:root{--bg: #f3f5f7;--card: #ffffff;--text: #1f2a33;--muted: #667684;--line: #d7dee5;--accent: #1f6feb;--ok: #1b7f4a;--bad: #b42318;--radius: 12px;font-family:Segoe UI,Tahoma,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text)}#root{min-height:100vh}.app{max-width:720px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column}.screen{padding:20px 16px 88px;flex:1}.nav{position:sticky;bottom:0;display:grid;grid-template-columns:repeat(4,1fr);gap:4px;padding:8px;background:var(--card);border-top:1px solid var(--line)}.nav button,.btn,.select,.choice{font:inherit}.nav button{border:0;background:transparent;color:var(--muted);padding:10px 6px;border-radius:8px}.nav button.active{background:#e8f0fe;color:var(--accent);font-weight:600}h1,h2{margin:0 0 12px;line-height:1.25}p{margin:0 0 12px;color:var(--muted);line-height:1.45}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:12px}.card ul{margin:0 0 12px;padding-left:1.2em;color:var(--muted);line-height:1.45}.btn{display:inline-flex;align-items:center;justify-content:center;width:100%;border:0;border-radius:10px;padding:12px 16px;background:var(--accent);color:#fff;font-weight:600;cursor:pointer}.btn:disabled{opacity:.55;cursor:default}.btn.secondary{background:#e8eef5;color:var(--text)}.btn+.btn{margin-top:8px}.stack{display:grid;gap:10px}.label{display:block;margin-bottom:6px;font-size:14px;color:var(--muted)}.select{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:8px;background:#fff}.chart{width:100%;overflow:auto;background:#fafafa;border-radius:8px;border:1px solid var(--line)}.chart svg{display:block;width:100%;height:auto}.badge{display:inline-block;padding:4px 8px;border-radius:999px;background:#e8f0fe;color:var(--accent);font-size:13px;margin-bottom:10px}.ok{color:var(--ok);font-weight:600}.bad{color:var(--bad);font-weight:600}.error{color:var(--bad)}.stat-row{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--line)}.stat-row:last-child{border-bottom:0}