/* ===================================================
   Cebuano Daily Study PWA - Design System & Styles
   =================================================== */

:root {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-card: #1E293B;
  --bg-card-hover: #273549;
  --bg-input: #0F172A;
  
  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-dim: #64748B;
  
  --border-color: #334155;
  --border-focus: #38BDF8;
  
  --primary: #38BDF8;
  --primary-glow: rgba(56, 189, 248, 0.2);
  --accent: #F59E0B;
  --success: #10B981;
  --danger: #EF4444;
  
  /* Grammar Syntax Color-Coding Badges */
  --vip-bg: rgba(37, 99, 235, 0.2);
  --vip-text: #60A5FA;
  --vip-border: #2563EB;
  
  --verb-bg: rgba(5, 150, 105, 0.2);
  --verb-text: #34D399;
  --verb-border: #059669;
  
  --magnet-bg: rgba(220, 38, 38, 0.2);
  --magnet-text: #F87171;
  --magnet-border: #DC2626;
  
  --linker-bg: rgba(217, 119, 6, 0.2);
  --linker-text: #FBBF24;
  --linker-border: #D97706;
  
  --particle-bg: rgba(124, 58, 237, 0.2);
  --particle-text: #A78BFA;
  --particle-border: #7C3AED;
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.35);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.45);
}

/* Light Theme Variables */
body.light-theme {
  --bg-primary: #F8FAFC;
  --bg-secondary: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F1F5F9;
  --bg-input: #F1F5F9;
  
  --text-main: #0F172A;
  --text-muted: #475569;
  --text-dim: #94A3B8;
  
  --border-color: #E2E8F0;
  --border-focus: #0284C7;
  
  --primary: #0284C7;
  --primary-glow: rgba(2, 132, 199, 0.15);
  
  --vip-bg: #EFF6FF;
  --vip-text: #1D4ED8;
  --vip-border: #BFDBFE;
  
  --verb-bg: #ECFDF5;
  --verb-text: #047857;
  --verb-border: #A7F3D0;
  
  --magnet-bg: #FEF2F2;
  --magnet-text: #B91C1C;
  --magnet-border: #FECACA;
  
  --linker-bg: #FFFBEB;
  --linker-text: #B45309;
  --linker-border: #FDE68A;
  
  --particle-bg: #F5F3FF;
  --particle-text: #6D28D9;
  --particle-border: #DDD6FE;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
}

/* Reset & Base */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 680px;
  margin: 0 auto;
  width: 100%;
  position: relative;
}

/* App Header */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(12px);
}

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

.app-logo {
  font-size: 26px;
  display: flex;
  align-items: center;
}

.header-titles h1 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.3px;
  line-height: 1.2;
}

.header-subtitle {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

.icon-btn {
  background: transparent;
  border: none;
  font-size: 17px;
  color: var(--text-muted);
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.icon-btn.syncing .sync-icon {
  display: inline-block;
  animation: spin 1s infinite linear;
}

@keyframes spin {
  100% { transform: rotate(360deg); }
}

/* Status Banner */
.status-banner {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 8px 16px;
  font-size: 12px;
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.3s ease;
}

.status-banner.hidden {
  display: none;
}

/* Main Content Area */
.main-content {
  flex: 1;
  padding: 16px 16px 90px 16px;
}

.tab-pane {
  display: none;
  animation: fadeIn 0.25s ease-out;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Cards System */
.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 18px;
  margin-bottom: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header-with-icon {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.card-header-with-icon .card-icon {
  font-size: 20px;
}

.card-header-with-icon h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
}

/* Hero Cards */
.lesson-hero-card {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.15), rgba(30, 41, 59, 0.6));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 16px;
  position: relative;
  overflow: hidden;
}

.section-hero {
  margin-bottom: 18px;
}

.section-hero h2 {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 4px;
}

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

.lesson-badge-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.lesson-main-title {
  font-size: 22px;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.4px;
  color: var(--text-main);
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-primary {
  background-color: var(--primary);
  color: #0F172A;
}

.badge-neutral {
  background-color: var(--bg-card-hover);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.badge-vip {
  background-color: var(--vip-bg);
  color: var(--vip-text);
  border: 1px solid var(--vip-border);
}

.badge-verb {
  background-color: var(--verb-bg);
  color: var(--verb-text);
  border: 1px solid var(--verb-border);
}

.badge-magnet {
  background-color: var(--magnet-bg);
  color: var(--magnet-text);
  border: 1px solid var(--magnet-border);
}

.badge-linker {
  background-color: var(--linker-bg);
  color: var(--linker-text);
  border: 1px solid var(--linker-border);
}

.badge-particle {
  background-color: var(--particle-bg);
  color: var(--particle-text);
  border: 1px solid var(--particle-border);
}

/* Item Lists */
.takeaway-list, .tricks-list, .formula-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.takeaway-item, .trick-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.5;
}

.bullet-dot {
  color: var(--primary);
  font-size: 16px;
  line-height: 1.2;
}

/* Formulas */
.formula-block {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 14px;
}

.formula-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
  letter-spacing: 0.5px;
}

.formula-code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--primary);
  word-break: break-word;
}

