/* ═══════════════════════════════════════════════
   Akamonkai Japanese — Offline Course Theme
   Modern, responsive, dark/light mode
   ═══════════════════════════════════════════════ */

/* --- CSS Custom Properties (Light Mode) --- */
:root {
  --bg-primary: #f8f9fa;
  --bg-secondary: #ffffff;
  --bg-tertiary: #e9ecef;
  --text-primary: #1a1a2e;
  --text-secondary: #495057;
  --text-muted: #868e96;
  --accent: #e63946;
  --accent-hover: #c1121f;
  --accent-light: #ffe0e3;
  --border: #dee2e6;
  --shadow: rgba(0, 0, 0, 0.08);
  --shadow-lg: rgba(0, 0, 0, 0.12);
  --sidebar-width: 300px;
  --topbar-height: 56px;
  --radius: 8px;
  --radius-sm: 4px;
  --transition: 0.2s ease;
  --font-sans: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  --success: #2d6a4f;
  --success-bg: #d8f3dc;
  --warning: #e9c46a;
  --info: #457b9d;
}

/* --- Dark Mode --- */
[data-theme="dark"] {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-tertiary: #16213e;
  --text-primary: #f0f0f0;
  --text-secondary: #d0d0d0;
  --text-muted: #9a9ab0;
  --accent: #e63946;
  --accent-hover: #ff6b6b;
  --accent-light: #2a1a1e;
  --border: #2a2a3e;
  --shadow: rgba(0, 0, 0, 0.3);
  --shadow-lg: rgba(0, 0, 0, 0.5);
  --success: #52b788;
  --success-bg: #1b3a2a;
  --info: #a8dadc;
}

/* --- Reset --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- App Layout --- */
.app {
  display: flex;
  min-height: 100vh;
}

/* --- Sidebar --- */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  transition: transform var(--transition);
  overflow: hidden;
}

.sidebar-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.02em;
}

.logo-sub {
  display: block;
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.sidebar-close {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px 8px;
}

.sidebar-search {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-search input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-family: var(--font-sans);
  outline: none;
  transition: border-color var(--transition);
}

.sidebar-search input:focus {
  border-color: var(--accent);
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 8px 0;
}

.nav-link {
  display: block;
  padding: 6px 20px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.82rem;
  line-height: 1.4;
  transition: all var(--transition);
  border-left: 3px solid transparent;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.nav-link.active {
  background: var(--accent-light);
  color: var(--accent);
  border-left-color: var(--accent);
  font-weight: 500;
}

.nav-link.completed::before {
  content: '✓ ';
  color: var(--success);
}

.nav-home, .nav-worksheets {
  padding: 10px 20px;
  font-weight: 500;
  font-size: 0.9rem;
}

.nav-section-toggle,
.nav-day-toggle {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 10px 20px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 0.88rem;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  text-align: left;
  transition: background var(--transition);
}

.nav-section-toggle:hover,
.nav-day-toggle:hover {
  background: var(--bg-tertiary);
}

.nav-section-toggle::after,
.nav-day-toggle::after {
  content: '▸';
  transition: transform var(--transition);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.nav-section-toggle.open::after,
.nav-day-toggle.open::after {
  transform: rotate(90deg);
}

.nav-section-items,
.nav-day-items {
  display: none;
  padding-left: 0;
}

.nav-section-items.open,
.nav-day-items.open {
  display: block;
}

.nav-day {
  padding-left: 12px;
}

.nav-day .nav-link {
  padding-left: 32px;
  font-size: 0.78rem;
}

/* --- Main Content --- */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-width: 0;
}

/* --- Top Bar --- */
.topbar {
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  padding: 0 24px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 50;
  gap: 16px;
}

.hamburger {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text-primary);
  padding: 4px;
}

.breadcrumb {
  flex: 1;
  font-size: 0.82rem;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.breadcrumb a {
  color: var(--accent);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.topbar-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

.sync-status {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  white-space: nowrap;
}

