html - background image can't move up with content -
i developing phone application using jquery mobile. set background image following div: (code copy developer tools after page rendered)
<div data-role="page" id="create_member" data-dom-cache="true" tabindex="0" class="ui-page ui-page-theme-a ui-page-active" style="height: 568px;"><div data-role="content" class="ui-content" role="main">
css:
#create_member { background-image: url("../images/common/bg.png"); background-repeat: no-repeat; background-size: contain; background-position: top; }
bg.png 640x1136 background , fit iphone5 size.
there banner beneath it:
<div class="banner"> <div class="bannerbg"><img src="skin/images/red_banner.png" \=""> </div> </div>
css:
#create_member .banner { margin-top: 34%; } .bannerbg { border-radius: 15px; -webkit-border-radius: 15px; -moz-border-radius: 15px; background: #ffe6b8; } .banner img { width: 97%; margin-top: 5px; }
however, when try scroll page down, found background fixed, banner can moved not background.
how make banner sits background , when scroll device, move together?
from understand want use background-image
css attribute pick image , have sort of banner attached it. see fiddle confirm if behaviour looking for. missing having parent element relative
positioning , child element absolute
positioning.
why use absolute positioning banner
in absolute positioning model, box explicitly offset respect containing block - w3
why need relative positioning containing block
a relatively positioned box establishes new containing block absolutely positioned descendants. - w3
if didn't have relative
positioning, banner instead follow body
has containing block. following 2 postioning properties, trick use bottom
, left
, right
@ 0px
have stick banner @ bottom of parent, while still scaling in height it's own content.
.banner { position:relative; } .bannerbg { position:absolute; bottom:0px; left:0px; right:0px; }
not sure if it's looking for. let me know can adjust answer if didn't it! :-)
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