I found it when I add the cols and rows property to Textarea, it works fine:
<!DOCTYPE html> <html> <head> <title>Demo</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <style type="text/css"> body { background: none repeat scroll 0 0 #EFEFEF; overflow: hidden; position: relative; margin: 0px; padding: 10px; } div, dl, dt, dd, ul, ol, li, h1, h2, h3, h4, h5, h6, pre, form, fieldset, input, textarea, p, blockquote, th, td { margin: 0; padding: 0; } #content{ height:200px; } fieldset,textarea{ border: 0 none; } #LeftPanel { width: 48%; float: left; height:100%; } .window { border: 1px solid #ADADAD; width: 100%; float: left; } .top { height: 25%; } .bottom { height: 75%; } .code{ width:100%; height: 100%; } </style> </head> <body> <div id="content"> <fieldset id="LeftPanel"> <div id="div_A" class="window top"> <textarea rows="20" cols="40" id="code_A" class="code">A</textarea> </div> <div id="div_B" class="window bottom"> <textarea rows="20" cols="4" id="code_B" class="code">B</textarea> </div> </fieldset> </div> </body> </html>
source share