* { margin: 0; padding: 0; box-sizing: border-box; }
        body { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); min-height: 100vh; display: flex; align-items: center; justify-content: center; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }
        
        .login-container { width: 100%; max-width: 420px; padding: 2rem; }
        
        .login-card { background: white; border-radius: 16px; padding: 2.5rem; box-shadow: 0 20px 60px rgba(0,0,0,0.3); }
        
        .login-header { text-align: center; margin-bottom: 2rem; }
        .login-header h1 { font-size: 1.5rem; color: #1F2937; margin-bottom: 0.5rem; }
        .login-header p { color: #9CA3AF; font-size: 0.875rem; }
        
        .tabs { display: flex; gap: 0; margin-bottom: 2rem; background: #F3F4F6; border-radius: 8px; padding: 4px; }
        .tab { flex: 1; text-align: center; padding: 0.625rem; font-size: 0.875rem; font-weight: 500; color: #6B7280; cursor: pointer; border-radius: 6px; transition: all 0.2s; }
        .tab.active { background: white; color: #3B82F6; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
        
        .form-group { margin-bottom: 1.25rem; }
        .form-group label { display: block; font-size: 0.875rem; font-weight: 500; color: #374151; margin-bottom: 0.5rem; }
        .form-group input { width: 100%; padding: 0.75rem 1rem; border: 1px solid #E5E7EB; border-radius: 8px; font-size: 0.875rem; transition: all 0.2s; }
        .form-group input:focus { outline: none; border-color: #3B82F6; box-shadow: 0 0 0 3px rgba(59,130,246,0.1); }
        
        .btn { width: 100%; padding: 0.75rem; border: none; border-radius: 8px; font-size: 0.875rem; font-weight: 500; cursor: pointer; transition: all 0.2s; }
        .btn-primary { background: #3B82F6; color: white; }
        .btn-primary:hover { background: #2563EB; }
        .btn-primary:disabled { opacity: 0.6; cursor: not-allowed; }
        
        .error-msg { color: #EF4444; font-size: 0.8rem; margin-bottom: 1rem; display: none; text-align: center; }
        .success-msg { color: #10B981; font-size: 0.8rem; margin-bottom: 1rem; display: none; text-align: center; }
        
        .guest-link { text-align: center; margin-top: 1.5rem; }
        .guest-link a { color: #6B7280; font-size: 0.8rem; text-decoration: none; }
        .guest-link a:hover { color: #3B82F6; }
        
        @media (max-width: 768px) {
            .login-container { padding: 1rem; }
            .login-card { padding: 1.5rem; }
            .login-header h1 { font-size: 1.25rem; }
            .login-header p { font-size: 0.8rem; }
            .form-group input { font-size: 0.9rem; padding: 0.625rem 0.75rem; }
            .tab { font-size: 0.8rem; padding: 0.5rem; }
        }