having trouble with autolayout -- simple calculator app
<p>I'm new to autolayout and is having trouble arranging UIButtons and UILabels in a simple calculator app. </p>

<p>Here is <a href="https://github.com/dzjustinli2/CalculatorSelf" rel="nofollow noreferrer">Github page</a> that contain my current calculator app. </p>

<p>1) I cant make the "0" so that it is vertically aligned with "1", "4", "7"</p>

<p>2) I want to make the border of UIButton and UILabel 1px black. I can't find settings that can change border color and border width of UIButton in Storyboard inspectors.</p>

<p>3) How do I make "calculateStepsLabel" and "resultLabel" transparent so that whatever is in the background can be partially seen. </p>

<p><a href="https://i.stack.imgur.com/kA2lh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kA2lh.png" alt="My Calculator"></a><a href="https://i.stack.imgur.com/vnnRs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vnnRs.png" alt="Calculator app"></a></p>