/* Deep Sleep Source Design Tokens */

:root {
  /* Colors */
  --color-background: #FDF8F3;
  --color-background-alt: #E6E0F0;
  --color-accent-primary: #8B7355;
  --color-accent-secondary: #B8C9B8;
  --color-text-primary: #3D4A5C;
  --color-text-muted: #6B6157;
  --color-text-light: #5D6B8A;
  --color-border: rgba(93, 107, 138, 0.1);
  --color-border-strong: rgba(93, 107, 138, 0.15);

  /* Typography */
  --font-serif: 'Source Serif 4', Georgia, serif;
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Layout */
  --max-width: 1200px;
  --max-width-article: 720px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  font-family: var(--font-serif);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.6;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text-primary);
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-md);
}

p {
  margin-bottom: var(--spacing-lg);
}

a {
  color: inherit;
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

a:hover {
  opacity: 0.7;
}

/* Focus States for Accessibility */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 3px;
  opacity: 1;
}

.nav-link:focus-visible,
.category-tag:focus-visible {
  border-radius: 3px;
}

.topic-card:focus-visible {
  outline-offset: 2px;
}

.back-to-top:focus-visible {
  outline-color: var(--color-background);
  outline-offset: -4px;
}

/* Underline links only in body text / article content */
.article__content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* Skip Link (Accessibility) */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--spacing-md);
  z-index: 1000;
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-text-primary);
  color: var(--color-background);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 4px;
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--spacing-md);
  opacity: 1;
}

/* Utility Classes */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
}

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

.text-muted {
  color: var(--color-text-muted);
}

.text-light {
  color: var(--color-text-light);
}

.font-sans {
  font-family: var(--font-sans);
}

/* Category Tags */
.category-tag {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--color-accent-primary);
  transition: color var(--transition-fast);
}

.category-tag:hover {
  color: var(--color-text-muted);
  opacity: 1;
}

/* Navigation Link Style */
.nav-link {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  letter-spacing: 0.5px;
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-text-light);
  opacity: 1;
}

/* Blockquotes */
blockquote {
  border-left: 3px solid var(--color-accent-primary);
  padding-left: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
  font-style: italic;
  font-size: 1.15rem;
  color: var(--color-text-primary);
}

blockquote cite {
  display: block;
  margin-top: var(--spacing-sm);
  font-style: normal;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Header */
.header {
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--color-border);
}

.header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header__logo {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.header__logo:hover {
  color: var(--color-text-primary);
  opacity: 1;
}

.header__nav {
  display: flex;
  gap: var(--spacing-xl);
}

/* Footer */
.footer {
  margin-top: var(--spacing-3xl);
  padding: var(--spacing-2xl) 0 var(--spacing-xl);
  border-top: 1px solid var(--color-border);
}

.footer__content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--color-border);
}

.footer__brand {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer__logo {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.footer__tagline {
  font-size: 0.85rem;
}

.footer__nav {
  display: flex;
  gap: var(--spacing-xl);
}

.footer__copyright {
  text-align: center;
  font-size: 0.85rem;
}

/* Section Styles */
.section {
  padding: var(--spacing-2xl) 0;
  border-top: 1px solid var(--color-border);
}

.section__title {
  font-size: 0.75rem;
  font-family: var(--font-sans);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
}

/* Articles Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg) var(--spacing-2xl);
}

/* Topics Grid */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-md);
}

/* Popular List */
.popular-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.popular-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
}

.popular-item__rank {
  font-size: 1.5rem;
  font-weight: 600;
  min-width: 2rem;
}

.popular-item__content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.popular-item__title {
  font-size: 1.05rem;
  font-weight: 500;
  line-height: 1.4;
  transition: color var(--transition-fast);
}

.popular-item__title:hover {
  color: var(--color-text-muted);
  opacity: 1;
}

.popular-item__category {
  font-size: 0.8rem;
  text-transform: capitalize;
}

/* Article Card */
.article-card {
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--color-border);
}

.article-card:last-child {
  border-bottom: none;
}

.article-card__meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xs);
}

.article-card__separator {
  font-size: 0.75rem;
}

.article-card__date {
  font-size: 0.75rem;
}

.article-card__link {
  display: block;
  margin: var(--spacing-sm) 0;
}

.article-card__title {
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.4;
  transition: color var(--transition-fast);
}

.article-card__link:hover .article-card__title {
  color: var(--color-text-muted);
}

