body {
  display: flex;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
  padding: 20px;
}

.contenedor {
  background: white;
  padding: 40px;
  border-radius: 20px;
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
  max-width: 600px;
  width: 100%;
}

h1 {
  text-align: center;
  margin-bottom: 30px;
  font-size: 32px;
  text-decoration: underline;
}

.input-group {
  display: flex;
  gap: 10px;
  margin-bottom: 30px;
}

input[type="text"] {
  flex: 1;
  padding: 15px;
  font-size: 16px;
  border: 2px solid #ddd;
  border-radius: 8px;
  outline: none;
}

.btn-agregar {
  padding: 15px 25px;
  font-size: 16px;
  font-weight: bold;
  background-color: #764ba2;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.lista-tareas {
  list-style: none;
  padding: 0;
  margin: 0 0 20px 0;
  max-height: 400px;
  overflow-y: auto;
}

.tarea-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px;
  background: #f8f9fa;
  border-radius: 8px;
  margin-bottom: 10px;
  border-left: 4px solid #667eea;
}

.tarea-item.completada {
  background: #d4edda;
  border-left-color: #28a745;
}

.tarea-item.completada .tarea-texto {
  text-decoration: line-through;
  color: #6c757d;
}

input[type="checkbox"] {
  width: 20px;
  height: 20px;
  cursor: pointer;
}

.tarea-texto {
  flex: 1;
  font-size: 16px;
  word-break: break-word;
}

.btn-eliminar {
  padding: 8px 12px;
  background-color: #dc3545;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-size: 14px;
}

.mensaje-vacio {
  text-align: center;
  color: #999;
  font-size: 16px;
  font-style: italic;
  padding: 40px 20px;
  display: none;
}

.mensaje-vacio.visible {
  display: block;
}

.acciones {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.btn-accion {
  flex: 1;
  padding: 12px;
  font-size: 14px;
  font-weight: bold;
  background-color: #28a745;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.btn-peligro {
  background-color: #dc3545;
}

.estadisticas {
  display: flex;
  justify-content: space-around;
  padding: 20px;
  background-color: #c3cfe2;
  border-radius: 10px;
  font-weight: bold;
  color: #333;
  margin-bottom: 20px;
}

.estadisticas span {
  font-size: 14px;
}

.volver {
  display: block;
  text-align: center;
  padding: 12px 25px;
  background-color: #667eea;
  text-decoration: none;
  color: white;
  border-radius: 10px;
  font-weight: bold;
}

/* Scrollbar personalizada */
.lista-tareas::-webkit-scrollbar {
  width: 8px;
}

.lista-tareas::-webkit-scrollbar-track {
  background: #f1f1f1;
  border-radius: 10px;
}

.lista-tareas::-webkit-scrollbar-thumb {
  background: #667eea;
  border-radius: 10px;
}

.lista-tareas::-webkit-scrollbar-thumb:hover {
  background: #5568d3;
}