/* Variables del Sistema de Diseño */
:root {
  --font-family: 'Outfit', sans-serif;
  
  /* Modo Oscuro (Por defecto) */
  --bg-color: #0b0f19;
  --bg-gradient: radial-gradient(circle at top, #1e2640 0%, #0b0f19 100%);
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-shadow: rgba(0, 0, 0, 0.3);
  --primary-accent: #4f46e5;
  --primary-accent-hover: #4338ca;
  --primary-accent-glow: rgba(79, 70, 229, 0.4);
  --secondary-accent: rgba(255, 255, 255, 0.1);
  --secondary-accent-hover: rgba(255, 255, 255, 0.15);
  --danger-accent: #ef4444;
  --danger-accent-hover: #dc2626;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --border-radius-lg: 24px;
  --border-radius-md: 16px;
  --border-radius-sm: 8px;
  --transition-speed: 0.3s;
}

/* Modo Claro overrides */
body.light-mode {
  --bg-color: #f3f4f6;
  --bg-gradient: radial-gradient(circle at top, #e0e7ff 0%, #f3f4f6 100%);
  --text-primary: #1f2937;
  --text-secondary: #4b5563;
  --glass-bg: rgba(255, 255, 255, 0.5);
  --glass-border: rgba(255, 255, 255, 0.7);
  --glass-shadow: rgba(0, 0, 0, 0.06);
  --primary-accent: #3b82f6;
  --primary-accent-hover: #2563eb;
  --primary-accent-glow: rgba(59, 130, 246, 0.25);
  --secondary-accent: rgba(0, 0, 0, 0.05);
  --secondary-accent-hover: rgba(0, 0, 0, 0.08);
}

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

body {
  font-family: var(--font-family);
  background: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  overflow-x: hidden;
  transition: background var(--transition-speed), color var(--transition-speed);
}

/* Contenedor de la Aplicación (Priorizando Móviles) */
.app-container {
  width: 100%;
  max-width: 500px; /* Ancho máximo ideal para PC que simula pantalla de móvil */
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 16px;
  position: relative;
}

/* Header */
.app-header {
  padding: 8px 0 16px 0;
  border-bottom: 1px solid var(--glass-border);
  margin-bottom: 16px;
}

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

h1 {
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--primary-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Icon Buttons (Theme toggle) */
.icon-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 4px 6px var(--glass-shadow);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.2s, background-color var(--transition-speed);
}

.icon-btn:hover {
  transform: scale(1.05);
  background-color: var(--secondary-accent-hover);
}

.icon-btn svg {
  width: 20px;
  height: 20px;
}

/* Alternancia de iconos para tema claro/oscuro */
body.dark-mode .sun-icon { display: block; }
body.dark-mode .moon-icon { display: none; }
body.light-mode .sun-icon { display: none; }
body.light-mode .moon-icon { display: block; }

/* Main Content Area */
.app-main {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* Screens */
.screen {
  display: none;
  flex-direction: column;
  flex-grow: 1;
  width: 100%;
  animation: fadeIn 0.4s ease-out forwards;
}

.screen.active {
  display: flex;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Pantalla de Selección */
.section-intro {
  margin-bottom: 20px;
  text-align: center;
}

.section-intro h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.section-intro p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.exams-grid {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* Glass Card */
.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-lg);
  padding: 20px;
  box-shadow: 0 8px 32px var(--glass-shadow);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

/* Tarjetas de Examen */
.exam-card {
  cursor: pointer;
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
}

.exam-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary-accent);
  box-shadow: 0 12px 40px var(--primary-accent-glow);
}

.exam-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.exam-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.4;
  margin-bottom: 16px;
}

/* Botones */
.primary-btn, .secondary-btn, .danger-btn, .voice-btn {
  font-family: var(--font-family);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 12px 20px;
  border-radius: var(--border-radius-md);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: background-color 0.2s, transform 0.1s, box-shadow 0.2s;
  width: 100%;
}

.primary-btn {
  background-color: var(--primary-accent);
  color: #ffffff;
  box-shadow: 0 4px 14px var(--primary-accent-glow);
}

