/**
 * Layout System
 * Grid-based responsive layout
 */

/* ===== ROOT LAYOUT ===== */

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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

body {
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);

  /* Smooth color transitions for theme switching */
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

/* ===== MAIN LAYOUT CONTAINER ===== */

.layout-container {
  display: grid;
  min-height: 100vh;
}

/* Mobile: Single column */
@media (max-width: 767px) {
  .layout-container {
    display: block;
    padding: 0;
    position: relative;
  }

  .main-nav {
    /* Slide-in panel from left - COMPLETELY REMOVED FROM LAYOUT FLOW */
    position: fixed !important;
    top: 0 !important;
    left: -100% !important;
    width: calc(100% - 32px);
    max-width: 408px;
    height: 100dvh !important;
    max-height: 100dvh !important;
    background: var(--color-background) !important;
    border: none !important;
    border-right: var(--border-width) solid var(--color-border);
    border-radius: 0 !important;
    z-index: 2000;
    overflow-y: auto;
    transition: left var(--transition-smooth);
    box-shadow: none;
    padding: var(--spacing-3xl) var(--spacing-xl) var(--spacing-xl) 32px !important;
    margin: 0;
  }

  .main-nav.is-open {
    left: 0 !important;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.3);
  }

  /* Reduce padding on nav content when open */
  .main-nav.is-open .nav-content {
    padding-left: 0 !important;
  }

  /* Mobile navigation backdrop */
  .mobile-nav-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(0, 0, 0, 0.33);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-smooth);
    z-index: 1999;
  }

  .mobile-nav-backdrop.is-open {
    opacity: 1;
    pointer-events: auto;
  }

  /* Mobile content with margins around it */
  .main-content {
    max-width: 100% !important;
    margin: 0 0 24px 0 !important;
    padding: 24px 15px !important;
    border-radius: var(--border-radius-md);
    border: var(--border-width) solid var(--color-border);
    overflow-x: hidden;
    box-sizing: border-box;
  }
}

/* Tablet & Small Desktop: Two columns - compact nav */
@media (min-width: 768px) and (max-width: 1279px) {
  .layout-container {
    grid-template-columns: 280px 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
  }

  .mobile-header {
    display: none;
  }

  /* Hide mobile theme toggle on tablet */
  .mobile-theme-toggle {
    display: none !important;
  }

  /* Make main-content liquid on tablet */
  .main-content {
    max-width: 100% !important;
    width: 100% !important;
    min-width: 0 !important;
  }

  /* Compact nav styling */
  .main-nav {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  /* Reduce chapter item spacing */
  .chapter-item {
    padding: var(--spacing-md) 0;
  }

  /* Compact chapter typography */
  .chapter-trigger .chapter-number {
    font-size: 12px !important;
    line-height: 18px !important;
    letter-spacing: 2.5px !important;
  }

  .chapter-trigger .chapter-title {
    font-size: 16px !important;
    line-height: 24px !important;
  }

  /* Compact section links */
  .section-link .section-title {
    font-size: 14px !important;
    line-height: 20px !important;
  }

  .chapter-sections {
    gap: var(--spacing-sm) !important;
  }

  /* Compact book header */
  .book-title {
    font-size: 20px !important;
    line-height: 28px !important;
  }

  .book-subtitle {
    font-size: 16px !important;
    line-height: 24px !important;
  }

  .book-author {
    font-size: 16px !important;
  }

  /* Reduce nav content gap */
  .nav-content {
    gap: var(--spacing-md) !important;
  }

  /* Compact download button */
  .download-btn {
    font-size: 12px !important;
    padding: var(--spacing-sm) var(--spacing-md) !important;
  }

  /* Compact reading content typography */
  .main-content h1,
  .chapter-header .chapter-title {
    font-size: 2.5rem !important; /* 40px, down from 56px */
    line-height: 1.2 !important;
  }

  .main-content h2 {
    font-size: 2rem !important; /* 32px */
    line-height: 2.5rem !important; /* 40px */
  }

  .main-content h3 {
    font-size: 1.5rem !important; /* 24px, down from 32px */
    line-height: 1.3 !important;
  }

  .main-content h4 {
    font-size: 1.25rem !important; /* 20px, down from 24px */
    line-height: 1.4 !important;
  }

  .main-content p,
  .main-content li {
    font-size: 1rem !important; /* 16px, down from 18px */
    line-height: 1.6 !important;
  }

  .chapter-header .chapter-number {
    font-size: 0.875rem !important; /* 14px, down from 16px */
    letter-spacing: 0.25em !important;
  }
}

/* Desktop: Two columns - normal nav */
@media (min-width: 1280px) and (max-width: 1439px) {
  .layout-container {
    grid-template-columns: var(--nav-width) 1fr;
    gap: var(--layout-gap);
    padding: var(--spacing-lg);
  }

