:root{--bg:#f8fafc;--panel:#ffffff;--muted:#64748b;--text:#0f172a;--stroke:#e2e8f0;--primary:#2563eb;--primary-600:#1d4ed8;--radius:16px;--shadow:0 10px 30px rgba(2,6,23,.06), 0 4px 10px rgba(2,6,23,.04);--font: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);line-height:1.45}.app{max-width:1040px;margin:24px auto;padding:0 16px}.header{position:sticky;top:0;z-index:10;-webkit-backdrop-filter:saturate(180%) blur(8px);backdrop-filter:saturate(180%) blur(8px);background:#ffffffd9;border-bottom:1px solid var(--stroke)}.header-inner{max-width:1040px;margin:0 auto;display:flex;gap:12px;align-items:center;padding:14px 16px}.input,select{border:1px solid var(--stroke);background:#fff;color:var(--text);padding:10px 12px;border-radius:12px;min-width:220px}.btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:1px solid var(--stroke);background:#fff;color:var(--text);padding:10px 14px;border-radius:999px;cursor:pointer;transition:.2s transform,.2s box-shadow,.2s background,.2s border-color}.btn:hover{transform:translateY(-1px);box-shadow:var(--shadow)}.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}.btn.primary:hover{background:var(--primary-600)}.btn.small{padding:8px 12px}.section{background:var(--panel);border:1px solid var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-top:16px}.controls{display:flex;flex-wrap:wrap;gap:10px;align-items:center}.kv{display:flex;flex-wrap:wrap;gap:8px 12px;align-items:center;color:var(--muted);font-size:14px;margin-top:10px}.progress{margin-left:auto;color:var(--muted)}.hero{background:linear-gradient(180deg,#2563eb0f,#2563eb00);border:1px solid #dbeafe;border-radius:var(--radius);padding:16px;margin-top:16px}.card{position:relative;border-radius:var(--radius);background:#fff;border:1px solid var(--stroke);box-shadow:var(--shadow);min-height:220px;padding:24px;display:grid;place-content:center;text-align:center;cursor:pointer;transition:.2s transform}.card:hover{transform:translateY(-1px)}.card .front,.card .back{font-size:26px;font-weight:700}.card .note{font-size:12px;color:var(--muted);margin-top:8px}.controls-row{display:flex;gap:10px;align-items:center;margin-top:10px}.row-end{margin-left:auto}.badge{font-size:12px;color:var(--muted)}.saved h3{margin:0 0 8px}.saved-list{display:grid;gap:8px;list-style:none;padding:0}.saved-item{display:flex;gap:8px;align-items:center}.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,Courier New,monospace}