/* CSS Variable Definitions for Calming Theme System */
:root {
  --font-sans: 'Outfit', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Theme: Dark (default) */
  --bg-app: #090d16;
  --bg-card: #121824;
  --bg-card-hover: #1b2436;
  --border: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #64748b;
  --text-subtle: #475569;
  
  --primary: #38bdf8;
  --primary-rgb: 56, 189, 248;
  --primary-hover: #0ea5e9;
  
  --success: #34d399;
  --danger: #f87171;
  --danger-bg: rgba(248, 113, 113, 0.15);
  --success-bg: rgba(52, 211, 153, 0.1);

  --shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.3);
  --glow: 0 0 20px rgba(56, 189, 248, 0.15);
}

/* Light Theme overrides */
html[data-theme="light"] {
  --bg-app: #f0f4f8;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --border: #cbd5e1;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;
  
  --primary: #0284c7;
  --primary-rgb: 2, 132, 199;
  --primary-hover: #0369a1;
  
  --success: #059669;
  --danger: #dc2626;
  --danger-bg: rgba(220, 38, 38, 0.1);
  --success-bg: rgba(5, 150, 105, 0.08);

  --shadow: 0 4px 20px -2px rgba(148, 163, 184, 0.2);
  --glow: 0 0 20px rgba(2, 132, 199, 0.08);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Ambient glow decoration */
.ambient-glow {
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 350px;
  background: radial-gradient(circle, rgba(var(--primary-rgb), 0.08) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}

/* App Wrapper Container */
.app-container {
  width: 100%;
  max-width: 1000px;
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

/* Ad Placement Slots */
.ad-slot {
  width: 100%;
  margin: 12px 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

.ad-placeholder {
  width: 100%;
  max-width: 728px;
  height: 90px;
  background-color: var(--bg-card);
  border: 1px dashed var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  opacity: 0.75;
  transition: border-color 0.2s ease;
}

.ad-placeholder:hover {
  border-color: var(--primary);
}

/* Header & Logo */
.main-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.4rem;
  font-weight: 700;
  user-select: none;
}

.logo-text span {
  color: var(--primary);
}

/* Navigation Tabs */
.nav-tabs {
  display: flex;
  gap: 8px;
  background-color: var(--bg-card);
  padding: 4px;
  border-radius: 30px;
  border: 1px solid var(--border);
}

.nav-tab {
  display: flex;
  align-items: center;
  gap: 6px;
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 8px 16px;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-weight: 500;
  cursor: pointer;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.nav-tab svg {
  transition: stroke 0.2s ease;
}

.nav-tab:hover {
  color: var(--text-main);
}

.nav-tab.active {
  background-color: var(--primary);
  color: var(--bg-app);
}

.nav-tab.active svg {
  stroke: var(--bg-app);
}

/* Header actions & theme toggle */
.header-actions {
  display: flex;
  align-items: center;
}

.icon-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 10px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.icon-btn:hover {
  border-color: var(--primary);
  transform: scale(1.05);
}

/* Toggle icon display states */
html[data-theme="dark"] .sun-icon { display: block; }
html[data-theme="dark"] .moon-icon { display: none; }
html[data-theme="light"] .sun-icon { display: none; }
html[data-theme="light"] .moon-icon { display: block; }

/* Main Content Area */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.content-section {
  display: none;
  flex-direction: column;
  animation: fadeIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.content-section.active {
  display: flex;
}

/* Config Bar Options */
.config-bar {
  display: flex;
  gap: 24px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.config-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.config-label {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.radio-toggle {
  display: flex;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2px;
}

.toggle-opt {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 6px 12px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.toggle-opt:hover {
  color: var(--text-main);
}

.toggle-opt.active {
  background-color: var(--border);
  color: var(--primary);
}

/* Stats Panel */
.stats-panel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  text-align: center;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-num {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-num.text-danger {
  color: var(--danger);
}

.stat-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Typing Containers and Overlays */
.typing-container-wrapper {
  position: relative;
  border: 1px solid var(--border);
  background-color: var(--bg-card);
  border-radius: 16px;
  padding: 24px;
  box-shadow: var(--shadow);
  overflow: hidden;
  margin-bottom: 24px;
}

.typing-container-wrapper:focus-within {
  border-color: var(--primary);
  box-shadow: var(--glow);
}

.typing-container {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  line-height: 2.1rem;
  height: 126px; /* Approx 3 lines of text */
  overflow: hidden;
  position: relative;
  user-select: none;
  outline: none;
  white-space: pre-wrap;
  word-break: break-all;
}

/* Word & Character highlighting */
.word {
  display: inline-block;
  margin-right: 0.55em;
  scroll-margin: 20px;
}

.char {
  position: relative;
  color: var(--text-subtle);
  transition: color 0.1s ease;
}

