/* Palette and typography */
:root {
  --color-primary: #b3d4fc;
  --color-secondary: #000000;
  --color-background-light: #ffffff;
  --color-background: #ffffff;
  --color-highlight: #b3d4fc;
}

html {
  font-size: 20px;
}
/* Subscription box for newsletter */
#subscribe {
  border: 1px solid var(--color-secondary);
  padding: 1em;
  margin: 2em 0;
  background-color: var(--color-background);
}
#subscribe h2, #subscribe h3 {
  margin-top: 0;
}
#subscribe input[type="email"] {
  max-width: 300px;
  margin-right: 0.5em;
}
.subscribe-status {
  margin-top: 1em;
  font-size: 0.9em;
  color: var(--color-secondary);
}

body {
  margin: 0 auto;
  word-spacing: 0.5em;
  max-width: 90vw;
  padding: 0;
  font-family: 'Courier New', Courier, monospace;
  background-color: var(--color-background-light);
  color: var(--color-secondary);
  line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--color-secondary);
  margin: 1em 0 0.5em;
}

h1 { font-size: 2em; }
 h2 { font-size: 1.75em; }
 h3 { font-size: 1.5em; }

p {
  margin: 0 0 1em;
}

ul {
  margin: 0 0 1em 1.5em;
  padding: 0;
}

a {
  color: var(--color-secondary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Buttons */
.button, .btn, button {
  display: inline-block;
  padding: 0.5em 1em;
  background-color: var(--color-background);
  color: var(--color-secondary);
  text-decoration: none;
  border: 1px solid var(--color-secondary);
  border-radius: 3px;
  cursor: pointer;
  font-size: 1em;
}

.button:hover, .btn:hover, button:hover {
  background-color: var(--color-primary);
  color: var(--color-secondary);
}

/* Forms */
input[type="text"], input[type="email"], textarea, select {
  background-color: var(--color-background);
  color: var(--color-secondary);
  width: 100%;
  max-width: 100%;
  padding: 0.5em;
  margin-bottom: 1em;
  border: 1px solid var(--color-secondary);
  border-radius: 3px;
  box-sizing: border-box;
}

input[type="submit"], button[type="submit"] {
  padding: 0.75em 1.5em;
  background-color: var(--color-background);
  color: var(--color-secondary);
  border: 1px solid var(--color-secondary);
  border-radius: 3px;
  cursor: pointer;
}
input[type="submit"]:hover, button[type="submit"]:hover {
  background-color: var(--color-primary);
  color: var(--color-secondary);
}

/* Header */
header {
  background-color: var(--color-background);
  padding: 20px 40px;
  border-bottom: 1px solid var(--color-secondary);
}
/* Header container: center logo and nav above two-columns layout */
.header-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2em;
  max-width: 1200px;
  margin: 0 auto;
}
/* Logo container: title and logo then tagline below */
.logo {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
/* Inline heading: title and logo */
.logo-heading {
  display: flex;
  align-items: center;
}
.logo-heading h1 {
  margin: 0;
  font-size: 2.5em;
  color: var(--color-secondary);
}
.logo-heading .site-logo {
  height: 50px;
  width: auto;
  margin-left: 0.5em;
}
.logo h1 {
  margin: 0;
  font-size: 2.5em;
  color: var(--color-secondary);
}
.logo .tagline {
  margin: 0;
  font-size: 1em;
  color: var(--color-secondary);
}
.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}
.main-nav li {
  margin-left: 1.5em;
}
.main-nav a {
  color: var(--color-secondary);
  font-weight: bold;
  text-transform: uppercase;
  font-size: 0.9em;
  text-decoration: none;
}
.main-nav a:hover {
  background-color: var(--color-highlight);
  color: var(--color-secondary);
}
mark, .highlight {
  background-color: var(--color-highlight);
  color: var(--color-secondary);
}

