/**
 * Layout Component
 * Full accessibility support
 * Main layout structure for applications with navigation, header, footer
 */

/* ========================================
   LAYOUT CUSTOM PROPERTIES
   ======================================== */

.l-layout {
  /* Layout dimensions */
  --l-layout-padding: var(--ds-space-l);
  --l-layout-drawer-inline-size: 320px;
  --l-layout-nav-inline-size: 280px;
  --l-layout-nav-collapsed-size: 3.5rem;
  
  /* Colors */
  --l-layout-background-color: var(--ds-color-background);
  --l-layout-nav-background: var(--ds-color-surface);
  --l-layout-nav-border-color: var(--ds-color-border);
  --l-layout-header-background: var(--ds-color-surface);
  --l-layout-header-border-color: var(--ds-color-border);
  --l-layout-footer-background: var(--ds-color-surface);
  --l-layout-footer-border-color: var(--ds-color-border);
  
  /* Shadows */
  --l-layout-nav-shadow: var(--ds-shadow-s);
  --l-layout-header-shadow: var(--ds-shadow-s);
  --l-layout-drawer-shadow: var(--ds-shadow-l);
  
  /* Z-index */
  --l-layout-nav-z-index: var(--ds-z-navigation);
  --l-layout-header-z-index: var(--ds-z-header);
  --l-layout-drawer-z-index: var(--ds-z-drawer);
  --l-layout-backdrop-z-index: var(--ds-z-overlay);
  
  /* Transitions */
  --l-layout-transition: transform var(--ds-duration-normal) var(--ds-ease-out),
                         width var(--ds-duration-normal) var(--ds-ease-out),
                         opacity var(--ds-duration-fast) var(--ds-ease-out);
}

/* ========================================
   BASE LAYOUT STYLES
   ======================================== */

.l-layout {
  display: grid;
  grid-template-areas: 
    "nav header header"
    "nav main main"
    "nav footer footer";
  grid-template-columns: var(--l-layout-nav-inline-size) 1fr auto;
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
  background: var(--l-layout-background-color);
  position: relative;
}

/* Navigation area */
.l-layout__nav {
  grid-area: nav;
  background: var(--l-layout-nav-background);
  border-inline-end: 1px solid var(--l-layout-nav-border-color);
  box-shadow: var(--l-layout-nav-shadow);
  z-index: var(--l-layout-nav-z-index);
  transition: var(--l-layout-transition);
  overflow: hidden;
}

/* Header area */
.l-layout__header {
  grid-area: header;
  background: var(--l-layout-header-background);
  border-bottom: 1px solid var(--l-layout-header-border-color);
  z-index: var(--l-layout-header-z-index);
  position: relative;
}

/* Main content area */
.l-layout__main {
  grid-area: main;
  padding: var(--l-layout-padding);
  overflow: auto;
  min-height: 0; /* Allow content to shrink */
}

/* Footer area */
.l-layout__footer {
  grid-area: footer;
  background: var(--l-layout-footer-background);
  border-top: 1px solid var(--l-layout-footer-border-color);
  z-index: var(--l-layout-header-z-index);
}

/* Drawer (optional sidebar) */
.l-layout__drawer {
  position: fixed;
  top: 0;
  inset-inline-end: 0;
  width: var(--l-layout-drawer-inline-size);
  height: 100vh;
  background: var(--l-layout-nav-background);
  border-inline-start: 1px solid var(--l-layout-nav-border-color);
  box-shadow: var(--l-layout-drawer-shadow);
  z-index: var(--l-layout-drawer-z-index);
  transform: translateX(100%);
  transition: var(--l-layout-transition);
  overflow: auto;
}

.l-layout__drawer.is-open {
  transform: translateX(0);
}

/* Backdrop for mobile drawer */
.l-layout__backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--ds-color-overlay);
  z-index: calc(var(--l-layout-backdrop-z-index) - 1);
  opacity: 0;
  visibility: hidden;
  transition: var(--l-layout-transition);
}

.l-layout__backdrop.is-visible {
  opacity: 1;
  visibility: visible;
}

/* ========================================
   LAYOUT VARIANTS
   ======================================== */

/* Collapsed navigation */
.l-layout--nav-collapsed {
  grid-template-columns: var(--l-layout-nav-collapsed-size) 1fr auto;
}

.l-layout--nav-collapsed .l-layout__nav {
  width: var(--l-layout-nav-collapsed-size);
}

/* Hidden navigation */
.l-layout--nav-hidden {
  grid-template-areas: 
    "header header header"
    "main main main"
    "footer footer footer";
  grid-template-columns: 1fr auto;
}

.l-layout--nav-hidden .l-layout__nav {
  display: none;
}

/* Full width layout (no navigation) */
.l-layout--full-width {
  grid-template-areas: 
    "header"
    "main"
    "footer";
  grid-template-columns: 1fr;
}

