After observing for a while, it appears that the "My Works" and "My Profiles" sections are utilizing the class col-xs-3 for each element. To ensure responsiveness, consider using classes like
class="col-lg-3 col-md-3 col-sm-6 col-xs-12"
With this setup, you will have four elements per row on larger screens, two elements per row on smaller screens, and one element per row on very small screens. Using col-xs-3 for all elements forces four elements per row on all screen sizes.
Additionally, the input fields in the last section lack bootstrap classes for centering. One approach is to use
col-md-6 col-md-3-offset
This will center your input (3 grid cells empty + 6 grid cells with input + 3 grid cells empty).
Alternatively, you can refer to resources like Twitter Bootstrap 3: How to center a block.
Bootstrap offers numerous classes for customization, but it may require some exploration.