/* styles.css */
/* Sistema de Diseño para Santiago Molina - Tin Whistle desde Cero */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
  /* Paleta de Colores (Tema Emerald & Gold Oscuro) */
  --primary: hsl(155, 85%, 15%);       /* Verde Irlandés profundo */
  --primary-glow: hsl(155, 80%, 25%);  /* Brillo verde */
  --primary-light: hsl(155, 50%, 45%); /* Verde más claro */
  --accent: hsl(45, 80%, 55%);         /* Oro/Latón del Whistle */
  --accent-hover: hsl(45, 90%, 65%);   /* Oro brillante */
  
  --bg-dark: #0a0e0c;                  /* Fondo negro oliva */
  --bg-body: #101613;                  /* Fondo principal oscuro */
  --bg-card: #18221d;                  /* Fondo de tarjetas verde oscuro */
  --bg-input: #1d2b24;                 /* Fondo de inputs */
  
  --border: hsla(155, 30%, 25%, 0.4);  /* Bordes sutiles verdes */
  --border-focus: hsla(45, 80%, 55%, 0.6); /* Borde oro */
  
  --text-main: #f0f4f2;                /* Texto blanco roto */
  --text-muted: #9eb1a7;               /* Texto secundario verde apagado */
  --text-inverse: #0a0e0c;             /* Texto oscuro sobre fondo claro */
  
  --success: #10b981;
  
  /* Fuentes */
  --font-title: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  
  /* Efectos y Sombras */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  --glass-bg: rgba(24, 34, 29, 0.7);
  --glass-blur: blur(12px);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset Global */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  scrollbar-width: thin;
  scrollbar-color: var(--primary-light) var(--bg-card);
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Scrollbars */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-card);
}
::-webkit-scrollbar-thumb {
  background: var(--primary-light);
  border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}
a:hover {
  color: var(--accent-hover);
}

button {
  cursor: pointer;
  border: none;
  font-family: inherit;
  transition: var(--transition);
}

/* Contenedor Principal SPA */
#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.view-section {
  display: none;
  flex: 1;
  animation: fadeIn 0.4s ease-out forwards;
}

.view-section.active {
  display: flex;
  flex-direction: column;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Barra de Navegación */
.navbar {
  background-color: var(--bg-dark);
  border-bottom: 1px solid var(--border);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: var(--glass-blur);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-icon {
  color: var(--accent);
  width: 28px;
  height: 28px;
}

.logo-img {
  height: 55px;
  width: auto;
  filter: invert(1) brightness(1.8);
  transition: var(--transition);
  display: block;
}

.logo-img:hover {
  filter: invert(1) brightness(2.2) drop-shadow(0 0 6px var(--accent));
  transform: scale(1.02);
}

.nav-brand-text {
  font-family: var(--font-title);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--text-main) 40%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
  background-color: var(--primary);
}

.nav-user-info {
  display: flex;
  align-items: center;
  gap: 1rem;
  border-left: 1px solid var(--border);
  padding-left: 1.5rem;
}

.student-badge {
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  font-size: 0.8rem;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
}

.logout-btn {
  background: transparent;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 0.25rem 0.5rem;
}

.logout-btn:hover {
  color: #ef4444;
}

.menu-toggle {
  display: none;
  background: transparent;
  color: var(--text-main);
  font-size: 1.5rem;
}

/* Landing Page / Activación */
.landing-hero {
  padding: 6rem 2rem 4rem;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.badge-tag {
  background-color: hsla(45, 80%, 55%, 0.15);
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 0.35rem 1rem;
  font-weight: 600;
  font-size: 0.85rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.landing-hero h1 {
  font-family: var(--font-title);
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1px;
}

.landing-hero h1 span {
  color: var(--accent);
  background: linear-gradient(135deg, var(--accent) 30%, var(--primary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.landing-hero p {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 650px;
}

.landing-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, #b89127 100%);
  color: var(--text-inverse);
  font-weight: 700;
  font-size: 1rem;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 15px rgba(229, 193, 88, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(229, 193, 88, 0.4);
}

.btn-secondary {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  font-weight: 600;
  font-size: 1rem;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-md);
}

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

.landing-features {
  padding: 4rem 2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.5rem 2rem;
  border-radius: var(--radius-lg);
  transition: var(--transition);
}

.feature-card:hover {
  border-color: var(--primary-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon-wrapper {
  background-color: hsla(155, 50%, 45%, 0.1);
  border: 1px solid rgba(11, 124, 67, 0.2);
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  margin-bottom: 1.5rem;
}

