Animated Login Form in CSS

<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="login-container">
  <div class="login-header">
    <div class="logo-icon">
      <ion-icon name="lock-closed-outline"></ion-icon>
    </div>
    <h2>Welcome Back</h2>
    <p>Please enter your credentials to continue</p>
  </div>

  <div class="form-group">
    <label for="email">Email Address</label>
    <div class="input-wrapper">
      <ion-icon name="mail-outline" class="input-icon"></ion-icon>
      <input type="email" id="email" placeholder="Enter your email" autocomplete="email">
    </div>
    <div class="error-message" id="emailError">Please enter a valid email address</div>
  </div>

  <div class="form-group">
    <label for="password">Password</label>
    <div class="input-wrapper">
      <ion-icon name="lock-closed-outline" class="input-icon"></ion-icon>
      <input type="password" id="password" placeholder="Enter your password" autocomplete="current-password">
      <ion-icon name="eye-outline" class="toggle-password" onclick="togglePassword()"></ion-icon>
    </div>
    <div class="error-message" id="passwordError">Password must be at least 6 characters</div>
  </div>

  <div class="form-options">
    <label class="remember-me">
      <input type="checkbox" id="remember">
      <span>Remember me</span>
    </label>
    <a href="#" class="forgot-password">Forgot Password?</a>
  </div>

  <button class="login-btn" onclick="handleLogin()">
    Sign In
  </button>

  <div class="divider">
    <span>OR</span>
  </div>

  <div class="social-login">
    <button class="social-btn" onclick="socialLogin('google')">
      <ion-icon name="logo-google"></ion-icon>
      Google
    </button>
    <button class="social-btn" onclick="socialLogin('github')">
      <ion-icon name="logo-github"></ion-icon>
      GitHub
    </button>
  </div>

  <div class="signup-link">
    Don't have an account? <a href="#">Sign Up</a>
  </div>
</div>

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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            background: linear-gradient(135deg, #10451d, #1a6b2f, #10451d);
            background-size: 400% 400%;
            animation: gradientShift 15s ease infinite;
            padding: 1rem;
        }

        @keyframes gradientShift {
            0%, 100% {
                background-position: 0% 50%;
            }
            50% {
                background-position: 100% 50%;
            }
        }

        .login-container {
            background: white;
            padding: 3rem 2.5rem;
            border-radius: 24px;
            box-shadow: 0 20px 60px rgba(16, 69, 29, 0.4);
            width: 100%;
            max-width: 420px;
            animation: slideIn 0.6s ease-out;
        }

        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(-30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .login-header {
            text-align: center;
            margin-bottom: 2.5rem;
        }

        .logo-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, #10451d, #1a6b2f);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            animation: pulse 2s ease-in-out infinite;
        }

        @keyframes pulse {
            0%, 100% {
                transform: scale(1);
                box-shadow: 0 0 0 0 rgba(16, 69, 29, 0.4);
            }
            50% {
                transform: scale(1.05);
                box-shadow: 0 0 0 10px rgba(16, 69, 29, 0);
            }
        }

        .logo-icon ion-icon {
            font-size: 2.5rem;
            color: white;
        }

        .login-header h2 {
            color: #10451d;
            font-size: 1.875rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }

        .login-header p {
            color: #6c757d;
            font-size: 0.925rem;
        }

        .form-group {
            margin-bottom: 1.5rem;
            position: relative;
        }

        .form-group label {
            display: block;
            color: #2c3e50;
            font-size: 0.875rem;
            font-weight: 500;
            margin-bottom: 0.5rem;
            transition: all 0.3s ease;
        }

        .input-wrapper {
            position: relative;
        }

        .input-icon {
            position: absolute;
            left: 1rem;
            top: 50%;
            transform: translateY(-50%);
            font-size: 1.25rem;
            color: #6c757d;
            transition: all 0.3s ease;
        }

        .form-group input {
            width: 100%;
            padding: 0.875rem 1rem 0.875rem 3rem;
            border: 2px solid #e0e0e0;
            border-radius: 12px;
            font-size: 0.95rem;
            transition: all 0.3s ease;
            outline: none;
        }

        .form-group input:focus {
            border-color: #10451d;
            box-shadow: 0 0 0 4px rgba(16, 69, 29, 0.1);
        }