.primary-btn:hover {
  background-color: var(--primary-accent-hover);
  box-shadow: 0 6px 20px var(--primary-accent-glow);
}

.secondary-btn {
  background-color: var(--secondary-accent);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
}

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

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

.danger-btn:hover {
  background-color: var(--danger-accent);
  color: #ffffff;
}

.text-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
}

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

/* Pantalla de Práctica */
.practice-header {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 14px 20px;
  margin-bottom: 16px;
  border-radius: var(--border-radius-md);
}

.progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}

#score-counter {
  font-weight: 700;
  color: var(--primary-accent);
}

.progress-bar-container {
  height: 6px;
  background: var(--secondary-accent);
  border-radius: 3px;
  overflow: hidden;
  width: 100%;
}

.progress-bar-fill {
  height: 100%;
  background: var(--primary-accent);
  border-radius: 3px;
  transition: width 0.4s ease;
}

/* Pregunta Card */
.question-card {
  margin-bottom: 16px;
  position: relative;
  overflow: hidden;
}

.question-badge {
  font-size: 0.7rem;
  text-transform: uppercase;
  font-weight: 800;
  letter-spacing: 0.05em;
  background: var(--primary-accent);
  color: #fff;
  padding: 3px 8px;
  border-radius: var(--border-radius-sm);
  display: inline-block;
  margin-bottom: 8px;
}

#question-text {
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.5;
}

/* Modo Tabs */
.mode-tabs {
  display: flex;
  background: var(--secondary-accent);
  padding: 4px;
  border-radius: var(--border-radius-md);
  margin-bottom: 16px;
}

.tab-btn {
  flex: 1;
  background: none;
  border: none;
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 10px;
  border-radius: calc(var(--border-radius-md) - 4px);
  color: var(--text-secondary);
  cursor: pointer;
  transition: background-color 0.2s, color 0.2s;
}

.tab-btn.active {
  background-color: var(--glass-bg);
  color: var(--text-primary);
  box-shadow: 0 2px 8px var(--glass-shadow);
}

/* Contenedor de Modos */
.mode-container {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  margin-bottom: 16px;
  min-height: 250px;
}

.mode-content {
  display: none;
  flex-direction: column;
  flex-grow: 1;
  width: 100%;
}

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

/* Chat-bot */
.chat-messages-area {
  flex-grow: 1;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-md);
  padding: 16px;
  height: 220px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 12px;
  box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.1);
}

.chat-bubble {
  max-width: 85%;
  padding: 10px 14px;
  border-radius: var(--border-radius-md);
  font-size: 0.9rem;
  line-height: 1.45;
  animation: popMessage 0.25s ease-out forwards;
}

@keyframes popMessage {
  from { opacity: 0; transform: scale(0.95) translateY(5px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.chat-bubble.user {
  background-color: var(--primary-accent);
  color: #fff;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

.chat-bubble.ai {
  background-color: var(--secondary-accent);
  color: var(--text-primary);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
  border: 1px solid var(--glass-border);
}

.system-message {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
  align-self: center;
  padding: 4px 12px;
  background: var(--secondary-accent);
  border-radius: var(--border-radius-sm);
}

.chat-input-area {
  display: flex;
  gap: 8px;
}

.chat-input-area input {
  flex-grow: 1;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-md);
  padding: 12px 16px;
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s;
}

.chat-input-area input:focus {
  border-color: var(--primary-accent);
}

.chat-input-area button {
  width: auto;
  white-space: nowrap;
}

/* Live Voice */
.voice-status-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 16px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-md);
  margin-bottom: 12px;
  min-height: 100px;
}

/* Ondas de Voz */
.voice-waves {
  display: flex;
  align-items: center;
  gap: 4px;
  height: 30px;
}

.wave-bar {
  width: 4px;
  height: 6px;
  background-color: var(--text-secondary);
  border-radius: 2px;
  transition: height 0.15s, background-color var(--transition-speed);
}

/* Animaciones de voz activa */
.voice-waves.listening .wave-bar {
  background-color: var(--primary-accent);
  animation: bounceWave 0.6s infinite alternate;
}

