* {
    font-family: sans-serif;
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

div.yotsuba {
    background-image: url(yotsuba.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
    position: fixed;
    width: 100px;
    height: 100px;
    opacity: 0;
    animation: yotsuba 10s infinite;
    z-index: -1;
    filter: blur(1px) opacity(.5);
}

@keyframes yotsuba {
    0% {
        opacity: 0;
        transform: rotate(0);
    }
    50% {
        opacity: 1;
    }
    100% {
        opacity: 0;
        transform: rotate(270deg) translateY(100px);
    }
}

.title {
    width: fit-content;
    height: fit-content;
    position: fixed;
    margin: auto;
    inset: 0;
    font-size: 4rem;
    animation: title 3s forwards;
}

@keyframes title {
    0% {
        opacity: 0;
        transform: scale(0);
    }
    10% {
        opacity: 1;
    }
    80% {
        opacity: 0;
        transform: scale(1000%);
    }
    85% {
        opacity: 0;
        transform: scale(1);
    }
    100% {
        opacity: 1;
    }
}

.description {
    text-align: center;
    max-width: 80vw;
    height: fit-content;
    position: fixed;
    margin: auto;
    top: 10px;
    left: 0;
    right: 0;
    opacity: 0;
    animation: description .5s forwards;
    animation-delay: 2s;
}

@keyframes description {
    0% {
        top: 20px;
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

.menu {
    width: fit-content;
    margin: auto;
    position: fixed;
    bottom: 10px;
    left: 0;
    right: 0;
    color: #555;
}
button {
    display: block;
    background-color: #8CC63F;
    color: #fff;
    border: 3px solid #fff;
    border-radius: 99px;
    margin: 0 10px;
    padding: 5px 20px;
    cursor: pointer;
}

#modal-back {
    background-color: #000000a0;
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: 2;
    display: none;
    cursor: pointer;
}

#modal-back:focus {
    background-color: #00000050;
}

#modal {
    background-color: #fff;
    position: fixed;
    width: fit-content;
    max-width: fit-content;
    height: fit-content;
    margin: auto;
    padding: 10px 30px 20px;
    inset: 0;
    z-index: 3;
    animation: modal .4s forwards ease-in-out;
    display: none;
}

@keyframes modal {
  0% {
    opacity: 0;
    transform: scale(0.5);
    filter: brightness(1);
  }
  50% {
    opacity: 1;
    transform: scale(1.1);
    filter: brightness(1.1);
  }
  100% {
    transform: scale(1);
    filter: brightness(1);
  }
}

input[type='text'] {
    width: 20rem;
    max-width: 100%;
    border: none;
    padding: 5px;
    border-bottom: 1px solid #ccc;
    transition: .3s;
}
input[type='text']:focus {
    outline: none;
    background: #8CC63F20;
}

#modal button {
    width: fit-content;
    border: none;
    margin: 10px 10px;
}

#url {
    color: #555;
}

a {
    color: #555;
}