body, html {
    margin: 0;
    padding: 0;
    height: 100%;
    font-family: 'Noto Sans JP', sans-serif;
}

body {
    background-color: #091B29;
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

body::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        60deg,
        #091B29,
        rgba(255, 255, 255, 0.2) 50%,
        #091B29
    );
    background-size: 400% 400%;
    animation: moveBackground var(--animation-duration, 12s) linear infinite var(--animation-direction, normal);
    z-index: 0;
}

footer {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    text-align: center;
    color: #ffffff;
    background-color: #000D12;
    padding: 10px;
    font-size: 14px;
    border-top: 5px solid transparent;
    background-image: linear-gradient(#091B29, #091B29), linear-gradient(to right, rgba(255,255,255,0.1), rgba(0,0,0,0.5));
    background-clip: padding-box, border-box;
    background-origin: padding-box, border-box;
}

.container {
    padding: 20px;
    max-width: 600px;
    position: relative;
    z-index: 1;
}

.logo {
    max-width: 200px;
    margin-bottom: 20px;
}

h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 20px;
}

p {
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
}

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