/* Layout & Grid Architecture */

/* Accessibility: Skip to Content Link */
.skip-to-content {
  position: absolute;
  top: -100px;
  left: 1rem;
  background-color: var(--primary);
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 700;
  z-index: 9999;
  transition: top 0.2s ease;
  box-shadow: var(--shadow-lg);
}

.skip-to-content:focus {
  top: 1rem;
  outline: 3px solid var(--accent);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

@media (max-width: 640px) {
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }
}

/* ==========================================================================
   Pre-Production Warning Banner
   ========================================================================== */
.preprod-banner {
  background: rgba(217, 119, 6, 0.12);
  border-bottom: 1px solid rgba(217, 119, 6, 0.3);
  font-size: 0.8125rem;
  line-height: 1.45;
  padding: 0.35rem 0;
  position: relative;
  z-index: 101;
  color: var(--text-main);
}

.preprod-container {
  display: block;
}

.preprod-text {
  line-height: 1.5;
}

.preprod-banner .badge {
  display: inline-flex;
  vertical-align: middle;
  margin-right: 0.5rem;
  margin-top: -2px;
  padding: 0.15rem 0.5rem;
  font-size: 0.6875rem;
}

.preprod-link {
  display: inline-flex;
  align-items: center;
  margin-left: 0.5rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  white-space: nowrap;
  transition: color 0.15s ease;
}

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

/* ==========================================================================
   Site Header & Sticky Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

[data-theme="dark"] .site-header {
  background: rgba(11, 15, 25, 0.88);
}

.header-container {
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
}

/* Brand Link: Logo matches height of both text rows combined */
.brand-link {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-shrink: 0;
}

.brand-logo {
  height: 42px;
  width: auto;
  object-fit: contain;
  transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.brand-link:hover .brand-logo {
  transform: scale(1.05);
}

.brand-text {
  display: flex;
  flex-direction: column;
  justify-content: center;
  line-height: 1.15;
}

.brand-name {
  font-size: 1.35rem;
  font-weight: 850;
  letter-spacing: -0.025em;
  color: var(--text-main);
}

.brand-tag {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--accent);
  margin-top: 1px;
}

/* Desktop Navigation */
.desktop-nav {
  display: flex;
  align-items: center;
}

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

.nav-link {
  display: inline-block;
  padding: 0.45rem 0.75rem;
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-md);
  transition: color 0.15s ease, background-color 0.15s ease;
}

.nav-link:hover {
  color: var(--text-main);
  background-color: var(--bg-subtle);
}

.nav-link.active {
  color: var(--accent);
  background-color: var(--primary-light);
  font-weight: 600;
}

/* Header Actions (Tightened, Zero Dead Space) */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Compact GitHub Star Button */
.github-header-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.38rem 0.65rem;
  border-radius: var(--radius-md);
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.15s ease;
}

.github-header-btn:hover {
  background-color: var(--bg-subtle);
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

.github-label {
  font-size: 0.8rem;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  transition: color 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}

.theme-toggle-btn:hover {
  color: var(--text-main);
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

/* Mobile Hamburger Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  gap: 4px;
  padding: 7px;
}

.hamburger-bar {
  display: block;
  width: 18px;
  height: 2px;
  background-color: var(--text-main);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-bar:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Mobile Navigation Drawer */
.mobile-nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 300px;
  max-width: 85vw;
  height: 100vh;
  height: 100dvh;
  background-color: var(--bg-surface);
  border-left: 1px solid var(--border-color);
  z-index: 105;
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  visibility: hidden;
  pointer-events: none;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.3s ease;
  overflow-y: auto;
  padding: 5rem 1.5rem 2rem 1.5rem;
}

.mobile-nav-drawer.open {
  transform: translateX(0);
  visibility: visible;
  pointer-events: auto;
}

.mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.mobile-nav-link {
  display: block;
  padding: 0.75rem 1rem;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-md);
  transition: color 0.15s ease, background-color 0.15s ease;
}

.mobile-nav-link:hover, .mobile-nav-link.active {
  color: var(--accent);
  background-color: var(--primary-light);
  font-weight: 600;
}

.mobile-drawer-actions {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.mobile-drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 104;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.mobile-drawer-backdrop.open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

@media (max-width: 992px) {
  .desktop-nav { display: none; }
  .mobile-menu-toggle { display: flex; }
}

@media (max-width: 768px) {
  .demo-placeholder-btn { display: none; }
  .header-actions { gap: 0.4rem; }
  .header-container { gap: 0.75rem; }
}

@media (max-width: 480px) {
  .github-header-btn { display: none; }
  .brand-tag { display: none; }
  .brand-logo { height: 36px; }
  .brand-name { font-size: 1.1rem; }
  .header-container { height: 64px; }
}

/* ==========================================================================
   Footer Layout
   ========================================================================== */
.site-footer {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 4.5rem 0 2rem 0;
  margin-top: 5rem;
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.footer-logo {
  height: 38px;
  width: auto;
  object-fit: contain;
}

.footer-brand-name {
  font-size: 1.35rem;
  font-weight: 850;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.footer-tagline {
  color: var(--text-muted);
  font-size: 0.925rem;
  line-height: 1.6;
  max-width: 380px;
  margin-bottom: 1.5rem;
}

.footer-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.footer-heading {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-notice {
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-bottom-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.footer-bottom-links a {
  color: var(--text-muted);
  transition: color 0.15s ease;
}

.footer-bottom-links a:hover {
  color: var(--accent);
}

@media (max-width: 900px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 600px) {
  .footer-top {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}