Columns not working without custom CSS

To achieve correct display of columns I had to add custom CSS.

Example:

[su_row ][su_column span="4"]
Content 1
[/su_column]
[su_column span="4"]
Content 2
[/su_column]
[su_column span="4"]
Content 3
[/su_column]
[/su_row]

To see these 3 columns side by side I had to add:

.col-sm-4 {
    float: left;
}

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