Insurance Premium Breakdown

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import Patch

categories = ['Base\nPremium', 'Age\nFactor', 'Driving\nHistory', 'Vehicle\nType', 
              'Coverage\nLevel', 'Multi-Policy\nDiscount', 'Loyalty\nDiscount', 'Final\nPremium']
values = [0, 180, 95, 120, 85, -145, -65, 0]

initial = 850
running_total = initial
bottoms, heights, colors = [], [], []

for i, (cat, val) in enumerate(zip(categories, values)):
    if 'Base' in cat:
        bottoms.append(0)
        heights.append(initial)
        colors.append('#4927F5')
    elif 'Final' in cat:
        bottoms.append(0)
        heights.append(running_total)
        colors.append('#6CF527')
    elif val > 0:
        bottoms.append(running_total)
        heights.append(val)
        colors.append('#F5276C')
        running_total += val
    else:
        bottoms.append(running_total + val)
        heights.append(abs(val))
        colors.append('#27F5B0')
        running_total += val

fig, ax = plt.subplots(figsize=(14, 8), facecolor='#0a0a0f')
ax.set_facecolor('#0a0a0f')

x = np.arange(len(categories))
bars = ax.bar(x, heights, bottom=bottoms, color=colors, width=0.65, edgecolor='#1e293b', linewidth=1)

for i, (bar, val, bot, height) in enumerate(zip(bars, values, bottoms, heights)):
    y_pos = bot + height / 2
    if 'Base' in categories[i] or 'Final' in categories[i]:
        label = str(height)
        ax.text(bar.get_x() + bar.get_width()/2, y_pos, label, ha='center', va='center', 
                fontsize=11, fontweight='bold', color='white')
    else:
        label = '+' + str(val) if val > 0 else str(val)
        ax.text(bar.get_x() + bar.get_width()/2, y_pos, label, ha='center', va='center', 
                fontsize=10, fontweight='bold', color='white')

for i in range(len(x) - 1):
    y = initial if i == 0 else bottoms[i] + heights[i]
    ax.plot([x[i] + 0.35, x[i+1] - 0.35], [y, y], color='#475569', linestyle='--', linewidth=1.5, alpha=0.7)

ax.set_xlim(-0.6, len(categories) - 0.4)
ax.set_ylim(0, max(b + h for b, h in zip(bottoms, heights)) * 1.1)
ax.set_xticks(x)
ax.set_xticklabels(categories, fontsize=9, color='#e2e8f0')
ax.set_ylabel('Annual Premium', fontsize=12, color='#e2e8f0', fontweight='500')
ax.set_title('Auto Insurance Premium Calculation', fontsize=16, color='white', fontweight='bold', pad=20)
ax.tick_params(axis='y', colors='#e2e8f0', labelsize=10)
ax.yaxis.grid(True, linestyle='--', alpha=0.3, color='#334155')
ax.set_axisbelow(True)
for spine in ax.spines.values():
    spine.set_color('#334155')

change = running_total - initial
pct = (change / initial) * 100
ax.annotate('Net Adjustment: ' + ('+' if change > 0 else '') + str(change) + ' (' + str(round(pct, 1)) + ' pct)', 
            xy=(0.98, 0.95), xycoords='axes fraction',
            fontsize=11, color='#6CF527' if change < initial * 0.5 else '#F5B027', ha='right', fontweight='bold',
            bbox=dict(boxstyle='round,pad=0.4', facecolor='#1e293b', edgecolor='#6CF527', alpha=0.9))

legend_elements = [Patch(facecolor='#4927F5', label='Base Premium'), Patch(facecolor='#F5276C', label='Surcharges'),
                   Patch(facecolor='#27F5B0', label='Discounts'), Patch(facecolor='#6CF527', label='Final Premium')]
ax.legend(handles=legend_elements, loc='upper left', bbox_to_anchor=(0, -0.1), ncol=4, fontsize=9,
          facecolor='#1e293b', edgecolor='#334155', labelcolor='white')

plt.tight_layout()
plt.subplots_adjust(bottom=0.15)
plt.show()