input: Write a function to create a data visualization dashboard using Matplotlib in Python. The function should generate a basic line plot with custom styling and display it.
  assert create_dashboard([])==None
  assert create_dashboard([1, 2, 3, 4, 5], [10, 25, 30, 50, 80])==None
output: def create_dashboard(x=[], y=[]):
      import matplotlib.pyplot as plt
      if x and y:
          plt.plot(x, y, color='blue', linestyle='--', linewidth=2, marker='o', markersize=8)
          plt.title('Custom Line Plot')
          plt.xlabel('X-axis')
          plt.ylabel('Y-axis')
          plt.grid(True)
          plt.show()