bootstrap4中自定义表单

<form class="form-inline justify-content-center" method="post" action="/?">
<input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
<input type="text" class="col-sm-7 form-control btn-lg" id="key" name="key" placeholder="key">
<button type="submit" id="submit" name="submit" class="btn btn-primary btn-lg">Search</button>
</form>

#######################################
{% extends 'base.html' %}

{% block title %}Home{% endblock %}

{% block content %}
<div class="container h-100">
<div class="container h-100">
<div class="row h-100 page-header justify-content-center align-items-center">
<h1>Si Helper</h1>
</div>
</div>
<form class="form-inline justify-content-center" method="post" action="/?">
<input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
<input type="text" class="col-sm-7 form-control btn-lg" id="key" name="key" placeholder="key">
<button type="submit" id="submit" name="submit" class="btn btn-primary btn-lg">Search</button>
</form>
</div>
{% endblock %}

{% block footer %}{% endblock %}