* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    position: relative;
    outline-style: none;
}

html, body {
    width: 100%;
    height: 100%;
}

body {
    background-color: #111;
    color: #fff;
    font-size: 12px;
    line-height: 20px;
    font-family: Tahoma, Geneva, 'Dejavu Sans', Arial, Helvetica, sans-serif;
}

.hidden {
    display: none !important;
    visibility: hidden !important;
}

.diag {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9000000;
    background-color: rgba(0, 0, 0, .6);
}
.diag-rtx {
    background-color: #040404;
}
.diag-box {
    background-color: #eee;
    color: #000;
}
.diag-rtx .diag-box {
    background-color: #000;
    color: #fff;
    font-size: 2em;
    line-height: 1.5em;
    width: 100%;
    text-align: center;
}