3D DNA Double Helix Structure

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure(figsize=(12, 9), facecolor='#ffffff')
ax = fig.add_subplot(111, projection='3d')
ax.set_facecolor('#ffffff')

t = np.linspace(0, 6*np.pi, 300)
z = np.linspace(0, 10, 300)

# Double helix strands
helix1_x = np.cos(t)
helix1_y = np.sin(t)

helix2_x = np.cos(t + np.pi)
helix2_y = np.sin(t + np.pi)

# Plot strands
ax.plot(helix1_x, helix1_y, z, linewidth=3, color='#3B82F6')
ax.plot(helix2_x, helix2_y, z, linewidth=3, color='#EF4444')

# Base pair connections
for i in range(0, len(t), 8):
    ax.plot([helix1_x[i], helix2_x[i]], [helix1_y[i], helix2_y[i]], [z[i], z[i]], 
            color='#10B981', alpha=0.6, linewidth=1.5)

ax.set_xlabel('X', fontsize=11, color='#1f2937')
ax.set_ylabel('Y', fontsize=11, color='#1f2937')
ax.set_zlabel('Z', fontsize=11, color='#1f2937')
ax.set_title('DNA Double Helix', fontsize=14, color='#1f2937', fontweight='bold', pad=15)

ax.tick_params(colors='#374151', labelsize=9)
ax.xaxis.pane.fill = False
ax.yaxis.pane.fill = False
ax.zaxis.pane.fill = False
ax.xaxis.pane.set_edgecolor('#e5e7eb')
ax.yaxis.pane.set_edgecolor('#e5e7eb')
ax.zaxis.pane.set_edgecolor('#e5e7eb')
ax.grid(True, alpha=0.3, color='#d1d5db')

plt.tight_layout()
plt.show()