/*
Theme Name: TechBlog
Theme URI: https://markkempers.nl/techblog
Author: Mark Kempers
Author URI: https://tech.markkempers.nl
Description: A clean, modern WordPress theme for technical blog articles with tag support, about page, and RSS feed.
Version: 1.0.0
Requires at least: 6.0
Tested up to: 6.5
Requires PHP: 8.0
License: GNU General Public License v2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: techblog
Tags: blog, technology, minimal, dark, rss, tags
*/

/* =============================================
   CSS VARIABLES & DESIGN TOKENS
   ============================================= */
:root {
  /* Colors */
  --color-bg:           #0d1117;
  --color-surface:      #161b22;
  --color-surface-2:    #21262d;
  --color-border:       #30363d;
  --color-text:         #e6edf3;
  --color-text-muted:   #8b949e;
  --color-accent:       #58a6ff;
  --color-accent-dim:   #1f3a5c;
  --color-accent-hover: #79c0ff;
  --color-green:        #3fb950;
  --color-orange:       #f0883e;
  --color-red:          #f85149;
  --color-tag-bg:       #21262d;
  --color-tag-text:     #58a6ff;
  --color-tag-border:   #388bfd40;
  --color-code-bg:      #161b22;
  --color-heading:      #f0f6fc;

  /* Typography */
  --font-mono:   'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-body:   'IBM Plex Sans', 'Segoe UI', system-ui, sans-serif;
  --font-display:'IBM Plex Mono', var(--font-mono);

  /* Spacing */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2rem;
  --space-2xl: 3rem;
  --space-3xl: 5rem;

  /* Layout */
  --max-width:        720px;
  --max-width-wide:   1100px;
  --sidebar-width:    260px;
  --radius:           6px;
  --radius-lg:        12px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
}

/* =============================================
   RESET & BASE
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  min-height: 100vh;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--color-accent-hover); }

/* =============================================
   TYPOGRAPHY
   ============================================= */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--color-heading);
  line-height: 1.3;
  font-weight: 600;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(1.6rem, 4vw, 2.4rem); }
h2 { font-size: clamp(1.3rem, 3vw, 1.8rem); margin-top: var(--space-2xl); margin-bottom: var(--space-md); }
h3 { font-size: 1.25rem; margin-top: var(--space-xl); margin-bottom: var(--space-sm); }
h4 { font-size: 1.05rem; margin-top: var(--space-lg); margin-bottom: var(--space-sm); }

p { margin-bottom: var(--space-md); }

/* =============================================
   HEADER / NAVIGATION
   ============================================= */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.header-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
}

.site-branding a {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-heading);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.site-branding a::before {
  content: '>';
  color: var(--color-accent);
  font-size: 1rem;
}

.site-branding a:hover { color: var(--color-accent); }

.main-nav ul {
  list-style: none;
  display: flex;
  gap: var(--space-lg);
  align-items: center;
}

.main-nav a {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-text-muted);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius);
  transition: color 0.2s, background 0.2s;
  letter-spacing: 0.03em;
}

.main-nav a:hover,
.main-nav .current-menu-item a {
  color: var(--color-accent);
  background: var(--color-accent-dim);
}

.rss-link {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-orange) !important;
  border: 1px solid var(--color-orange);
  padding: 3px 10px !important;
  border-radius: 20px;
  transition: background 0.2s !important;
}
.rss-link:hover { background: rgba(240,136,62,0.12) !important; }

/* =============================================
   LAYOUT
   ============================================= */
.site-main {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  gap: var(--space-2xl);
  align-items: start;
}

.site-main.full-width {
  grid-template-columns: 1fr;
  max-width: var(--max-width);
}

/* =============================================
   POSTS LIST (HOME / ARCHIVE)
   ============================================= */
.posts-list { display: flex; flex-direction: column; gap: var(--space-md); }

.post-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
}

.post-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 3px; height: 100%;
  background: var(--color-accent);
  opacity: 0;
  transition: opacity 0.2s;
}

.post-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.post-card:hover::before { opacity: 1; }

.post-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.post-card-meta .reading-time::before { content: '· '; }

.post-card-title {
  font-size: 1.2rem;
  margin-bottom: var(--space-sm);
  margin-top: 0;
}
.post-card-title a { color: var(--color-heading); }
.post-card-title a:hover { color: var(--color-accent); }

.post-card-excerpt {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.65;
  margin-bottom: var(--space-md);
}

.post-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

/* =============================================
   TAGS
   ============================================= */
.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  border: 1px solid var(--color-tag-border);
  padding: 2px 10px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  transition: background 0.2s, border-color 0.2s;
}
.tag-pill::before { content: '#'; opacity: 0.6; }
.tag-pill:hover {
  background: var(--color-accent-dim);
  border-color: var(--color-accent);
  color: var(--color-accent-hover);
}

/* =============================================
   SINGLE POST
   ============================================= */
.single-post-header {
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-xl);
}

.single-post-header .post-category {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}