.sync-status[data-state="ok"] {
  color: var(--success);
  border-color: color-mix(in srgb, var(--success) 35%, var(--border));
  background: color-mix(in srgb, var(--success-bg) 70%, var(--bg-secondary));
}

.sync-status[data-state="warn"] {
  color: var(--warning);
  border-color: color-mix(in srgb, var(--warning) 40%, var(--border));
  background: color-mix(in srgb, var(--warning) 14%, var(--bg-secondary));
}

.sync-status[data-state="error"] {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border));
  background: color-mix(in srgb, var(--accent-light) 75%, var(--bg-secondary));
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition);
}

.theme-toggle:hover {
  background: var(--bg-tertiary);
}

/* --- Content Wrapper --- */
.content-wrapper {
  max-width: 900px;
  margin: 0 auto;
  padding: 32px 24px;
}

/* --- Dashboard --- */
.dashboard-hero {
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  margin-bottom: 32px;
  text-align: center;
}

.dashboard h1 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text-primary);
}

.dashboard-subtitle {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.progress-overview {
  max-width: 500px;
  margin: 0 auto 20px;
}

.resume-section {
  margin-top: 16px;
}

.resume-btn {
  display: inline-block;
  padding: 10px 24px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  transition: all var(--transition);
}

.resume-btn:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px var(--shadow-lg);
}

.bookmarks-section {
  margin-bottom: 32px;
}

.bookmarks-section h2 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.bookmarks-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.bookmark-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-primary);
  font-size: 0.88rem;
  transition: all var(--transition);
}

.bookmark-item:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

.section-heading {
  font-size: 1.2rem;
  margin-bottom: 16px;
}

.progress-bar-container {
  height: 12px;
  background: var(--bg-tertiary);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 8px;
}

.progress-bar-container.small {
  height: 6px;
  margin-bottom: 0;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #ff6b6b);
  border-radius: 6px;
  transition: width 0.5s ease;
}

.progress-text {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.week-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

.week-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-decoration: none;
  color: var(--text-primary);
  transition: all var(--transition);
  display: block;
}

.week-card:hover {
  box-shadow: 0 4px 24px var(--shadow-lg);
  transform: translateY(-2px);
  border-color: var(--accent);
}

.week-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.week-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4px;
}

.week-count-badge {
  background: var(--accent-light);
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  min-width: 24px;
  text-align: center;
}

.week-progress-text {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 4px;
  display: block;
}

.week-start-btn {
  display: inline-block;
  margin-top: 12px;
  padding: 6px 14px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: all var(--transition);
}

.week-start-btn:hover {
  background: var(--accent);
  color: #fff;
}

.week-days {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.week-progress {
  margin-top: 12px;
}

/* --- Lesson --- */
.lesson-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 24px;
  gap: 16px;
  flex-wrap: wrap;
}

.lesson-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  flex: 1;
}

.lesson-badges {
  display: flex;
  gap: 6px;
  margin-bottom: 8px;
  width: 100%;
}

.lesson-badge {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.week-badge { background: var(--info); color: #fff; }
.day-badge { background: var(--bg-tertiary); color: var(--text-secondary); border: 1px solid var(--border); }
.type-badge { background: var(--bg-tertiary); color: var(--text-muted); border: 1px solid var(--border); }
.type-video { background: #e63946; color: #fff; border-color: transparent; }
.type-download { background: var(--success); color: #fff; border-color: transparent; }

.lesson-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.bookmark-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 4px 8px;
  transition: all var(--transition);
  line-height: 1;
  color: var(--text-muted);
}

.bookmark-toggle:hover {
  border-color: var(--warning);
  color: var(--warning);
}

.bookmark-toggle.active {
  color: var(--warning);
  border-color: var(--warning);
  background: color-mix(in srgb, var(--warning) 12%, var(--bg-secondary));
}

.complete-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  white-space: nowrap;
  font-size: 0.88rem;
  color: var(--text-secondary);
  user-select: none;
}