.feature-card h3 {
  font-family: var(--font-title);
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Auth Page */
.auth-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 70px);
  padding: 2rem;
}

.auth-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  width: 100%;
  max-width: 450px;
  padding: 3rem 2.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.auth-card h2 {
  font-family: var(--font-title);
  font-size: 2rem;
  margin-bottom: 0.5rem;
  text-align: center;
}

.auth-subtitle {
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 2rem;
  font-size: 0.95rem;
}

.auth-alert-info {
  background-color: hsla(45, 80%, 55%, 0.08);
  border: 1px dashed var(--accent);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.auth-alert-info p {
  margin-bottom: 0.5rem;
}
.auth-alert-info strong {
  color: var(--accent);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-muted);
}

.form-group input {
  width: 100%;
  background-color: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px hsla(45, 80%, 55%, 0.15);
}

.auth-error {
  color: #ef4444;
  font-size: 0.85rem;
  margin-top: 0.5rem;
  display: none;
}

.auth-submit-btn {
  width: 100%;
  margin-top: 1.5rem;
}

.auth-switch {
  text-align: center;
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.auth-switch a {
  font-weight: 600;
}

/* Student Dashboard */
.dashboard-hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--bg-dark) 100%);
  border-bottom: 1px solid var(--border);
  padding: 3rem 2rem;
}

.dashboard-hero-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 2rem;
}

.dashboard-welcome h1 {
  font-family: var(--font-title);
  font-size: 2.2rem;
  margin-bottom: 0.5rem;
}

.dashboard-welcome p {
  color: var(--text-muted);
}

.progress-widget {
  background-color: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  min-width: 280px;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.progress-header span:last-child {
  color: var(--accent);
}

.progress-bar-bg {
  background-color: var(--bg-dark);
  height: 8px;
  border-radius: 4px;
  overflow: hidden;
}

.progress-bar-fill {
  background: linear-gradient(90deg, var(--primary-light), var(--accent));
  height: 100%;
  width: 0%;
  transition: width 0.8s ease-out;
}

.progress-text {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.dashboard-grid {
  max-width: 1200px;
  margin: 2.5rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2.5rem;
}

.dashboard-section-title {
  font-family: var(--font-title);
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.dashboard-section-title svg {
  color: var(--accent);
}

/* Syllabus Cards */
.syllabus-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.module-group {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.module-header {
  background-color: rgba(7, 72, 40, 0.2);
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  font-family: var(--font-title);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-main);
}

.module-lessons {
  display: flex;
  flex-direction: column;
}

.lesson-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
  cursor: pointer; /* Indica que toda la fila es interactiva */
}

.lesson-item:last-child {
  border-bottom: none;
}

.lesson-item:hover {
  background-color: rgba(7, 72, 40, 0.15); /* Resaltado verde celta */
  border-color: rgba(229, 193, 88, 0.3);
}

.lesson-item:hover .enter-lesson-btn {
  color: var(--accent-hover);
  transform: translateX(4px);
}

.lesson-main-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.lesson-checkbox {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: transparent;
  transition: var(--transition);
}

.lesson-item.completed .lesson-checkbox {
  background-color: var(--success);
  border-color: var(--success);
  color: white;
}

.lesson-details h4 {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-main);
}

.lesson-item.completed .lesson-details h4 {
  color: var(--text-muted);
  text-decoration: line-through;
}

.lesson-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.lesson-duration {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.enter-lesson-btn {
  background: transparent;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  white-space: nowrap; /* Evita que el texto se divida en 2 líneas */
  transition: var(--transition);
}

.enter-lesson-btn:hover {
  color: var(--accent-hover);
  transform: translateX(4px);
}

/* Sidebar Widget */
.widget-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2rem;
  border-radius: var(--radius-lg);
  margin-bottom: 2rem;
}

.widget-card h3 {
  font-family: var(--font-title);
  font-size: 1.25rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
}

.shortcut-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
}

/* Course Viewer (Visor) */
.viewer-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  flex: 1;
  height: calc(100vh - 70px);
  overflow: hidden;
}

/* Viewer Sidebar */
.viewer-sidebar {
  background-color: var(--bg-dark);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.sidebar-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-header h2 {
  font-family: var(--font-title);
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  cursor: pointer;
  transition: color 0.2s ease;
}

.sidebar-header h2:hover {
  color: var(--accent);
}

.sidebar-syllabus {
  flex: 1;
}

.sidebar-module-title {
  background-color: rgba(255, 255, 255, 0.02);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1.25rem;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.sidebar-lesson-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: var(--transition);
}

