Problem with images, section and scrollbar - html

Question

First problem is the "about myself" (home_about_box), doing something that will not allow me to put it on top of an image. I think it has something to do with the margin, but I have not found a solution.
Second problem is that the images in the Portfolio section (portfolio_home), will not touch each other, it leaves a blank space between the pictures.
Last problem is with having a horizontal scrollbar on the bottom of my page. I have searched for a solution, but not found any.
If you have any solution, I would appreciate you posting the code and an explanation, as I am quite new to this!
Cheers! Any constructive feedback is well appreciated!
HTML
<section class="home.about">
<div class="about.bg">
<div class="home_about_box">
<h1>About Myself</h1>
<p>Lorem ipsum...</p>
<p>Lorem ipsum...</p>
</div>
</div>
</section>
<section class="portfolio_home" id="portfolio">
<h1>Some of my work</h1>
<figure class="port-item">
<!-- Portfolio 1 -->
<img src="https://i.imgur.com/eBRYWII.png" alt="portfolio item"/>
<figcaption class="port-desc">
<p>Geofilters</p>
</figcaption>
</figure>
<!-- Portfolio 2 -->
<figure class="port-item">
<img src="https://i.imgur.com/gAfgliA.png" alt="portfolio item"/>
<figcaption class="port-desc">
<p>Quixz eSports</p>
</figcaption>
</figure>
<!-- Portfolio 3 -->
<figure class="port-item">
<img src="https://i.imgur.com/IjoGmUT.png" alt="portfolio item"/>
<figcaption class="port-desc">
<p>3D Renders</p>
</figcaption>
</figure>
<!-- Portfolio 4 -->
<figure class="port-item">
<img src="https://i.imgur.com/4zymXa8.png" alt="portfolio item"/>
<figcaption class="port-desc">
<p>Backgrounds</p>
</figcaption>
</figure>
</section>
<section class="cta">
<div class="container">
<h1 class="title title-cta">Want to see more?
<span>Then what are you waiting for?</span>
</h1>
See More
</div>
</section>
CSS
* {
box-sizing: border-box;
transition: all ease-in-out 250ms;
}
body {
margin: 0;
font-family: "Lato", sans-serif;
text-align: center;
}
img {
max-width: 100%;
height: auto;
padding: 1em .5em 0;
background-size: cover;
}
.container {
width: calc(100%-4px);
margin: 0 auto;
}
/* Header
========= */
header {
position: absolute;
width: 100%;
}
nav ul {
margin: 0;
padding: 1em 0;
list-style: none;
}
nav li {
display: inline-block;
margin: .5em
}
nav a {
font-weight: 900;
text-decoration: none;
text-transform: uppercase;
font-size: .9rem;
padding: .5em;
color: #FFF;
}
nav a:hover,
nav a:focus{
color: #DDD;
}
#media (min-width: 60rem) {
.logo{
float: left;
text-align: center;
align-content: center;
}
nav{
float: right;
text-align: center;
margin-right: 1em;
}
}
/* Buttons
========== */
.button_top {
display: inline-block;
font-size: 1.3rem;
text-decoration: none;
text-transform: uppercase;
border-width: 2px;
border-style: solid;
border-color: #174FC1;
padding: .5em 1em;
color: #FFF;
}
.button_top:hover,
.button_top:focus {
background: #174FC1;
color: #FFF;
}
.button_dark {
display: inline-block;
font-size: 1.3rem;
text-decoration: none;
text-transform: uppercase;
border-width: 2px;
border-style: solid;
border-color: #FFF;
padding: .5em 1em;
color: #FFF;
margin-bottom: 1em;
}
.button_dark:hover,
.button_dark:focus {
background: #FFF;
color: #000;
}
#media (min-width: 25rem) {
.button_top {
font-size: 1.7rem;
padding: .3em 1em
}
}
#media (min-width: 60rem) {
.button_top {
font-size: 2.4rem;
padding: .3em 1em;
margin-top: -1em;
}
}
