Semi transparent image hanging out of a semi transparent div - html

Question

I'm trying to build a website header that is semi transparent, and contains a semi transparent image that hangs outside the of the header div, like in the image linked below.
Because of overlapping opacities, I can't simply put a semi transparent image in to a semi transparent div and add a negative margin to the image. The best I could come up with was taking the height of the header image, and cutting that bit of the logo image, like in image attached. However that's not ideal, as doesn't play nice responsively etc etc.
Any ideas of how I might achieve this look?
Thanks in advance.

Answer 1

If you know the height of your menu then you can place both the logo and the menu inside of a container. Then position the logo with the top value equalling the height of the menu.
.header-bg {
background: rgba(225, 225, 225, 0.5);
position: relative;
height: 60px;
}
.header-bg .logo {
width: 90px;
height: 90px;
background: rgba(225, 225, 225, 0.5);
position: absolute;
top: 60px;
left: 10%;
}
See this fiddle: http://jsfiddle.net/3kxBt/1/
Hope that helps in some way.

Answer 2

This is an interesting problem and there are a couple ways to solve it; two come immediately to my mind.
The first is your method; carefully position things so that you don't have multiple translucent sections overlapping. This wouldn't be too difficult; if you go with this method I would recommend breaking the header into sections left and right of the image and using absolute positioning.
The second and easier way is to create a version of the picture with the semi-transparent white overlay you desire already applied. Then you can use that as the background for the menu and image. The only tricky thing here is you have to make sure the images line up by either using fixed positioning or calculated pixel offsets. This approach has been around for a long time and you can see any early example (2001-ish) of it here.

Answer 3

My take on it is to create a :before pseudo-element. It has its problems, including what if the logo changes in size at some point, but overall it works.
HTML
<a class="logo" href="#">
<img src="https://example.com/logo.png" />
</a>
CSS
nav a.logo {
position: relative;
...
display: inline-block;
line-height: 0.0001em;
font-size: 0.0001em;
}
nav a.logo img {
position: relative; /* for z-index issues. giving the image a relative
position automatically will place it above the
absolutely positioned :before element. This is
because the before element is rendered before the
image */
}
nav a.logo:before {
content: '';
position: absolute;
display: block;
width: 100%;
height: 71px;
bottom: 0;
left: 0;
background: rgba(0,0,0,0.4);
...
}
Demo: http://jsfiddle.net/ZP6LQ/1/show
Source: http://jsfiddle.net/ZP6LQ/1/

Answer 4

You can use rgba color format for background of both the .logo and the header to achieve your desired effect. However, you have to give position: absolute; to your .logo class because it needs to come right below the header. If you put your .logo on top of your header, then colors will overlap and won't look right. So, it needs to starts at the bottom of the header.
The header should have position: relative; so that your .logo is positioned relatively to the header. This way, you don't even need to know the height of your header because when you define top position of your .logo, you can simply use top: 100% so that it always starts right below your header. You don't have to hardcode that top value.
Now, you need to shift your actual logo (image) inside your .logo on top because its appearing below the header right now. For that you can simply push the image by giving it negative margin-top value.
SEE THE DEMO
The code would look like this:
HTML
<header>
<h1 class="logo">
<img src="/image/path" alt="logo">
</h1>
</header>
CSS
header {
background: rgba(255,255,255, 0.7);
position: relative;
}
.logo {
position: absolute;
top: 100%;
background: rgba(255,255,255, 0.7);
}
.logo img {
margin-top: -50px;
}