Немного красивее для mongodb.version () 3.0
db.collection.aggregate([
{$match: {created_at:{$exists:1}}},
{$group: {
_id: {$add:[
{$dayOfYear: "$created_at" },
{$multiply: [{$year: "$created_at"}, 1000]}
]},
count: {$sum: 1 }
}},
{$sort:{_id:-1}}
])
<div class="card container">
<div class="container">
<div class="search-box d-md-inline-flex">
<!-- col1 -->
<div class="card border-0 p-3">
<input class="btn btn-primary" type="text" name="" value="All categories">
</div>
<!-- col2 -->
<div class="card border-0 p-3">
<input class="form-control mr-2" type="text" name="departure" placeholder="Departure">
</div>
<!-- col3 -->
<div class="card border-0 p-3">
<input class="form-control mr-2" type="text" name="destination" placeholder="Destination">
</div>
<!-- col4 -->
<div class="card border-0 p-3">
<input class="form-control mr-2" type="text" name="type" placeholder="Travel Period">
</div>
<!-- Submit -->
<div class="card border-0 p-3">
<input class="btn btn-primary" type="submit" name="" value="go">
</div>
</div><!--/search-box -->
</div>
</div>
Используйте класс контейнера для переноса содержимого. Для отзывчивости используйте lg, md, sm для классов.
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