Inline block element, not inline in this case - html

Question

I have set my search bar div element as inline-block, as well as the img.
However, the div element is below the image, instead on the same horizontal line.
Anyone can advise me why this is happening?
body {
margin: 0;
}
#header {
width: 100%;
height: 60px;
background-color: #f1f1f1;
}
#header img {
height: 56px;
display: inline-block;
margin-left: 20px;
}
#search {
display: inline-block;
}
#search input {
display: inline-block;
width: 584px;
height: 38px;
border: 1px solid #d9d9d9;
}
#search input:hover {
border: 1px solid black;
}
<div id="header">
<img src="http://orig04.deviantart.net/1d83/f/2013/087/5/6/google_icon_by_slamiticon-d5z7lrp.png" />
<div id="search">
<form>
<input type="text" name="search" />
</form>
</div>
</div>

Answer 1

Your styles are working as they should; the #search input element's width is just too wide! Try looking at the result on a wider screen, and you will see the elements appear inline as expected.
Anticipating your next question, you can prevent wrapping of inline elements using the rule (on the container, e.g. #header):
white-space: nowrap
Anticipating your next question (if I may be so bold), you will probably want to set CSS rule:
vertical-align: middle
on both #header img and #search to get the look you want.

Answer 2

Here is the code snippet with what you want. The problem here is width of input. Since its more it bring the div to next line.
body {
margin: 0;
}
#header {
width: 100%;
height: 60px;
background-color: #f1f1f1;
}
#header img {
height: 56px;
display: inline-block;
margin-left: 20px;
}
#search {
display: inline-block;
height: 100%;
position: relative;
top: -22px;
}
#search input {
display: inline-block;
width: 480px;
height: 38px;
border: 1px solid #d9d9d9;
}
#search input:hover {
border: 1px solid black;
}
<div id="header">
<img src="http://orig04.deviantart.net/1d83/f/2013/087/5/6/google_icon_by_slamiticon-d5z7lrp.png" />
<div id="search">
<form>
<input type="text" name="search" />
</form>
</div>
</div>

Answer 3

The total width of image and search input is greater than full width of screen. Try with lesser width either of image or search input.
try this one
body {
margin: 0;
}
#header {
width: 100%;
height: 60px;
background-color: #f1f1f1;
}
#header img {
height: 56px;
display: inline-block;
margin-left: 5px;
}
#search {
display: inline-block;
height: 100%;
position: relative;
top: -22px;
}
#search input {
display: inline-block;
width: 450px;
height: 38px;
border: 1px solid #d9d9d9;
}
#search input:hover {
border: 1px solid black;
}
<div id="header">
<img src="http://orig04.deviantart.net/1d83/f/2013/087/5/6/google_icon_by_slamiticon-d5z7lrp.png" />
<div id="search">
<form>
<input type="text" name="search" />
</form>
</div>
</div>