.complete-toggle input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* --- Video --- */
.video-container {
  margin-bottom: 24px;
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
}

.iframe-container {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
}

.video-iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.local-video .lesson-video {
  width: 100%;
  display: block;
  max-height: 500px;
}

.lesson-video {
  width: 100%;
  display: block;
  max-height: 500px;
}

.lesson-videos {
  margin-bottom: 24px;
}

/* --- Notes --- */
.lesson-notes {
  margin-bottom: 32px;
}

.lesson-notes h3 {
  margin-bottom: 8px;
  font-size: 1.1rem;
}

.notes-textarea {
  width: 100%;
  min-height: 120px;
  padding: 12px 16px;
  font-family: var(--font-sans);
  font-size: 0.92rem;
  line-height: 1.6;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-secondary);
  color: var(--text-primary);
  resize: vertical;
  transition: border-color var(--transition);
}

.notes-textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.notes-saved-msg {
  font-size: 0.78rem;
  color: var(--success);
  margin-top: 4px;
}

/* --- Lesson Counter --- */
.lesson-nav-counter {
  font-size: 0.82rem;
  color: var(--text-muted);
  align-self: center;
}

/* --- Nav Section Count --- */
.nav-section-count,
.nav-day-count {
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-tertiary);
  padding: 1px 6px;
  border-radius: 999px;
  margin-right: 20px;
}

/* --- Nav Link Icon --- */
.nav-link-icon {
  margin-right: 4px;
  font-size: 0.7rem;
}

/* --- Downloads page small button --- */
.download-btn-sm {
  display: inline-block;
  padding: 6px 14px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: all var(--transition);
}

.download-btn-sm:hover {
  background: var(--accent-hover);
}

.video-controls-custom {
  padding: 8px 16px;
  background: var(--bg-tertiary);
  display: flex;
  gap: 12px;
  align-items: center;
}

.playback-speed {
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-family: var(--font-sans);
}

.video-placeholder {
  padding: 40px;
  text-align: center;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.video-placeholder a {
  color: var(--accent);
}

/* --- Lesson Body (content from Teachable) --- */
.lesson-body {
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 32px;
}

.lesson-body h1, .lesson-body h2, .lesson-body h3,
.lesson-body h4, .lesson-body h5, .lesson-body h6 {
  margin-top: 1.5em;
  margin-bottom: 0.5em;
  font-weight: 600;
  color: var(--text-primary);
}

.lesson-body h2 { font-size: 1.3rem; }
.lesson-body h3 { font-size: 1.15rem; }

.lesson-body p {
  margin-bottom: 1em;
}

.lesson-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  margin: 16px 0;
}

.lesson-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.92rem;
}

.lesson-body th, .lesson-body td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  text-align: left;
}

.lesson-body th {
  background: var(--bg-tertiary);
  font-weight: 600;
}

.lesson-body tr:nth-child(even) {
  background: var(--bg-tertiary);
}

.lesson-body code {
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.88em;
}

.lesson-body blockquote {
  border-left: 4px solid var(--accent);
  padding: 12px 20px;
  margin: 16px 0;
  background: var(--bg-tertiary);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text-secondary);
}

.lesson-body ul, .lesson-body ol {
  margin: 12px 0;
  padding-left: 24px;
}

.lesson-body li {
  margin-bottom: 4px;
}

.lesson-body a {
  color: var(--accent);
  text-decoration: none;
}

.lesson-body a:hover {
  text-decoration: underline;
}

/* Imported lesson HTML often contains hardcoded light colors. */
[data-theme="dark"] .lesson-body [style*="background:white"],
[data-theme="dark"] .lesson-body [style*="background: white"],
[data-theme="dark"] .lesson-body [style*="background-color:white"],
[data-theme="dark"] .lesson-body [style*="background-color: white"],
[data-theme="dark"] .lesson-body [style*="background:rgb(255,255,255)"],
[data-theme="dark"] .lesson-body [style*="background: rgb(255, 255, 255)"],
[data-theme="dark"] .lesson-body [style*="background-color:rgb(255,255,255)"],
[data-theme="dark"] .lesson-body [style*="background-color: rgb(255, 255, 255)"] {
  background: transparent !important;
}

