style.css

html {
    box-sizing: border-box;
    font-family: 'Helvetica', sans-serif;
}

*, *:before, *:after {
    box-sizing: inherit;
}

.main {
    height: 100vh;
    width: 100vw;
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    justify-content: center;
}

h1, h2, p, h3 {
    text-align: center;
}

h1 {
    margin: 0px;
}

h2 {
    font-weight: normal;
    font-size: large;
}

a {
    height: 30px;
    padding: 5px 10px;
    color: black;
    text-decoration: none;
    border-radius: 20px;
    border: 2px solid black;
}

a:hover {
    background-color: black;
    color: white;
}

input {
    margin: auto;
}

#header {
    width: 100vw;
    padding-left: 5vw;
    padding-right: 5vw;
    display: flex;
    flex-flow: row nowrap;
    align-items: center;
    justify-content: space-between;
}

#timer #score {
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    justify-content: center;
}

#questions {
    display: flex;
    flex-flow: column nowrap;
    justify-content: center;
    align-items: center;
}