/* ============================================
   Plastic Pollution - Britannica Style
   ============================================ */

:root {
  --color-primary: #0066cc;
  --color-primary-dark: #004c99;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-border: #e0e0e0;
  --color-bg-light: #f8f9fa;
  --color-white: #ffffff;
  --color-accent: #00a878;
  --color-warning: #cc3300;

  --font-serif: "Georgia", "Times New Roman", Times, serif;
  --font-sans: "Helvetica Neue", Helvetica, Arial, sans-serif;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;

  --max-width: 1200px;
  --sidebar-width: 280px;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-serif);
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-white);
}

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

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

/* ============================================
   Header
   ============================================ */
.site-header {
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-sm) 0;
  position: sticky;
  top: 0;
  background: var(--color-white);
  z-index: 1000;
}

.header-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}

/* ============================================
   Language Switcher
   ============================================ */
.language-switcher {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-family: var(--font-sans);
  font-size: 0.875rem;
}

.lang-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-light);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 4px;
  transition: all 0.2s ease;
}

.lang-btn:hover {
  background: var(--color-bg-light);
  color: var(--color-primary);
}

.lang-btn.active {
  color: var(--color-primary);
  background: var(--color-bg-light);
}

.lang-separator {
  color: var(--color-border);
  font-weight: 300;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.5px;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text);
}

/* ============================================
   Main Layout
   ============================================ */
.main-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-lg) var(--spacing-lg);
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  gap: var(--spacing-xl);
}

/* ============================================
   Article Content
   ============================================ */
.article-content {
  min-width: 0;
}

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

.article-category {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-xs);
}

.article-title {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.article-subtitle {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  color: var(--color-text-light);
  line-height: 1.6;
  max-width: 700px;
}

.article-meta {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: var(--spacing-sm);
  padding-top: var(--spacing-sm);
  border-top: 1px solid var(--color-border);
}

/* Hero Image */
.article-hero {
  margin-bottom: var(--spacing-xl);
}

.article-hero img {
  width: 100%;
  height: auto;
  border-radius: 4px;
}

.article-hero-caption {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: var(--spacing-xs);
  line-height: 1.5;
}

/* Article Sections */
.article-section {
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-xs);
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

.article-body {
  font-size: 1.0625rem;
  line-height: 1.8;
}

.article-body p {
  margin-bottom: var(--spacing-md);
}

.article-body strong {
  font-weight: 700;
  color: var(--color-text);
}

.article-body blockquote {
  border-left: 4px solid var(--color-primary);
  padding-left: var(--spacing-md);
  margin: var(--spacing-lg) 0;
  font-style: italic;
  color: var(--color-text-light);
  background: var(--color-bg-light);
  padding: var(--spacing-md);
  border-radius: 0 4px 4px 0;
}

/* Info Box */
.info-box {
  background: var(--color-bg-light);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
}

.info-box-title {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.info-box ul {
  list-style: none;
  padding-left: 0;
}

.info-box li {
  padding: var(--spacing-xs) 0;
  padding-left: var(--spacing-sm);
  position: relative;
}

.info-box li::before {
  content: "•";
  color: var(--color-primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* Key Facts Box */
.key-facts {
  background: linear-gradient(135deg, #f0f7ff 0%, #e8f4f8 100%);
  border: 1px solid #cce5ff;
  border-radius: 8px;
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
}

.key-facts-title {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.key-facts-list {
  list-style: none;
}

.key-facts-list li {
  padding: var(--spacing-xs) 0;
  padding-left: var(--spacing-md);
  position: relative;
}

.key-facts-list li::before {
  content: "✓";
  color: var(--color-accent);
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* Statistics Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin: var(--spacing-lg) 0;
}

.stat-card {
  background: var(--color-bg-light);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: var(--spacing-md);
  text-align: center;
}

.stat-number {
  font-family: var(--font-sans);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

.stat-label {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: var(--spacing-xs);
}

/* Solutions Section */
.solutions-list {
  list-style: none;
  counter-reset: solution-counter;
}

.solutions-list li {
  counter-increment: solution-counter;
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-xl);
  position: relative;
}

.solutions-list li::before {
  content: counter(solution-counter);
  position: absolute;
  left: 0;
  top: 0;
  width: 36px;
  height: 36px;
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1rem;
}

.solution-title {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1.125rem;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text);
}

/* References */
.references-section {
  background: var(--color-bg-light);
  padding: var(--spacing-lg);
  border-radius: 4px;
  margin-top: var(--spacing-xl);
}

.references-list {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  list-style: none;
}

.references-list li {
  padding: var(--spacing-xs) 0;
  word-break: break-all;
}

.references-list a {
  color: var(--color-primary);
}

/* ============================================
   Sidebar
   ============================================ */
.article-sidebar {
  position: relative;
}

.sidebar-sticky {
  position: sticky;
  top: 100px;
}

/* Table of Contents */
.toc-container {
  background: var(--color-bg-light);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.toc-title {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.toc-list {
  list-style: none;
}

.toc-list li {
  margin-bottom: var(--spacing-xs);
}

.toc-list a {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--color-text-light);
  display: block;
  padding: var(--spacing-xs) 0;
  transition: color 0.2s ease;
}

.toc-list a:hover,
.toc-list a.active {
  color: var(--color-primary);
}

.toc-list ul {
  list-style: none;
  padding-left: var(--spacing-sm);
  margin-top: var(--spacing-xs);
}

/* Quick Facts Sidebar */
.quick-facts {
  background: var(--color-white);
  border: 2px solid var(--color-primary);
  border-radius: 4px;
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.quick-facts-title {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
  text-align: center;
}

.quick-facts-list {
  list-style: none;
}

.quick-facts-list li {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  padding: var(--spacing-xs) 0;
  border-bottom: 1px solid var(--color-border);
}

.quick-facts-list li:last-child {
  border-bottom: none;
}

/* Ask Anything Box */
.ask-box {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  border-radius: 8px;
  padding: var(--spacing-lg);
  text-align: center;
}

.ask-box-title {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.ask-box-text {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.9;
}

.ask-box-btn {
  display: inline-block;
  background: var(--color-white);
  color: var(--color-primary);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  padding: var(--spacing-xs) var(--spacing-lg);
  border-radius: 4px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.ask-box-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  text-decoration: none;
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
  background: var(--color-bg-light);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-xl);
}

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

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.footer-section h4 {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  margin-bottom: var(--spacing-xs);
}

.footer-section a {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

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

.footer-bottom {
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-bottom p {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text-light);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 992px) {
  .main-container {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    order: -1;
  }

  .sidebar-sticky {
    position: static;
  }

  .toc-container {
    display: none;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .language-switcher {
    display: none;
  }

  .header-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md);
  }

  .header-nav.active {
    display: block;
  }

  /* Mobile language switcher in nav */
  .header-nav.active .language-switcher {
    display: flex;
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
  }

  .article-title {
    font-size: 1.875rem;
  }

  .article-subtitle {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .main-container {
    padding: var(--spacing-md);
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }

  .article-title {
    font-size: 1.5rem;
  }

  .section-title {
    font-size: 1.25rem;
  }
}

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

.text-center {
  text-align: center;
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.highlight {
  background: linear-gradient(120deg, #fff3cd 0%, #ffe69c 100%);
  padding: 2px 6px;
  border-radius: 2px;
}