.first_title {
    color: red;
}
#first_title:hover {
    background-color: antiquewhite;
}
.first_title,#first_title {
    font-size: 40px;
}
ul>li:first-child {
    color: red;
}
[type="submit"] {
    font-size: 2em;
}

.flex-test {
    height: 60px;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #fff;
    border-bottom:1px solid rgb(229,230,235)
}

#overflowTest {
    width: 200px;
    height: 200px;
    overflow: scroll;
    border: 1px solid rgb(150, 18, 18);
}