Major updates:

- add number of tries option
- resolved issue with multiple instances (#15)
- code improvements
- options more organized
- readme improvements
- demo updated
- add basic unit test with Jest
- drop support for IE10

.babelrc

@@ -1,12 +1,15 @@
 {
     "presets": [
-        ["@babel/preset-env", {
-            "targets": {
-            "browsers": [
-                "last 5 versions",
-                "Explorer >= 10"
-                ]
+        [
+            "@babel/preset-env",
+            {
+                "targets": {
+                    "browsers": [
+                        "last 5 versions",
+                        "Explorer >= 11"
+                    ]
+                }
             }
-        }]
+        ]
     ]
 }

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 npm-debug.log
-.DS_Store
+coverage/
+.DS_Store

README.md

@@ -1,12 +1,16 @@
 # JavaScript Captcha #
-### Simple captcha component (~2KB) written in pure JavaScript with no dependencies ###
+### Simple captcha component (<2KB) written in pure JavaScript with no dependencies ###
 
-Easy to resolve random math addition rendered within basic canvas element.
+Simple numeric captcha rendered within basic [canvas element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/canvas).
+
+### Demo ###
+
+Demo can be seen [here](https://www.rvdizajn.com/js-captcha/).
 
 ### Install ###
 
 ```
-npm install js-captcha
+npm install js-captcha --save
 ```
 
 ### Usage ###
@@ -19,8 +23,7 @@ or
 ```
 import jCaptcha from 'jCaptcha';
 ```
-
-Set captcha input element:
+Define main captcha input element in HTML:
 ```
 <input class="jCaptcha" type="text" placeholder="Type in result please">
 ```
@@ -29,53 +32,73 @@ Initialize it:
 ```
 <script>
     var myCaptcha = new jCaptcha({
+        el: '.jCaptcha',
+        canvas: {
+            class: 'jCaptchaCanvas',
+            style: {
+                // required properties for captcha stylings:
+                width: 100,
+                height: 15,
+                textBaseline: 'top',
+                font: '15px Arial',
+                textAlign: 'left',
+                fillStyle: '#ddd'
+            }
+        },
         // set callback function for success and error messages:
-        callback: ( response, $captchaInputElement ) => {
+        callback: ( response, $captchaInputElement, numberOfTries ) => {
             if ( response == 'success' ) {
-                // success
+                // success handle, e.g. continue with form submit
             }
             if ( response == 'error' ) {
-                // error
+                // error handle, e.g. add error class to captcha input
+
+                if (numberOfTries === 3) {
+                    // maximum attempts handle, e.g. disable form
+                }
             }
         }
     });
 </script>
 ```
 
-Call `validate()` method when required (e.g. on submit event):
+And then call `validate()` method when required (e.g. on form submit event):
 ```
 <script>
     myCaptcha.validate();
 </script>
 ```
 
-No extra styling included, just style it as you wish, see options below.
+No stylings included, just style it as you wish, see options below.
 
 ### Options ###
 
-jCaptcha can take an optional parameters - an object of key/value settings:
+jCaptcha can take an optional parameter - an [Object] of key/value settings:
+
+ Name                | Required | Type          | Default     | Description |
+| ---                | ---      | ---           | ---         | ---         |
+| el                 | false     | [String]      | 'jCaptcha'  | CSS class for input element |
+| requiredValue      | false    | [String]      | '*'         | Render new random numbers on error validate |
+| resetOnError      | false    | [Boolean]      | true         | Mandatory field indicator |
+| focusOnError      | false    | [Boolean]      | true         | Focus input field on error validate |
+| clearOnSubmit     | false    | [Boolean]      | true'         | Clear input value on every validate |
+| callback          | false    | [Function]     | null         | As invoked function these useful arguments are returned: response (type: *String*, value: *'success'* or *'error'*), captcha (type: *Element*) and number of tries (type: *Number*) |
+| canvasClass       | false    | [String]      | 'jCaptchaCanvas'         | CSS class of canvas captcha
+| canvasStyle      | true    | [Object]      | {}         | Canvas stylings object, required for canvas appearance |
+| canvasStyle.width      | false    | [Number]      | null         | Width of canvas captcha element (in px) |
+| canvasStyle.height      | false    | [Number]      | null         | Height of canvas captcha element (in px) |
+| canvasStyle.font      | false    | [String]      | ''         | Font size and font family of canvas captcha element |
+| canvasStyle.fillStyle      | false    | [String]      | ''         | Text color of canvas captcha element |
+| canvasStyle.textAlign      | false    | [String]      | ''         | Text align of canvas captcha element |
+| canvasStyle.textBaseline      | false    | [String]      | ''         | Text baseline of canvas captcha element |
 
-- **el** String *(default:jCaptcha)* - css class for input element
-- **requiredValue** String *(default:\*)* - required filed indicator
-- **resetOnError** Boolean *(default:true)* - render new random numbers on error validate
-- **focusOnError** Boolean *(default:true)* - focus input field on error validate
-- **clearOnSubmit** Boolean *(default:true)* - clear input value on every validate
-- **canvasWidth** Number *(default:50)* - width of canvas captcha element (in px)
-- **canvasHeight** Number *(default:15)* - height of canvas captcha element (in px)
-- **canvasFontSize** String *(default:15px)* - font size of canvas captcha element
-- **canvasFontFamily** String *(default:Arial)* - font family of canvas captcha element
-- **canvasFillStyle** String *(default:#ddd)* - text color of canvas captcha element
-- **callback** Object *(default:null)* - as invoked function these useful arguments are returned: *response* and *captcha input node*
 
 ### API ###
 
-`reset()` - generate new random numbers
+`reset()` - generate and render new random numbers
 
 `validate()` - validate entered result in input field
 
-### Demo ###
-
-Demo available [here](https://www.rvdizajn.com/js-captcha/).
 
 ### Browser support ###