.sidebar-lesson-item:hover {
  background-color: rgba(255, 255, 255, 0.01);
}

.sidebar-lesson-item.active {
  background-color: rgba(7, 72, 40, 0.25);
  border-left: 3px solid var(--accent);
}

.sidebar-lesson-check {
  width: 16px;
  height: 16px;
  border: 1.5px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  color: transparent;
  margin-top: 2px;
  flex-shrink: 0;
}

.sidebar-lesson-item.completed .sidebar-lesson-check {
  background-color: var(--success);
  border-color: var(--success);
  color: white;
}

.sidebar-lesson-title {
  font-size: 0.88rem;
  font-weight: 500;
  line-height: 1.4;
}

.sidebar-lesson-item.completed .sidebar-lesson-title {
  color: var(--text-muted);
}

/* Viewer Content Area */
.viewer-content {
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: 2rem;
  background-color: var(--bg-body);
}

.viewer-content > * {
  max-width: 900px;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
}

.video-container {
  position: relative;
  width: 100%;
  aspect-ratio: 16/9;
  background-color: black;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  margin-bottom: 1rem;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.lesson-content-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-top: 1.5rem;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.lesson-content-title h1 {
  font-family: var(--font-title);
  font-size: 1.8rem;
  font-weight: 700;
}

.lesson-content-title p {
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.complete-lesson-toggle-btn {
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.complete-lesson-toggle-btn.completed {
  background-color: var(--success);
  border-color: #34d399;
}

.complete-lesson-toggle-btn:hover {
  transform: translateY(-1px);
}

.lesson-description-text {
  margin-top: 1rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Tabs System */
.lesson-tabs {
  margin-top: 2.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 1.5rem;
}

.tab-btn {
  background: transparent;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 0.25rem;
  border-bottom: 2px solid transparent;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-pane {
  display: none;
  padding: 2rem 0;
  animation: fadeIn 0.3s ease-out forwards;
}

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

/* Material Tab contents */
.material-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.material-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  display: flex;
  gap: 1.25rem;
}

.material-card-icon {
  background-color: hsla(45, 80%, 55%, 0.1);
  border: 1px solid rgba(229, 193, 88, 0.2);
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  flex-shrink: 0;
}

.material-card-info {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  flex: 1;
}

.material-card-info h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.material-card-info p {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 1rem;
}

.download-link {
  align-self: flex-start;
  background-color: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--accent);
  padding: 0.45rem 1rem;
  font-size: 0.85rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.download-link:hover {
  background-color: var(--accent);
  color: var(--text-inverse);
  border-color: var(--accent);
}

/* Custom Audio Player */
.audio-player-ui {
  background-color: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.75rem;
}

.audio-controls button {
  background: transparent;
  color: var(--accent);
  font-size: 1.25rem;
}

.audio-controls button:hover {
  color: var(--accent-hover);
}

.audio-progress-container {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.audio-slider {
  flex: 1;
  height: 4px;
  background-color: var(--bg-dark);
  border-radius: 2px;
  position: relative;
  cursor: pointer;
}

.audio-slider-fill {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  background-color: var(--accent);
  width: 0%;
  border-radius: 2px;
}

/* Study Notes Tab */
.notes-editor {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.notes-textarea {
  width: 100%;
  min-height: 200px;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: var(--text-main);
  padding: 1.25rem;
  font-family: inherit;
  font-size: 0.95rem;
  resize: vertical;
  transition: var(--transition);
}

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

.notes-status-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.notes-save-btn {
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 600;
}

.notes-save-btn:hover {
  background-color: var(--primary-glow);
}

/* Q&A / Community Tab */
.qa-forum {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.qa-post-editor {
  display: flex;
  gap: 1rem;
}

.qa-input {
  flex: 1;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  font-family: inherit;
}

.qa-input:focus {
  outline: none;
  border-color: var(--accent);
}

.qa-post-btn {
  background-color: var(--primary);
  color: var(--text-main);
  padding: 0 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
}

.qa-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.qa-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
}

.qa-item-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.qa-user {
  font-weight: 600;
  color: var(--accent);
}

.qa-item-body {
  font-size: 0.92rem;
}

.qa-reply {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 1rem;
}

.qa-reply-badge {
  background-color: hsla(45, 80%, 55%, 0.1);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  align-self: flex-start;
  text-transform: uppercase;
}

.qa-reply-content h5 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.qa-reply-content p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* Fingering Chart Styles */
.fingering-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
}

