/* ===================================================================
   CSS CUSTOM PROPERTIES (Theme Colors)
   =================================================================== */
:root {
  --color-primary: #3B82F6;
  --color-primary-hover: #2563EB;
  --color-primary-light: #EFF6FF;
  --color-secondary: #6366F1;
  --color-accent: #1E293B;
  --color-background: #FFFFFF;
  --color-surface: #F8FAFC;
  --color-text: #1E293B;
  --color-text-muted: #64748B;
  --color-border: #CBD5E1;
  --color-header-bg: #1E293B;
  --color-header-text: #F8FAFC;

  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --container-max: 1120px;
  --content-max: 760px;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
  --transition: 150ms ease;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-background);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, picture, video, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-hover); }

/* ===================================================================
   LAYOUT
   =================================================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.main {
  min-height: 60vh;
  padding: 2.5rem 0 4rem;
}

/* ===================================================================
   HEADER
   =================================================================== */
.header {
  background: var(--color-header-bg);
  border-bottom: 2px solid var(--color-primary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo { display: flex; align-items: center; gap: 0.5rem; }
.logo img {
  height: 36px;
  width: auto;
  max-width: 180px;
  object-fit: contain;
  image-rendering: -webkit-optimize-contrast;
}
.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-header-text);
}

.nav-main {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link {
  padding: 0.5rem 0.875rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-header-text);
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
  opacity: 0.85;
}

.nav-link:hover {
  opacity: 1;
  background: rgba(255,255,255,0.1);
  color: var(--color-header-text);
}

.nav-link:first-child {
  opacity: 1;
  font-weight: 600;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-header-text);
  padding: 0.5rem;
}

/* Mobile nav */
@media (max-width: 768px) {
  .menu-toggle { display: block; }
  .nav-main {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-header-bg);
    border-bottom: 2px solid var(--color-primary);
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow-md);
  }
  .nav-main.nav-open { display: flex; }
  .nav-link {
    width: 100%;
    padding: 0.75rem 1rem;
  }
}

/* ===================================================================
   FOOTER
   =================================================================== */
.footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  text-align: center;
}

.footer-brand strong {
  font-size: 1.1rem;
  color: var(--color-accent);
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: 0.25rem;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem 1.5rem;
}

.footer-nav a {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-nav a:hover { color: var(--color-primary); }

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ===================================================================
   TYPOGRAPHY (Prose / Article Content)
   =================================================================== */
.prose { max-width: var(--content-max); }

.prose h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.25;
  margin-bottom: 1rem;
}

.prose h2 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.prose h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.prose p {
  margin-bottom: 1.25rem;
}

.prose ul, .prose ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.prose li {
  margin-bottom: 0.5rem;
}

.prose li strong {
  color: var(--color-accent);
}

.prose blockquote {
  border-left: 4px solid var(--color-primary);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: var(--color-surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--color-text-muted);
}

.prose img {
  border-radius: var(--radius-lg);
  margin: 2rem auto;
  box-shadow: var(--shadow);
}

.prose a { text-decoration: underline; text-underline-offset: 2px; }
.prose a:hover { text-decoration-color: var(--color-primary-hover); }

.prose code {
  background: var(--color-surface);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
}

.prose pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: 1.25rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.5rem 0;
}

.prose pre code {
  background: none;
  padding: 0;
  font-size: 0.875rem;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

.prose th, .prose td {
  border: 1px solid var(--color-border);
  padding: 0.625rem 0.875rem;
  text-align: left;
}

.prose th {
  background: var(--color-surface);
  font-weight: 600;
}

/* ===================================================================
   PAGE HEADER
   =================================================================== */
.page-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.page-header p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

/* ===================================================================
   ARTICLE CARD (Homepage & Category pages)
   =================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .articles-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .articles-grid { grid-template-columns: repeat(3, 1fr); }
}

.article-card {
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: box-shadow var(--transition), border-color var(--transition);
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.article-card-category {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

.article-card h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.article-card h2 a {
  color: inherit;
  text-decoration: none;
}

.article-card h2 a:hover { color: var(--color-primary); }

.article-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  flex: 1;
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.article-card-meta .read-more-link {
  margin-left: auto;
  color: var(--color-primary);
  font-weight: 500;
}

.article-card-meta .read-more-link:hover {
  color: var(--color-primary-hover);
}

/* ===================================================================
   ARTICLE PAGE
   =================================================================== */
.article-header {
  margin-bottom: 2rem;
}

.article-header .category-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  margin-bottom: 0.75rem;
}

.article-header h1 {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.25;
  margin-bottom: 1rem;
}

@media (max-width: 640px) {
  .article-header h1 { font-size: 1.75rem; }
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 1.5rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border);
}

.article-tags a, .tag {
  display: inline-block;
  font-size: 0.8rem;
  padding: 0.25rem 0.75rem;
  background: var(--color-surface);
  color: var(--color-text-muted);
  border-radius: 9999px;
  border: 1px solid var(--color-border);
  transition: all var(--transition);
}

.article-tags a:hover, .tag:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ===================================================================
   ADSENSE CONTAINERS
   — Hidden by default, expands only when ad is filled
   =================================================================== */
.ad-container,
.ad-container-article {
  text-align: center;
  margin: 0;
  height: 0;
  overflow: hidden;
}

/* Show container only when AdSense fills the slot */
.ad-container:has(ins[data-ad-status="filled"]),
.ad-container-article:has(ins[data-ad-status="filled"]) {
  margin: 2rem 0;
  height: auto;
  overflow: visible;
}

/* ===================================================================
   INFO BOX (used in institutional pages)
   =================================================================== */
.info-box {
  background: var(--color-surface);
  padding: 1.25rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  margin-top: 2rem;
}

.info-box p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0;
}

.info-box strong { color: var(--color-text); }
.info-box a { color: var(--color-primary); text-decoration: underline; }

/* ===================================================================
   BREADCRUMB
   =================================================================== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
}

.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb span { margin: 0 0.25rem; }

/* ===================================================================
   CATEGORY FILTER (Homepage)
   =================================================================== */
.category-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.category-nav a {
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.4rem 1rem;
  border-radius: 9999px;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  transition: all var(--transition);
}

.category-nav a:hover,
.category-nav a.active {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-light);
}

/* ===================================================================
   UTILITIES
   =================================================================== */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.text-primary { color: var(--color-primary); }
.text-muted { color: var(--color-text-muted); }
.text-sm { font-size: 0.875rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mt-8 { margin-top: 2rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-8 { margin-bottom: 2rem; }
.font-bold { font-weight: 700; }

/* RTL Support */
[dir="rtl"] .breadcrumb,
[dir="rtl"] .article-meta,
[dir="rtl"] .footer-nav,
[dir="rtl"] .category-nav { direction: rtl; }

[dir="rtl"] .prose blockquote {
  border-left: none;
  border-right: 4px solid var(--color-primary);
  border-radius: var(--radius) 0 0 var(--radius);
}

[dir="rtl"] .prose ul, [dir="rtl"] .prose ol {
  padding-left: 0;
  padding-right: 1.5rem;
}