  .mobile-header {
    display: none;
  }

  /* Hide mobile theme toggle on desktop */
  .mobile-theme-toggle {
    display: none !important;
  }

  /* Make main-content liquid on desktop */
  .main-content {
    max-width: 100% !important;
    width: 100% !important;
    min-width: 0 !important;
  }
}

/* Desktop: Three columns (nav + content + annotation space) */
@media (min-width: 1440px) {
  .layout-container {
    grid-template-columns: var(--nav-width) minmax(0, var(--content-max-width)) var(--annotation-width);
    gap: var(--layout-gap);
    padding: var(--spacing-lg) 0 var(--spacing-lg) var(--spacing-lg);
    max-width: 100%;
    margin: 0 auto;
    transition: grid-template-columns 300ms ease;
  }

  /* When annotation is expanded - expand the annotation column */
  .layout-container.annotation-expanded {
    grid-template-columns: var(--nav-width) minmax(0, var(--content-max-width)) var(--annotation-width-expanded);
  }

  .mobile-header {
    display: none;
  }

  /* Hide mobile theme toggle on large desktop */
  .mobile-theme-toggle {
    display: none !important;
  }
}

/* ===== MOBILE HEADER ===== */

.mobile-header {
  position: fixed;
  top: 20px;
  left: 6px;
  z-index: 1000;
  background: transparent;
  display: none; /* Hidden by default */
  background-color: #FFF;
  width: 100%;
  margin-top: -22px;
  justify-content: flex-start;
  padding: 10px 0;
  margin-left: -5px;
  box-shadow: 0px 10px 20px #0000001A;
}

/* Show mobile header only on mobile */
@media (max-width: 767px) {
  .mobile-header {
    display: flex;
    align-items: center;
  }
}

.mobile-header .mobile-menu-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6px 4px;
  border: none !important;
  border-radius: 0 !important;
  background: transparent;
  cursor: pointer;
  transition: opacity var(--transition-base);
}

.mobile-header .mobile-menu-btn:hover {
  opacity: 0.8;
}

.mobile-header .hamburger-icon {
  width: 24px;
  height: 20px;
  display: block;
  object-fit: contain;
  border-radius: 0 !important;
}

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

.main-nav {
  position: sticky;
  top: var(--spacing-lg);
  height: calc(100vh - var(--spacing-lg) * 2);
  overflow-y: auto;
  background: transparent;
  border: none;
  border-radius: 0;
  padding: var(--spacing-xl);
}

/* Custom scrollbar for nav */
.main-nav::-webkit-scrollbar {
  width: 6px;
}

.main-nav::-webkit-scrollbar-track {
  background: transparent;
}

.main-nav::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

.main-nav::-webkit-scrollbar-thumb:hover {
  background: var(--color-dark-navy-50);
}

/* ===== MAIN CONTENT ===== */

.main-content {
  position: relative;
  max-width: var(--content-max-width);
  width: 100%;
  min-width: 0;
  padding: var(--spacing-xl);
  background: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--border-radius-xl) var(--border-radius-xl) 0 0;
  min-height: 100vh;
  box-shadow: 0px 0px 24px rgba(0, 0, 0, 0.08);
  box-sizing: border-box;
}

/* Mobile content styling moved to main mobile media query above */

/* Theme toggle switch positioning - all screen sizes */
.theme-toggle-switch {
  position: absolute;
  top: 24px;
  right: 24px;
  z-index: var(--z-sticky);
}

/* Mobile theme toggle (in navigation) */
.mobile-theme-toggle {
  position: static !important;
  margin: var(--spacing-md) 0;
  display: none; /* Hidden by default */
}

/* Show mobile theme toggle only on mobile */
@media (max-width: 767px) {
  .mobile-theme-toggle {
    display: flex !important;
  }

  /* Hide desktop theme toggle on mobile */
  #desktop-theme-toggle {
    display: none !important;
  }
}

/* ===== ANNOTATIONS CONTAINER ===== */

.annotations-container {
  position: relative;
  pointer-events: none;
}

/* Desktop: Right sidebar - fixed width */
@media (min-width: 1440px) {
  .annotations-container {
    width: var(--annotation-width);
    padding: var(--spacing-lg);
    transition: width 300ms ease;
  }

  /* When expanded, take full width of the grid column */
  .layout-container.annotation-expanded .annotations-container {
    width: 100%;
  }
}

/* Mobile & Tablet: Full screen overlay */
@media (max-width: 1439px) {
  .annotations-container {
    inset: 0;
    z-index: var(--z-modal);
  }
}

/* ===== UTILITY CLASSES ===== */

/* Container max-width */
.container {
  width: 100%;
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--spacing-md);
  padding-right: var(--spacing-md);
}

/* Section spacing */
.section {
  padding-top: var(--spacing-2xl);
  padding-bottom: var(--spacing-2xl);
}

@media (max-width: 767px) {
  .section {
    padding-top: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
  }
}

/* Visually hidden but accessible */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}