:root{--bg: #0f172a;--panel: #ffffff;--muted: #64748b;--border: #e2e8f0;--accent: #2563eb;--accent-ink: #ffffff;--pass-bg: #dcfce7;--pass-ink: #166534;--fail-bg: #fef9c3;--fail-ink: #854d0e;--error-bg: #fee2e2;--error-ink: #991b1b;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:#0f172a}*{box-sizing:border-box}body{margin:0;background:#f1f5f9}.app{display:flex;flex-direction:column;height:100vh}.header{display:flex;align-items:baseline;gap:12px;padding:14px 20px;background:var(--bg);color:#fff}.header h1{font-size:18px;margin:0;letter-spacing:.3px}.header .sub{color:#94a3b8;font-size:13px}.header-actions{margin-left:auto;display:flex;align-items:center;gap:10px}.ref-btn{background:transparent;color:#e2e8f0;border:1px solid #334155;border-radius:6px;padding:5px 10px;font-size:13px;font-weight:600;cursor:pointer}.ref-btn:hover{border-color:#475569}.lang-select{background:#1e293b;color:#e2e8f0;border:1px solid #334155;border-radius:6px;padding:5px 10px;font-size:13px;font-weight:600;cursor:pointer}.lang-select:hover{border-color:#475569}.lang-select:focus{outline:2px solid var(--accent);outline-offset:1px}.tagline-bar{background:linear-gradient(90deg,#2563eb,#7c3aed);color:#fff;text-align:center;font-size:16px;font-weight:700;letter-spacing:.3px;padding:10px 16px}.body{display:flex;flex:1;min-height:0}.sidebar{width:340px;flex-shrink:0;overflow-y:auto;background:var(--panel);border-right:1px solid var(--border);padding:10px}.cat-title{font-size:11px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin:14px 8px 6px}.ex-item{display:flex;align-items:center;gap:8px;width:100%;text-align:left;border:1px solid transparent;background:transparent;border-radius:8px;padding:8px 10px;cursor:pointer;font-size:13px;color:#1e293b}.ex-item:hover{background:#f8fafc}.ex-item.active{background:#eff6ff;border-color:#bfdbfe}.ex-item.scratch{font-weight:600;margin-bottom:4px}.ex-num{flex-shrink:0;width:22px;height:22px;display:grid;place-items:center;background:#f1f5f9;border-radius:6px;font-size:11px;color:var(--muted)}.ex-prompt{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.main{flex:1;min-width:0;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:14px}.prompt-card{background:var(--panel);border:1px solid var(--border);border-radius:10px;padding:14px 16px}.prompt-meta{display:flex;align-items:center;gap:8px;margin-bottom:8px}.ex-id{color:var(--muted);font-size:12px}.prompt-text{margin:0;font-size:15px;line-height:1.5}.badge{font-size:11px;padding:2px 8px;border-radius:999px;background:#e2e8f0;color:#334155;text-transform:capitalize}.badge.beginner{background:#dcfce7;color:#166534}.badge.intermediate{background:#dbeafe;color:#1e40af}.badge.advanced{background:#fae8ff;color:#86198f}.editor{width:100%;min-height:150px;resize:vertical;font-family:Cascadia Code,Fira Code,Consolas,monospace;font-size:14px;line-height:1.5;padding:12px 14px;border:1px solid var(--border);border-radius:10px;background:#0b1220;color:#e2e8f0;-moz-tab-size:2;tab-size:2}.editor:focus{outline:2px solid var(--accent);outline-offset:1px}.toolbar{display:flex;align-items:center;gap:10px}.btn{border:1px solid var(--border);background:#fff;border-radius:8px;padding:8px 16px;font-size:14px;font-weight:600;cursor:pointer}.btn:hover:not(:disabled){background:#f8fafc}.btn.primary{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}.btn.primary:hover:not(:disabled){background:#1d4ed8}.btn:disabled{opacity:.5;cursor:not-allowed}.hint{color:var(--muted);font-size:12px}.banner{border-radius:8px;padding:10px 14px;font-size:14px}.banner.pass{background:var(--pass-bg);color:var(--pass-ink)}.banner.fail{background:var(--fail-bg);color:var(--fail-ink)}.banner.error{background:var(--error-bg);color:var(--error-ink)}.results-meta{font-size:12px;color:var(--muted);margin-bottom:6px}.grid-wrap{overflow:auto;border:1px solid var(--border);border-radius:10px;background:var(--panel)}.grid{border-collapse:collapse;width:100%;font-size:13px}.grid