[data-theme="dark"] .lesson-body [style*="color: rgb(91, 91, 91)"],
[data-theme="dark"] .lesson-body [style*="color:rgb(91,91,91)"],
[data-theme="dark"] .lesson-body [style*="color:#5b5b5b"] {
  color: var(--text-secondary) !important;
}

/* Some overview lessons carry many inline styles; force readable dark-mode text blocks. */
[data-theme="dark"] .lesson-body p,
[data-theme="dark"] .lesson-body li,
[data-theme="dark"] .lesson-body ol,
[data-theme="dark"] .lesson-body ul,
[data-theme="dark"] .lesson-body span,
[data-theme="dark"] .lesson-body div {
  background-color: transparent !important;
}

[data-theme="dark"] .lesson-body p,
[data-theme="dark"] .lesson-body li,
[data-theme="dark"] .lesson-body span,
[data-theme="dark"] .lesson-body div {
  color: var(--text-secondary);
}

/* Japanese text specific */
.lesson-body ruby {
  ruby-align: center;
}

.lesson-body ruby rt {
  font-size: 0.6em;
  color: var(--text-muted);
}

/* Froala inline video embeds */
.lesson-body .fr-video {
  display: block;
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  margin: 16px 0;
}

.lesson-body .fr-video iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
  border-radius: var(--radius);
}

/* --- Downloads --- */
.lesson-downloads {
  margin-bottom: 32px;
}

.lesson-downloads h3 {
  margin-bottom: 12px;
  font-size: 1.1rem;
}

.download-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-primary);
  transition: all var(--transition);
  margin-bottom: 8px;
}

.download-btn:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 12px var(--shadow);
}

.download-icon {
  font-size: 1.5rem;
}

.download-text {
  flex: 1;
  font-size: 0.9rem;
}

.download-action {
  background: var(--accent);
  color: white;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
}

/* --- Quiz --- */
.lesson-quiz {
  margin-bottom: 32px;
}

.lesson-quiz h3 {
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.quiz-question {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}

.q-text {
  font-weight: 600;
  margin-bottom: 12px;
  font-size: 1rem;
}

.q-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.q-option {
  padding: 10px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: left;
  font-size: 0.9rem;
  font-family: var(--font-sans);
  color: var(--text-primary);
  transition: all var(--transition);
}

.q-option:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

.q-option.correct {
  background: var(--success-bg) !important;
  border-color: var(--success) !important;
  color: var(--success);
}

.q-option.incorrect {
  background: var(--accent-light) !important;
  border-color: var(--accent) !important;
  opacity: 0.7;
}

.q-option.disabled {
  pointer-events: none;
}

.q-feedback {
  margin-top: 8px;
  font-size: 0.88rem;
  font-weight: 500;
  display: none;
}

.q-feedback.show {
  display: block;
}

.quiz-results {
  padding: 16px 20px;
  background: var(--success-bg);
  border-radius: var(--radius);
  font-weight: 600;
  display: none;
}

.quiz-results.show {
  display: block;
}

/* --- Lesson Navigation --- */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.lesson-nav-btn {
  padding: 10px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-primary);
  font-size: 0.9rem;
  transition: all var(--transition);
}

.lesson-nav-btn:hover:not(.disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.lesson-nav-btn.disabled {
  opacity: 0.4;
  cursor: default;
}

/* --- Grammar Slide Viewer Controls --- */
.grammar-slide-viewer {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
}

.grammar-slide-viewer .gs-prev,
.grammar-slide-viewer .gs-next {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition);
}

.grammar-slide-viewer .gs-prev:hover:not(:disabled),
.grammar-slide-viewer .gs-next:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.grammar-slide-viewer .gs-prev:disabled,
.grammar-slide-viewer .gs-next:disabled {
  opacity: 0.45;
  cursor: default;
}

