*,*:before,*:after{box-sizing:border-box}html{line-height:1.15;-webkit-text-size-adjust:100%}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;line-height:1.6}h1,h2,h3,h4,h5,h6{margin:0;font-weight:600}p{margin:0}ul,ol{margin:0;padding:0;list-style:none}a{text-decoration:none}img{max-width:100%;height:auto}button{background:none;border:none;padding:0;margin:0;font:inherit;cursor:pointer}input,textarea,select{font:inherit;margin:0}table{border-collapse:collapse;border-spacing:0}#app{padding:2rem;max-width:1200px;margin:0 auto}.controls{margin:1rem 0;display:flex;gap:1rem}.btn{background-color:#007bff;color:#fff;border:none;padding:.6rem 1.2rem;font-size:.9rem;font-weight:500;border-radius:6px;cursor:pointer;transition:background-color .2s,transform .1s}.btn:hover{background-color:#0056b3}.btn:active{transform:translateY(1px)}#canvas{border:1px solid #ccc;display:block}.tabs-nav{display:flex;margin-bottom:1.5rem;padding-bottom:.5rem}.tab-btn{padding:.5rem 1rem;background:#f0f0f0;font-weight:500}.tab-btn.active{background:#007bff;color:#fff}.tab-pane{display:none}.tab-pane.active{display:block}