When coding in HTML5 and CSS3, you will almost always encounter errors with code being read differently in different browsers. This particularly happens with CSS3 coding, which certain browsers interpret differently, which can result in a different looking webpage on certain browsers. To achieve unity, there's a miracle called browser-specific CSS hacks to help you target the errors in certain browsers and correct them. The hacks allow you to apply CSS to a certain browser, without applying it to another. This is great for getting a webpage to look identical in all browsers. Full list of CSS hacks: Spoiler /***** Selector Hacks ******/ /* IE6 and below */ * html #uno { color: red } /* IE7 */ *:first-child+html #dos { color: red } /* IE7, FF, Saf, Opera */ html>body #tres { color: red } /* IE8, FF, Saf, Opera (Everything but IE 6,7) */ html>/**/body #cuatro { color: red } /* Opera 9.27 and below, safari 2 */ html:first-child #cinco { color: red } /* Safari 2-3 */ html[xmlns*=""] body:last-child #seis { color: red } /* safari 3+, chrome 1+, opera9+, ff 3.5+ */ body:nth-of-type(1) #siete { color: red } /* safari 3+, chrome 1+, opera9+, ff 3.5+ */ body:first-of-type #ocho { color: red } /* saf3+, chrome1+ */ @media screen and (-webkit-min-device-pixel-ratio:0) { #diez { color: red } } /* iPhone / mobile webkit */ @media screen and (max-device-width: 480px) { #veintiseis { color: red } } /* Safari 2 - 3.1 */ html[xmlns*=""]:root #trece { color: red } /* Safari 2 - 3.1, Opera 9.25 */ *|html[xmlns*=""] #catorce { color: red } /* Everything but IE6-8 */ :root *> #quince { color: red } /* IE7 */ *+html #dieciocho { color: red } /* Firefox only. 1+ */ #veinticuatro, x:-moz-any-link { color: red } /* Firefox 3.0+ */ #veinticinco, x:-moz-any-link, x:default { color: red } /***** Attribute Hacks ******/ /* IE6 */ #once { _color: blue } /* IE6, IE7 */ #doce { *color: blue; /* or #color: blue */ } /* Everything but IE6 */ #diecisiete { color/**/: blue } /* IE6, IE7, IE8 */ #diecinueve { color: blue\9; } /* IE7, IE8 */ #veinte { color/*\**/: blue\9; } /* IE6, IE7 -- acts as an !important */ #veintesiete { color: blue !ie; } /* string after ! can be anything */ To use them, simply change the class/id tag to whatever HTML element you are manipulating, apply the CSS needed to correct the browser-specific error, and save in your CSS file. Simple as that! Hope you enjoyed my run-down of CSS hacks, and please feel free to leave any questions below!