.ch_container {
            max-width: 800px;
            margin: 20px auto;
            padding: 0 15px;
        }

        .ch_card {
            border: 1px solid #6c757d;
            border-radius: 8px;
            background-color: #fff;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            overflow: hidden;
        }

        .ch_card-header {
            background-color: #f8f9fa;
            border-bottom: 1px solid #dee2e6;
            padding: 12px 20px;
        }

        .ch_card-title {
            margin: 0;
            font-size: 1.1rem;
            font-weight: 500;
            color: #495057;
        }

        .ch_card-body {
            padding: 20px;
        }

        .ch_form-row {
            display: flex;
            flex-wrap: wrap;
            margin: 0 -15px;
        }

        .ch_form-group {
            padding: 0 15px;
            margin-bottom: 20px;
        }

        .ch_col-md-6 {
            flex: 0 0 50%;
            max-width: 50%;
        }

        @media (max-width: 768px) {
            .ch_col-md-6 {
                flex: 0 0 100%;
                max-width: 100%;
            }
        }

        .ch_label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: #495057;
        }

        .ch_input-group {
            display: flex;
            width: 100%;
            position: relative;
            flex-wrap: wrap;
        }

        .ch_form-control {
            flex: 1;
            padding: 8px 12px;
            font-size: 14px;
            border: 1px solid #ced4da;
            border-radius: 4px 0 0 4px;
            outline: none;
            transition: border-color 0.15s ease-in-out;
        }

        .ch_form-control:focus {
            border-color: #80bdff;
            box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
        }

        .ch_form-control.ch_is-invalid {
            border-color: #dc3545;
        }

        .ch_input-group-append {
            display: flex;
        }

        .ch_input-group-text {
            padding: 8px 12px;
            font-size: 14px;
            background-color: #e9ecef;
            border: 1px solid #ced4da;
            border-left: none;
            border-radius: 0 4px 4px 0;
            color: #495057;
        }

        .ch_btn {
            padding: 8px 12px;
            font-size: 14px;
            border: 1px solid #ced4da;
            border-left: none;
            border-radius: 0 4px 4px 0;
            background-color: #f8f9fa;
            color: #495057;
            cursor: pointer;
            transition: all 0.15s ease-in-out;
        }

        .ch_btn:hover {
            background-color: #e9ecef;
        }

        .ch_btn-light {
            background-color: #f8f9fa;
            border-color: #ced4da;
        }

        .ch_invalid-feedback {
            display: none;
            width: 100%;
				    margin-top: 0;
				    font-size: 13px;
				    color: #dc3545;
        }

        .ch_form-control.ch_is-invalid ~ .ch_invalid-feedback {
            display: block;
        }

        .ch_card-footer {
            background-color: #f8f9fa;
            border-top: 1px solid #dee2e6;
            padding: 15px 20px;
        }

        .ch_text-right {
            text-align: right;
        }

        .ch_btn-group {
            display: inline-flex;
            gap: 0;
        }

        .ch_btn-group .ch_btn {
            border-radius: 0;
            border-left: 1px solid #ced4da;
        }

        .ch_btn-group .ch_btn:first-child {
            border-radius: 4px 0 0 4px;
        }

        .ch_btn-group .ch_btn:last-child {
            border-radius: 0 4px 4px 0;
        }

        .ch_btn-info {
            background-color: #17a2b8;
            border-color: #17a2b8;
            color: #fff;
        }

        .ch_btn-info:hover {
            background-color: #138496;
            border-color: #117a8b;
        }

        .ch_btn-outline-info {
            background-color: transparent;
            border-color: #17a2b8;
            color: #17a2b8;
        }

        .ch_btn-outline-info:hover {
            background-color: #17a2b8;
            color: #fff;
        }

        .ch_collapse {
            display: none;
        }

        .ch_collapse.ch_show {
            display: block;
        }

        .ch_bg-white {
            background-color: #fff;
        }

        .ch_text-dark {
            color: #343a40;
        }

        .ch_result-content {
            padding: 15px;
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            border-radius: 4px;
            color: #155724;
            margin-top: 10px;
        }

        .ch_result-title {
            font-weight: bold;
            margin-bottom: 10px;
        }

        .ch_result-item {
            margin-bottom: 5px;
        }

        .ch_form-text {
            margin-top: 10px;
            font-size: 0.875rem;
            color: #6c757d;
        }

        .ch_formula-text {
            margin-top: 20px;
            font-size: 0.9rem;
            color: #495057;
        }

        .ch_formula-text p {
            margin: 10px 0;
        }

        .ch_d-none {
            display: none;
        }

        .ch_d-sm-block {
            display: block;
        }

        .ch_d-md-block {
            display: block;
        }

        .ch_d-sm-none {
            display: none;
        }

        .ch_d-md-none {
            display: none;
        }

        @media (max-width: 576px) {
            .ch_d-sm-block {
                display: block;
            }
            .ch_d-sm-none {
                display: none;
            }
        }

        @media (max-width: 768px) {
            .ch_d-md-block {
                display: block;
            }
            .ch_d-md-none {
                display: none;
            }
        }

        .ch_mb-1 {
            margin-bottom: 0.25rem;
        }

        .ch_mb-3 {
            margin-bottom: 1rem;
        }

        .ch_pb-2 {
            padding-bottom: 0.5rem;
        }

        .ch_mt-4 {
            margin-top: 1.5rem;
        }

        .ch_text-muted {
            color: #6c757d;
            margin-top: 20px;
    			display: block;
        }