style.css

body {
    color: #14171a;
    background: #e6ecf0
}

#_plain {
    width: 100%;
    height: 100%
}

#_code {
    width: 100%;
    height: 100%
}

#_convert {
    position: absolute;
    top: 15px;
    right: 15px;
    opacity: .6;
    cursor: pointer
}

textarea {
    padding: 10px
}

button {
    height: 30px
}

#_eval {
    position: absolute;
    top: 50px;
    right: 15px;
    opacity: .6;
    cursor: pointer
}

#_length {
    position: absolute;
    top: 85px;
    right: 15px;
    opacity: .6;
    cursor: pointer;
    pointer-events: none;
}

table {
    width: 100%;
    height: calc(100vh - 300px)
}

table td {
    position: relative;
    padding: 10px
}

.title h1 {
    font-size: 60px
}

.title h1,
.title p {
    text-align: center
}

.title p {
    font-style: italic;
    font-size: 20px
}