.container {
width: 100px;
height: 100px;
position: relative;
}
.first,
.second,
.third,
.fourth {
width: 100%;
height: 100%;
position: absolute;
top: 0;
left: 0;
}
.second {
z-index: 10;
}
.third {
z-index: 20;
}
.fourth {
z-index: 30;
}
body {
font-family: Monospace; font-size: 50px;
}
<div class="container">
<div class="first">↔</div>
<div class="second">↕</div>
</div>
<div class="container">
<div class="first">⤨</div>
<div class="second">⤪</div>
</div>
<div class="container">
<div class="first">⭦</div>
<div class="second">⭧</div>
<div class="third">⭨</div>
<div class="fourth">⭩</div>
</div>
transform: rotate(45deg)
。 - undefinedTo get <span style="position:relative; font-size:2rem">↕<span style="position:absolute; left:-.25em; top:-.025em;">↔</span></span> <code><a href="https://www.compart.com/en/unicode/U+2195">use ↕</a> <a href="https://www.compart.com/en/unicode/U+2194">and ↔</a></code>