@keyframes hidden {
    0% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}
body {
    background-image: url("../images/background.png");
    background-size: 100%;
    margin: 0;
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    height: 100vh;
    color: yellow;
    width: 100vw;
    filter: drop-shadow(0 0 0.5rem yellow);
}
.section_a,
.section_b {
    width: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
.section_b img {
    border-radius: 15px;
    margin: 10px;
    height: 35vh;
}
.section_b .IceLiu_Area  {
    position: relative;
    z-index: -1;
}
.section_b .IceLiu_Area #IceLiu_Forward {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    opacity: 0.5;
    border-radius: 0 0 15px 15px;
}
.title {
    margin: 0;
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: baseline;
    gap: 20px;
    font-weight: normal;
}
.title p {
    margin: 0;
    font-weight: bold;
}
.page_foot {
    position: absolute;
    bottom: 0;
}
#counter,
#percent {
    font-weight: bold;
    font-size: 50px;
}
.window {
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.697);
}
.window .content {
    border-radius: 20px;
    width: 800px;
    height: 500px;
    color: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background-color: white;
}
.window .content img {
    width: 100px;
}
#start {
    width: 100px;
    height: 40px;
    border-radius: 20px;
    border: none;
    background-color: #2e84f1;
    color: white;
    font-size: 20px;
}