/* ==========================================================================
   DeutschLernen - Grammatik Studio Stylesheet
   Design: Modern Glassmorphism, Dual Theme (Dark/Light), Mobile First,
           WCAG AA Accessible, Full Arabic (RTL) Compatibility.
   ========================================================================== */

:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2235;
  --bg-card-hover: #222d46;
  --bg-card-glass: rgba(26, 34, 53, 0.75);
  --border: #2a3550;
  --border-light: #3b486b;
  --text-primary: #f0f4fc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent-gold: #f59e0b;
  --accent-gold-glow: rgba(245, 158, 11, 0.25);
  --accent-red: #ef4444;
  --accent-green: #10b981;
  --accent-green-glow: rgba(16, 185, 129, 0.25);
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;

  --level-a1: #0ea5e9;
  --level-a2: #10b981;
  --level-b1: #f59e0b;
  --level-b2: #a855f7;

  --font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px var(--accent-gold-glow);
}

body.light-mode, [data-theme="light"], html.light-mode {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-card-glass: rgba(255, 255, 255, 0.9);
  --border: #e2e8f0;
  --border-light: #cbd5e1;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
}

/* Base resets */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* RTL Support */
[dir="rtl"] {
  text-align: right;
}
[dir="rtl"] .header-left,
[dir="rtl"] .header-controls {
  flex-direction: row-reverse;
}
[dir="rtl"] .topic-item-header {
  flex-direction: row-reverse;
}
[dir="rtl"] .rule-bullet {
  padding-right: 18px;
  padding-left: 0;
}
[dir="rtl"] .rule-bullet::before {
  right: 0;
  left: auto;
}

/* Top App Header */
.app-header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 12px 20px;
  position: relative;
  z-index: 50;
}

.header-container {
  max-width: 1320px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.back-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  padding: 6px 11px;
  border-radius: 8px;
  background: transparent;
  border: 1px solid transparent;
  transition: var(--transition);
}

.back-link:hover {
  color: var(--text-primary);
  background: var(--bg-card);
  border-color: var(--border);
}

.brand-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-title span:first-child {
  color: var(--accent-gold);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-icon {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  padding: 6px 11px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  transition: var(--transition);
}

.btn-icon:hover {
  border-color: var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
}

/* Language selector pills */
.lang-selector-group {
  display: inline-flex;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 2px;
  gap: 2px;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
}

.lang-btn:hover {
  color: var(--text-primary);
}

.lang-btn.active {
  background: var(--accent-gold);
  color: #000;
}

/* Main Container Layout */
.grammatik-container {
  max-width: 1320px;
  margin: 0 auto;
  padding: 20px;
  flex: 1;
  width: 100%;
}

/* Hero & Overall Progress Bar */
.grammatik-hero {
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 18px 24px;
}

.hero-text h1 {
  font-size: 24px;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.hero-text p {
  font-size: 14px;
  color: var(--text-secondary);
}

.hero-progress-box {
  min-width: 240px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.hero-progress-header {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
}

.progress-track {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
  border: 1px solid var(--border);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-green));
  border-radius: var(--radius-full);
  transition: width 0.4s ease;
  width: 0%;
}

/* Two-Column Workspace Layout */
.grammatik-workspace {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
  align-items: start;
}

/* Sidebar / Topics Drawer */
.topics-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.search-box {
  position: relative;
}

.search-input {
  width: 100%;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  font-size: 13px;
  color: var(--text-primary);
  outline: none;
  transition: var(--transition);
}

.search-input:focus {
  border-color: var(--accent-gold);
  box-shadow: 0 0 0 2px var(--accent-gold-glow);
}

/* Level filter chips */
.level-chips-container {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.level-chip {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
}

.level-chip:hover {
  color: var(--text-primary);
  border-color: var(--border-light);
}

.level-chip.active {
  background: var(--accent-gold);
  color: #000;
  border-color: var(--accent-gold);
}

/* Topic Navigation List */
.topic-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: calc(100vh - 310px);
  overflow-y: auto;
  padding-right: 4px;
}

.topic-nav-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  cursor: pointer;
  transition: var(--transition);
}

