mod_rewrite module allows to manipulate url using unlimited number of rules . Each rule consist of unlimited number of condition

• Problems

  This line enable URL Rewriting . It must be enabled via the RewriteEngine directive! and if your .htaccess file is going to use rewrite rules, you should always include this line. Otherwise, you can’t be sure if its enabled or not. The string “on” is case insensitive.

Syntax

The CSS3 box-sizing property allows us to include the padding and border in an element's total width and height.

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CSS3 box-sizing Property

Those wishes were granted when the box-sizing property was introduced in CSS3. Though box-sizing has three possible values (content-box, padding-box, and border-box), the most popular value is border-box.

Today, the current versions of all browsers use the original "width or height + padding + border = actual width or height" box model. With box-sizing: border-box;, we can change the box model to what was once the "quirky" way, where an element's specified width and height aren't affected by padding or borders. This has proven so useful in responsive design that it's found its way into reset styles.

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Vendor Prefixes

Every current browser supports box-sizing: border-box; unprefixed, so the need for vendor prefixes is fading. But, if you need to support older versions of Safari (< 5.1), Chrome (< 10), and Firefox (< 29), you should include the prefixes -webkit and -moz, like this:

html {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
*, *:before, *:after {
  -webkit-box-sizing: inherit;
  -moz-box-sizing: inherit;
  box-sizing: inherit;
  }

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Example
div1 {
      width: 300px;
    height: 100px;
    border: 1px solid blue;
    box-sizing: border-box;
}

div2 {
      width: 300px;
    height: 100px;
    padding: 50px;
    border: 1px solid red;
    box-sizing: border-box;
}

Try above example