Allow a div to cover the whole page instead of the area within the container

Question

I\'m trying to make a semi-transparent div cover the whole screen. I tried this:

#dimScreen
{
    width: 100%;
    height: 100%;
    background:rgba(255,255,         


        

Answer 1

Use position:fixed this way your div will remain over the whole viewable area continuously ..

give your div a class overlay and create the following rule in your CSS

.overlay{
    opacity:0.8;
    background-color:#ccc;
    position:fixed;
    width:100%;
    height:100%;
    top:0px;
    left:0px;
    z-index:1000;
}

Demo: http://www.jsfiddle.net/TtL7R/1/

Answer 2

Set the html and body tags height to 100% and remove the margin around the body:

html, body {
    height: 100%;
    margin: 0px; /* Remove the margin around the body */
}

Now set the position of your div to fixed:

#dimScreen
{
    width: 100%;
    height: 100%;
    background:rgba(255,255,255,0.5);

    position: fixed;
    top: 0px;
    left: 0px;

    z-index: 1000; /* Now the div will be on top */
}

Demo: http://jsfiddle.net/F3LHW/

Answer 3

You need to set the parent element to 100% as well

html, body {
    height: 100%;
}

Demo (Changed the background for demo purpose)

---

Also, when you want to cover entire screen, seems like you want to dim, so in this case, you need to use position: fixed;

#dimScreen {
    width: 100%;
    height: 100%;
    background:rgba(255,255,255,0.5); 
    position: fixed;
    top: 0;
    left: 0;
    z-index: 100; /* Just to keep it at the very top */
}

If that's the case, than you don't need html, body {height: 100%;}

Demo 2

Answer 4

This will do the trick!

div {
  height: 100vh;
  width: 100vw;
}

Answer 5

Apply a css-reset to reset all the margins and paddings like this

/* http://meyerweb.com/eric/tools/css/reset/ 

v2.0 | 20110126 License: none (public domain) */

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
font-size: 100%;
font: inherit;
vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section {
display: block;
}
body {
line-height: 1;
}
ol, ul {
list-style: none;
}
blockquote, q {
quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
content: '';
content: none;
}
table {
border-collapse: collapse;
border-spacing: 0;
}

You can use various css-resets as you need, normal and use in css

 html
 {
  margin: 0px;
 padding: 0px;
 }

body
{
margin: 0px;
padding: 0px;
}

Answer 6

Try this

#dimScreen {
    width: 100%;
    height: 100%;
    background:rgba(255,255,255,0.5);
    position: fixed;
    top: 0;
    left: 0;
}