/* ==========================================================================
   TechBlog — Layout & Responsive (layout.css)
   ==========================================================================
   Structural layout primitives, grid systems, and responsive breakpoints.
   ========================================================================== */

/* --------------------------------------------------------------------------
   Container
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-5);
  padding-right: var(--space-5);
}

.container--narrow {
  max-width: 800px;
}

.container--wide {
  max-width: 1400px;
}

/* --------------------------------------------------------------------------
   Grid System
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--space-5);
}

/* Auto-fill responsive grid — cards flow naturally */
.grid--auto {
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}

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

.grid--3col {
  grid-template-columns: repeat(3, 1fr);
}

.grid--4col {
  grid-template-columns: repeat(4, 1fr);
}

/* --------------------------------------------------------------------------
   Main Layout — Content + Sidebar
   -------------------------------------------------------------------------- */
.main-layout {
  display: grid;
  grid-template-columns: 3fr 1fr;
  gap: var(--space-7);
  align-items: start;
}

.main-layout__content {
  min-width: 0; /* prevent grid blowout */
}

.main-layout__sidebar {
  min-width: 0;
}

/* --------------------------------------------------------------------------
   Article Layout — Content + TOC
   -------------------------------------------------------------------------- */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: var(--space-7);
  align-items: start;
}

.article-layout__content {
  min-width: 0;
}

.article-layout__aside {
  min-width: 0;
}

/* --------------------------------------------------------------------------
   Section Spacing
   -------------------------------------------------------------------------- */
.section {
  padding-top: var(--space-7);
  padding-bottom: var(--space-7);
}

.section--lg {
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
}

.section__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.section__title {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
}

.section__link {
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-accent-primary);
  transition: opacity var(--transition-fast);
}

.section__link:hover {
  opacity: 0.8;
}

/* --------------------------------------------------------------------------
   Page Body Offset (for fixed navbar)
   -------------------------------------------------------------------------- */
.page-body {
  padding-top: 72px;
}

/* --------------------------------------------------------------------------
   Divider
   -------------------------------------------------------------------------- */
.divider {
  width: 100%;
  height: 1px;
  background: var(--color-border);
  border: none;
  margin: var(--space-6) 0;
}

/* --------------------------------------------------------------------------
   Screen Reader Only
   -------------------------------------------------------------------------- */
.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;
}

/* ==========================================================================
   RESPONSIVE — Tablet (max-width: 1024px)
   ========================================================================== */
@media (max-width: 1024px) {
  /* Sidebar drops below main content */
  .main-layout {
    grid-template-columns: 1fr;
  }

  .main-layout__sidebar {
    order: 2;
  }

  /* Article TOC drops below */
  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-layout__aside {
    order: -1;
  }

  /* Sidebar un-sticks */
  .sidebar {
    position: static;
  }

  .toc {
    position: static;
  }

  /* Grid adjustments */
  .grid--3col {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid--4col {
    grid-template-columns: repeat(2, 1fr);
  }

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

  /* Footer adjustments */
  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ==========================================================================
   RESPONSIVE — Mobile (max-width: 768px)
   ========================================================================== */
@media (max-width: 768px) {
  /* Typography scale down */
  :root {
    --text-4xl: 1.875rem;
    --text-5xl: 2.25rem;
  }

  .container {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }

  /* Navbar: show hamburger, hide menu */
  .navbar {
    padding: 0;
  }

  .navbar__inner {
    padding: var(--space-3) 0;
  }

  .navbar__hamburger {
    display: flex;
  }

  .navbar__menu {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: var(--space-6);
    padding-top: var(--space-7);
    background: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: var(--z-navbar);
  }

  .navbar__menu--open {
    transform: translateX(0);
  }

  .navbar__menu .navbar__link {
    font-size: var(--text-lg);
  }

  .navbar__search {
    display: none;
  }

  /* Single-column everything */
  .grid--2col,
  .grid--3col,
  .grid--4col {
    grid-template-columns: 1fr;
  }

  .grid--auto {
    grid-template-columns: 1fr;
  }

  .related-posts__grid {
    grid-template-columns: 1fr;
  }

  /* Hero adjustments */
  .hero {
    min-height: 50vh;
    padding: var(--space-6) var(--space-4);
  }

  .hero__title {
    font-size: var(--text-3xl);
  }

  .hero__excerpt {
    font-size: var(--text-base);
  }

  /* Article adjustments */
  .article-header__title {
    font-size: var(--text-2xl);
  }

  .article-content {
    font-size: var(--text-base);
  }

  /* Section spacing */
  .section {
    padding-top: var(--space-6);
    padding-bottom: var(--space-6);
  }

  .section--lg {
    padding-top: var(--space-7);
    padding-bottom: var(--space-7);
  }

  /* Footer */
  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .footer__bottom-inner {
    flex-direction: column;
    gap: var(--space-3);
    text-align: center;
  }

  .footer__bottom-links {
    justify-content: center;
  }

  /* Newsletter */
  .newsletter__form {
    flex-direction: column;
  }

  .newsletter {
    padding: var(--space-6) var(--space-5);
  }

  /* Share buttons wrap */
  .share-buttons {
    flex-wrap: wrap;
  }
}

/* ==========================================================================
   RESPONSIVE — Small Mobile (max-width: 480px)
   ========================================================================== */
@media (max-width: 480px) {
  /* Tighter padding */
  .container {
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }

  /* Further reduce typography */
  :root {
    --text-3xl: 1.5rem;
    --text-4xl: 1.75rem;
    --text-5xl: 2rem;
  }

  /* Compact cards */
  .card__body {
    padding: var(--space-4);
  }

  .card__title {
    font-size: var(--text-base);
  }

  .card__excerpt {
    font-size: var(--text-xs);
    -webkit-line-clamp: 2;
  }

  /* Hero tighter */
  .hero {
    min-height: 40vh;
    padding: var(--space-5) var(--space-3);
    margin-top: 60px;
  }

  .hero__title {
    font-size: var(--text-2xl);
  }

  .hero__meta {
    flex-wrap: wrap;
    gap: var(--space-2);
  }

  /* Article header */
  .article-header {
    margin-top: 60px;
    padding: var(--space-6) 0 var(--space-5);
  }

  .article-header__title {
    font-size: var(--text-xl);
  }

  /* Filter bar smaller pills */
  .filter-btn {
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
  }

  /* Sidebar section */
  .sidebar__section {
    padding: var(--space-4);
  }

  /* Buttons */
  .btn {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-xs);
  }

  .btn--lg {
    padding: var(--space-3) var(--space-5);
    font-size: var(--text-sm);
  }

  /* Pagination */
  .pagination__btn {
    width: 36px;
    height: 36px;
    font-size: var(--text-xs);
  }
}

/* ==========================================================================
   RESPONSIVE — Landscape Phone / Short Viewports
   ========================================================================== */
@media (max-height: 500px) and (orientation: landscape) {
  .hero {
    min-height: auto;
    padding: var(--space-5) var(--space-4);
  }
}

/* ==========================================================================
   PRINT STYLES
   ========================================================================== */
@media print {
  .navbar,
  .sidebar,
  .toc,
  .footer,
  .newsletter,
  .share-buttons,
  .back-to-top,
  .filter-bar,
  .theme-toggle {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

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

  .article-content a::after {
    content: ' (' attr(href) ')';
    font-size: 0.8em;
    color: #666;
  }
}