Modern Login Form

.login-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 20px;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

.login-form {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-radius: 20px;
  padding: 40px;
  width: 100%;
  max-width: 400px;
  box-shadow: 
    0 20px 40px rgba(0, 0, 0, 0.1),
    0 0 0 1px rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.form-header {
  text-align: center;
  margin-bottom: 32px;
}

.form-title {
  font-size: 28px;
  font-weight: 700;
  color: #1a1a1a;
  margin: 0 0 8px 0;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.form-subtitle {
  font-size: 16px;
  color: #666;
  margin: 0;
}

.input-group {
  margin-bottom: 24px;
}

.input-wrapper {
  position: relative;
}

.form-input {
  width: 100%;
  height: 56px;
  padding: 16px 48px 16px 16px;
  border: 2px solid #e1e5e9;
  border-radius: 12px;
  font-size: 16px;
  background: #fff;
  transition: all 0.3s ease;
  outline: none;
  box-sizing: border-box;
}

.form-input:focus {
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-input:focus + .form-label,
.form-input:not(:placeholder-shown) + .form-label {
  transform: translateY(-28px) scale(0.85);
  color: #667eea;
  background: #fff;
  padding: 0 8px;
}

.form-label {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 16px;
  color: #999;
  pointer-events: none;
  transition: all 0.3s ease;
  background: transparent;
}

.input-icon {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  color: #999;
  transition: color 0.3s ease;
}

.form-input:focus ~ .input-icon {
  color: #667eea;
}

.password-toggle {
  position: absolute;
  right: 48px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  width: 20px;
  height: 20px;
  color: #999;
  cursor: pointer;
  transition: color 0.3s ease;
}

.password-toggle:hover {
  color: #667eea;
}

.password-toggle svg {
  width: 100%;
  height: 100%;
}

.form-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
}

.checkbox-wrapper {
  display: flex;
  align-items: center;
  cursor: pointer;
}

.checkbox-input {
  display: none;
}

.checkbox-custom {
  width: 18px;
  height: 18px;
  border: 2px solid #e1e5e9;
  border-radius: 4px;
  margin-right: 8px;
  position: relative;
  transition: all 0.3s ease;
}

.checkbox-input:checked + .checkbox-custom {
  background: #667eea;
  border-color: #667eea;
}

.checkbox-input:checked + .checkbox-custom::after {
  content: '';
  position: absolute;
  left: 5px;
  top: 2px;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-label {
  font-size: 14px;
  color: #666;
}

.forgot-link {
  font-size: 14px;
  color: #667eea;
  text-decoration: none;
  transition: color 0.3s ease;
}

.forgot-link:hover {
  color: #5a6fd8;
}

.login-btn {
  width: 100%;
  height: 56px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  border: none;
  border-radius: 12px;
  color: white;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  margin-bottom: 24px;
}

.login-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

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

.login-btn.loading .btn-text {
  opacity: 0;
}

.login-btn.loading .btn-loader {
  display: flex !important;
}

.btn-loader {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  align-items: center;
  justify-content: center;
}

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top: 2px solid white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

.divider {
  position: relative;
  text-align: center;
  margin: 24px 0;
}

.divider::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: #e1e5e9;
}

.divider-text {
  background: rgba(255, 255, 255, 0.95);
  padding: 0 16px;
  font-size: 14px;
  color: #999;
}

.social-login {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}

.social-btn {
  flex: 1;
  height: 48px;
  border: 2px solid #e1e5e9;
  border-radius: 12px;
  background: white;
  color: #666;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.social-btn:hover {
  border-color: #667eea;
  background: #f8f9ff;
}

.social-btn svg {
  width: 20px;
  height: 20px;
}

.google-btn:hover {
  border-color: #4285f4;
  background: #f8f9ff;
}

.github-btn:hover {
  border-color: #333;
  background: #f8f9ff;
}

.form-footer {
  text-align: center;
}

.signup-text {
  font-size: 14px;
  color: #666;
  margin: 0;
}

.signup-link {
  color: #667eea;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.signup-link:hover {
  color: #5a6fd8;
}

/* Responsive design */
@media (max-width: 480px) {
  .login-container {
    padding: 16px;
  }
  
  .login-form {
    padding: 32px 24px;
  }
  
  .form-title {
    font-size: 24px;
  }
  
  .social-login {
    flex-direction: column;
  }
}

document.addEventListener('DOMContentLoaded', () => {
  const loginForm = document.getElementById('loginForm');
  const passwordToggle = document.getElementById('passwordToggle');
  const passwordInput = document.getElementById('password');
  const loginBtn = loginForm.querySelector('.login-btn');
  const emailInput = document.getElementById('email');
  const rememberCheckbox = document.getElementById('remember');
  
  // Password visibility toggle
  passwordToggle.addEventListener('click', () => {
    const eyeOpen = passwordToggle.querySelector('.eye-open');
    const eyeClosed = passwordToggle.querySelector('.eye-closed');
    
    if (passwordInput.type === 'password') {
      passwordInput.type = 'text';
      eyeOpen.style.display = 'none';
      eyeClosed.style.display = 'block';
    } else {
      passwordInput.type = 'password';
      eyeOpen.style.display = 'block';
      eyeClosed.style.display = 'none';
    }
  });
  
