* {
    --main-background-color: #010717;
    --main-text-color: #fff;
    --main-nav-background-color: #21b5c1;
    --main-nav-text-color: #fff;
    --main-nav-link-color: #fff;
    --main-nav-link-hover-color: #ffffa9;

    --link-color: #00f;
    --link-hover-color: #00f;
    --link-text-decoration: none;
    --link-hover-text-decoration: underline;

    --main-content-section-background-color: #fff;
    --main-content-section-background-opacity: 0.85;
    --main-content-section-background-color-rgba: rgba(255, 255, 255, var(--main-content-section-background-opacity));
    --main-content-section-text-color: #000;

    --footer-background-color: #fff;
    --footer-background-opacity: 0.85;
    --footer-background-color-rgba: rgba(255, 255, 255, var(--footer-background-opacity));
    --footer-text-color: #000;
}

body {
    background-color: #010717;
    color: #fff;
    box-sizing: border-box;
}

a {
    color: var(--link-color);
    text-decoration: var(--link-text-decoration);
    transition: all 0.3s;
}

a:hover {
    color: var(--link-hover-color);
    text-decoration: var(--link-hover-text-decoration);
}

a[href^="http"]::after {
    content: "";
    font-size: 0.75em;
    display: inline-block;
    width: 1em;
    height: 1em;
    background-image: url('../img/link_external.svg');
    background-size: cover;
    margin-left: 2px;
    vertical-align: super;
}

.img-fluid {
    width: 100%;
    height: auto;
    object-fit: cover;
}

.section {
    padding: 12px;
}

.article {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 0 auto;
}

ul.no-list-decoration {
    list-style: none;
    padding: 0;
}

.highlight {
    font-weight: bold;
}

@media screen and (min-width: 768px) {
    .article {
        justify-content: center;
    }

    .article.img-left {
        flex-direction: row;
    }

    .article.img-right {
        flex-direction: row-reverse;
    }

    .article .img, .article .text-content {
        flex: 1;
        min-width: 0;
    }

    .article .img {
        width: 0;
        object-fit: cover;
    }

    .article .text-content {
        text-align: left;
    }
}

meteor-background {
    z-index: -99;
}

main-navbar {
    position: fixed;
    top: 0;
    z-index: 99;
}

main-navbar nav-brand img {
    width: 100%;
    height: 48px;
}

main-navbar::part(main) {
    background-color: var(--main-nav-background-color);
    color: var(--main-nav-text-color);
    border-radius: 0px 0px 12px 12px;
}

main-navbar nav-menu::part(item-menu) {
    background-color: var(--main-nav-background-color);
    border-radius: 12px;
}

main-navbar nav-button {
    --nav-link-color: var(--main-nav-link-color);
    --nav-link-hover-color: var(--main-nav-link-hover-color);
}

@media screen and (min-width: 768px) {
    main-navbar nav-menu::part(item-menu) {
        background-color: transparent;
        border-radius: 0px;
    }
}

main {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.main-container {
    width: 100%;
    text-align: center;
    padding: 0 0;
    margin: 72px 0;
    flex: 1;
}

.main-content {
    margin: 24px auto;
    padding: 0 12px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.main-content .section {
    background-color: var(--main-content-section-background-color-rgba);
    color: var(--main-content-section-text-color);
    border-radius: 12px;
    scroll-margin-top: 72px;
}

.introduction .introduction-caution {
    font-size: 0.5em;
    opacity: 0.75;
}

.introduction .introduction-content {
    margin:0 auto;
    padding: 2em 0;
    width: 100%;
    text-align: left;
    font-size: 1.25em;
}

.introduction .introduction-content .main-text {
    font-size: 1.35em;
}

.introduction .introduction-content .catch-copy {
    padding-top: 5em;
    text-align: right;
    font-weight: bold;
}

.article .post-script {
    margin: 0;
    font-size: 0.5em;
}

.restrict-area.mark::before {
    content: '🔞';
    padding-right: 0.25em;
}


ul.center-block {
    display: inline-block;
    text-align: left;
}

@media screen and (min-width: 768px) {
    .main-content {
        max-width: 1200px;
    }

    .introduction .introduction-content {
        max-width: 900px;
    }
}

.main-header .brand-logo {
    width: 100%;
    max-width: 400px;
    padding: 2em;
}

footer {
    padding: 12px;
    background-color: var(--footer-background-color-rgba);
    color: var(--footer-text-color);
    border-radius: 12px 12px 0px 0px;
    -webkit-border-radius: 12px 12px 0px 0px;
    -moz-border-radius: 12px 12px 0px 0px;
}