.article-card__excerpt {
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
}

/* Featured Article */
.featured {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
  padding: var(--spacing-2xl) 0;
}

.featured__image-container {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: 8px;
}

.featured__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.featured:hover .featured__image {
  transform: scale(1.02);
}

.featured__content {
  padding: var(--spacing-lg) 0;
}

.featured__link {
  display: block;
  margin: var(--spacing-md) 0;
}

.featured__title {
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.25;
  transition: color var(--transition-fast);
}

.featured__link:hover .featured__title {
  color: var(--color-text-muted);
}

.featured__excerpt {
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: var(--spacing-lg);
}

.featured__read-more {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

.featured__read-more:hover {
  color: var(--color-text-muted);
  opacity: 1;
}

/* Topic Card */
.topic-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-lg);
  background: var(--color-background-alt);
  border-radius: 12px;
  text-align: center;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(93, 107, 138, 0.08);
  opacity: 1;
}

.topic-card__icon {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-accent-primary);
}

.topic-card__name {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.topic-card__count {
  font-size: 0.75rem;
}

/* Article Page */
.article {
  padding: var(--spacing-2xl) 0;
}

.article__header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.article__title {
  font-size: 2.5rem;
  line-height: 1.2;
  margin: var(--spacing-md) 0;
}

.article__subtitle {
  font-size: 1.25rem;
  line-height: 1.5;
  margin-bottom: var(--spacing-md);
}

.article__meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  font-size: 0.85rem;
}

.article__separator {
  font-size: 0.75rem;
}

.article__read-time {
  font-size: 0.85rem;
}

.article__image-container {
  max-width: 1000px;
  margin: 0 auto var(--spacing-2xl);
}

.article__image {
  width: 100%;
  height: auto;
  border-radius: 8px;
}

.article__caption {
  text-align: center;
  font-size: 0.9rem;
  margin-top: var(--spacing-sm);
}

.article__content {
  font-size: 1.125rem;
  line-height: 1.8;
}

.article__content h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-md);
}

.article__content p {
  margin-bottom: var(--spacing-lg);
}

.article__content ul,
.article__content ol {
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-lg);
}

.article__content li {
  margin-bottom: var(--spacing-sm);
}

/* Category Page */
.category-header {
  padding: var(--spacing-3xl) 0;
  text-align: center;
  max-width: var(--max-width-article);
  margin: 0 auto;
}

.category-label {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--color-text-muted);
  background: var(--color-background-alt);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 3px;
  margin-bottom: var(--spacing-md);
}

.category-title {
  font-size: 2.5rem;
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

.category-description {
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-sm);
}

.category-count {
  font-size: 0.85rem;
}

.no-articles {
  text-align: center;
  font-size: 1rem;
  padding: var(--spacing-2xl) 0;
}

/* Ad Placeholders - Hidden until ad network is active */
/* To enable: remove display: none and add your ad network code */
.ad-placeholder {
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(230, 224, 240, 0.3);
  border: 1px dashed var(--color-border-strong);
  border-radius: 4px;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  margin: var(--spacing-xl) auto;
}

.ad-placeholder.leaderboard {
  width: 100%;
  max-width: 728px;
  height: 90px;
}

.ad-placeholder.medium-rectangle {
  width: 300px;
  height: 250px;
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-text-primary);
  color: var(--color-background);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--transition-normal), visibility var(--transition-normal), transform var(--transition-normal), background var(--transition-fast);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  z-index: 100;
}

.back-to-top:hover {
  background: var(--color-text-muted);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* Responsive Styles */
@media (max-width: 900px) {
  .articles-grid {
    grid-template-columns: 1fr;
  }

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

  .featured {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .featured__title {
    font-size: 1.5rem;
  }

  .category-title {
    font-size: 2rem;
  }
}

/* Mobile Navigation */
.header__menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  margin-right: calc(-1 * var(--spacing-sm));
}

.header__menu-icon {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  position: relative;
  transition: background var(--transition-fast);
}

.header__menu-icon::before,
.header__menu-icon::after {
  content: '';
  position: absolute;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  left: 0;
  transition: transform var(--transition-fast);
}

.header__menu-icon::before {
  top: -7px;
}

.header__menu-icon::after {
  bottom: -7px;
}

.header__menu-toggle[aria-expanded="true"] .header__menu-icon {
  background: transparent;
}