.char.correct {
  color: var(--text-main);
}

.char.incorrect {
  color: var(--danger);
  background-color: var(--danger-bg);
  border-radius: 2px;
}

/* Elegant Blinking Caret */
.caret {
  position: absolute;
  width: 2px;
  height: 1.25em;
  background-color: var(--primary);
  animation: blink 0.9s infinite;
  transform: translateY(2px);
  pointer-events: none;
  transition: left 0.08s ease, top 0.08s ease;
}

.hidden-input {
  position: absolute;
  opacity: 0;
  z-index: -100;
  pointer-events: none;
}

/* Typing Overlays */
.typing-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(9, 13, 22, 0.85);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: opacity 0.2s ease;
  z-index: 10;
}

html[data-theme="light"] .typing-overlay {
  background-color: rgba(240, 244, 248, 0.85);
}

.typing-overlay p {
  font-weight: 500;
  color: var(--primary);
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 12px 24px;
  border-radius: 30px;
  box-shadow: var(--shadow);
}

/* Typing Loader */
.typing-loader {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  font-family: var(--font-sans);
}

/* Buttons and Controls */
.controls-bar {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-bottom: 24px;
}

.btn {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: 8px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--bg-app);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

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

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

/* Results Dashboard Modal overlay style */
.results-modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(5px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
}

.results-modal.show {
  display: flex;
  animation: fadeIn 0.2s ease;
}

.results-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  width: 100%;
  max-width: 500px;
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 20px 25px -5px rgba(0,0,0,0.5);
  text-align: center;
  animation: scaleUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.results-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 24px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 28px;
}

.result-box {
  background-color: rgba(var(--primary-rgb), 0.03);
  border: 1px solid var(--border);
  padding: 16px;
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.result-val {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 700;
}

.result-val.highlight {
  color: var(--primary);
}

.result-lbl {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
}

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

/* Typing Lessons Layout styling */
.lessons-header {
  text-align: center;
  margin-bottom: 32px;
}

.lessons-header h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.lessons-header p {
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto;
}

.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.lesson-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  cursor: pointer;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  box-shadow: var(--shadow);
}

.lesson-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  background-color: var(--bg-card-hover);
}

.lesson-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.lesson-tag {
  background-color: rgba(var(--primary-rgb), 0.08);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 6px;
}

.lesson-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
}

.lesson-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.35rem;
  flex-grow: 1;
}

.lesson-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  font-weight: 500;
}

.lesson-progress-lbl {
  color: var(--success);
}

/* Lesson Arena & Hand Placement Styles */
.lesson-arena-view {
  animation: fadeIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.lesson-arena-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.btn-back {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px 14px;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

.btn-back:hover {
  color: var(--text-main);
  border-color: var(--primary);
}

.finger-placement-guide {
  display: flex;
  flex-direction: column;
  gap: 16px;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 24px;
}

.instruction-box h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 4px;
}

.instruction-box p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.keyboard-guide {
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-items: center;
  padding: 10px 0;
  user-select: none;
}

.kbd-row {
  display: flex;
  gap: 4px;
}

.key {
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--text-muted);
  background-color: rgba(255, 255, 255, 0.02);
  transition: all 0.15s ease;
}

.key-space {
  width: 160px;
}

/* Key guide highlighting states */
.key.highlight-left, .key.highlight-right {
  background-color: var(--primary);
  color: var(--bg-app);
  border-color: var(--primary);
  box-shadow: 0 0 10px rgba(var(--primary-rgb), 0.4);
  transform: scale(1.05);
}

/* Helper styles */
.hidden {
  display: none !important;
}

.text-danger {
  color: var(--danger) !important;
}

.text-success {
  color: var(--success) !important;
}

/* Footer layout */
.main-footer {
  text-align: center;
  padding: 24px 0 12px 0;
  font-size: 0.8rem;
  color: var(--text-subtle);
  border-top: 1px solid var(--border);
  margin-top: auto;
}

/* Animations */
@keyframes blink {
  50% { opacity: 0; }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes scaleUp {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

/* Mobile & Tablet Responsiveness */
@media (max-width: 768px) {
  .main-header {
    justify-content: center;
  }
  .nav-tabs {
    order: 3;
    width: 100%;
    justify-content: space-around;
  }
  .typing-container {
    font-size: 1.2rem;
    line-height: 1.8rem;
    height: 108px;
  }
  .results-card {
    padding: 20px;
  }
  .results-grid {
    grid-template-columns: 1fr;
  }
  .kbd-row {
    transform: scale(0.85);
  }
  .key {
    width: 26px;
    height: 26px;
    font-size: 0.65rem;
  }
  .key-space {
    width: 120px;
  }
}

@media (max-width: 480px) {
  .stats-panel {
    grid-template-columns: repeat(2, 1fr);
  }
  .kbd-row {
    transform: scale(0.65);
  }
}