How to manipulate an input field if a check box is checked - css

Question

I m having problem with css of a tooltip. Tooltip belongs to an input field and if an other checkbox is checked, this tooltip needs to be placed correctly on the input field. so the check box is :
<input type="checkbox" id="telefonBox" />
and the input field which tooltip needs to be placed :
<input type="text" class="form-control tooltip-berater" id="agentName"/>
What i tried is
input[id=telefonBox]:checked + .tooltip-berater + .tooltip > .tooltip-inner {top: 875px !important; left: 30px; max-width:300px;}
(Basically i m trying to write: if a checkbox with this id checked, then do some stuff in this css classes)
But doesnt function at all. What am i missing?

Answer 1

If both inputs are children of the same div, but not directly next to each other (in the HTML markup) then you need to use ~ operator instead of +.
+ works like:
<div class="parent">
<div class="first"></div>
<div class="second></div>
</div
.first + .second {
// do stuff with second
}
~ works like:
<div class="parent">
<div class="first"></div>
<div class="inbetween"></div>
<div class="second"></div>
</div
.first ~ .second {
// you can still do stuff with second
}
There is no selector which would help you in other cases possible in your HTML markup, especially:
When .second div is placed earlier than .first
When .second div has different parent from .first
In those cases you will need to use JavaScript to select and change your element's CSS.

Answer 2

Heres a fiddle i made that changes colour of input box: https://jsfiddle.net/8we5u1vs/
Is that the kind of thing you want? Obviously its much simpler than what you're talking about. You havnt added much code so hard to tell, could you show code or fiddle for an example of the tooltip?
input[id=telefonBox]:checked + .tooltip-berater {
background-color:red;
}

Answer 3

You can try this way, but text input is still available via tab key.
div {
display: inline-block;
position: relative;
line-height: 1.25em;
border: 1px solid;
background: white;
}
input[type=text] {
border: 1px solid white;
line-height: inherit;
}
span {
position: absolute;
left: 0;
top: 0;
right: 0;
bottom: 0;
text-align: center;
display: none;
border: 1px solid white;
background: white;
}
input[type=checkbox]:checked + div span {
display: block;
}
<input type=checkbox>
<div>
<input type=text>
<span>N/A</span>
</div>