/**
 * QubikStack - Layout CSS
 * Header, Sticky Navigation, Mobile Drawer, Footer, Scroll Progress, Floating Controls
 */

/* ==========================================================================
   Scroll Progress Bar
   ========================================================================== */
.scroll-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--grad-primary);
  z-index: calc(var(--z-header) + 10);
  transition: width 0.1s ease-out;
  box-shadow: 0 0 10px var(--color-primary);
}

/* ==========================================================================
   Site Header & Navigation
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: var(--z-header);
  display: flex;
  align-items: center;
  transition: height var(--transition-base), background-color var(--transition-base), backdrop-filter var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  height: var(--header-height-scrolled);
  background-color: var(--surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border-subtle);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  z-index: 2;
}

.brand-logo-img {
  height: 42px;
  width: auto;
  transition: transform var(--transition-bounce);
}

.brand-logo-link:hover .brand-logo-img {
  transform: scale(1.04) rotate(1deg);
}

/* Primary Desktop Navigation */
.nav-desktop {
  display: none;
}

@media (min-width: 1024px) {
  .nav-desktop {
    display: flex;
    align-items: center;
    gap: 1.75rem;
  }
}

.nav-link {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 0.5rem 0.25rem;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-base);
}

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

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Dropdown Navigation Menu */
.nav-item-dropdown {
  position: relative;
}

.nav-item-dropdown:hover .nav-dropdown-menu,
.nav-item-dropdown:focus-within .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: -1rem;
  min-width: 260px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: 0.75rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition-fast);
  z-index: 10;
  backdrop-filter: blur(20px);
}

.nav-dropdown-link {
  display: flex;
  flex-direction: column;
  padding: 0.75rem 0.85rem;
  min-height: 44px;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
  border-left: 2px solid transparent;
}

.nav-dropdown-link:hover,
.nav-dropdown-link.active {
  background-color: var(--bg-tertiary);
  border-left-color: var(--color-primary);
}

.nav-dropdown-link.active .nav-dropdown-link-title {
  color: var(--color-primary);
}

.nav-dropdown-link-title {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.nav-dropdown-link-desc {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Header Action Right (Theme Toggle & CTA) */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

@media (max-width: 540px) {
  .header-actions .btn {
    display: none;
  }
  .brand-logo-img {
    height: 32px;
  }
  .header-actions {
    gap: 0.5rem;
  }
}

/* Theme Toggle Button (Min 44px tap target) */
.theme-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--surface-card);
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--color-primary);
  background: var(--bg-tertiary);
  transform: scale(1.05);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-bounce);
}

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

/* Mobile Menu Toggle Button (Min 44px tap target) */
.mobile-menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--surface-card);
  padding: 12px;
  z-index: calc(var(--z-drawer) + 1);
}

@media (min-width: 1024px) {
  .mobile-menu-toggle {
    display: none;
  }
}

.mobile-menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

.mobile-menu-toggle.is-active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle.is-active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.is-active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ==========================================================================
   Mobile Navigation Drawer & Overlay
   ========================================================================== */
.mobile-drawer-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100dvh;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  z-index: var(--z-drawer);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.mobile-drawer-overlay.is-active {
  opacity: 1;
  visibility: visible;
}

.mobile-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 85%;
  max-width: 360px;
  height: 100dvh;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border-medium);
  z-index: calc(var(--z-drawer) + 1);
  padding: 5.5rem 1.75rem 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transform: translateX(100%);
  visibility: hidden;
  transition: transform var(--transition-slow), visibility var(--transition-slow);
  overflow-y: auto;
}

.mobile-drawer.is-active {
  transform: translateX(0);
  visibility: visible;
}

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

.mobile-nav-link {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 0.5rem;
  border-radius: var(--radius-sm);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  color: var(--color-primary);
  background: rgba(var(--color-primary-rgb), 0.08);
}

.mobile-nav-group {
  display: flex;
  flex-direction: column;
}

.mobile-nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  min-height: 44px;
}

.mobile-nav-row .mobile-nav-link {
  flex: 1;
}

.mobile-nav-expand-btn {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-left: 0.5rem;
}

.mobile-nav-expand-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.mobile-nav-expand-btn .expand-icon {
  width: 18px;
  height: 18px;
  transition: transform var(--transition-base);
}

.mobile-nav-group.is-open .mobile-nav-expand-btn .expand-icon {
  transform: rotate(180deg);
}

.mobile-nav-sublinks {
  padding-left: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  border-left: 2px solid var(--border-subtle);
  max-height: 0;
  opacity: 0;
  visibility: hidden;
  overflow: hidden;
  transition: max-height var(--transition-base), opacity var(--transition-base), visibility var(--transition-base);
}

.mobile-nav-group.is-open .mobile-nav-sublinks {
  max-height: 250px;
  opacity: 1;
  visibility: visible;
  margin-top: 0.25rem;
  margin-bottom: 0.5rem;
}

.mobile-nav-sublink {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.mobile-nav-sublink:hover {
  color: var(--color-primary);
  background: var(--bg-tertiary);
}

.mobile-nav-sublink.active {
  color: var(--color-primary);
  font-weight: 600;
  background: rgba(var(--color-primary-rgb), 0.12);
  border-left: 3px solid var(--color-primary);
}

.mobile-drawer-footer {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ==========================================================================
   Global Footer
   ========================================================================== */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding-top: var(--section-spacing);
  padding-bottom: 2rem;
  position: relative;
  z-index: var(--z-base);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  margin-bottom: 4rem;
}

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
  }
}

.footer-col-brand {
  max-width: 340px;
}

.footer-brand-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: 1.25rem;
  line-height: 1.7;
}

.footer-col-title {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
  position: relative;
}

.footer-col-title::after {
  content: '';
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-primary);
  margin-top: 6px;
  border-radius: var(--radius-full);
}

.footer-links-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-link {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  max-width: 100%;
}

.footer-link:hover {
  color: var(--color-primary);
  transform: translateX(4px);
}

.footer-contact-info {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.footer-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.footer-contact-icon {
  width: 18px;
  height: 18px;
  color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 3px;
}

.footer-bottom-bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}

@media (min-width: 768px) {
  .footer-bottom-bar {
    flex-direction: row;
  }
}

.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.75rem 1.25rem;
}

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

/* ==========================================================================
   Floating Controls (Back to Top & Sticky Contact)
   ========================================================================== */
.floating-actions {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: var(--z-sticky);
}

.back-to-top-btn {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--surface-card);
  border: 1px solid var(--border-medium);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all var(--transition-base);
}

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

.back-to-top-btn:hover {
  background: var(--grad-primary);
  color: #000000;
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

.back-to-top-btn svg {
  width: 20px;
  height: 20px;
}