betaflight-configurator/tabs/configuration.css

.tab-configuration {
    position: relative;
}
.tab-configuration .groupTitle {
    padding: 0 0 5px 0;
    margin: 0 0 10px 0;

    font-size: 16px;

    border-bottom: 1px solid #dddddd;
}
.tab-configuration .hugeWhitespace {
    height: 100px;
}
.tab-configuration dl.features {
}
.tab-configuration dl.features dt {
    float: left;

    width: 10px;
    height: 18px;
    line-height: 18px;
}
.tab-configuration dl.features dt input {
    margin-top: 2px;
}
.tab-configuration dl.features dd {
    margin: 0 0 0 20px;
    height: 18px;

    line-height: 18px;
}

.tab-configuration .buttons {
    position: fixed;

    width: calc(100% - 20px);
    bottom: 10px;
}
.tab-configuration .save {
    display: block;
    float: right;

    height: 28px;
    line-height: 28px;

    padding: 0 15px 0 15px;

    text-align: center;
    font-weight: bold;

    border: 1px solid silver;
    background-color: #ececec;
}
.tab-configuration .save:hover {
    background-color: #dedcdc;
}