Block elements inside button element acts unexpected - css

Question

I am trying to create a button that shows a loading spinner when waiting for a response. But there is some weird things going on which I do not understand at all.
I have the following HTML with a bunch of CSS:
<button type="submit" disabled="true" class="btn btn-blue btn-loading">
<div class="btn-loading-text">Update profile</div>
<div class="btn-loading-spinner"></div>
</button>
If you comment out the spinner element, then the "Update profile" aligns itself in the center even tho I did not ask it to.
* {
box-sizing: border-box;
}
.btn-loading {
border-radius: 2px;
font-size: 13px;
font-family: arial, helvetica, sans-serif;
text-decoration: none;
display: inline-block;
font-weight: bold;
outline: 0;
background: #f5f5f5 !important;
border: 1px solid #ddd !important;
color: #aaa !important;
cursor: default !important;
overflow: hidden;
height: 40px;
}
.btn-loading-text {
float: left;
margin: 0px 15px 0px 15px;
}
.btn-loading-spinner {
float: left;
height: 25px;
width: 25px;
margin: 7px 15px 6px -5px;
position: relative;
animation: rotation .9s infinite linear;
border-left: 3px solid #ddd;
border-right: 3px solid #ddd;
border-bottom: 3px solid #ddd;
border-top: 3px solid #aaa;
border-radius: 100%;
}
#keyframes rotation {
from {
transform: rotate(0deg);
}
to {
transform: rotate(359deg);
}
}
<button type="submit" disabled="true" class="btn-loading">
<div class="btn-loading-text">Update profile</div>
<!--<div class="btn-loading-spinner"></div>-->
</button>
But when the spinner element is there it suddently goes to the top. I have no idea what's going on.
* {
box-sizing: border-box;
}
.btn-loading {
border-radius: 2px;
font-size: 13px;
font-family: arial, helvetica, sans-serif;
text-decoration: none;
display: inline-block;
font-weight: bold;
outline: 0;
background: #f5f5f5 !important;
border: 1px solid #ddd !important;
color: #aaa !important;
cursor: default !important;
overflow: hidden;
height: 40px;
}
.btn-loading-text {
float: left;
margin: 0px 15px 0px 15px;
}
.btn-loading-spinner {
float: left;
height: 25px;
width: 25px;
margin: 7px 15px 6px -5px;
position: relative;
animation: rotation .9s infinite linear;
border-left: 3px solid #ddd;
border-right: 3px solid #ddd;
border-bottom: 3px solid #ddd;
border-top: 3px solid #aaa;
border-radius: 100%;
}
#keyframes rotation {
from {
transform: rotate(0deg);
}
to {
transform: rotate(359deg);
}
}
<button type="submit" disabled="true" class="btn-loading">
<div class="btn-loading-text">Update profile</div>
<div class="btn-loading-spinner"></div>
</button>

Answer 1

The content of a button element are vertically aligned to the middle.
When you only have .btn-loading-text, that element is 16px tall, and the button is 38px tall, so .btn-loading-text is aligned to the middle.
However, when you also include .btn-loading-spinner, which is 38px tall (including borders and margins), the content of the button is as tall as the tallest of the elements, so 38px. So the alignment to the middle is not noticeable.
If you want to align each element to the middle, instead of aligning the content as a whole, you can use display: inline-block instead of float: left, and vertical-align: middle.
.btn-loading-text, .btn-loading-spinner {
float: none; /* Initial value */
display: inline-block;
vertical-align: middle;
}
* {
box-sizing: border-box;
}
.btn-loading {
border-radius: 2px;
font-size: 13px;
font-family: arial, helvetica, sans-serif;
text-decoration: none;
display: inline-block;
font-weight: bold;
outline: 0;
background: #f5f5f5 !important;
border: 1px solid #ddd !important;
color: #aaa !important;
cursor: default !important;
overflow: hidden;
height: 40px;
}
.btn-loading-text, .btn-loading-spinner {
display: inline-block;
vertical-align: middle;
}
.btn-loading-text {
margin: 0px 15px 0px 15px;
}
.btn-loading-spinner {
height: 25px;
width: 25px;
margin: 7px 15px 6px -5px;
position: relative;
animation: rotation .9s infinite linear;
border-left: 3px solid #ddd;
border-right: 3px solid #ddd;
border-bottom: 3px solid #ddd;
border-top: 3px solid #aaa;
border-radius: 100%;
}
#keyframes rotation {
from {
transform: rotate(0deg);
}
to {
transform: rotate(359deg);
}
}
<button type="submit" disabled="true" class="btn-loading">
<div class="btn-loading-text">Update profile</div>
<div class="btn-loading-spinner"></div>
</button>