html, body {
  height: 100%;
}

body {
background-image: -webkit-radial-gradient(center top, circle farthest-corner, #FFF 0%, #D8DFE9 100%);
  background-image: radial-gradient(circle farthest-corner at center top, #FFF 0%, #D8DFE9 100%);
  overflow: hidden;
  justify-content: center;
  align-items: left;
  display: flex;
  flex-direction: column;
}

.text-box {
     margin-top: 10vh;
}

.btn:link,
.btn:visited {
    text-transform: uppercase;
    text-decoration: none;
    padding: 15px 40px;
    display: inline-block;
    border-radius: 20px;
    transition: all .2s;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.btn:active {
    transform: translateY(-1px);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}

.btn-white {
    background-color: grey;
    color: white;
}

.btn::after {
    content: "";
    display: inline-block;
    border-radius: 20px;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
    transition: all .4s;
}

.btn-white::after {
    background-color: #fff;
}

.btn:hover::after {
    transform: scaleX(1.4) scaleY(1.6);
    opacity: 0;
}

.btn-animated {
    animation: moveInBottom 5s ease-out;
    animation-fill-mode: backwards;
}

@keyframes moveInBottom {
    0% {
        opacity: 0;
        transform: translateY(30px);
    }

    100% {
        opacity: 1;
        transform: translateY(0px);
    }
}
img{
        width: 100px;
        height: 50px;
        padding-left: 20px;
        padding-right: 20px;
    }
    img:hover{
        opacity: 50%;
    }
    img:active{
        opacity: 100%;
    }
.difflvl-txt{
    padding: 10px;
}
.glow-on-hover {
    width: 220px;
    height: 50px;
    border: none;
    outline: none;
    color: #fff;
    background: #111;
    cursor: pointer;
    position: relative;
    z-index: 0;
    border-radius: 10px;
}

.glow-on-hover:before {
    content: '';
    background: linear-gradient(45deg, #ff0000, #ff7300, #fffb00, #48ff00, #00ffd5, #002bff, #7a00ff, #ff00c8, #ff0000);
    position: absolute;
    top: -2px;
    left:-2px;
    background-size: 400%;
    z-index: -1;
    filter: blur(5px);
    width: calc(100% + 4px);
    height: calc(100% + 4px);
    animation: glowing 20s linear infinite;
    opacity: 0;
    transition: opacity .3s ease-in-out;
    border-radius: 10px;
}

.glow-on-hover:active {
    color: #000
}

.glow-on-hover:active:after {
    background: transparent;
}

.glow-on-hover:hover:before {
    opacity: 1;
}

.glow-on-hover:after {
    z-index: -1;
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: #111;
    left: 0;
    top: 0;
    border-radius: 10px;
}

@keyframes glowing {
    0% { background-position: 0 0; }
    50% { background-position: 400% 0; }
    100% { background-position: 0 0; }
}