.fingering-controls {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.octave-selector {
  display: flex;
  background-color: var(--bg-dark);
  border: 1px solid var(--border);
  padding: 0.25rem;
  border-radius: var(--radius-md);
}

.octave-toggle-btn {
  flex: 1;
  text-align: center;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-muted);
  padding: 0.6rem 0.5rem;
  border-radius: var(--radius-sm);
  background: transparent;
  transition: var(--transition);
}

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

.octave-toggle-btn.active {
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}

.notes-selector {
  display: grid;
  grid-template-columns: repeat(4, 1fr); /* 4 columns instead of 3 since we have 8 notes per octave now, making a clean 4x2 grid! */
  gap: 0.75rem;
}

.note-selector-btn {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 1rem;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
}

.note-selector-btn:hover {
  border-color: var(--primary-light);
  background-color: rgba(11, 124, 67, 0.05);
}

.note-selector-btn.active {
  background-color: var(--primary);
  border-color: var(--accent);
  box-shadow: 0 0 12px rgba(229, 193, 88, 0.2);
}

.note-letter {
  font-family: var(--font-title);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--accent);
}

.note-selector-btn.active .note-letter {
  color: var(--text-main);
}

.note-name {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.note-selector-btn.active .note-name {
  color: var(--accent);
}

.chart-display-wrapper {
  display: flex;
  gap: 2rem;
  align-items: center;
  flex: 1;
}

.chart-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background-color: rgba(0, 0, 0, 0.25);
  padding: 1.5rem 1.25rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  min-width: 320px;
  position: relative;
}

.hand-column {
  display: flex;
  flex-direction: column;
}

.lhs-column {
  align-self: flex-start;
  margin-top: 50px;
}

.rhs-column {
  align-self: flex-end;
  margin-bottom: 50px;
}

.hand-bracket {
  display: flex;
  flex-direction: column;
  background-color: rgba(24, 34, 29, 0.4);
  padding: 0.6rem 0.85rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  text-align: center;
}

.lhs-column .hand-bracket {
  border-right: 3px solid var(--accent);
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}

.rhs-column .hand-bracket {
  border-left: 3px solid var(--accent);
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.hand-title {
  font-family: var(--font-title);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.hand-sub {
  font-size: 0.65rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
  white-space: nowrap;
}

.whistle-visualizer {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.whistle-mouthpiece {
  width: 22px;
  height: 35px;
  background: linear-gradient(90deg, #111 0%, #333 45%, #222 65%, #000 100%);
  border-top-left-radius: 6px;
  border-top-right-radius: 6px;
  border-bottom: 3px solid var(--accent);
  box-shadow: 0 -2px 5px rgba(0,0,0,0.4);
}

.whistle-body {
  width: 18px;
  height: 310px;
  background: linear-gradient(90deg, #bfa030 0%, #e5c158 35%, #d1aa26 65%, #8c6e0c 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 8px 0;
  box-shadow: 3px 5px 15px rgba(0, 0, 0, 0.4);
  position: relative;
}

.whistle-group {
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
  flex: 1;
  width: 100%;
}

.whistle-divider {
  width: 22px;
  height: 5px;
  background: linear-gradient(90deg, #111 0%, #333 40%, #000 100%);
  border-top: 1px solid rgba(255,255,255,0.1);
  border-bottom: 1px solid rgba(0,0,0,0.5);
  margin: 6px 0;
  box-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.whistle-flare {
  width: 22px;
  height: 12px;
  background: linear-gradient(90deg, #bfa030 0%, #e5c158 35%, #8c6e0c 100%);
  border-bottom-left-radius: 4px;
  border-bottom-right-radius: 4px;
  border-top: 1px solid rgba(0,0,0,0.2);
  box-shadow: 0 2px 4px rgba(0,0,0,0.4);
}

.whistle-hole {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  box-shadow: inset 1px 1px 2px rgba(0,0,0,0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  position: relative;
}

.whistle-hole.open {
  background: linear-gradient(135deg, #18221d, #080c0a);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.whistle-hole.closed {
  background: radial-gradient(circle, #f0b59b 0%, #bc7e64 70%, #683823 100%);
  border: 1px solid rgba(0, 0, 0, 0.5);
  transform: scale(1.2);
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.4);
}

.hole-number {
  font-size: 8px;
  font-weight: 800;
  pointer-events: none;
  transition: var(--transition);
  line-height: 1;
}

.whistle-hole.open .hole-number {
  color: var(--text-muted);
  opacity: 0.5;
}

.whistle-hole.closed .hole-number {
  color: #3f190c;
  opacity: 0.9;
}

.note-info-card {
  flex: 1;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--accent);
}

