius: 30%;
            bottom: 10%;
            right: 10%;
            animation: float 8s ease-in-out infinite reverse;
        }

        .shape-3 {
            width: 60px;
            height: 60px;
            background: #667eea;
            transform: rotate(45deg);
            top: 60%;
            left: 8%;
            animation: float 7s ease-in-out infinite;
        }

        @media (max-width: 768px) {
            .error-container {
                padding: 40px 20px;
            }

            .error-code {
                font-size: 80px;
            }

            .error-icon {
                font-size: 80px;
            }

            h1 {
                font-size: 28px;
            }

            p {
                font-size: 16px;
            }

            .button-group {
                flex-direction: column;
            }

            .btn {
                width: 100%;
                justify-content: center;
            }

            .suggestions {
                grid-template-columns: repeat(2, 1fr);
            }
        }

     // Search functionality
        const searchInput = document.getElementById('searchInput');
        const searchButton = document.querySelector('.search-box button');

        searchButton.addEventListener('click', performSearch);
        searchInput.addEventListener('keypress', (e) => {
            if (e.key === 'Enter') {
                performSearch();
            }
        });

        function performSearch() {
            const query = searchInput.value.trim();
            if (query) {
                // Redirect to search page or perform search
                window.location.href = `/search?q=${encodeURIComponent(query)}`;
            }
        }