Issue with Horizontal Alignment for Widgets

Hi,

I am building a site called http://www.heiu.sg/. If you open up the link, you would see that I have Smart Slider on top and another row of 3 widgets. The slider was forced stretched via Appearance -> Custom CSS:

.siteorigin-panels-stretch {
padding-right: 0 !important;
padding-left: 0 !important;
}

My questions are:
1. The 3 widgets alignment are off and I am trying to get all three to be aligned in the centre (horizontally). I tried to look up for the previous posts and tried to add the following but does not give what I need:

.sow-features-list .sow-features-feature {
text-align: center !important;
}

””and””

.widget-title {
text-align: center;
}

2. Earlier, I would like to keep my Slider to be centrally aligned and not full width so that its sides are aligned with the header and footer. But when I do that, the widgets are not aligned to the left side – tried to use Heading 1, Heading 2 or Paragraph to align the widgets but do not work either. Is there any solution for this?

Sorry for the long thread. Let me know if there is further clarifications needed. Thank you.