#media (min-width: 25rem) {
.button_dark {
font-size: 1.7rem;
padding: .3em 1em
}
}
#media (min-width: 60rem) {
.button_dark {
font-size: 2rem;
padding: .3em 1em;
}
}
.clearfix::after,
section::after,
footer::after{
content: "";
display: block;
clear: both;
}
/* Typography
========= */
.title {
font-size: 2rem;
margin-bottom: 1.6em;
margin-top: 5em;
}
.title span {
font-weight: 300;
display: block;
font-size: 1.3rem;
}
.title-cta {
margin: 0 0 1em;
}
#media (min-width: 60rem) {
.title{
font-size: 4rem;
margin-top: 1.5em;
}
}
h1 {
font-weight: 800;
margin-top: 0;
}
.unstyled-list {
margin: 0;
padding: 1.3em;
list-style-type: none;
text-align: left;
}
/* Home.hero
========= */
.home-hero {
background-image: url(https://i.imgur.com/yUFKqAe.jpg);
background-size: cover;
background-position: center;
padding: 1em;
color: #FFF;
width: 100vw;
height: 100vh;
}
#media (min-width: 25rem) {
.home-hero{
width: 100vw;
height: 100vh;
}
}
#media (min-width: 60rem) {
.home-hero{
width: 100vw;
height: auto;
}
}
#media (min-height: 30rem) {
.home-hero{
width: 100vw;
height: 100vh;
}
}
/*Home About */
.home_about_box {
background-color: #232323;
font-size: .8em;
padding: 4em;
outline: 2px solid #174fc1;
outline-offset: -3em;
color: #FFF;
position: relative
}
.home_about_box h1 {
color: #174fc1;
position: absolute;
left: 50%;
transform: translateX(-50%);
top: 1.3em;
background: #232323;
padding: 0 0.5em
}
#media (min-width: 25rem) {
h1 {
font-size: 1.6rem;
}
.home_about_box h1 {
top: 1.3rem;
}
}
#media (min-width: 60rem) {
h1 {
font-size: 1.2rem;
}
.about.bg {
background-image: url(https://i.imgur.com/aTF2hwR.jpg);
padding: 5em;
}
.home_about_box {
font-size: .8em;
width: 25em;
margin: 0;
}
.home_about_box h1 {
top: 1.5rem;
}
}
/* portfolio
*/
.portfolio_home {
margin: 1.8em 0 0;
background-size: cover;
}
.portfolio_home h1 {
color: #174FC1;
font-size: 3em;
margin: auto;
padding: 0 0 .3em 0;
}
.port-item {
margin: 0;
position: relative;
}
.port-item img {
display: block;
}
.port-desc {
position: absolute;
z-index: 100;
bottom: 0em;
left: 0em;
right: 0em;
color: #FFF;
background: rgba(0,0,0,.75);
padding-bottom: 1em;
padding-top: 1em;
}
.port-desc p {
margin: .5em;
background-size: 100% 100%;
}
#media (min-width: 40rem) {
.port-item {
width: 50%;
float: left;
}
}
#media (min-width: 60rem) {
.port-item {
width: 33.3333334%;
float: left;
overflow: hidden
}
.port-desc {
transform: translateY(150%);
}
.port-item:hover .port-desc {
transform: translateY(0%)
}
}
/* CTA
*/
.cta{
background-color: #174fc1;
padding: 0.1em;
}
.cta h1 {
margin-top: 1em;
color: #FFF
}
/* Footer */
footer {
background: #232323;
color: #FFF;
}

Answer 1

Firstly you need to minimize the codepen like the this you don't need everything in it.
First Problem:-
For the first issue make sure your z-index is greater than the element overlapping it in your case it's .port-desc giving a z-index of 100 so you need something more than 100.
.home_about_box {
background-color: #232323;
font-size: 0.8em;
padding: 4em;
outline: 2px solid #174fc1;
outline-offset: -3em;
color: #fff;
z-index: 101;
}
Second Problem:-
You need to remove the padding on left and right I assume that's what you meant when you say they are not touching.
img {
max-width: 100%;
height: auto;
padding: 1em 0.5em 0;
background-size: cover;
}
Third Problem:-
The scrollbar is due to width being 100wh, you can update the width to be 100%.
#media (min-height: 30rem) {
.home-hero {
width: 100%;
height: 100vh;
}
}