In your HTML file, please do the following:  Add an h1 tag with a class of text-center and add the text of "Lesson 13 Project".

In your HTML file, please do the following: 

• Add an h1 tag with a class of text-center and add the text of "Lesson 13 Project".
• Create a div class of container
  • Inside the container, create a div id of test-input
    • Inside the test-input, add the following:
      • input box with an id of isValidInput
      • button with an id of isValidBtn
    • Outside of the test-input, but inside the container, create a paragraph tag with an id of isValidMsg

CSS 
In your stylesheet, please add the following:

Set an asterisk with a property of box sizing equal to border box.
Set the body with the following properties:
set a property of font-family and set it equal to sans-serif.
set a minimum height of 100%.
set a vertical overflow of hidden.
Set a class called text-center and set it to align the text to the center.
Create a container class, and add the following properties:
set the display property to flex
justify the content to center
align the items to center
set the height to 100 viewport height
set the flex direction to column
Create an id of test-input
add a property of flex direction, and set it to row
Create an input selector (type of text) and combine it with a button selector. Then add the following:
set the padding to 10 pixels
set the font size to 18 pixels
Create an id of isValidMsg and add the following properties:
set the color to red
set the margin to 1 em
set the font style to italic
set the font weight to bold