:root {
            --primary: #3498db;
            --primary-dark: #2980b9;
            --secondary: #2c3e50;
            --danger: #e74c3c;
            --light: #ecf0f1;
            --gray: #7f8c8d;
            --gray-light: #bdc3c7;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            color: #333;
            line-height: 1.6;
        }
        
        .login-container {
            background-color: white;
            border-radius: 12px;
            box-shadow: var(--shadow);
            padding: 2.5rem;
            width: 100%;
            max-width: 400px;
            text-align: center;
            transition: var(--transition);
        }
        
        .logo {
            margin-bottom: 1.5rem;
            color: var(--secondary);
        }
        
        .logo i {
            font-size: 3rem;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        
        h2 {
            color: var(--secondary);
            margin-bottom: 1.5rem;
            font-size: 1.8rem;
            font-weight: 700;
        }
        
        form {
            display: flex;
            flex-direction: column;
            gap: 1.2rem;
            margin-bottom: 1.5rem;
        }
        
        .input-group {
            position: relative;
            text-align: left;
        }
        
        .input-group i {
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--gray);
            transition: var(--transition);
        }
        
        input {
            padding: 12px 15px 12px 45px;
            border: 1px solid var(--gray-light);
            border-radius: 8px;
            font-size: 1rem;
            transition: var(--transition);
            width: 100%;
        }
        
        input:focus {
            border-color: var(--primary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
        }
        
        input:focus + i {
            color: var(--primary);
        }
        
        button {
            background: linear-gradient(to right, var(--primary), var(--primary-dark));
            color: white;
            padding: 14px;
            border: none;
            border-radius: 8px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: 0 4px 6px rgba(52, 152, 219, 0.3);
        }
        
        button:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 8px rgba(52, 152, 219, 0.4);
        }
        
        .links {
            display: flex;
            flex-direction: column;
            gap: 0.8rem;
            margin-bottom: 1.5rem;
        }
        
        .links a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 5px;
        }
        
        .links a:hover {
            color: var(--primary-dark);
            text-decoration: underline;
        }
        
        .error-message {
            color: var(--danger);
            background-color: rgba(231, 76, 60, 0.1);
            padding: 12px;
            border-radius: 8px;
            margin-bottom: 1.2rem;
            font-size: 0.9rem;
            border-left: 4px solid var(--danger);
            text-align: left;
        }
        
        .error-message i {
            margin-right: 5px;
        }
        
        .back-btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 20px;
            background-color: var(--gray);
            color: white;
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            transition: var(--transition);
        }
        
        .back-btn:hover {
            background-color: var(--secondary);
            transform: translateY(-2px);
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }
        
        /* Responsive styles */
        @media screen and (max-width: 480px) {
            .login-container {
                padding: 2rem 1.5rem;
            }
            
            h2 {
                font-size: 1.6rem;
            }
            
            input {
                padding: 10px 12px 10px 40px;
                font-size: 0.95rem;
            }
            
            button {
                padding: 12px;
            }
            
            .links {
                flex-direction: column;
            }
        }
        
        @media screen and (max-width: 350px) {
            .login-container {
                padding: 1.5rem;
            }
            
            h2 {
                font-size: 1.4rem;
            }
            
            .logo i {
                font-size: 2.5rem;
            }
        }
        
        /* Animation */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(-10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .login-container {
            animation: fadeIn 0.5s ease-out;
        }