.grammar-slide-viewer .gs-counter {
  color: var(--text-secondary);
  font-size: 0.82rem;
  min-width: 48px;
  text-align: center;
}

/* --- Worksheets Hub --- */
.worksheets-hub h1 {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.worksheets-intro {
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-size: 0.92rem;
}

.worksheet-week-section {
  margin-top: 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--bg-secondary) 88%, var(--bg-tertiary));
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.worksheet-week-section:hover {
  border-color: var(--accent);
}

.worksheet-week-section[open] {
  border-color: var(--accent);
  box-shadow: 0 8px 28px var(--shadow);
}

.worksheet-week-header {
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 1.02rem;
  font-weight: 700;
  background: color-mix(in srgb, var(--bg-tertiary) 75%, var(--bg-secondary));
  transition: background var(--transition), color var(--transition);
  user-select: none;
}

.worksheet-week-header:hover {
  background: color-mix(in srgb, var(--accent) 12%, var(--bg-tertiary));
  color: var(--accent);
}

.worksheet-week-header::-webkit-details-marker {
  display: none;
}

.worksheet-week-header::before {
  content: '▸';
  color: var(--accent);
  font-size: 0.9rem;
  transition: transform var(--transition);
}

.worksheet-week-section[open] .worksheet-week-header::before {
  transform: rotate(90deg);
}

.worksheet-week-header span:first-of-type {
  flex: 1;
}

.worksheet-week-count {
  font-size: 0.75rem;
  font-weight: 700;
  color: #fff;
  min-width: 28px;
  height: 28px;
  line-height: 28px;
  text-align: center;
  padding: 0 8px;
  border-radius: 999px;
  background: var(--accent);
}

.worksheet-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px;
}

.worksheet-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  gap: 16px;
}

.worksheet-info h4 {
  font-size: 0.92rem;
  font-weight: 500;
}

.worksheet-lesson {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.worksheet-card .download-btn {
  margin-bottom: 0;
  padding: 8px 16px;
}

.no-worksheets {
  color: var(--text-muted);
  font-style: italic;
}

.placeholder {
  color: var(--text-muted);
  font-style: italic;
  padding: 40px;
  text-align: center;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
    box-shadow: 4px 0 24px var(--shadow-lg);
  }

  .sidebar-close {
    display: block;
  }

  .hamburger {
    display: block;
  }

  .main-content {
    margin-left: 0;
  }

  .content-wrapper {
    padding: 20px 16px;
  }

  .week-grid {
    grid-template-columns: 1fr;
  }

  .lesson-header {
    flex-direction: column;
  }

  .lesson-nav {
    flex-direction: column;
  }

  .worksheet-card {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .dashboard h1 {
    font-size: 1.2rem;
  }

  .lesson-header h1 {
    font-size: 1.2rem;
  }
}

/* --- iOS safe area --- */
@supports (padding: env(safe-area-inset-top)) {
  .topbar {
    padding-top: env(safe-area-inset-top);
      padding-left: calc(24px + env(safe-area-inset-left));
      padding-right: calc(24px + env(safe-area-inset-right));
    height: calc(var(--topbar-height) + env(safe-area-inset-top));
  }

  .sidebar {
    padding-top: env(safe-area-inset-top);
  }

  .content-wrapper {
      padding-top: calc(32px + env(safe-area-inset-top));
      padding-left: calc(24px + env(safe-area-inset-left));
      padding-right: calc(24px + env(safe-area-inset-right));
    padding-bottom: calc(24px + env(safe-area-inset-bottom));
  }
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

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

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* --- Print --- */
@media print {
  .sidebar, .topbar, .lesson-nav, .complete-toggle,
  .video-controls-custom, .download-action {
    display: none !important;
  }

  .main-content {
    margin-left: 0;
  }

  .content-wrapper {
    max-width: none;
  }
}