how to make cornered button with css? - css

Question

How do I make a button like this with pure CSS?
That's all that I've been capable of:
.sideMenuButton {
width: 100px;
height: 100px;
background: #6d1a3e;
position: relative;
transform: rotate(-90deg);
border: none;
}
.sideMenuButton:after {
content: '';
position: absolute;
bottom: 0;
left: 0;
border-top: 29px solid #6d1a3e;
border-left: 29px solid #fff;
width: 42px;
height: 0;
}
<button type="button" class="sideMenuButton">X</button>
but it's not working right way

Answer 1

Just a quick try. I hope this could help you.
You can add text by the text attribute of the button.
.button-container{
width: 100px;
height: 100px;
overflow: hidden;
position:relative;
margin: 5px;
}
.button {
width: 148px;
height: 200px;
transform: rotateZ(45deg);
overflow: hidden;
position: absolute;
top: -68px;
left: -43px;
}
.button::before{
content: attr(text);
background: #6d1a3e;
display: block;
width: 100px;
height: 100px;
transform: rotateZ(-45deg);
position: absolute;
top: 50px;
left: 50px;
border: 5px solid #a5285e;
cursor: pointer;
box-sizing: border-box;
text-align: center;
vertical-align: middle;
line-height: 69px;
font-size: 2.5em;
color: white;
}
.button::after{
content: '';
display: block;
position: absolute;
border-bottom: 7px solid #a5285e;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
height: 0;
width: 41px;
transform: rotateZ(90deg);
top: 99px;
left: 120px;
cursor: pointer;
}
.other.button::before{
border-left: none;
border-top: none;
line-height: 80px;
font-size: 3em;
}
<div class="button-container">
<div class="button" text="PDF"></div>
</div>
<div class="button-container">
<div class="button other" text="☰"></div>
</div>