/* Breakdown Examples */
.examples-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.example-card-item {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px;
}

.example-cebuano {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 4px;
}

.example-english {
  font-size: 13.5px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.syntax-tags-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* Practice Challenge */
.practice-question {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text-main);
}

.practice-action-area {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.practice-answer-box {
  background: var(--bg-primary);
  border: 1px solid var(--success);
  border-radius: var(--radius-md);
  padding: 14px;
  font-size: 15px;
  font-weight: 700;
  color: var(--success);
  animation: fadeIn 0.2s ease-out;
}

.practice-answer-box.hidden {
  display: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background-color: var(--primary);
  color: #0F172A;
}

.btn-primary:hover {
  filter: brightness(1.1);
}

.btn-secondary {
  background-color: var(--bg-card-hover);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

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

.btn-outline-danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--danger);
}

/* Chip Carousel */
.chip-carousel {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 12px;
  margin-bottom: 14px;
  scrollbar-width: none;
}

.chip-carousel::-webkit-scrollbar {
  display: none;
}

.chip {
  white-space: nowrap;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.chip.active, .chip:hover {
  background: var(--primary);
  color: #0F172A;
  border-color: var(--primary);
}

/* Rule Cards (Cheat Sheet) */
.rule-cards-grid {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.rule-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: all 0.2s ease;
}

.rule-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 8px;
}

.rule-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
}

.rule-explanation {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 12px;
  line-height: 1.5;
}

/* Vocab Controls & Flashcards */
.vocab-controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 14px;
  font-size: 15px;
  color: var(--text-dim);
}

.search-box input {
  width: 100%;
  padding: 12px 38px 12px 42px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-main);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s ease;
}

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

.clear-btn {
  position: absolute;
  right: 14px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 14px;
  cursor: pointer;
}

.clear-btn.hidden {
  display: none;
}

.study-mode-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 4px;
}

/* Toggle Switch */
.toggle-container {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
}

.toggle-container input {
  display: none;
}

.toggle-slider {
  width: 40px;
  height: 22px;
  background-color: var(--border-color);
  border-radius: var(--radius-full);
  position: relative;
  transition: background-color 0.2s ease;
}

.toggle-slider::before {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: white;
  top: 3px;
  left: 3px;
  transition: transform 0.2s ease;
}

.toggle-container input:checked + .toggle-slider {
  background-color: var(--primary);
}

.toggle-container input:checked + .toggle-slider::before {
  transform: translateX(18px);
}

.toggle-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
}

/* Vocab Cards */
.vocab-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.vocab-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.vocab-card:hover {
  border-color: var(--border-focus);
}

.vocab-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.vocab-cebuano-word {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.2px;
}

.vocab-category-tag {
  font-size: 11px;
  color: var(--text-dim);
  font-weight: 600;
  text-transform: uppercase;
}

.vocab-english {
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 8px;
  transition: opacity 0.2s ease;
}

.vocab-english.hidden-blur {
  filter: blur(5px);
  user-select: none;
  opacity: 0.5;
}

.vocab-example-block {
  border-top: 1px solid var(--border-color);
  padding-top: 8px;
  margin-top: 6px;
}

.vocab-example-cebuano {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-main);
}

.vocab-example-english {
  font-size: 12.5px;
  color: var(--text-muted);
}

/* Archive Timeline */
.timeline-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.timeline-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.timeline-num {
  background: var(--bg-card-hover);
  border: 1px solid var(--border-color);
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 14px;
  color: var(--primary);
  flex-shrink: 0;
}

.timeline-body {
  flex: 1;
}

.timeline-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.timeline-topic {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-main);
}

.timeline-date {
  font-size: 11px;
  color: var(--text-dim);
}

.timeline-concept {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.timeline-formula {
  font-family: ui-monospace, monospace;
  font-size: 12px;
  color: var(--primary);
  background: var(--bg-primary);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  display: inline-block;
}

/* Bottom Navigation Bar */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding: 8px 12px calc(8px + env(safe-area-inset-bottom, 0px));
  z-index: 100;
  max-width: 680px;
  margin: 0 auto;
}

.nav-item {
  background: transparent;
  border: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 6px 12px;
  border-radius: var(--radius-md);
  color: var(--text-dim);
  cursor: pointer;
  transition: all 0.2s ease;
  flex: 1;
}

.nav-icon {
  font-size: 20px;
  transition: transform 0.2s ease;
}

.nav-label {
  font-size: 11px;
  font-weight: 600;
}

.nav-item.active {
  color: var(--primary);
}

.nav-item.active .nav-icon {
  transform: scale(1.15);
}

/* Modal Dialog */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-backdrop.hidden {
  display: none;
}

.modal-dialog {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 440px;
  padding: 24px;
  box-shadow: var(--shadow-lg);
  animation: fadeIn 0.2s ease;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 800;
}

.modal-body {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

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

.form-input:focus {
  border-color: var(--border-focus);
}

.input-hint {
  font-size: 12px;
  color: var(--text-dim);
}

.modal-status-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 13px;
}

.status-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 6px;
}

.modal-actions .btn {
  flex: 1;
}