.topic-nav-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-1px);
}

.topic-nav-item.active {
  background: rgba(245, 158, 11, 0.08);
  border-color: var(--accent-gold);
  box-shadow: 0 0 12px var(--accent-gold-glow);
}

.topic-nav-item.done {
  border-left: 4px solid var(--accent-green);
}
[dir="rtl"] .topic-nav-item.done {
  border-left: 1px solid var(--border);
  border-right: 4px solid var(--accent-green);
}

.topic-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
}

.topic-icon {
  font-size: 16px;
}

.topic-level-badge {
  font-size: 11px;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
}

.badge-level-a1 {
  background: rgba(14, 165, 233, 0.15);
  color: var(--level-a1);
  border: 1px solid rgba(14, 165, 233, 0.4);
}
.badge-level-a2 {
  background: rgba(16, 185, 129, 0.15);
  color: var(--level-a2);
  border: 1px solid rgba(16, 185, 129, 0.4);
}
.badge-level-b1 {
  background: rgba(245, 158, 11, 0.15);
  color: var(--level-b1);
  border: 1px solid rgba(245, 158, 11, 0.4);
}
.badge-level-b2 {
  background: rgba(168, 85, 247, 0.15);
  color: var(--level-b2);
  border: 1px solid rgba(168, 85, 247, 0.4);
}

.topic-done-icon {
  color: var(--accent-green);
  font-weight: 900;
  font-size: 13px;
}

.topic-item-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
  line-height: 1.35;
}

.topic-item-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-muted);
}

/* Topic Main Arena */
.topic-arena {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  min-height: 600px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Mobile Back Button */
.mobile-back-row {
  display: none;
}

.btn-mobile-back {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Arena Header */
.arena-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.arena-title-group {
  flex: 1;
}

.arena-badges {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.active-level-pill {
  font-size: 12px;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.arena-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 4px;
}

.arena-desc {
  font-size: 14px;
  color: var(--text-secondary);
}

/* Mode Switcher Tabs (Rules vs Drills) */
.arena-tabs {
  display: inline-flex;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 4px;
  gap: 4px;
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  background: var(--accent-gold);
  color: #000;
}

/* Rules Section */
.rules-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.rule-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px;
}

.rule-summary-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-primary);
}

.rule-bullet {
  list-style: none;
  position: relative;
  padding-left: 18px;
  margin: 6px 0;
  color: var(--text-primary);
}

.rule-bullet::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent-gold);
  font-size: 18px;
  line-height: 1;
}

.rule-quote {
  border-left: 3px solid var(--accent-gold);
  background: rgba(245, 158, 11, 0.06);
  padding: 8px 12px;
  margin: 8px 0;
  border-radius: 4px;
  font-weight: 600;
}

/* Pro Tip Card */
.protip-card {
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.protip-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 800;
  color: var(--accent-gold);
  margin-bottom: 8px;
}

.protip-text {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-primary);
}

/* Examples Section */
.examples-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.examples-header {
  font-size: 15px;
  font-weight: 800;
  color: var(--text-primary);
}

.examples-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.example-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.example-de-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  direction: ltr !important; /* Always keep German sentence LTR */
  text-align: left !important;
}

.example-de {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--text-primary);
}

.btn-audio-play {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 14px;
  transition: var(--transition);
  color: var(--text-primary);
}

.btn-audio-play:hover {
  background: var(--accent-gold);
  color: #000;
  border-color: var(--accent-gold);
}

.btn-audio-play.playing {
  animation: pulse 1s infinite alternate;
  background: var(--accent-green);
  color: #fff;
}

@keyframes pulse {
  0% { transform: scale(1); }
  100% { transform: scale(1.15); box-shadow: 0 0 10px var(--accent-green-glow); }
}

.example-translated {
  font-size: 13px;
  color: var(--text-secondary);
}

/* Call to action: Start Drills */
.rules-footer {
  margin-top: 10px;
  display: flex;
  justify-content: flex-end;
}

.btn-cta-primary {
  background: linear-gradient(135deg, var(--accent-gold), #d97706);
  color: #000;
  border: none;
  font-size: 14px;
  font-weight: 800;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 14px var(--accent-gold-glow);
  transition: var(--transition);
}

.btn-cta-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--accent-gold-glow);
}

