* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .login-container {
            background: white;
            padding: 40px;
            border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
            width: 400px;
        }
        h1 {
            color: #333;
            text-align: center;
            margin-bottom: 10px;
        }
        .subtitle {
            color: #666;
            text-align: center;
            margin-bottom: 30px;
            font-size: 14px;
        }
        .form-group {
            margin-bottom: 20px;
        }
        label {
            display: block;
            color: #555;
            margin-bottom: 5px;
            font-weight: 600;
        }
        input {
            width: 100%;
            padding: 12px;
            border: 2px solid #ddd;
            border-radius: 10px;
            font-size: 16px;
            transition: border-color 0.3s;
        }
        input:focus {
            outline: none;
            border-color: #667eea;
        }
        button {
            width: 100%;
            padding: 14px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 18px;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.2s;
        }
        button:hover {
            transform: scale(1.02);
        }
        .error {
            color: #e74c3c;
            text-align: center;
            margin-top: 15px;
            display: none;
        }
        .loading {
            text-align: center;
            margin-top: 15px;
            display: none;
            color: #667eea;
        }
        .download {
            display: none;
        }