/* ============================================================
   READER — reader.html specific styles
   ============================================================ */

.reader-layout {
  display: grid;
  grid-template-columns: 260px 1fr 200px;
  gap: 0;
  min-height: calc(100vh - var(--header-h));
  align-items: start;
}

/* ============================================================
   Sidebar TOC
   ============================================================ */
.reader-sidebar {
  background: #fff;
  border-right: 1px solid var(--sw-border);
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 24px 0;
}
.sidebar-module-header {
  padding: 0 20px 16px;
  border-bottom: 1px solid var(--sw-border);
  margin-bottom: 16px;
}
.sidebar-module-icon {
  font-size: 1.4rem;
  margin-bottom: 4px;
}
.sidebar-module-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
}
.sidebar-module-progress {
  margin-top: 8px;
}
.toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.toc-item {
  padding: 0;
}
.toc-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 20px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none !important;
  border-left: 3px solid transparent;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
  cursor: pointer;
}
.toc-link:hover {
  background: var(--sw-light-bg);
  color: var(--text-primary);
}
.toc-link.active {
  color: var(--sw-blue);
  border-left-color: var(--sw-blue);
  background: var(--sw-blue-light);
  font-weight: 600;
}
.toc-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--sw-border);
  flex-shrink: 0;
  transition: background var(--transition);
}
.toc-link.read .toc-dot  { background: var(--sw-success); }
.toc-link.active .toc-dot { background: var(--sw-blue); }

/* Module navigation in sidebar */
.sidebar-module-nav {
  padding: 16px 20px 0;
  border-top: 1px solid var(--sw-border);
  margin-top: 12px;
}
.sidebar-module-nav a {
  display: block;
  font-size: 0.82rem;
  padding: 6px 0;
  color: var(--text-muted);
}
.sidebar-module-nav a:hover { color: var(--sw-blue); }

/* ============================================================
   Main Content Area
   ============================================================ */
.reader-main {
  padding: 32px 40px;
  max-width: 800px;
}
.reader-breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}
.reader-breadcrumb a { color: var(--sw-blue); }
.reader-breadcrumb span { color: var(--text-muted); }

/* Section Card */
.section-card {
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--sw-border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 16px;
  overflow: hidden;
  transition: border-color var(--transition);
}
.section-card.active { border-color: var(--sw-blue); }

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  cursor: pointer;
  user-select: none;
  gap: 12px;
  transition: background var(--transition);
}
.section-header:hover { background: var(--sw-light-bg); }

.section-title-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
}
.section-read-badge {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #eef2f7;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  flex-shrink: 0;
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition);
}
.section-read-badge.read {
  background: var(--sw-success);
  color: #fff;
}
.section-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}
.section-chevron {
  font-size: 0.75rem;
  color: var(--text-muted);
  transition: transform var(--transition);
  flex-shrink: 0;
}
.section-card.open .section-chevron { transform: rotate(180deg); }

.section-body {
  display: none;
  padding: 0 24px 24px;
  border-top: 1px solid var(--sw-border);
}
.section-card.open .section-body { display: block; }
.section-body-inner {
  padding-top: 20px;
}

/* Content typography */
.section-body-inner h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 20px 0 8px;
}
.section-body-inner h3:first-child { margin-top: 0; }
.section-body-inner p { color: var(--text-secondary); margin-bottom: 10px; }
.section-body-inner ul, .section-body-inner ol {
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.section-body-inner li { margin-bottom: 4px; }
.section-body-inner table { border-radius: var(--radius); overflow: hidden; width: 100%; margin-bottom: 12px; }

/* After reading, show a completion note */
.section-complete-note {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  padding: 10px 14px;
  background: var(--sw-success-bg);
  border-radius: var(--radius);
  font-size: 0.875rem;
  color: #1a7a33;
  font-weight: 500;
}

/* Module complete banner */
.module-complete-banner {
  background: linear-gradient(135deg, var(--sw-success), #2ecc71);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  margin-top: 24px;
  box-shadow: var(--shadow);
}
.module-complete-banner h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; }
.module-complete-banner p  { margin-bottom: 16px; opacity: 0.9; }
.module-complete-banner .btn-group { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* ============================================================
   Right Quick Nav
   ============================================================ */
.reader-quicknav {
  padding: 24px 20px;
  position: sticky;
  top: calc(var(--header-h) + 24px);
}
.quicknav-card {
  background: #fff;
  border: 1px solid var(--sw-border);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-sm);
}
.quicknav-card h4 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 12px;
}
.quicknav-card .btn { margin-bottom: 8px; font-size: 0.82rem; }
.quicknav-divider { border: none; border-top: 1px solid var(--sw-border); margin: 12px 0; }
.quicknav-stat {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}
.quicknav-stat strong { color: var(--text-primary); }

/* Module nav links */
.module-prev-next {
  display: flex;
  justify-content: space-between;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--sw-border);
}

/* ============================================================
   Mobile TOC bar (hidden on desktop)
   ============================================================ */
.mobile-toc-bar { display: none; }
.sidebar-overlay { display: none; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
  .reader-layout { grid-template-columns: 240px 1fr; }
  .reader-quicknav { display: none; }
}

@media (max-width: 768px) {
  /* Sticky bar with "Contents" toggle button */
  .mobile-toc-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    background: #fff;
    border-bottom: 1px solid var(--sw-border);
    position: sticky;
    top: var(--header-h);
    z-index: 90;
    box-shadow: var(--shadow-sm);
    gap: 12px;
  }
  .mobile-toc-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    min-width: 0;
  }

  /* Dim overlay behind sidebar drawer */
  .sidebar-overlay {
    position: fixed;
    inset: 0;
    top: var(--header-h);
    background: rgba(13, 36, 56, 0.45);
    z-index: 150;
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
  }
  .sidebar-overlay.active { display: block; }

  /* Single-column layout; sidebar removed from flow */
  .reader-layout { grid-template-columns: 1fr; }

  /* Sidebar becomes a fixed left drawer */
  .reader-sidebar {
    position: fixed;
    top: var(--header-h);
    left: 0;
    width: min(300px, 85vw);
    height: calc(100vh - var(--header-h));
    z-index: 200;
    border-right: 1px solid var(--sw-border);
    border-bottom: none;
    transform: translateX(-100%);
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
    overflow-y: auto;
  }
  .reader-sidebar.sidebar-open {
    transform: translateX(0);
  }

  /* Main content — full width, no horizontal bleed */
  .reader-main {
    padding: 20px 16px;
    max-width: 100%;
    min-width: 0;
    overflow-x: hidden;
  }

  /* Prevent tables & code from blowing out the layout */
  .section-body-inner table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  pre[class*="language-"] {
    max-width: 100%;
  }

  .module-prev-next { flex-direction: column; gap: 8px; }
}