        .form-group input:focus ~ .input-icon {
            color: #10451d;
        }

        .toggle-password {
            position: absolute;
            right: 1rem;
            top: 50%;
            transform: translateY(-50%);
            cursor: pointer;
            font-size: 1.25rem;
            color: #6c757d;
            transition: all 0.3s ease;
        }

        .toggle-password:hover {
            color: #10451d;
        }

        .form-options {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1.5rem;
            font-size: 0.875rem;
        }

        .remember-me {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            cursor: pointer;
            color: #6c757d;
        }

        .remember-me input[type="checkbox"] {
            width: 18px;
            height: 18px;
            cursor: pointer;
            accent-color: #10451d;
        }

        .forgot-password {
            color: #10451d;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
        }

        .forgot-password:hover {
            color: #1a6b2f;
            text-decoration: underline;
        }

        .login-btn {
            width: 100%;
            padding: 1rem;
            background: linear-gradient(135deg, #10451d, #1a6b2f);
            color: white;
            border: none;
            border-radius: 12px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(16, 69, 29, 0.3);
            position: relative;
            overflow: hidden;
        }

        .login-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 ease;
        }

        .login-btn:hover::before {
            left: 100%;
        }

        .login-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(16, 69, 29, 0.4);
        }

        .login-btn:active {
            transform: translateY(0);
        }

        .divider {
            display: flex;
            align-items: center;
            margin: 2rem 0;
            color: #6c757d;
            font-size: 0.875rem;
        }

        .divider::before,
        .divider::after {
            content: '';
            flex: 1;
            height: 1px;
            background: #e0e0e0;
        }

        .divider span {
            padding: 0 1rem;
        }

        .social-login {
            display: flex;
            gap: 1rem;
            margin-bottom: 2rem;
        }

        .social-btn {
            flex: 1;
            padding: 0.875rem;
            border: 2px solid #e0e0e0;
            border-radius: 12px;
            background: white;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            font-size: 0.875rem;
            font-weight: 500;
            color: #2c3e50;
        }

        .social-btn ion-icon {
            font-size: 1.25rem;
        }

        .social-btn:hover {
            border-color: #10451d;
            background: rgba(16, 69, 29, 0.05);
            transform: translateY(-2px);
        }

        .signup-link {
            text-align: center;
            color: #6c757d;
            font-size: 0.925rem;
        }

        .signup-link a {
            color: #10451d;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
        }

        .signup-link a:hover {
            color: #1a6b2f;
            text-decoration: underline;
        }

        .error-message {
            color: #dc3545;
            font-size: 0.825rem;
            margin-top: 0.5rem;
            display: none;
            animation: shake 0.3s ease;
        }

        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            25% { transform: translateX(-5px); }
            75% { transform: translateX(5px); }
        }

        .error-message.show {
            display: block;
        }

    function togglePassword() {
            const passwordInput = document.getElementById('password');
            const toggleIcon = document.querySelector('.toggle-password');
            
            if (passwordInput.type === 'password') {
                passwordInput.type = 'text';
                toggleIcon.setAttribute('name', 'eye-off-outline');
            } else {
                passwordInput.type = 'password';
                toggleIcon.setAttribute('name', 'eye-outline');
            }
        }

        function handleLogin() {
            const email = document.getElementById('email');
            const password = document.getElementById('password');
            const emailError = document.getElementById('emailError');
            const passwordError = document.getElementById('passwordError');
            
            let isValid = true;
            
            // Reset errors
            emailError.classList.remove('show');
            passwordError.classList.remove('show');
            email.style.borderColor = '#e0e0e0';
            password.style.borderColor = '#e0e0e0';
            
            // Validate email
            const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
            if (!email.value || !emailRegex.test(email.value)) {
                emailError.classList.add('show');
                email.style.borderColor = '#dc3545';
                isValid = false;
            }
            
            // Validate password
            if (!password.value || password.value.length < 6) {
                passwordError.classList.add('show');
                password.style.borderColor = '#dc3545';
                isValid = false;
            }
            
            if (isValid) {
                alert('Login successful! 🎉');
                // Here you would typically send data to your server
            }
        }

        function socialLogin(provider) {
            alert(`Signing in with ${provider}...`);
            // Here you would typically implement OAuth flow
        }

        // Add enter key support
        document.getElementById('password').addEventListener('keypress', function(e) {
            if (e.key === 'Enter') {
                handleLogin();
            }
        });

        document.getElementById('email').addEventListener('keypress', function(e) {
            if (e.key === 'Enter') {
                handleLogin();
            }
        });