.voice-waves.listening .wave-bar:nth-child(2) { animation-delay: 0.1s; }
.voice-waves.listening .wave-bar:nth-child(3) { animation-delay: 0.2s; }
.voice-waves.listening .wave-bar:nth-child(4) { animation-delay: 0.3s; }
.voice-waves.listening .wave-bar:nth-child(5) { animation-delay: 0.4s; }

.voice-waves.speaking .wave-bar {
  background-color: var(--success-color);
  animation: bounceWave 0.4s infinite alternate;
}

.voice-waves.speaking .wave-bar:nth-child(2) { animation-delay: 0.08s; }
.voice-waves.speaking .wave-bar:nth-child(3) { animation-delay: 0.16s; }
.voice-waves.speaking .wave-bar:nth-child(4) { animation-delay: 0.24s; }
.voice-waves.speaking .wave-bar:nth-child(5) { animation-delay: 0.32s; }

@keyframes bounceWave {
  from { height: 6px; }
  to { height: 26px; }
}

#voice-status-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Panel de Subtítulos */
.subtitles-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 14px;
  border-radius: var(--border-radius-md);
  margin-bottom: 12px;
  font-size: 0.85rem;
  line-height: 1.4;
  min-height: 110px;
  height: auto;
}

.subtitle-block {
  display: flex;
  gap: 6px;
}

.sub-label {
  font-weight: 700;
  color: var(--text-secondary);
  flex-shrink: 0;
}

.user-subtitle .sub-label { color: var(--primary-accent); }
.ai-subtitle .sub-label { color: var(--success-color); }

.subtitle-block p {
  color: var(--text-primary);
  font-style: italic;
}

.voice-controls {
  display: flex;
  justify-content: center;
}

.voice-btn {
  background-color: var(--primary-accent);
  color: #fff;
  border-radius: var(--border-radius-lg);
  box-shadow: 0 4px 14px var(--primary-accent-glow);
}

.voice-btn:hover {
  background-color: var(--primary-accent-hover);
}

.voice-btn.active {
  background-color: var(--danger-accent);
  box-shadow: 0 4px 14px rgba(239, 68, 68, 0.4);
}

/* Manejo de iconos en botón de voz */
.voice-btn .stop-icon { display: none; }
.voice-btn.active .mic-icon { display: none; }
.voice-btn.active .stop-icon { display: block; }
.voice-btn svg {
  width: 20px;
  height: 20px;
}

/* Footer de Acciones */
.action-footer {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  border-top: 1px solid var(--glass-border);
  padding-top: 16px;
  margin-top: auto;
}

.action-footer button {
  padding: 10px;
  font-size: 0.85rem;
}

/* Pantalla de Resultados */
.results-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 40px 20px;
  margin-top: 40px;
}

.trophy-icon {
  font-size: 4rem;
  margin-bottom: 16px;
  animation: popTrophy 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes popTrophy {
  from { transform: scale(0.5); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.results-container h2 {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 8px;
}

#results-exam-name {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 30px;
}

.score-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--secondary-accent);
  border-radius: var(--border-radius-lg);
  padding: 20px 40px;
  margin-bottom: 40px;
  border: 1px solid var(--glass-border);
}

.score-label {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.score-val {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary-accent);
}

/* Spinner de Carga */
.loading-spinner {
  text-align: center;
  padding: 40px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 90%;
  max-width: 320px;
  pointer-events: none;
}

.toast {
  background: rgba(15, 23, 42, 0.9);
  color: #fff;
  border: 1px solid var(--glass-border);
  padding: 12px 16px;
  border-radius: var(--border-radius-md);
  font-size: 0.85rem;
  font-weight: 600;
  text-align: center;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: slideUp 0.3s ease-out forwards, fadeOut 0.3s ease-out 2.7s forwards;
  pointer-events: auto;
}

.toast.correct {
  border-left: 4px solid var(--success-color);
}

.toast.give-up {
  border-left: 4px solid var(--warning-color);
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeOut {
  from { opacity: 1; }
  to { opacity: 0; }
}