How do I center a button within it's div class - html

Question

I have a button that needs to be centered in it's div class ex. div="sanfrancisco-image". It's placed 17px from the bottom of the box, however it will appear center, even though I've placed justify-self:center; and align-items: center; tabs.
Here's the codepen link: https://codepen.io/holmedw/pen/KrvJEb
.btn {
align-items: center;
position: absolute;
padding: 0 20px;
height: 40px;
font-size: 1em;
font-weight: 700;
text-transform: uppercase;
border: 2px black solid;
border-radius: 1px;
background: transparent;
cursor: pointer;
bottom: 17px;
justify-self: center;
}

Answer 1

No need for the align-items and justify-self. not sure they do any good, so try to remove them. on the css of the button? => set the following:
margin: 0px auto 0px auto;
try that and let me know if it works.

Answer 2

The quickest way to get what you want is to add position: relative to the .our-story-block, .our-dna-block, .sanfrancisco-block then you add a new div to include your button, like <div class="btn"><button>See More</button></div>. Set that div to position: absolute; bottom: 17px; width: 100%; left: 0; so it would center the absolute div inside a relative element. You won't need to include those values in your .btn css class anymore so just remove them.
.btn {
position: absolute;
width: 100%;
left: 0;
bottom: 17px;
}
.btn > button{
padding: 0 20px;
height: 40px;
font-size: 1em;
font-weight: 700;
text-transform: uppercase;
border: 2px black solid;
border-radius: 1px;
background: transparent;
cursor: pointer;
}