:root{font-family:system-ui,sans-serif;color:#172033;background:#f5f6f8}body{margin:0}.shell{min-height:100vh;display:grid;grid-template:auto 1fr / 15rem 1fr}header{grid-column:1 / -1;display:flex;justify-content:space-between;padding:1rem 1.5rem;background:#fff}nav{display:flex;flex-direction:column;gap:.5rem;padding:1rem;background:#202b45}nav a{color:#e8edf7;padding:.7rem;text-decoration:none;border-radius:.4rem}nav a.active{background:#38538c}main{padding:2rem}