:root {
    --theme-color: #3593a5;
    --common-font-family:
        -apple-system, BlinkMacSystemFont,
        "Hiragino Kaku Gothic ProN", "Hiragino Sans",
        "Noto Sans JP", "Yu Gothic", "Meiryo", sans-serif;
}

body {
    font-family: var(--common-font-family);
}

/* top image container */
header#site-head.withCenteredImage {
    background-color: var(--theme-color);
}

/* top image container */
header#site-head.withCenteredImage::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: var(--background-image);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 2.0s ease;
    pointer-events: none;
}

/* top image container */
header#site-head.withCenteredImage.loaded::before {
    opacity: 1;
}

/* logo on top of blog */
#blog-logo {
    max-height: 150px;
}

/* description under site title */
#site-head .blog-description,
#site-head.withCenteredImage .blog-description {
    font-family: var(--common-font-family);
    color: white;
    text-shadow: var(--theme-color) 0px 0px 3px,
        var(--theme-color) 0px 0px 5px,
        var(--theme-color) 0px 0px 10px;
}

/* buttons in site header */
#site-head a.btn,
#site-head #site-languages .btn-lang,
#site-head.withCenteredImage a.btn,
#site-head.withCenteredImage #site-languages .btn-lang {
    font-family: var(--common-font-family);
    color: white;
    font-size: 0.9em;
    background-color: transparent;
    border-color: white;
    border-style: solid;
    border-width: 1px;
    text-shadow: var(--theme-color) 0px 0px 3px,
        var(--theme-color) 0px 0px 5px,
        var(--theme-color) 0px 0px 10px;
    box-shadow: var(--theme-color) 0px 0px 10px;
}

/* buttons in site header */
#site-head a.btn:hover,
#site-head.withCenteredImage a.btn:hover {
    background-color: var(--theme-color);
    color: white;
    border-color: white;
}

#header-arrow {
    color: white
}

site-head #header-arrow:hover,
#site-head.withCenteredImage #header-arrow:hover {
    color: var(--theme-color);
}

/* text areas with dark background */
.post-holder.dark {
    --section-dark-bg-color: var(--theme-color);
}

/* about us page logo */
img.about-logo {
    max-height: 300px;
}

/* navigation menu items */
a.fn-item:hover,
a.fn-item.active {
    color: var(--theme-color);
}

.image-text.portrait>.image-text-image {
    margin: 0.4em 1em 0 0;
    border-radius: 20px;
    max-width: 200px;
}

@media (max-width: 600px) {
    .image-text.portrait>.image-text-image {
        max-width: 130px;
    }
}

.image-text-image {
    float: left;
}

/* table */
table tbody>tr:nth-child(even) {
    background-color: transparent;
}

/* error page */
body.error-page {
  background-color: var(--theme-color);
  color: #fff;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  text-align: center;
}

body.error-page main {
  max-width: 90%;
}

body.error-page h1 {
  font-size: 4rem;
  margin-bottom: 0.0em;
  letter-spacing: 0.05em;
}

body.error-page p {
  margin: 0.5em 0;
}

.error-page a.button {
  display: inline-block;
  padding: 0.6em 1.5em;
  border: 1.5px solid #fff;
  border-radius: 9999px;
  color: #fff;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  margin-top: 1.5em;
}

.error-page a.button:hover {
  background-color: #fff;
  color: var(--theme-color);
  transform: translateY(-2px);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}