.note-info-card h3 {
  font-family: var(--font-title);
  font-size: 1.4rem;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.note-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.note-desc {
  font-size: 0.9rem;
  margin: 0.75rem 0 1.25rem;
  color: var(--text-main);
}

.play-note-btn {
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.play-note-btn:hover {
  background-color: var(--accent);
  color: var(--text-inverse);
  border-color: var(--accent);
  transform: translateY(-2px);
}

/* Footer */
.footer {
  background-color: var(--bg-dark);
  border-top: 1px solid var(--border);
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: auto;
}

/* ==========================================================================
   Responsividad y Media Queries (Mobile-First / Desktop Adjustments)
   ========================================================================== */

@media (max-width: 968px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .viewer-layout {
    grid-template-columns: 1fr;
    height: auto;
    overflow: visible;
  }
  
  .viewer-sidebar {
    height: 300px;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  
  .fingering-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .chart-display {
    max-width: 500px;
    margin: 0 auto;
    width: 100%;
  }
}

@media (max-width: 768px) {
  .navbar {
    padding: 1rem;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .nav-links {
    display: none; /* Se controlará vía JS en mobile si es necesario */
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background-color: var(--bg-dark);
    border-bottom: 1px solid var(--border);
    padding: 1.5rem;
    gap: 1rem;
  }
  
  .nav-links.mobile-open {
    display: flex;
  }
  
  .nav-user-info {
    border-left: none;
    padding-left: 0;
    margin-top: 0.5rem;
    width: 100%;
    justify-content: space-between;
  }

  .landing-hero h1 {
    font-size: 2.2rem;
  }
  
  .landing-hero p {
    font-size: 1rem;
  }
  
  .landing-actions {
    flex-direction: column;
    width: 100%;
    max-width: 320px;
  }
  
  .landing-actions button {
    width: 100%;
  }

  .material-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .viewer-content {
    padding: 1rem;
  }
  
  .lesson-tabs {
    gap: 0.5rem;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }
  
  .tab-btn {
    padding: 0.75rem 0.5rem;
    font-size: 0.85rem;
  }

  .notes-status-row {
    flex-direction: column;
    gap: 0.75rem;
    align-items: stretch;
  }
  
  .notes-save-btn {
    width: 100%;
  }

  .enter-lesson-btn-text {
    display: none; /* Oculta el texto "Ver Lección" en móvil para liberar espacio */
  }

  .enter-lesson-btn {
    padding: 0.5rem;
    font-size: 1.1rem;
    gap: 0;
  }

  .landing-features {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 2rem 1.5rem;
  }

  .study-tools-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .courses-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .tutorials-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .reference-videos-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  .notes-selector {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .auth-card {
    padding: 2rem 1.5rem;
  }
  
  .dashboard-welcome h1 {
    font-size: 1.8rem;
  }
}

@media (max-width: 600px) {
  .chart-display-wrapper {
    flex-direction: column;
    align-items: stretch;
  }
  .chart-display {
    justify-content: space-evenly;
    min-width: unset;
  }
  .chart-display .hand-column {
    display: none !important;
  }
}

/* Study Tools Styles */
.study-tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: 2rem;
  align-items: start;
}

.tool-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  min-height: 290px;
  transition: var(--transition);
}

.tool-card:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow-md);
}

.tool-card-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
  color: var(--accent);
}

.tool-card-header h4 {
  font-family: var(--font-title);
  font-size: 1.1rem;
  color: var(--text-main);
}

.tool-card-body {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  flex: 1;
}

/* Metrónomo UI */
.metronome-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--bg-dark);
  border: 1px solid var(--border);
  padding: 0.75rem;
  border-radius: var(--radius-md);
  position: relative;
  overflow: hidden;
}

.metronome-indicator {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background-color: var(--bg-dark);
  border: 2px solid var(--border);
  transition: transform 0.1s ease-out, background-color 0.1s ease-out;
}

.bpm-display {
  font-family: var(--font-title);
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.bpm-unit {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
}

.metronome-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.bpm-range-slider {
  flex: 1;
  height: 5px;
  border-radius: 3px;
  accent-color: var(--accent);
  background-color: var(--bg-dark);
  cursor: pointer;
  outline: none;
}

.bpm-adjust-btn {
  background-color: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-main);
  font-size: 0.75rem;
  font-weight: 700;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.bpm-adjust-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.metronome-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.metronome-checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
}

/* Drones UI */
.drone-selector {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
}

