Hello ,dear readers, today bootstrap css will be discussed, though many references quoted from this book , examples and demos will be added in later blogs.

1.        Typography

       Starting with typography, Bootstrap uses Helvetica Neue, Helvetica, Arial, and sansserif in its default font stack.here,we can know the types of defalut fonts in Bootstrap.

if these fonts above are not installed in your computer and broswer, and  sansserif  will be used as its default font and showed to you.  All body copy has the font-size set at 14

pixels, with the line-height set at 20 pixels. The <p> tag has a margin-bottom of 10 pixels, or half the line-height(5 pixels).

       1.1     headings

       All six standard heading levels have been styled in Bootstrap range from <H1> to <H6>  with the <h1> at 36 pixels tall, and the <h6> down to 12 pixels (for reference,

default body text is 14 pixels tall). in order  to add an inline subheading to any of the headings ,you can add a <small> tag  around to create a subheading and make its color

lighter than the  parent heading.

      1.2    lead body copy

       To add some emphasis to a paragraph, add class="lead" 。This will give you larger font size, lighter weight, and a taller line height. This is generally used for

the first few paragraphs in a section, but it can really be used anywhere.

     1.3    Emphasis

     In addition to using the <small> tag within headings, as discussed above, you can also use it with body copy. When <small> is applied to body text, the font shrinks to

85% of  its original size.

      1.4    Bold

    To add emphasis to text, simply wrap it in a <strong> tag. This will add fontweight:bold; to the selected text.

      1.5   Italics

      For italics, wrap your content in the <em> tag. The term “em” derives from the w