:root{color-scheme:light dark;font-family:system-ui,sans-serif}body{margin:0;background:#f5f5f5;color:#1a1a1a}.app-header{display:flex;align-items:center;gap:1.5rem;padding:1rem 1.5rem;background:#1a1a2e;color:#fff}.app-header h1{font-size:1.25rem;margin:0}.app-header nav{display:flex;gap:1rem}.app-header nav a{color:#cfcfff;text-decoration:none}.app-header nav a.active{color:#fff;font-weight:600}main{padding:1.5rem;max-width:1100px;margin:0 auto}.add-form{display:flex;gap:.5rem;margin-bottom:1.5rem;flex-wrap:wrap}.add-form input{padding:.4rem .6rem}.board{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:.75rem}.board-column{background:#fff;border-radius:8px;padding:.75rem;min-height:120px}.board-column h3{margin-top:0;font-size:.9rem;text-transform:uppercase;color:#666}.card{background:#f0f0fa;border-radius:6px;padding:.5rem .75rem;margin-bottom:.5rem;font-size:.9rem}.error{color:#b00020}