.drone-key-btn {
  background-color: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.45rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

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

.drone-key-btn.active {
  background-color: var(--primary);
  border-color: var(--accent);
  color: var(--text-main);
  box-shadow: 0 0 8px rgba(229, 193, 88, 0.15);
}

.tool-action-btn {
  width: 100%;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.65rem;
  border-radius: var(--radius-md);
  margin-top: auto;
}

.tool-action-btn.active-btn {
  background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%) !important;
  border-color: #ef4444 !important;
  color: white !important;
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.3) !important;
}

/* ==================== ESTILOS DEL CATÁLOGO DE CURSOS ==================== */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(320px, 100%), 1fr));
  gap: 2.5rem;
}

.course-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-md);
}

.course-card-body {
  padding: 2rem 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  flex: 1;
}

.course-card-title {
  font-family: var(--font-title);
  font-size: 1.4rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-main);
  background: linear-gradient(135deg, var(--text-main) 40%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  cursor: pointer;
  transition: var(--transition);
}

.course-card-title:hover {
  filter: brightness(1.2);
}

.course-card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.5;
  flex: 1;
}

.course-card-meta {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.course-card-progress {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background-color: var(--bg-dark);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.course-card-progress-bar {
  height: 6px;
  background-color: #101613;
  border-radius: 3px;
  overflow: hidden;
}

.course-card-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-light), var(--accent));
  width: 0%;
  transition: width 0.6s ease-out;
}

.course-card-progress-text {
  display: flex;
  justify-content: space-between;
  font-size: 0.76rem;
  color: var(--text-muted);
  font-weight: 500;
}

.btn-enter-course {
  width: 100%;
  text-align: center;
  padding: 0.85rem;
  background-color: var(--primary);
  border: 1px solid var(--primary-light);
  color: var(--text-main);
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: 0.9rem;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn-enter-course:hover {
  background: linear-gradient(135deg, var(--accent) 0%, #b89127 100%);
  color: var(--text-inverse);
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(229, 193, 88, 0.2);
}

/* ==================== ESTILOS PARA TUTORIALES GRATUITOS ==================== */
.tutorials-filter-bar {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
  flex-wrap: wrap;
}

.filter-tab-btn {
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-title);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: var(--transition);
}

.filter-tab-btn:hover {
  color: var(--text-main);
  background-color: rgba(255, 255, 255, 0.02);
}

.filter-tab-btn.active {
  color: var(--accent);
  background-color: var(--primary);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-sm);
}

.tutorials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(320px, 100%), 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.tutorial-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  height: 100%;
}

.tutorial-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-md);
}

.tutorial-card:hover .tutorial-play-icon {
  transform: translate(-50%, -50%) scale(1.15);
  background-color: var(--accent);
  color: var(--text-inverse);
  box-shadow: 0 0 15px var(--accent);
}

.tutorial-thumbnail-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 16/9;
  background-size: cover;
  background-position: center;
  cursor: pointer;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}

.tutorial-thumbnail-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, rgba(0,0,0,0.1) 0%, rgba(16,22,19,0.7) 100%);
  transition: var(--transition);
}

.tutorial-card:hover .tutorial-thumbnail-overlay {
  background: linear-gradient(180deg, rgba(0,0,0,0) 0%, rgba(16,22,19,0.5) 100%);
}

.tutorial-play-icon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(1);
  width: 52px;
  height: 52px;
  background-color: rgba(16, 22, 19, 0.85);
  border: 2px solid var(--accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  transition: var(--transition);
  backdrop-filter: blur(4px);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.4);
}

.tutorial-play-icon svg {
  margin-left: 3px;
}

.tutorial-duration-tag {
  position: absolute;
  bottom: 0.75rem;
  right: 0.75rem;
  background-color: rgba(0, 0, 0, 0.75);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  padding: 0.25rem 0.5rem;
  font-size: 0.72rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.tutorial-card-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  flex: 1;
}

.tutorial-card-badges {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tutorial-badge-item {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 0.25rem 0.6rem;
  border-radius: 50px;
}

.tutorial-badge-item.instrument-whistle {
  background-color: hsla(45, 80%, 55%, 0.15);
  border: 1px solid var(--accent);
  color: var(--accent);
}

.tutorial-badge-item.instrument-gaita {
  background-color: rgba(16, 185, 129, 0.15);
  border: 1px solid var(--success);
  color: var(--success);
}

.tutorial-badge-item.difficulty-easy {
  background-color: rgba(59, 130, 246, 0.1);
  border: 1px solid #3b82f6;
  color: #60a5fa;
}