.single-post-header h1 {
  margin-bottom: var(--space-lg);
}

.post-meta-bar {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  flex-wrap: wrap;
}

.post-meta-bar span { display: flex; align-items: center; gap: 5px; }

.post-content {
  line-height: 1.8;
}

.post-content p { margin-bottom: var(--space-lg); }
.post-content ul, .post-content ol {
  padding-left: var(--space-xl);
  margin-bottom: var(--space-lg);
}
.post-content li { margin-bottom: var(--space-xs); }

.post-content blockquote {
  border-left: 3px solid var(--color-accent);
  padding: var(--space-md) var(--space-lg);
  margin: var(--space-xl) 0;
  background: var(--color-surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--color-text-muted);
  font-style: italic;
}

.post-content code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--color-code-bg);
  border: 1px solid var(--color-border);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--color-green);
}

.post-content pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  overflow-x: auto;
  margin: var(--space-xl) 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
}

.post-content pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--color-text);
}

.post-content img {
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  margin: var(--space-xl) auto;
}

.post-content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-xl) 0;
  font-size: 0.9rem;
}
.post-content th {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
}
.post-content td {
  border: 1px solid var(--color-border);
  padding: var(--space-sm) var(--space-md);
}
.post-content tr:hover td { background: var(--color-surface); }

.post-tags-footer {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.post-tags-footer h3 {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 var(--space-sm) 0;
}

.post-tags-footer .tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

/* =============================================
   SIDEBAR
   ============================================= */
.sidebar {
  position: sticky;
  top: 80px;
}

.sidebar-widget {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.sidebar-widget h3 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-top: 0;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}

/* Tags Cloud Widget */
.tags-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

/* Recent Posts Widget */
.recent-posts-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.recent-posts-list li {
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border);
}
.recent-posts-list li:last-child { border-bottom: none; padding-bottom: 0; }

.recent-posts-list a {
  font-size: 0.88rem;
  color: var(--color-text);
  font-weight: 500;
  display: block;
  margin-bottom: 2px;
}
.recent-posts-list a:hover { color: var(--color-accent); }

.recent-posts-list .post-date {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-text-muted);
}

/* RSS Widget */
.rss-widget-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  background: rgba(240,136,62,0.08);
  border: 1px solid rgba(240,136,62,0.25);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  color: var(--color-orange);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  transition: background 0.2s;
}
.rss-widget-link:hover { background: rgba(240,136,62,0.15); color: var(--color-orange); }

/* =============================================
   ABOUT PAGE
   ============================================= */
.about-page {
  max-width: var(--max-width);
  margin: 0 auto;
}

.about-hero {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: var(--space-2xl);
  align-items: start;
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-2xl);
  border-bottom: 1px solid var(--color-border);
}

.about-avatar {
  position: relative;
}

.about-avatar img {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-border);
}

.about-avatar-placeholder {
  width: 180px;
  height: 180px;
  background: var(--color-surface-2);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: var(--color-text-muted);
}

.about-intro h1 { margin-bottom: var(--space-sm); }
.about-intro .tagline {
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-size: 0.9rem;
  margin-bottom: var(--space-lg);
}

.about-links {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-top: var(--space-lg);
}

.about-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  padding: 6px 14px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  transition: border-color 0.2s, color 0.2s;
}
.about-link:hover { border-color: var(--color-accent); color: var(--color-accent); }

.about-content { line-height: 1.8; }
.about-content h2 { margin-top: var(--space-2xl); }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: var(--space-sm);
  margin: var(--space-lg) 0;
}

.skill-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-align: center;
  transition: border-color 0.2s, color 0.2s;
}
.skill-item:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* =============================================
   TAG ARCHIVE PAGE
   ============================================= */
.tag-archive-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
}

.tag-archive-header .label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-sm);
}

.tag-archive-header h1 { margin-bottom: var(--space-sm); }
.tag-archive-header h1 .tag-name { color: var(--color-accent); }
.tag-archive-header .count {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

/* =============================================
   PAGINATION
   ============================================= */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.pagination .page-numbers {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  border: 1px solid transparent;
  transition: all 0.2s;
}
.pagination .page-numbers:hover,
.pagination .page-numbers.current {
  background: var(--color-accent-dim);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* =============================================
   FOOTER
   ============================================= */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) var(--space-xl);
  margin-top: var(--space-3xl);
}

.footer-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
}
.footer-links a:hover { color: var(--color-accent); }

/* =============================================
   NO POSTS
   ============================================= */
.no-posts {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.no-posts::before {
  content: '404';
  display: block;
  font-size: 4rem;
  color: var(--color-border);
  margin-bottom: var(--space-lg);
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 900px) {
  .site-main {
    grid-template-columns: 1fr;
  }
  .sidebar { position: static; }
}

@media (max-width: 640px) {
  .header-inner { padding: 0 var(--space-md); }
  .site-main { padding: var(--space-lg) var(--space-md); }
  .about-hero { grid-template-columns: 1fr; }
  .about-avatar { margin: 0 auto; }
  .main-nav { display: none; }
}