Tự học HTML và CSS trong 1 giờ - part 44

Tham khảo tài liệu 'tự học html và css trong 1 giờ - part 44', công nghệ thông tin, đồ họa - thiết kế - flash phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 406 LESSON 13 Advanced CSS Page Layout in CSS LISTING Continued nav border-bottom 1px solid lime main margin-left margin-right border 0px solid lime margin-bottom margin-top nav a hover footer a hover color lime sidebar0 position absolute left 2em top 3em width 9em text-align right If that was hard to follow don t feel bad the difficulty was intentional. CSS rules are easily obfuscated if you re not careful. Most style sheets grow organically as piecemeal additions are made discipline is necessary to keep the style sheet readable. The style sheet in Listing is really the same style sheet as in Listing . Both are valid style sheets and both produce the same results when applied to the web page but the second one is easier to understand. Comments make clearer what each section of the style sheet does indentation and whitespace are used effectively and the order is much easier to follow. LISTING A Better-Organized Style Sheet default styles for the page body background-color white color 333333 font-family Verdana sans-serif margin 0 padding 0 a link color DD8800 text-decoration none a visited color CC8866 text-decoration none a hover color lime layout superstructure layout padding 1em top navigation bar nav position fixed top 0px left 0px color white width 100 padding-top 3px padding-bottom 3px background-color 333333 text-align center text-transform lowercase border-bottom 1px solid lime nav .section nav .shead nav .sitem nav h1 display inline nav .section Download from The Role of CSS in Web Design 407 LISTING Continued font-size 90 nav .shead nav .sitem padding-left 1em padding-right 1em nav hl font-size 1em background-color 333333 color white nav a hover footer a hover color lime nav a link nav a visited footer a link footer a visited text-decoration none color CCCCCC main content section main margin-left margin-right margin-bottom margin-top border 0px solid lime two .