/* Drills Section & Interactive Quiz */
.drills-content {
  display: none;
}

.drill-active-card {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.drill-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.drill-counter-pill {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
}

.drill-prompt-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
}

.drill-prompt-box .prompt-text {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.5;
  direction: ltr !important;
  display: inline-block;
}

.drill-options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.drill-option-btn {
  background: var(--bg-secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  transition: var(--transition);
  direction: ltr !important;
}

.drill-option-btn:hover:not(:disabled) {
  background: var(--bg-card-hover);
  border-color: var(--accent-gold);
  transform: translateY(-2px);
}

.option-letter {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 800;
  width: 26px;
  height: 26px;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.option-label {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
}

/* Correct & Incorrect States */
.drill-option-btn.correct {
  background: rgba(16, 185, 129, 0.15) !important;
  border-color: var(--accent-green) !important;
  color: #fff;
  box-shadow: 0 0 15px var(--accent-green-glow);
}
.drill-option-btn.correct .option-letter {
  background: var(--accent-green);
  color: #fff;
  border-color: var(--accent-green);
}

.drill-option-btn.incorrect {
  background: rgba(239, 68, 68, 0.15) !important;
  border-color: var(--accent-red) !important;
  opacity: 0.8;
}
.drill-option-btn.incorrect .option-letter {
  background: var(--accent-red);
  color: #fff;
  border-color: var(--accent-red);
}

/* Feedback Box */
.drill-feedback-box {
  display: none;
  border-radius: var(--radius-md);
  padding: 16px 20px;
  font-size: 14px;
}

.box-correct {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--accent-green);
}
.box-wrong {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--accent-red);
}
.box-dontknow {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid var(--accent-gold);
}

.feedback-title {
  font-size: 15px;
  font-weight: 800;
  margin-bottom: 6px;
}

.feedback-explanation {
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--text-primary);
}

/* Drill Actions Row: Don't Know & Next Question */
.drill-actions-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 10px;
}

.btn-dont-know {
  background: var(--bg-secondary);
  border: 1px dashed var(--accent-gold);
  color: var(--accent-gold);
  padding: 10px 18px;
  border-radius: var(--radius-md);
  font-size: 13.5px;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.btn-dont-know:hover {
  background: rgba(245, 158, 11, 0.12);
  border-style: solid;
}

.btn-next-drill {
  display: none;
  background: var(--accent-green);
  color: #fff;
  border: none;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
  transition: var(--transition);
}

.btn-next-drill:hover {
  background: #059669;
  transform: translateY(-1px);
}

/* Drill Results Summary Card */
.drill-results-card {
  display: none;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 24px;
  text-align: center;
}

.results-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.results-title {
  font-size: 24px;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.results-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.results-score-box {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 24px;
}

.score-number {
  font-size: 32px;
  font-weight: 900;
  color: var(--text-primary);
}

.score-badge {
  font-size: 16px;
  font-weight: 800;
  padding: 6px 16px;
  border-radius: var(--radius-full);
}

.badge-pass {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
  border: 1px solid var(--accent-green);
}
.badge-retry {
  background: rgba(239, 68, 68, 0.15);
  color: var(--accent-red);
  border: 1px solid var(--accent-red);
}

.results-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-secondary {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 10px 18px;
  border-radius: var(--radius-md);
  font-size: 13.5px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
}

/* ==========================================================================
   Responsive & Mobile Adaptations (Deniz Abad Mobile Feedback)
   ========================================================================== */
@media (max-width: 900px) {
  .grammatik-workspace {
    grid-template-columns: 1fr;
  }

  .topic-list {
    max-height: 380px;
  }

  /* When viewing topic on mobile, toggle between list and arena smoothly */
  body.mobile-viewing-topic .topics-sidebar {
    display: none;
  }

  body.mobile-viewing-topic .mobile-back-row {
    display: block;
    margin-bottom: 12px;
  }

  body:not(.mobile-viewing-topic) .topic-arena {
    display: none;
  }

  .drill-options-grid {
    grid-template-columns: 1fr;
  }

  .header-container {
    padding: 0 4px;
  }

  .app-header {
    position: relative !important;
  }
}

@media (max-width: 768px), (pointer: coarse) {
  .back-link,
  .btn-icon {
    min-height: 44px;
    min-width: 44px;
  }
}