var horizontalAccordions = $(".accordion.width");
horizontalAccordions.each(function() {
var accordion = $(this);
var collapse = accordion.find(".collapse");
var bodies = collapse.find("> *");
accordion.height(accordion.height());
bodies.width(bodies.eq(0).width());
collapse.not(".show").each(function() {
$(this).parent().find("[data-toggle='collapse']").addClass("collapsed");
});
});
.accordion.width {
border: 1px solid rgba(0, 0, 0, 0.125);
display: flex;
}
.accordion.width .card {
flex-direction: row;
flex-grow: 0;
flex-shrink: 1;
min-width: min-content;
}
.accordion.width .card .card-header {
cursor: pointer;
transform: rotate(180deg);
writing-mode: vertical-rl;
}
.accordion.width .card .card-header:not(.collapsed) {
pointer-events: none;
}
.collapsing.width {
transition: width 0.35s ease;
height: auto;
width: 0;
}
<link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.0/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<div class="accordion width" id="accordionHorizontalExample">
<div class="card">
<div class="card-header" data-toggle="collapse" data-target="#collapseOne">
Collapsible Group Item 1
</div>
<div id="collapseOne" class="collapse show width" data-parent="#accordionHorizontalExample">
<div class="card-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird
on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.
</div>
</div>
</div>
<div class="card">
<div class="card-header" data-toggle="collapse" data-target="#collapseTwo">
Collapsible Group Item 2
</div>
<div id="collapseTwo" class="collapse width" data-parent="#accordionHorizontalExample">
<div class="card-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird
on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.
</div>
</div>
</div>
<div class="card">
<div class="card-header" data-toggle="collapse" data-target="#collapseThree">
Collapsible Group Item 3
</div>
<div id="collapseThree" class="collapse width" data-parent="#accordionHorizontalExample">
<div class="card-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird
on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.
</div>
</div>
</div>
</div>