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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: url(https://cdn1.vieclam24h.vn/images/public/2024/05/15/bg_171576434650.png) no-repeat;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            position: relative;
        }

        .login-container {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
            padding: 40px;
            width: 100%;
            max-width: 400px;
            animation: slideIn 0.5s ease-out;
            position: relative;
            z-index: 1;
        }

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

        .login-header {
            text-align: center;
            margin-bottom: 30px;
        }

        .login-header h1 {
            color: #333;
            font-size: 28px;
            margin-bottom: 10px;
        }

        .login-header p {
            color: #666;
            font-size: 14px;
        }

        .form-group {
            margin-bottom: 20px;
        }

        .form-group label {
            display: block;
            color: #333;
            font-weight: 500;
            margin-bottom: 8px;
            font-size: 14px;
        }

        .form-group input {
            width: 100%;
            padding: 12px 15px;
            border: 2px solid #e0e0e0;
            border-radius: 10px;
            font-size: 14px;
            transition: all 0.3s ease;
            outline: none;
        }

        .form-group input:focus {
            border-color: #451DA0;
            box-shadow: 0 0 0 3px rgba(69, 29, 160, 0.1);
        }

        .form-group input.error {
            border-color: #dc3545;
        }

        .error-message {
            color: #dc3545;
            font-size: 13px;
            margin-top: 5px;
            display: block;
        }

        .forgot-password {
            text-align: right;
            margin-bottom: 20px;
        }

        .forgot-password a {
            color: #007bff;
            text-decoration: none;
            font-size: 13px;
            transition: color 0.3s ease;
        }

        .forgot-password a:hover {
            color: #0056b3;
            text-decoration: underline;
        }

        .btn-login {
            width: 100%;
            padding: 14px;
            background: #451DA0;
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.2s ease, box-shadow 0.3s ease;
        }

        .btn-login:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(69, 29, 160, 0.4);
            background: #5a29c4;
        }

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

        .divider {
            text-align: center;
            margin: 25px 0;
            position: relative;
        }

        .divider::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 0;
            right: 0;
            height: 1px;
            background: #e0e0e0;
        }

        .divider span {
            background: white;
            padding: 0 15px;
            color: #999;
            font-size: 13px;
            position: relative;
        }

        .register-link {
            text-align: center;
            margin-top: 20px;
        }

        .register-link p {
            color: #666;
            font-size: 14px;
        }

        .register-link a {
            color: #007bff;
            text-decoration: none;
            font-weight: 600;
            transition: color 0.3s ease;
        }

        .register-link a:hover {
            color: #0056b3;
            text-decoration: underline;
        }

        .alert {
            padding: 12px 15px;
            border-radius: 10px;
            margin-bottom: 20px;
            text-align: center;
            animation: fadeIn 0.3s ease;
        }

        .alert-success {
            background: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }

        .alert-danger {
            background: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }

        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }