/* ==========================================================================
   Base CSS — Reset, Typography, Layout Primitives
   ==========================================================================
   This file provides a clean foundation. Theme stylesheets should be loaded
   after this file and can override any of the custom properties or rules
   defined below.
   ========================================================================== */

/* ---------------------------------------------------------------------------
   Custom Properties (Design Tokens)
   Themes override these to change the entire look.
   --------------------------------------------------------------------------- */
:root {
  /* Colors — neutral palette; themes replace these */
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-text: #1a1a2e;
  --color-text-muted: #6b7280;
  --color-heading: #111827;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-border: #e5e7eb;
  --color-link: var(--color-primary);
  --color-link-hover: var(--color-primary-hover);

  /* Typography */
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    monospace;
  --font-body: var(--font-sans);
  --font-heading: var(--font-sans);

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;

  --leading-tight: 1.25;
  --leading-normal: 1.6;
  --leading-relaxed: 1.75;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Layout */
  --max-width: 1200px;
  --max-width-content: 720px;
  --container-padding: var(--space-4);

  /* Borders & Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -4px rgba(0, 0, 0, 0.1);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

/* ---------------------------------------------------------------------------
   Reset
   Based on modern-normalize with additional opinionated resets.
   --------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  -moz-tab-size: 4;
  tab-size: 4;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: none;
}

a {
  color: var(--color-link);
  text-decoration: underline;
  text-decoration-skip-ink: auto;
  text-underline-offset: 0.15em;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-link-hover);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  color: var(--color-heading);
  line-height: var(--leading-tight);
  overflow-wrap: break-word;
}

p {
  overflow-wrap: break-word;
}

ul,
ol {
  list-style: none;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--space-8) 0;
}

/* ---------------------------------------------------------------------------
   Accessibility
   --------------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 1000;
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: #fff;
  text-decoration: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-4);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

/* ---------------------------------------------------------------------------
   Typography — Prose (article content)
   --------------------------------------------------------------------------- */
.prose {
  max-width: var(--max-width-content);
  font-size: var(--text-lg);
  line-height: var(--leading-relaxed);
}

.prose > * + * {
  margin-top: 1.25em;
}

.prose h2 {
  font-size: var(--text-2xl);
  margin-top: 2em;
  margin-bottom: 0.75em;
}

.prose h3 {
  font-size: var(--text-xl);
  margin-top: 1.75em;
  margin-bottom: 0.5em;
}

.prose h4 {
  font-size: var(--text-lg);
  margin-top: 1.5em;
  margin-bottom: 0.5em;
}

.prose ul,
.prose ol {
  padding-left: 1.5em;
}

.prose ul {
  list-style-type: disc;
}

.prose ol {
  list-style-type: decimal;
}

.prose li + li {
  margin-top: 0.5em;
}

.prose blockquote {
  border-left: 4px solid var(--color-primary);
  padding: var(--space-4) var(--space-6);
  margin-left: 0;
  margin-right: 0;
  background: var(--color-surface);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
  color: var(--color-text-muted);
}

.prose pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: var(--space-4);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-surface);
  padding: 0.125em 0.375em;
  border-radius: var(--radius-sm);
}

.prose pre code {
  background: transparent;
  padding: 0;
  font-size: inherit;
}

.prose img {
  border-radius: var(--radius-md);
}

.prose a {
  font-weight: 500;
}

.prose table {
  width: 100%;
  font-size: var(--text-base);
}

.prose th,
.prose td {
  padding: var(--space-2) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

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

/* ---------------------------------------------------------------------------
   Layout Utilities
   --------------------------------------------------------------------------- */
.section {
  padding: var(--space-16) 0;
}

.section-container,
.header-container,
.footer-container,
.page-header-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section-title {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-8);
}

.section-cta {
  text-align: center;
  margin-top: var(--space-8);
}

/* ---------------------------------------------------------------------------
   Buttons
   --------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast),
    color var(--transition-fast), box-shadow var(--transition-fast);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  color: #fff;
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background-color: var(--color-primary);
  color: #fff;
}

/* ---------------------------------------------------------------------------
   Site Header
   --------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

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

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.site-logo {
  text-decoration: none;
  font-weight: 700;
  font-size: var(--text-xl);
  color: var(--color-heading);
}

.site-logo:hover {
  color: var(--color-primary);
}

.site-city {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-weight: 500;
}

.nav-list {
  display: flex;
  gap: var(--space-6);
}

.nav-link {
  text-decoration: none;
  color: var(--color-text);
  font-weight: 500;
  font-size: var(--text-sm);
  padding: var(--space-1) 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-link:hover,
.nav-link--active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 4px;
}

.hamburger-line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition-base), opacity var(--transition-base),
      visibility var(--transition-base);
  }

  .site-nav--open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-list {
    flex-direction: column;
    padding: var(--space-4);
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: var(--space-3) var(--space-4);
    border-bottom: none;
    border-radius: var(--radius-sm);
  }

  .nav-link:hover,
  .nav-link--active {
    background: var(--color-surface);
    border-bottom-color: transparent;
  }
}

/* ---------------------------------------------------------------------------
   Hero
   --------------------------------------------------------------------------- */
.hero {
  padding: var(--space-20) 0;
  background: var(--color-surface);
  text-align: center;
}

.hero-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.hero-title {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

.hero-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* ---------------------------------------------------------------------------
   Page Header (non-home pages)
   --------------------------------------------------------------------------- */
.page-header {
  padding: var(--space-16) 0 var(--space-8);
  background: var(--color-surface);
}

.page-title {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-3);
}

.page-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
}

/* ---------------------------------------------------------------------------
   Article Card
   --------------------------------------------------------------------------- */
.articles-grid,
.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-8);
}

.article-card {
  display: flex;
  flex-direction: column;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition-base),
    transform var(--transition-base);
}

.article-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.article-card-image-link {
  display: block;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.article-card-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.article-card:hover .article-card-image {
  transform: scale(1.03);
}

.article-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: var(--space-6);
}

.article-card-categories {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.article-card-category {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
}

.article-card-title {
  font-size: var(--text-xl);
  margin-bottom: var(--space-3);
  line-height: var(--leading-tight);
}

.article-card-link {
  text-decoration: none;
  color: var(--color-heading);
}

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

.article-card-excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-normal);
  flex: 1;
  margin-bottom: var(--space-4);
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: auto;
}

.meta-separator {
  color: var(--color-border);
}

/* ---------------------------------------------------------------------------
   Article Page
   --------------------------------------------------------------------------- */
.article {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-12) var(--container-padding);
}

.article-header {
  max-width: var(--max-width-content);
  margin-bottom: var(--space-8);
}

.article-categories {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.article-category {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  text-decoration: none;
}

.article-category:hover {
  text-decoration: underline;
}

.article-title {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.article-description {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-top: var(--space-4);
  line-height: var(--leading-relaxed);
}

.article-hero {
  margin-bottom: var(--space-8);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.article-hero-image {
  width: 100%;
}

.article-hero-caption {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  padding: var(--space-2) 0;
  text-align: center;
}

.article-content {
  max-width: var(--max-width-content);
}

.article-footer {
  max-width: var(--max-width-content);
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.article-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.article-tags-label {
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.article-tag {
  font-size: var(--text-sm);
  color: var(--color-primary);
  text-decoration: none;
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast),
    border-color var(--transition-fast);
}

.article-tag:hover {
  background: var(--color-surface);
  border-color: var(--color-primary);
}

.article-updated {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-4);
}

/* ---------------------------------------------------------------------------
   Article Pagination
   --------------------------------------------------------------------------- */
.article-pagination {
  max-width: var(--max-width-content);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.pagination-prev,
.pagination-next {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-4);
  text-decoration: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.pagination-prev:hover,
.pagination-next:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.pagination-next {
  text-align: right;
  grid-column: 2;
}

.pagination-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.pagination-title {
  font-size: var(--text-sm);
  color: var(--color-heading);
  font-weight: 600;
}

/* ---------------------------------------------------------------------------
   Article Figure (shortcode)
   --------------------------------------------------------------------------- */
.article-figure {
  margin: var(--space-8) 0;
}

.article-figure img {
  border-radius: var(--radius-md);
}

.article-figure figcaption {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-align: center;
  margin-top: var(--space-2);
}

/* ---------------------------------------------------------------------------
   Category Badge
   --------------------------------------------------------------------------- */
.categories-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.category-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: background-color var(--transition-fast),
    border-color var(--transition-fast);
}

.category-badge:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* ---------------------------------------------------------------------------
   Empty State
   --------------------------------------------------------------------------- */
.empty-state {
  text-align: center;
  padding: var(--space-16) var(--space-4);
}

.empty-state-text {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 480px;
  margin: 0 auto;
}

/* ---------------------------------------------------------------------------
   About Section (homepage)
   --------------------------------------------------------------------------- */
.about-content {
  max-width: var(--max-width-content);
}

.about-content p {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
}

/* ---------------------------------------------------------------------------
   Site Footer
   --------------------------------------------------------------------------- */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-16);
}

.footer-main {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-brand {
  max-width: 360px;
}

.footer-logo {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-heading);
  text-decoration: none;
  display: inline-block;
  margin-bottom: var(--space-4);
}

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

.footer-description {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-relaxed);
}

.footer-nav-group {
  display: contents;
}

.footer-heading {
  font-size: var(--text-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-heading);
  margin-bottom: var(--space-4);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.social-links {
  display: flex;
  gap: var(--space-4);
}

.social-link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.social-link:hover {
  color: var(--color-primary);
}

.footer-bottom {
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

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

.footer-city-info {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

@media (max-width: 768px) {
  .footer-main {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .footer-nav-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ---------------------------------------------------------------------------
   Responsive
   --------------------------------------------------------------------------- */
@media (max-width: 640px) {
  :root {
    --text-4xl: 1.875rem;
    --text-3xl: 1.5rem;
  }

  .hero {
    padding: var(--space-12) 0;
  }

  .section {
    padding: var(--space-12) 0;
  }

  .articles-grid,
  .featured-grid {
    grid-template-columns: 1fr;
  }

  .article-pagination {
    grid-template-columns: 1fr;
  }

  .pagination-next {
    grid-column: 1;
    text-align: left;
  }
}

/* ---------------------------------------------------------------------------
   Print Styles
   --------------------------------------------------------------------------- */
@media print {
  .site-header,
  .site-footer,
  .mobile-menu-toggle,
  .article-pagination,
  .skip-link {
    display: none !important;
  }

  body {
    font-size: 12pt;
    line-height: 1.5;
    color: #000;
    background: #fff;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  .article {
    max-width: 100%;
    padding: 0;
  }

  .article-content {
    max-width: 100%;
  }
}