Website rendering differently from the local version

I'm having a strange problem where the local index.html that I open isn't being presented the same way as the index.html being hosted on my domain. Here is the CSS:

/*
==========================
Universal
==========================
*/

* {
  font-family: "Heebo";
}

h1 {
  font-size: 4rem;
  color: #4d4d4d;
}

h4 {
  font-size: 2rem;
  color: #0072ff;
}

h2 {
  font-size: 3rem;
  color: #0072ff;
  padding: 2rem 2rem;
}

p {
  line-height: 2rem;
  padding: 0 2rem;
  font-size: 1.5rem;
  color: #4d4d4d;
}

a {
  outline: none;
}

.center {
  margin-left: auto;
  margin-right: auto;
}

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

.center-v {
  display: flex;
  align-items: center;
}

/*
==========================
Home
==========================
*/

.hero {
  background-color: #ffffff;
}

.intro {
  padding-top: 5rem;
}

.img-circle {
  border-radius: 50%;
}

.hero-link {
  color: #000000;
  font-size: 3rem;
}

.fa {
  font-size: 5.5rem;
  padding: 0.5rem 2rem;
  color: #4d4d4d;
}

.fa:focus {
  color: #4d4d4d;
}

.fa:hover {
  color: #0072ff;
}

.fa-home {
    font-size: 3rem;
    position: fixed;
}

.fa-project {
    color: #ffffff;
    z-index: 11;
  font-size: 4rem;
  position: absolute;
  bottom: 0;
  right: 0;
}

/*
==========================
Project tiles
==========================
*/

@media (max-width: 1000px) {
  #project-break {
    width: 100%;
    margin-left: 0;
  }
}

.tile {
  height: 27rem;
  width: 100%;
  margin:10px;
  display:inline-block;
  background-size:cover;
  position:relative;
  cursor:pointer;
  -webkit-transition: all 0.4s ease-out;
  -o-transition: all 0.4s ease-out;
  -moz-transition: all 0.4s ease-out;
  -ms-transition: all 0.4s ease-out;
  transition: all 0.4s ease-out;
  box-shadow: 0px 35px 77px -17px rgba(0,0,0,0.44);
  overflow:hidden;
  color:white;
}

.tile img {
  height:100%;
  width:100%;
  position:absolute;
  top:0;
  left:0;
  z-index:0;
    -webkit-transition: all 0.4s ease-out;
  -o-transition: all 0.4s ease-out;
  -moz-transition: all 0.4s ease-out;
  -ms-transition: all 0.4s ease-out;
  transition: all 0.4s ease-out;
}

.tile .text {
    z-index: 11;
  position:absolute;
  padding:30px;
  height:calc(100% - 60px);
}

.tile h1 {
    color: #ffffff;
  font-size: 2rem;
  font-weight:300;
  text-shadow: 2px 2px 10px rgba(0,0,0,0.3);
}

.tile p {
    color: #ffffff;
  font-weight: 300;
  margin: 20px 0 0 0;
    -webkit-transform: translateX(-200px);
    -o-transform: translateX(-200px);
    -moz-transform: translateX(-200px);
    -ms-transform: translateX(-200px);
  transform: translateX(-200px);
  transition-delay: 0.2s;
}

.animate-text {
  opacity:0;
  -webkit-transition: all 0.6s ease-in-out;
  -o-transition: all 0.6s ease-in-out;
  -moz-transition: all 0.6s ease-in-out;
  -ms-transition: all 0.6s ease-in-out;
  transition: all 0.6s ease-in-out;
}

.tile:hover {
  box-shadow: 0px 35px 77px -17px rgba(0,0,0,0.64);
  -webkit-transform: scale(1.05);
  -o-transform: scale(1.05);
  -moz-transform: scale(1.05);
  -ms-transform: scale(1.05);
  transform: scale(1.05);
}

.tile:hover img {
  opacity: 0.2;
}

.tile:hover .animate-text {
  -webkit-transform: translateX(0);
  -o-transform: translateX(0);
  -moz-transform: translateX(0);
  -ms-transform: translateX(0);
  transform: translateX(0);
  opacity:1;
}

/*
.tile:hover span {
  opacity:1;
  transform:translateY(0px);
    -webkit-transform:translateY(0px);
    -o-transform:translateY(0px);
    -moz-transform:translateY(0px);
    -ms-transform:translateY(0px);
}
*/

@media (max-width: 550px) {
    .tile h1 {
        font-size: 2rem;
    }

    .tile p {
        font-size: 1.3rem;
        line-height: 1.5rem;
    }
}

.fa-fade {
    -webkit-transition: all 0.2s ease-in-out;
    -o-transition: all 0.2s ease-in-out;
    -moz-transition: all 0.2s ease-in-out;
    -ms-transition: all 0.2s ease-in-out;
    transition: all 0.2s ease-in-out;
}

.pomodoro {
  background-image: url("assets/pomodoro-site.png");
    background-position: center;
}

.duelr {
  background-image: url("assets/duelr-site.png");
    background-position: center;
}

.grt-bot {
  background-image: url("assets/grt-site.png");
    background-position: center;
}

.pomodoro:after,
.duelr:after,
.grt-bot:after {
  content: " ";
  z-index: 10;
  position: absolute;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
}

p > a {
    color: #ffffff;
}

p > a:hover {
    color: #0072ff;
}

As a visual example, here is my font-size which is set to 1.5rem in the CSS. I know rem units scale with the window size, but both are being opened on the same device: