*, *:after, *::before {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}


.bt-menu-disable {
    color: #555 !important; 
    pointer-events: none !important;
    cursor: default !important;
}
.bt-menu.bt-menu-close {
    bottom: 0;
    position: fixed;
    z-index: 2;
    -webkit-transition: border-width 0.3s, background-color 0.3s;
    transition: border-width 0.3s, background-color 0.3s;
}

.bt-menu {
    position: absolute;
    width: 100%;
    -webkit-transition: height 0s 0.3s;
    transition: height 0s 0.3s;
}

.bt-menu-close {
    position: absolute;
    left: 0;
    width: 100%;
    list-style: none;
    text-align: center;
    white-space: nowrap;
    margin: 0;
    padding: 0;
    background-color: grey;
    height: 2rem;
    bottom: 0;
}

.bt-menu a:hover {
    cursor: pointer;
}

.bt-menu li {
    display: inline-block;
    width: 20%;
    height: 100%;
    font-size: 1.5rem;
}

.bt-menu li:nth-child(2) {
    margin-right: 1em;
}

.bt-menu li:nth-child(3) {
    margin-left: 1em;
}


.bt-menu li a {
    display: block;
    outline: none;
    color: #fff;
    text-decoration: none;
    text-transform: uppercase;
    height: 100%;
    width: 100%;
    padding-top: .25rem;
}

.bt-menu li a:hover, .bt-menu ul li a:focus {
    color: rgba(100, 200, 250, 1);
    cursor: pointer;
}


@media only screen and (orientation: portrait) and (min-width: 400px) {
    .bt-menu ul {
    }
}

@media only screen and (orientation: portrait) and (min-width: 600px) {
    .bt-menu ul {
    }
}

@media only screen and (orientation: portrait) and (min-width: 1200px) {
    .bt-menu ul {
    }
}

@media only screen and (orientation: landscape) and (min-width: 1000px) {
    .bt-menu ul {
    }
}

@media only screen and (orientation: landscape) and (min-height: 800px) {
    .bt-menu ul {
    }
}