.tutorial-badge-item.difficulty-medium {
  background-color: rgba(245, 158, 11, 0.1);
  border: 1px solid #f59e0b;
  color: #fbbf24;
}

.tutorial-badge-item.difficulty-hard {
  background-color: rgba(239, 68, 68, 0.1);
  border: 1px solid #ef4444;
  color: #f87171;
}

.tutorial-card-title {
  font-family: var(--font-title);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-main);
}

.tutorial-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.5rem;
  flex: 1;
}

.tutorial-card-cta {
  border-top: 1px solid var(--border);
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: rgba(255, 255, 255, 0.01);
}

.tutorial-cta-link {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 0.25rem;
  transition: var(--transition);
}

.tutorial-cta-link:hover {
  color: var(--accent-hover);
  transform: translateX(3px);
}

/* ==================== ESTILOS PARA MODAL DE VIDEO ==================== */
.video-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(10, 14, 12, 0.9);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  backdrop-filter: blur(8px);
  animation: modalFadeIn 0.3s ease-out forwards;
}

.video-modal-overlay.active {
  display: flex;
}

.video-modal-container {
  position: relative;
  width: 100%;
  max-width: 900px;
  background-color: var(--bg-dark);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  animation: modalSlideUp 0.3s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.video-modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 38px;
  height: 38px;
  background-color: rgba(0, 0, 0, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  font-size: 1.8rem;
  line-height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 10;
  transition: var(--transition);
}

.video-modal-close:hover {
  background-color: #ef4444;
  border-color: #ef4444;
  color: white;
}

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

.video-modal-iframe-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

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

@keyframes modalSlideUp {
  from { transform: translateY(30px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@media (max-width: 768px) {
  .video-modal-overlay {
    padding: 1rem;
  }
  .video-modal-close {
    top: 0.5rem;
    right: 0.5rem;
    width: 32px;
    height: 32px;
    font-size: 1.4rem;
    line-height: 28px;
  }
}

/* Instrument Tabs in Fingering Chart */
.instrument-selector-tabs {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
}

.instrument-tab-btn {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-md);
  font-family: var(--font-title);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.instrument-tab-btn:hover {
  border-color: var(--accent);
  color: var(--text-main);
}

.instrument-tab-btn.active {
  background-color: var(--accent);
  border-color: var(--accent);
  color: #111;
}

/* Half closed hole state */
.whistle-hole.half-closed {
  background: linear-gradient(90deg, #bc7e64 50%, #18221d 50%);
  border: 1px solid rgba(255, 255, 255, 0.35);
  transform: scale(1.15);
  box-shadow: 0 0 3px rgba(0, 0, 0, 0.4);
}

.whistle-hole.half-closed .hole-number {
  color: #3f190c;
  opacity: 0.85;
}

/* Gaita visualizer styling - Conical chanter design with drop-shadow */
.gaita-visualizer {
  display: flex;
  flex-direction: column;
  align-items: center;
  filter: drop-shadow(3px 5px 6px rgba(0, 0, 0, 0.45));
}

.puntero-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
  width: 100%;
}

.gaita-visualizer .puntero-stock {
  width: 24px;
  height: 48px;
  background: linear-gradient(90deg, #180a04 0%, #3d2012 35%, #2a150a 65%, #180a04 100%);
  border-radius: 8px / 16px; /* Bulbous turned wood shape */
  border-top: 10px solid #c8b18a; /* Cork joint simulation at top */
  border-bottom: 6px solid #e2d8bd; /* Ivory ring joint at bottom */
  margin-bottom: -1px;
  z-index: 2;
}

.gaita-visualizer .puntero-body {
  width: 32px;
  height: 375px;
  background: linear-gradient(90deg, #120602 0%, #331a0e 35%, #221109 65%, #120602 100%);
  clip-path: polygon(25% 0%, 75% 0%, 100% 100%, 0% 100%); /* Conical taper: top is 16px wide, bottom is 32px wide */
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 0 25px 0;
  position: relative;
  z-index: 1;
}

.gaita-visualizer .puntero-group {
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
  flex: 1;
  width: 100%;
}

.gaita-visualizer .puntero-divider {
  width: 24px;
  height: 4px;
  background: linear-gradient(90deg, #120602 0%, #4a2817 35%, #2c160c 65%, #120602 100%);
  margin: 6px 0;
  border-top: 1px solid rgba(255,255,255,0.05);
  border-bottom: 1px solid rgba(0,0,0,0.4);
}