  // Form validation
  function validateEmail(email) {
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    return emailRegex.test(email);
  }
  
  function validatePassword(password) {
    return password.length >= 6;
  }
  
  function showError(input, message) {
    // Remove existing error
    const existingError = input.parentNode.querySelector('.error-message');
    if (existingError) {
      existingError.remove();
    }
    
    // Add error styling
    input.style.borderColor = '#e74c3c';
    
    // Add error message
    const errorDiv = document.createElement('div');
    errorDiv.className = 'error-message';
    errorDiv.textContent = message;
    errorDiv.style.cssText = `
      color: #e74c3c;
      font-size: 12px;
      margin-top: 4px;
      margin-left: 4px;
    `;
    input.parentNode.appendChild(errorDiv);
  }
  
  function clearError(input) {
    const errorMessage = input.parentNode.querySelector('.error-message');
    if (errorMessage) {
      errorMessage.remove();
    }
    input.style.borderColor = '#e1e5e9';
  }
  
  // Real-time validation
  emailInput.addEventListener('blur', () => {
    if (emailInput.value && !validateEmail(emailInput.value)) {
      showError(emailInput, 'Please enter a valid email address');
    } else {
      clearError(emailInput);
    }
  });
  
  passwordInput.addEventListener('blur', () => {
    if (passwordInput.value && !validatePassword(passwordInput.value)) {
      showError(passwordInput, 'Password must be at least 6 characters');
    } else {
      clearError(passwordInput);
    }
  });
  
  // Form submission
  loginForm.addEventListener('submit', async (e) => {
    e.preventDefault();
    
    const email = emailInput.value.trim();
    const password = passwordInput.value;
    const remember = rememberCheckbox.checked;
    
    // Clear previous errors
    clearError(emailInput);
    clearError(passwordInput);
    
    let hasErrors = false;
    
    // Validate email
    if (!email) {
      showError(emailInput, 'Email is required');
      hasErrors = true;
    } else if (!validateEmail(email)) {
      showError(emailInput, 'Please enter a valid email address');
      hasErrors = true;
    }
    
    // Validate password
    if (!password) {
      showError(passwordInput, 'Password is required');
      hasErrors = true;
    } else if (!validatePassword(password)) {
      showError(passwordInput, 'Password must be at least 6 characters');
      hasErrors = true;
    }
    
    if (hasErrors) {
      return;
    }
    
    // Show loading state
    loginBtn.classList.add('loading');
    loginBtn.disabled = true;
    
    try {
      // Simulate API call
      await new Promise(resolve => setTimeout(resolve, 2000));
      
      // Simulate successful login
      console.log('Login successful:', { email, remember });
      
      // Show success message
      const successDiv = document.createElement('div');
      successDiv.textContent = 'Login successful! Redirecting...';
      successDiv.style.cssText = `
        background: #d4edda;
        color: #155724;
        padding: 12px;
        border-radius: 8px;
        margin-bottom: 16px;
        text-align: center;
        border: 1px solid #c3e6cb;
      `;
      loginForm.insertBefore(successDiv, loginForm.firstChild);
      
      // Simulate redirect after delay
      setTimeout(() => {
        console.log('Redirecting to dashboard...');
      }, 1500);
      
    } catch (error) {
      console.error('Login failed:', error);
      
      // Show error message
      const errorDiv = document.createElement('div');
      errorDiv.textContent = 'Login failed. Please check your credentials.';
      errorDiv.style.cssText = `
        background: #f8d7da;
        color: #721c24;
        padding: 12px;
        border-radius: 8px;
        margin-bottom: 16px;
        text-align: center;
        border: 1px solid #f5c6cb;
      `;
      loginForm.insertBefore(errorDiv, loginForm.firstChild);
      
    } finally {
      // Hide loading state
      loginBtn.classList.remove('loading');
      loginBtn.disabled = false;
    }
  });
  
  // Social login handlers
  const socialBtns = document.querySelectorAll('.social-btn');
  socialBtns.forEach(btn => {
    btn.addEventListener('click', (e) => {
      const provider = btn.classList.contains('google-btn') ? 'Google' : 'GitHub';
      console.log(`${provider} login clicked`);
      
      // Add loading state to social button
      btn.style.opacity = '0.7';
      btn.disabled = true;
      
      // Simulate social login
      setTimeout(() => {
        btn.style.opacity = '1';
        btn.disabled = false;
        console.log(`${provider} login completed`);
      }, 1500);
    });
  });
  
  // Input focus effects
  const inputs = document.querySelectorAll('.form-input');
  inputs.forEach(input => {
    input.addEventListener('focus', () => {
      input.parentNode.classList.add('focused');
    });
    
    input.addEventListener('blur', () => {
      input.parentNode.classList.remove('focused');
    });
  });
  
  // Keyboard shortcuts
  document.addEventListener('keydown', (e) => {
    // Enter key to submit form
    if (e.key === 'Enter' && (emailInput === document.activeElement || passwordInput === document.activeElement)) {
      loginForm.dispatchEvent(new Event('submit'));
    }
  });
});