styles.css

:root {
    --bronze: #cd7f32;
    --side-nav-width: 20%;
    --mainBG: #111111
}

body {
    overflow: hidden;
    height: 100vh;
    background-color: var(--mainBG);
    color: #fff;
    margin: 0;
    padding: 0;
    font-family: Manrope, sans-serif;
}

main {
    overflow-y: auto;
}

ul {
    list-style: none;
    text-align: center;
    padding: 0;
}

li {
    list-style: none;
    color: #fff;
    text-align: center;
    vertical-align: center;
}

.mainProgressBarArea {
    display: flex;
    flex-direction: row;
    border-top: 2px solid red;
    border-bottom: 2px solid white;
    width: 100%;
}

.tabSeparator {
    margin-top: 15px;
    margin-bottom: 15px;
    width: var(--side-nav-width);
    color: yellow;
    text-align: center;
}

.progressBarBig {
    position: relative;
    margin-top: 20px;
    margin-bottom: 20px;
    height: 50px;
    border: 2px solid white;
    margin-left: 5%;
    width: 70%;
}

.progressBarBigText {
    position: absolute;
    bottom: 0;
    height: 25px;
    border: 2px solid white;
    border-top-left-radius: 20%;
    border-top-right-radius: 20%;
    background-color: black;
    z-index: 10;
    text-align: center;
}

#progression {
    width: 5%;
    background-color: purple;
    height: 100%;
}

#level {
    right: 550px;
    width: 100px;
}

#EXP {
    right: 400px;
    width: 150px;
}

#perSecCurr {
    right: 250px;
    width: 150px;
    color: gold;
}

#perSecPrev {
    right: 100px;
    width: 150px;
    color: var(--bronze);
}

#coinWorth {
    right: 0;
    width: 100px;
    color: gold;
}

aside {
    border-right: 1px solid #ededed;
    flex: 1 0 0%;
    max-width: var(--side-nav-width);
    left: 0;
}

.wrapper {
    display: flex;
    flex-direction: row;
    height: 100%;
}

@media (max-width: 500px) {
    .wrapper {
        flex-direction: column-reverse;
    }

    ul {
        display: flex;
        align-items: center;
        justify-content: space-between;
    }
}

.wrapper_inner {
    position: relative;
    margin: 50px;
    height: 400px;
    width: 900px;
    border: 2px solid white;
}

.tabColumn {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    left: 0;
    width: 100%;
}

.tab {
    padding: 16px;
    border-top: 1px solid black;
    border-bottom: 1px solid black;
    justify-content: space-between;
}

.tabs {
    text-align: center;
}

#coin-upgrades {
    display: flex;
    flex-direction: row;
    justify-content: center;
}

.coin-upgrade {
    display: flex;
    flex-direction: column;
    text-align: center;
    align-items: center;
    border: 2px solid gold;
    padding: 12px;
    margin-left: 10px;
    margin-right: 10px;
}

.coin-upgrade-txt {
    height: auto;
    margin: auto;
}

.coin-upgrade > button {
    height: 20px;
    width: 150px;
    cursor: pointer;
    background-color: var(--mainBG);
    color: white
}