.header__menu-toggle[aria-expanded="true"] .header__menu-icon::before {
  transform: rotate(45deg) translate(5px, 5px);
}

.header__menu-toggle[aria-expanded="true"] .header__menu-icon::after {
  transform: rotate(-45deg) translate(5px, -5px);
}

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

  .header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-background);
    padding: var(--spacing-lg) var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: var(--spacing-md);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  }

  .header__nav.is-open {
    display: flex;
  }

  .header__nav .nav-link {
    padding: var(--spacing-sm) 0;
    font-size: 1rem;
  }

  .header {
    position: relative;
  }

  .footer__nav {
    display: none;
  }

  .footer__content {
    justify-content: center;
  }

  .footer__brand {
    align-items: center;
  }

  .article__title {
    font-size: 1.75rem;
  }

  .article__subtitle {
    font-size: 1.1rem;
  }

  .article__content {
    font-size: 1rem;
  }

  .ad-placeholder.leaderboard {
    max-width: 300px;
    height: 250px;
  }
}

@media (max-width: 600px) {
  .topics-grid {
    grid-template-columns: 1fr;
  }

  .category-header {
    padding: var(--spacing-2xl) 0;
  }

  .category-title {
    font-size: 1.75rem;
  }

  .category-description {
    font-size: 1rem;
  }
}

/* Search Toggle Button */
.header__search-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.header__search-toggle:hover {
  color: var(--color-text-primary);
}

/* Search Overlay */
.search-overlay {
  position: fixed;
  inset: 0;
  z-index: 999;
  background: rgba(61, 74, 92, 0.6);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 12vh;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.search-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.search-overlay__inner {
  background: var(--color-background);
  border-radius: 12px;
  max-width: 640px;
  width: 100%;
  max-height: 70vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.2);
}

.search-overlay__header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.search-overlay__input {
  flex: 1;
  font-family: var(--font-sans);
  font-size: 1.1rem;
  border: none;
  outline: none;
  background: none;
  color: var(--color-text-primary);
}

.search-overlay__input::placeholder {
  color: var(--color-text-muted);
}

.search-overlay__close {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.search-overlay__close:hover {
  color: var(--color-text-primary);
}

.search-overlay__results {
  overflow-y: auto;
  padding: var(--spacing-md) var(--spacing-lg);
}

.search-hint,
.search-no-results {
  padding: var(--spacing-lg) 0;
  text-align: center;
  font-size: 0.9rem;
}

.search-result {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border);
  text-decoration: none;
  transition: background var(--transition-fast);
}

.search-result:last-child {
  border-bottom: none;
}

.search-result:hover {
  opacity: 1;
}

.search-result:hover .search-result__title {
  color: var(--color-text-muted);
}

.search-result__title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 500;
  line-height: 1.4;
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

.search-result__excerpt {
  font-size: 0.85rem;
  line-height: 1.5;
}

/* Related Articles */
.related-articles {
  margin-top: var(--spacing-3xl);
  padding-top: var(--spacing-2xl);
  border-top: 1px solid var(--color-border);
}

.related-articles__list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}

.related-article {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  text-decoration: none;
}

.related-article:hover {
  opacity: 1;
}

.related-article:hover .related-article__title {
  color: var(--color-text-muted);
}

.related-article__image-container {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border-radius: 6px;
}

.related-article__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.related-article:hover .related-article__image {
  transform: scale(1.03);
}

.related-article__content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.related-article__title {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1.4;
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

@media (max-width: 768px) {
  .related-articles__list {
    grid-template-columns: 1fr;
  }

  .related-article {
    flex-direction: row;
    gap: var(--spacing-md);
  }

  .related-article__image-container {
    width: 120px;
    flex-shrink: 0;
    aspect-ratio: 4 / 3;
  }
}

/* Static Page Content */
.page-content {
  max-width: var(--max-width-article);
  margin: 0 auto;
  padding: var(--spacing-2xl) 0;
}

.page-content h1 {
  font-size: 2rem;
  margin-bottom: var(--spacing-xl);
}

.page-content h2 {
  font-size: 1.35rem;
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-md);
}

.page-content h3 {
  font-size: 1.1rem;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-sm);
}

.page-content p {
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: var(--spacing-lg);
}

.page-content ul,
.page-content ol {
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-lg);
}

.page-content li {
  margin-bottom: var(--spacing-sm);
  line-height: 1.6;
}

.page-content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}