betaflight-configurator/tabs/cli.css

.tab-cli {
    height: 100%;
}
.tab-cli p {
    padding: 5px;
    border: 1px dotted silver;
}
.tab-cli .window {
    margin-top: 10px;
    height: calc(100% - 80px); /* - (p, textarea) */

    padding: 5px;

    overflow-y: scroll;
    overflow-x: hidden;

    font-family: monospace;
    color: white;

    border: 1px solid silver;
    background-color: black;

    -webkit-user-select: text;
}
.tab-cli textarea {
    -webkit-box-sizing: border-box;

    width: 100%;

    margin-top: 8px;

    height: 22px;
    line-height: 20px;

    padding-left: 5px;

    border: 1px solid silver;

    resize: none;
}