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<div class="row">
<div class="col my-auto"> <!-- my for y-axis -->
</div>
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<div class="container">
<div class="row">
<div class="col-sm-5 mx-auto">
Centered
</div>
</div>
</div>
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container d-flex align-items-center justify-content-center
class="container d-flex align-items-center justify-content-center"