body { font-family: 'Segoe UI', sans-serif; background: #f4f7f6; margin: 0; }
.hidden { display: none; }
.vista { display: none; }
.vista.active { display: block; }
.container { display: flex; justify-content: center; align-items: center; height: 100vh; }
.login-box { background: white; padding: 40px; border-radius: 10px; box-shadow: 0 4px 10px rgba(0,0,0,0.1); }
.sidebar { width: 220px; background: #003366; color: white; height: 100vh; position: fixed; padding: 20px; }
.content { margin-left: 260px; padding: 40px; }
table { width: 100%; border-collapse: collapse; background: white; }
th, td { border: 1px solid #ddd; padding: 12px; }
th { background: #003366; color: white; }
.chart-container { width: 600px; height: 400px; }