/* Layout and spacing styles */

/* Header */
header {
  position: sticky;
  top: 0;
  background-color: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  height: var(--header-height);
  display: flex;
  align-items: center;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 0 var(--container-padding);
}

/* Logo/branding */
.logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.logo:hover {
  color: var(--color-accent);
  text-decoration: none;
}

/* Navigation */
nav {
  display: flex;
  gap: var(--spacing-lg);
}

nav a {
  color: var(--color-text-primary);
  font-weight: 500;
  transition: color var(--transition-fast);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: 4px;
}

nav a:hover {
  color: var(--color-accent);
  background-color: var(--color-bg-secondary);
  text-decoration: none;
}

nav a.active {
  color: var(--color-accent);
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: calc(var(--spacing-sm) - 2px);
}

/* Main content */
.main-content {
  padding: var(--spacing-2xl) 0;
  flex: 1;
  width: 100%;
}

/* Section */
section {
  margin-bottom: var(--spacing-2xl);
}

section:last-child {
  margin-bottom: 0;
}

/* Article header */
.article-header {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--color-border);
}

.article-header h1 {
  margin-top: 0;
  margin-bottom: var(--spacing-lg);
}

.article-meta {
  display: flex;
  gap: var(--spacing-lg);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  flex-wrap: wrap;
  align-items: center;
}

.article-meta span {
  display: flex;
  align-items: center;
}

.article-meta a {
  color: var(--color-text-secondary);
}

.article-meta a:hover {
  color: var(--color-accent);
}

/* Posts grid/list */
.posts-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-xl);
  margin: var(--spacing-xl) 0;
}

.posts-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

/* Post card */
.post-card {
  padding: var(--spacing-lg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  transition: all var(--transition-default);
  background-color: var(--color-bg-primary);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.post-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.08);
  transform: translateY(-2px);
}

.post-card h3 {
  margin-top: 0;
  margin-bottom: var(--spacing-md);
  color: var(--color-accent);
  transition: color var(--transition-fast);
}

.post-card:hover h3 {
  color: var(--color-accent-hover);
}

.post-card-excerpt {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  flex-grow: 1;
  font-size: var(--font-size-base);
  line-height: 1.6;
}

.post-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.post-date {
  color: var(--color-text-secondary);
}

.post-read-time {
  color: var(--color-text-secondary);
}

/* Tags */
.tags {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin: var(--spacing-lg) 0;
}

.tag {
  display: inline-block;
  background-color: var(--color-bg-secondary);
  color: var(--color-text-primary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 16px;
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.tag:hover {
  background-color: var(--color-accent);
  color: white;
  text-decoration: none;
}

/* Navigation buttons */
.navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: var(--spacing-2xl) 0;
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--color-border);
  gap: var(--spacing-lg);
}

.nav-previous,
.nav-next {
  flex: 1;
}

.nav-previous a,
.nav-next a {
  display: block;
  padding: var(--spacing-lg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.nav-previous a:hover,
.nav-next a:hover {
  border-color: var(--color-accent);
  background-color: var(--color-bg-secondary);
}

.nav-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  display: block;
  margin-bottom: var(--spacing-sm);
}

.nav-title {
  color: var(--color-accent);
  font-weight: 600;
}

/* Footer */
footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-2xl) 0;
  margin-top: auto;
  width: 100%;
}

footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
}

.footer-text {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-links a:hover {
  color: var(--color-accent);
}

/* Page layout */
html,
body {
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

/* Back to top button */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 44px;
  height: 44px;
  background-color: var(--color-accent);
  color: white;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-default);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-4px);
}