body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: #333;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
            background-color: #f8f9fa;
        }
        .container {
            background-color: #ffffff;
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            padding: 30px;
            margin-bottom: 20px;
        }
        h1 {
            color: #2c3e50;
            text-align: center;
            margin-bottom: 10px;
        }
        h2 {
            color: #2c3e50;
            border-bottom: 2px solid #3498db;
            padding-bottom: 10px;
            margin-top: 30px;
        }
        .form-group {
            margin-bottom: 20px;
        }
        label {
            display: block;
            margin-bottom: 5px;
            font-weight: bold;
            color: #2c3e50;
        }
        input, select {
            width: 100%;
            padding: 12px;
            border: 2px solid #e1e8ed;
            border-radius: 6px;
            font-size: 16px;
            box-sizing: border-box;
        }
        input:focus, select:focus {
            outline: none;
            border-color: #3498db;
        }
        button {
            background-color: #3498db;
            color: white;
            padding: 12px 24px;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            font-size: 16px;
            margin: 5px;
            transition: background-color 0.3s;
        }
        button:hover {
            background-color: #2980b9;
        }
        .btn-secondary {
            background-color: #95a5a6;
        }
        .btn-secondary:hover {
            background-color: #7f8c8d;
        }
        .btn-success {
            background-color: #2ecc71;
        }
        .btn-success:hover {
            background-color: #27ae60;
        }
        .btn-danger {
            background-color: #e74c3c;
        }
        .btn-danger:hover {
            background-color: #c0392b;
        }
        .password-display {
            background-color: #f8f9fa;
            border: 2px solid #e1e8ed;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
            text-align: center;
            font-family: 'Courier New', monospace;
            font-size: 1.2em;
            word-break: break-all;
            position: relative;
        }
        .password-text {
            margin: 0;
            color: #2c3e50;
        }
        .copy-btn {
            position: absolute;
            top: 10px;
            right: 10px;
            background-color: #3498db;
            color: white;
            border: none;
            border-radius: 4px;
            padding: 5px 10px;
            cursor: pointer;
            font-size: 12px;
        }
        .copy-btn:hover {
            background-color: #2980b9;
        }
        .strength-meter {
            height: 8px;
            border-radius: 4px;
            margin: 10px 0;
            background-color: #e9ecef;
            overflow: hidden;
        }
        .strength-fill {
            height: 100%;
            transition: width 0.3s ease, background-color 0.3s ease;
            width: 0%;
        }
        .strength-weak { background-color: #e74c3c; }
        .strength-fair { background-color: #f39c12; }
        .strength-good { background-color: #f1c40f; }
        .strength-strong { background-color: #2ecc71; }
        .strength-very-strong { background-color: #27ae60; }
        .strength-label {
            font-size: 0.9em;
            font-weight: bold;
            margin-top: 5px;
        }
        .checkbox-group {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 10px;
            margin: 15px 0;
        }
        .checkbox-item {
            display: flex;
            align-items: center;
            padding: 10px;
            background-color: #f8f9fa;
            border: 2px solid #e1e8ed;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.3s;
        }
        .checkbox-item:hover {
            background-color: #e9ecef;
            border-color: #3498db;
        }
        .checkbox-item input[type="checkbox"] {
            width: auto;
            margin-right: 10px;
        }
        .checkbox-item label {
            margin: 0;
            cursor: pointer;
            flex: 1;
        }
        .length-slider {
            width: 100%;
            margin: 10px 0;
        }
        .length-display {
            text-align: center;
            font-size: 1.2em;
            font-weight: bold;
            color: #3498db;
            margin: 10px 0;
        }
        .info-box {
            background-color: #d1ecf1;
            border: 1px solid #bee5eb;
            border-radius: 8px;
            padding: 15px;
            margin: 15px 0;
        }
        .info-box h3 {
            margin-top: 0;
            color: #0c5460;
        }
        .password-history {
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 8px;
            padding: 15px;
            margin: 15px 0;
        }
        .history-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 8px 0;
            border-bottom: 1px solid #e9ecef;
            font-family: 'Courier New', monospace;
        }
        .history-item:last-child {
            border-bottom: none;
        }
        .history-password {
            flex: 1;
            margin-right: 10px;
        }
        .history-strength {
            font-size: 0.8em;
            padding: 2px 6px;
            border-radius: 3px;
            color: white;
        }
        .strength-weak-badge { background-color: #e74c3c; }
        .strength-fair-badge { background-color: #f39c12; }
        .strength-good-badge { background-color: #f1c40f; }
        .strength-strong-badge { background-color: #2ecc71; }
        .strength-very-strong-badge { background-color: #27ae60; }
        .clear-history {
            background-color: #e74c3c;
            color: white;
            border: none;
            border-radius: 4px;
            padding: 5px 10px;
            cursor: pointer;
            font-size: 12px;
            margin-top: 10px;
        }
        .clear-history:hover {
            background-color: #c0392b;
        }
        @media (max-width: 768px) {
            .checkbox-group {
                grid-template-columns: 1fr;
            }
            .password-display {
                font-size: 1em;
            }
        }