@keyframes body {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 100;
    }
}
@keyframes background {
    0% {
        transform: scale(1);
        filter: blur(0px);
    }
    100% {
        transform: scale(1.5);
        filter: blur(4px);
    }
}
@keyframes title {
    0% {
        opacity: 0;
        top: 32px;
    }

    50% {
        opacity: 0;
        top: 32px;
    }

    100% {
        opacity: 1;
        top: 0px;
    }
}

@keyframes sub-title {
    0% {
        opacity: 0;
        top: -32px;
    }

    50% {
        opacity: 0;
        top: -32px;
    }

    100% {
        opacity: 1;
        top: 0px;
    }
}

@keyframes line {
    0% {
        width: 0%;
    }

    100% {
        width: 50%;
    }
}

@keyframes start-button {
    0% {
        opacity: 0;
        bottom: 32px;
    }

    50% {
        opacity: 0;
        bottom: 32px;
    }

    100% {
        opacity: 1;
        bottom: 0px;
    }
}

html,
body,
.background,
.index {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    animation: body 0.5s;
    overflow: hidden;
}

.background {
    position: absolute;
    filter: blur(4px);
    background-image: url("../images/background.jpg");
    background-size: cover;
    box-shadow: 0px;
    z-index: -999;
    transform: scale(1.5); 
    animation: background 30s;
}

.index {
    position: absolute;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.index .title {
    position: relative;
    margin: 16px 0;
    color: white;
    font-size: 64px;
    text-shadow: 8px 8px 8px rgb(0, 0, 0);
    animation: title 1.5s;
}

.index .sub-title {
    position: relative;
    margin: 16px 0;
    color: white;
    font-size: 48px;
    text-shadow: 8px 8px 8px rgb(0, 0, 0);
    animation: sub-title 1.5s;
}

.index .line {
    width: 50%;
    height: 1px;
    background-color: rgb(223, 223, 223);
    border: 0px;
    animation: line 1.3s;
}
.index .start {
    position: relative;
    margin: 16px 0;
    padding: 8px 128px;
    background-color: rgb(97, 193, 110);
    color: white;
    font-size: 32px;
    text-decoration: none;
    animation: start-button 1.5s;
    transition: all 0.5s;
}
.index .start:hover {
    opacity: 0.6;
}