/* Footer */
footer {
  background-color: var(--color-background);
  color: var(--color-secondary);
  text-align: center;
  padding: 1em 0;
  margin-top: 2em;
}
footer a {
  color: var(--color-secondary);
  text-decoration: none;
}
footer a:hover {
  text-decoration: underline;
}
/* Two-column layout for vision and actions */
.two-columns {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2em;
  margin-bottom: 2em;
  position: relative;
}
/* Vertical divider between two columns */
.two-columns::before {
  content: '';
  position: absolute;
  top: 1em;
  bottom: 1em;
  left: 50%;
  width: 1px;
  background-color: var(--color-secondary);
  transform: translateX(-50%);
}
/* Elegant divider between the two columns */
.two-columns > section:first-child {
  /* spacing from vertical divider */
  padding-right: 1.5em;
}
.two-columns > section:last-child {
  padding-left: 1.5em;
}
/* Blog */
#blog {
  margin: 2em 0;
}
#blog-posts article {
  margin-bottom: 2em;
}
/* Blog previews grid */
#blog-previews {
  display: grid;
  /* max 4 columns per row */
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5em;
}
.post-preview {
  border: 1px solid var(--color-secondary);
  padding: 1em;
  background: var(--color-background);
  box-sizing: border-box;
}
.post-preview img {
  display: block;
}
.post-preview h3 {
  margin: 0.5em 0 0.5em;
}
/* Post detail container: slightly wider to accommodate two-column layout */
/* Post detail container: more width and slight left offset */
.post-detail {
  max-width: 1080px;
  margin: 2em auto;
  padding: 1em;
  position: relative;
  left: -5%;
}
.post-detail img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1em 0;
}
#blog-posts img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1em 0;
}
/* Portrait thumbnails: float left and wrap text */
.post-preview.portrait img {
  float: left;
  width: 500px;
  height: auto;
  margin: 20px;
}
/* Landscape thumbnails: fixed height, center horizontally */
.post-preview:not(.portrait) img {
  height: 500px;
  width: auto;
  margin: 20px auto;
}
/* Preview metadata: themes, author, summary */
.post-preview .post-themes {
  margin: 0.5em 0;
}
.post-preview .post-themes .theme {
  display: inline-block;
  background-color: var(--color-highlight);
  color: var(--color-secondary);
  padding: 0.2em 0.5em;
  border-radius: 3px;
  margin-right: 0.3em;
  font-size: 0.85em;
}
.post-preview .post-meta {
  font-size: 0.85em;
  color: #555;
  margin-bottom: 0.5em;
}
.post-preview .post-summary {
  margin-bottom: 1em;
}

/* Detail page metadata and content styling */
.post-detail h1 {
  margin-top: 0;
}
.post-detail .post-header-image {
  max-width: 100%;
  margin: 1em 0;
}
.post-detail .post-themes {
  margin: 0.5em 0;
}
.post-detail .post-themes .theme {
  display: inline-block;
  background-color: var(--color-highlight);
  color: var(--color-secondary);
  padding: 0.2em 0.5em;
  border-radius: 3px;
  margin-right: 0.3em;
  font-size: 0.85em;
}
.post-detail .post-meta {
  font-size: 0.9em;
  color: #555;
  margin-bottom: 1em;
}
/* Detail page content: default single column, two-column only with .two-col */
.post-detail .post-content {
  margin-top: 1em;
}
/* Two-column layout for post content with custom divider */
.post-detail.two-col .post-content {
  /* Layout post content in two columns when class two-col is present */
  column-count: 2;
  column-gap: 2em;
  position: relative;
}
/* Elegant vertical divider between post content columns */
.post-detail.two-col .post-content::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 2em;
  bottom: 2em;
  width: 1px;
  background-color: var(--color-secondary);
  transform: translateX(-50%);
}
/* Highlight hyperlinks in post content: white text on black background */
.post-detail .post-content a {
  background-color: var(--color-secondary);
  color: var(--color-background-light);
  padding: 0.1em 0.2em;
  border-radius: 2px;
  text-decoration: none;
}
.post-detail .post-content a:hover {
  opacity: 0.8;
}
/* Subscription box for newsletter */
#subscribe {
  border: 1px solid var(--color-secondary);
  padding: 1em;
  margin: 2em 0;
  background-color: var(--color-background);
}
#subscribe h2, #subscribe h3 {
  margin-top: 0;
}
#subscribe input[type="email"] {
  max-width: 300px;
  margin-right: 0.5em;
}
.subscribe-status {
  margin-top: 1em;
  font-size: 0.9em;
  color: var(--color-secondary);
}
/* Disable two-column layout on small screens for post content */
@media (max-width: 600px) {
  .post-detail.two-col .post-content {
    column-count: 1;
    column-gap: normal;
  }
  .post-detail.two-col .post-content::before {
    display: none;
  }
}