.l-layout--full-width .l-layout__nav {
  display: none;
}

/* Sticky header */
.l-layout--sticky-header .l-layout__header {
  position: sticky;
  top: 0;
  box-shadow: var(--l-layout-header-shadow);
}

/* Sticky footer */
.l-layout--sticky-footer .l-layout__footer {
  position: sticky;
  bottom: 0;
  box-shadow: 0 -1px 3px var(--ds-color-shadow);
}

/* No padding main */
.l-layout--no-padding .l-layout__main {
  padding: 0;
}

/* Compact padding */
.l-layout--compact .l-layout__main {
  padding: var(--ds-space-m);
}

/* ========================================
   TOP BAR INTEGRATION
   ======================================== */

.l-layout__top-bar {
  background: var(--ds-color-primary);
  color: var(--ds-color-text-on-primary);
  padding: var(--ds-space-s) var(--ds-space-m);
  display: flex;
  align-items: center;
  gap: var(--ds-space-m);
  position: relative;
  z-index: calc(var(--l-layout-header-z-index) + 1);
}

.l-layout--with-top-bar {
  grid-template-areas: 
    "topbar topbar topbar"
    "nav header header"
    "nav main main"
    "nav footer footer";
  grid-template-rows: auto auto 1fr auto;
}

.l-layout--with-top-bar .l-layout__top-bar {
  grid-area: topbar;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

/* Tablet breakpoint */
@media (max-width: 1024px) {
  .l-layout {
    grid-template-areas: 
      "header header"
      "main main"
      "footer footer";
    grid-template-columns: 1fr auto;
  }
  
  .l-layout__nav {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    transform: translateX(-100%);
    z-index: var(--l-layout-drawer-z-index);
  }
  
  .l-layout__nav.is-open {
    transform: translateX(0);
  }
  
  .l-layout--nav-collapsed {
    grid-template-columns: 1fr auto;
  }
}

/* Mobile breakpoint */
@media (max-width: 768px) {
  .l-layout__main {
    padding: var(--ds-space-m);
  }
  
  .l-layout__drawer {
    width: 100%;
    max-width: var(--l-layout-drawer-inline-size);
  }
  
  .l-layout--compact .l-layout__main {
    padding: var(--ds-space-s);
  }
}

/* Small mobile */
@media (max-width: 480px) {
  .l-layout__main {
    padding: var(--ds-space-s);
  }
  
  .l-layout__drawer {
    width: 100%;
  }
}

/* ========================================
   NAVIGATION TOGGLE
   ======================================== */

.l-layout__nav-toggle {
  display: none;
  position: fixed;
  top: var(--ds-space-m);
  left: var(--ds-space-m);
  z-index: calc(var(--l-layout-drawer-z-index) + 1);
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  border: none;
  border-radius: var(--ds-radius-s);
  background: var(--ds-color-surface);
  color: var(--ds-color-text);
  box-shadow: var(--ds-shadow-m);
  cursor: pointer;
  transition: var(--l-layout-transition);
}

.l-layout__nav-toggle:hover {
  background: var(--ds-color-surface-hover);
}

.l-layout__nav-toggle:focus {
  outline: none;
  box-shadow: var(--ds-shadow-focus);
}

.l-layout__nav-toggle .c-icon {
  width: 1.25rem;
  height: 1.25rem;
}

@media (max-width: 1024px) {
  .l-layout__nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }
}

/* ========================================
   PRINT STYLES
   ======================================== */

@media print {
  .l-layout {
    grid-template-areas: 
      "header"
      "main"
      "footer";
    grid-template-columns: 1fr;
    min-height: auto;
  }
  
  .l-layout__nav,
  .l-layout__drawer,
  .l-layout__backdrop,
  .l-layout__nav-toggle {
    display: none !important;
  }
  
  .l-layout__main {
    padding: 0;
  }
  
  .l-layout__header,
  .l-layout__footer {
    box-shadow: none;
    border: none;
  }
}

/* ========================================
   ACCESSIBILITY
   ======================================== */

/* Focus management */
.l-layout__skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--ds-color-surface);
  color: var(--ds-color-text);
  padding: var(--ds-space-s) var(--ds-space-m);
  border-radius: var(--ds-radius-s);
  text-decoration: none;
  z-index: 9999;
  transition: top 0.3s;
}

.l-layout__skip-link:focus {
  top: 6px;
}

/* High contrast mode */
@media (prefers-contrast: high) {
  .l-layout__nav,
  .l-layout__header,
  .l-layout__footer {
    border-width: 2px;
  }
  
  .l-layout__nav-toggle {
    border: 2px solid;
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .l-layout,
  .l-layout *,
  .l-layout *::before,
  .l-layout *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}