.gaita-visualizer .puntero-bell {
  width: 48px; /* Flaired out at bottom */
  height: 52px;
  background: linear-gradient(90deg, #120602 0%, #331a0e 35%, #221109 65%, #120602 100%);
  border-bottom: 8px solid #e2d8bd; /* Ivory decorative ring at the bottom rim */
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  border-bottom-left-radius: 24px 45px; /* Curved bell flare */
  border-bottom-right-radius: 24px 45px;
  margin-top: -1px;
  z-index: 2;
}

/* Back thumb hole layout */
.gaita-visualizer .thumb-hole-container {
  position: absolute;
  left: -45px;
  top: 15px;
  display: flex;
  align-items: center;
  gap: 5px;
  background-color: rgba(0, 0, 0, 0.5);
  padding: 4px 8px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  z-index: 5;
}

.gaita-visualizer .hole-label-side {
  font-size: 8px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

.gaita-visualizer .thumb-hole {
  width: 12px;
  height: 12px;
  border: 1px dashed rgba(255, 255, 255, 0.4);
}

/* Offset pinky hole */
.gaita-visualizer .offset-hole {
  transform: translateX(-5px) scale(1);
  margin-left: -10px;
}

/* PDF Preview & Reference Videos */
.btn-preview-pdf, .btn-search-youtube {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(229, 193, 88, 0.08);
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.btn-preview-pdf:hover, .btn-search-youtube:hover {
  background: var(--accent);
  color: var(--primary);
  box-shadow: 0 0 8px rgba(229, 193, 88, 0.3);
}

.pdf-preview-container {
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  transition: all 0.3s ease;
}

.reference-videos-section {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  grid-column: 1 / -1; /* Ocupa todo el ancho en grids */
}

.reference-videos-section h3 {
  font-family: var(--font-title);
  font-size: 1.25rem;
  margin-bottom: 1.25rem;
  color: var(--text-light);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.reference-videos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(280px, 100%), 1fr));
  gap: 1.25rem;
}

.reference-video-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
}

.reference-video-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(229, 193, 88, 0.15);
}

.ref-video-thumbnail {
  aspect-ratio: 16 / 9;
  background-size: cover;
  background-position: center;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ref-video-play-btn {
  width: 44px;
  height: 44px;
  border-radius: 50px;
  background: var(--accent);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.85;
  transition: all 0.2s ease;
  box-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

.reference-video-card:hover .ref-video-play-btn {
  opacity: 1;
  transform: scale(1.1);
  box-shadow: 0 0 15px var(--accent);
}

.ref-video-info {
  padding: 0.75rem 1rem;
}

.ref-video-info h4 {
  font-size: 0.88rem;
  margin-bottom: 0.25rem;
  color: var(--text-light);
  line-height: 1.3;
}

.ref-video-info p {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Viewer Player Workspace (splits video and PDF side-by-side) */
.viewer-player-workspace {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  width: 100%;
  transition: all 0.3s ease;
  margin-bottom: 1.5rem;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 1024px) {
  .viewer-player-workspace.split-active {
    grid-template-columns: 1.15fr 0.85fr; /* 57.5% video, 42.5% PDF */
    max-width: 1500px; /* Expand layout to accommodate both screens */
    height: 65vh; /* Set a viewport-relative height for the workspace */
    min-height: 520px;
    max-height: 750px;
  }
}

.viewer-pdf-splitview {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  height: 550px; /* Default height on portrait/mobile */
}

@media (min-width: 1024px) {
  .viewer-player-workspace.split-active .video-container {
    height: 100%;
    aspect-ratio: auto; /* Let it fill the grid cell height */
    margin-bottom: 0;
  }
  .viewer-pdf-splitview {
    height: auto; /* Stretch height to match grid row height */
  }
  .viewer-player-workspace.split-active .viewer-pdf-splitview {
    height: 100%; /* Stretch to fill the 65vh height of workspace */
  }
}

.viewer-pdf-splitview-header {
  background-color: rgba(255, 255, 255, 0.02);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.viewer-pdf-splitview-header h3 {
  font-family: var(--font-title);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-light);
  margin: 0;
}

.btn-close-pdf-splitview {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
  padding: 0;
  transition: color 0.2s ease;
}

.btn-close-pdf-splitview:hover {
  color: var(--accent);
}

.viewer-pdf-splitview-body {
  flex: 1;
  width: 100%;
  background-color: var(--bg-dark);
}

.viewer-pdf-splitview-body iframe {
  width: 100%;
  height: 100%;
  border: none;
}