.app{grid-template-columns:minmax(0,1fr) 500px}.side .preview-panel{position:sticky;top:16px}.help{color:var(--muted);margin:-4px 0 10px;font-size:.82rem}.seg{gap:16px;display:flex}.seg label,.tpl-opt{color:var(--ink);cursor:pointer;align-items:center;gap:6px;margin:0;font-weight:500;display:flex}.seg input,.tpl input{accent-color:var(--brand)}.tpl{grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:14px;display:grid}.tpl-opt{border:1px solid var(--line);background:#fff;border-radius:10px;justify-content:center;padding:10px}.tpl-opt.on{border-color:var(--brand);background:var(--brand-soft);color:var(--brand);font-weight:700}.tpl-opt{position:relative}.tpl-opt input{opacity:0;width:1px;height:1px;position:absolute;top:0;left:0}.tpl-opt:focus-within{outline:2px solid var(--brand);outline-offset:1px}textarea{resize:vertical}.mock-head{border:1px solid var(--line);color:var(--muted);background:#f1f5f9;border-bottom:0;border-radius:10px 10px 0 0;flex-direction:column;gap:2px;margin:0;padding:10px 14px;font-size:.8rem;display:flex}.mock-body{border:1px solid var(--line);background:#fff;border-radius:0 0 10px 10px;padding:16px 14px 20px;overflow-x:auto}.mock-body>p{color:#222;margin:0 0 16px;font:14px/1.5 Arial,sans-serif}.sig-preview{min-height:90px}.btn.wide{width:100%;margin-top:12px;font-size:1.05rem}.row.tight{gap:8px;margin-top:8px}.row.tight .btn{padding:10px;font-size:.92rem}.status{min-height:1.2em;color:var(--brand);font-weight:600}.howto{border-top:1px solid var(--line);margin-top:10px;padding-top:10px}.howto summary{cursor:pointer;margin-bottom:8px;font-weight:700}.howto .tabs{margin:8px 0 4px}.howto ol{color:#334155;margin:6px 0 0;padding-left:20px;font-size:.88rem}.howto li{margin-bottom:4px}@media (width<=1060px){.app{grid-template-columns:1fr}.side .preview-panel{position:static}}