body {
    margin: 0;
    padding: 0;
    display: flex;
    font-family: Arial, Helvetica, sans-serif;
}

button {
    margin: 0 5vw;
    font-size: 1.5vw;
    height: 3vw;
    text-align: center;
    background: white;
}

button:hover {
    background-color: #3484F0;
    color: white;
}

input[type="radio"] {
    display: none;
}

    input[type="radio"] + label {
        background-color: white;
        cursor: pointer;
        display: block;
        margin: auto;
        height: auto;
        width: 45vw;
        text-align: center;
        line-height: 2.5vw;
        padding: 1.5vw 0;
        font-size: 1.6vw;
    }

    input[type="radio"]:checked + label {
        background-color: #3484F0;
        color: white;
    }

.multiple-choice {
    background: #C4DBFA;
    width: 62vw;
    height: auto;
    margin: 2vw 7vw;
}

    .multiple-choice p {
        display: block;
        width: 45vw;
        margin: auto;
        padding: 2vw 0;
    }

    .multiple-choice h2 {
        display: block;
        width: 50vw;
        margin: auto;
    }

.graph {
    background: black;
    width: 62vw;
    margin: 2vw 7vw;
}

.title-line {
    background: black;
    border: solid 1px black;
    width: auto;
    display: block;
}

.explain {
    width: 62vw;
    margin: 2vw 7vw;
}

    .explain p {
        font-size: 1.5vw;
        line-height: 2.3vw;
    }

.video {
    width: 64vw;
    margin: 2vw 6vw;
}

h1 {
    padding: 4vw 6vw 2vw 6vw;
    text-align: left;
    font-size: 3vw;
    margin: 0;
}

h2 {
    padding: 2vw 6vw 0 6vw;
    text-align: left;
    font-size: 2.5vw;
    margin: 0;
}

h3 {
    padding: 2vw 6vw 0 6vw;
    text-align: left;
    font-size: 2.5vw;
    margin: 0;
}

#prev, #next{
    background: #3484F0;
    padding: 1vw;
    border-radius: 3vw;
}

::-webkit-scrollbar {
    display: none;
}

#prev a, #next a{
    color:white;
}
#menu {
    width: 20%;
    background: white;
    color: black;
    overflow-y: scroll;
}
#main {
    width: 80%;
    height: auto;
    border: solid 5px white;
    margin-left: 4%;
}

#menu {
    border: solid 5px #3484F0;
    height: 100vh;
    position: fixed;
}

#title {
    color: white;
    background: #3484F0;
    font-size: 250%;
    padding: 20% 0%;
    text-align: center;
    margin: 0;
}

#selected_one {
    font-weight: 800;
    text-decoration: underline;
}

.section {
    height: auto;
    width: auto;
    padding-left: 1vw;
    margin-left: 1vw;
    text-align: left;
    padding: 2vw 0 2vw 0;
    font-size: 1.5vw;
    font-weight: bold;
}

    .section a:hover {
        text-decoration: underline;
    }

    .section a {
        font-size: 1.2vw;
        padding-left: 1.5vw;
    }

a {
    text-decoration: none;
    color: black;
    display: inline-block;
}

table {
    border-collapse: collapse;
}

th, td {
    font-size: 1.5vw;
    border: solid 2px black;
    padding: 1vw 4vw;
}


ul {
    font-size: 1.5vw;
    margin-left: 4vw;
}

li {
    padding-top: 1vw;
    padding-bottom: 1vw;
}