th,.grid td{text-align:left;padding:8px 12px;border-bottom:1px solid var(--border);white-space:nowrap}.grid th{position:sticky;top:0;background:#f8fafc;font-weight:600;color:#334155}.grid tbody tr:hover{background:#f8fafc}.null{color:#cbd5e1;font-style:italic}.muted{color:var(--muted);padding:10px 12px;margin:0;font-size:13px}code{background:#e2e8f0;padding:1px 6px;border-radius:4px;font-size:.9em}.drawer-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:#0f172a73;opacity:0;pointer-events:none;transition:opacity .2s;z-index:40}.drawer-backdrop.open{opacity:1;pointer-events:auto}.drawer{position:fixed;top:0;right:0;height:100vh;width:460px;max-width:92vw;background:#fff;box-shadow:-8px 0 24px #0000002e;transform:translate(100%);transition:transform .22s ease;z-index:50;display:flex;flex-direction:column}.drawer.open{transform:translate(0)}.drawer-head{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;border-bottom:1px solid var(--border)}.drawer-head h2{margin:0;font-size:16px}.drawer-close{background:none;border:none;font-size:26px;line-height:1;cursor:pointer;color:var(--muted)}.drawer-body{overflow-y:auto;padding:16px 18px 40px}.drawer-body h3{font-size:12px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin:22px 0 8px}.drawer-intro{font-size:14px;line-height:1.5;margin:0}.cmd-list{margin:0}.cmd{padding:8px 0;border-bottom:1px solid #f1f5f9}.cmd dt{font-family:Cascadia Code,Consolas,monospace;font-weight:700;color:#0f172a;font-size:13px}.cmd dd{margin:4px 0 0;font-size:13px;color:#334155;line-height:1.45}.cmd-ex{display:block;margin-top:5px;background:#0b1220;color:#e2e8f0;padding:5px 8px;border-radius:6px;font-size:12px;white-space:pre-wrap}.tbl{padding:8px 0;border-bottom:1px solid #f1f5f9}.tbl-name{font-family:Cascadia Code,Consolas,monospace;font-weight:700;font-size:13px;color:#0f172a}.tbl-note{font-size:12px;color:var(--muted);margin:2px 0 5px}.tbl-cols{display:block;background:#f1f5f9;padding:5px 8px;border-radius:6px;font-size:12px;color:#334155;line-height:1.5}.status-table{font-size:13px;border-collapse:collapse}.status-table td{padding:2px 12px 2px 0}.status-table td:first-child{color:var(--accent);font-family:Cascadia Code,Consolas,monospace;text-align:right}.drawer-tip{margin-top:18px;font-size:12px;color:var(--muted);font-style:italic}.lesson-group{margin-bottom:6px}.lesson-head{display:flex;align-items:center;gap:8px;width:100%;text-align:left;border:1px solid transparent;background:transparent;border-radius:8px;padding:8px 10px;margin:10px 0 2px;cursor:pointer;font-size:13px;font-weight:700;color:#0f172a}.lesson-head:hover{background:#f8fafc}.lesson-head.active{background:#eef2ff;border-color:#c7d2fe}.lesson-head-num{flex-shrink:0;width:22px;height:22px;display:grid;place-items:center;background:var(--accent);color:#fff;border-radius:6px;font-size:11px}.lesson-head-title{flex:1}.ex-item.indent{padding-left:16px}.lesson-meta{display:flex;align-items:center;gap:10px;margin-bottom:6px}.lesson-badge{background:var(--accent);color:#fff}.lesson-title{margin:2px 0 4px;font-size:20px}.lesson-summary{margin:0 0 12px;color:var(--muted);font-size:14px}.lesson-para{margin:0 0 10px;font-size:15px;line-height:1.6}.lesson-example{background:#f8fafc;border:1px solid var(--border);border-radius:10px;padding:12px 14px;margin:14px 0}.lesson-example-label{font-size:11px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin-bottom:6px}.lesson-example-sql{display:block;background:#0b1220;color:#e2e8f0;padding:8px 12px;border-radius:8px;font-family:Cascadia Code,Consolas,monospace;font-size:13px;white-space:pre-wrap;line-height:1.5}.lesson-example-note{margin:8px 0 10px;font-size:13px;color:#334155}.btn.sm{padding:6px 12px;font-size:13px}.lesson-practice{margin-top:16px;border-top:1px solid var(--border);padding-top:12px}.lesson-practice-title{font-size:11px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin:0 0 6px 2px}