@font-face {
    font-family: 'firefly';
    src: url(ZCOOLKuaiLe-Regular.ttf);
}

* {
    padding: 0;
    margin: 0;
}

body {
    height: 100vh;
    background: url(yh.bmp) no-repeat;
    background-size: cover;
}

ul {
    list-style: none;
}

button {
    outline: none;
    border: none;
}

.firefly {
    width: 180px;
    height: 60px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: linear-gradient(to right, #6EB46E 10%, #55B455);
    border-radius: 40px;
    opacity: .88;
    cursor: pointer;
    transition: 1s;
}

.firefly:hover {
    box-shadow: 0 0 10px #B4FFB4;
}

.firefly p {
    line-height: 60px;
    font-size: 22px;
    color: #F5DD8F;
    font-family: firefly;
    opacity: .88;
}

.lightning {
    width: 95%;
    height: 80%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 40px;
    transition: .8s;
    overflow: hidden;
}

.firefly:hover .lightning {
    box-shadow: 0 0 4px #B4FFB4 inset;
}

.lightning ul {
    opacity: 0;
    transition: .8s;
}

.firefly:hover ul {
    opacity: .8;
}

.lightning ul li {
    width: 5px;
    height: 5px;
    background-color: #91FA91;
    position: absolute;
    bottom: 10%;
    border-radius: 50%;
    opacity: .6;
    animation: fireflymove infinite linear;
}

@keyframes fireflymove {
    100% {
        bottom: 100%;
    }
}