:root{--bg: #f8fafc;--surface: #ffffff;--ink: #1e293b;--ink-soft: #64748b;--line: #e2e8f0;--c-a: #ef4444;--c-b: #3b82f6;--c-ok: #16a34a;--c-hint: #f59e0b;--radius: 18px;--shadow: 0 4px 18px rgba(30, 41, 59, .07);--tap: 48px;font-family:Segoe UI,Noto Sans TC,PingFang TC,Microsoft JhengHei,system-ui,sans-serif;color:var(--ink)}*{box-sizing:border-box;margin:0;padding:0}html,body{background:var(--bg);min-height:100%}body{-webkit-tap-highlight-color:transparent;overscroll-behavior:none}button{font:inherit;color:inherit;background:none;border:none;cursor:pointer;touch-action:manipulation}.splash{position:fixed;inset:0;z-index:50;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;background:radial-gradient(circle at 30% 25%,rgba(59,130,246,.08),transparent 55%),radial-gradient(circle at 72% 70%,rgba(239,68,68,.08),transparent 55%),var(--bg);touch-action:none;cursor:pointer}.splash-logo{width:clamp(120px,26vmin,200px);height:auto;overflow:visible}.splash-title{font-size:clamp(2rem,7vmin,3.2rem);font-weight:800;letter-spacing:.03em}.splash-sub{color:var(--ink-soft);font-size:clamp(.95rem,3vmin,1.15rem)}.app{max-width:1040px;margin:0 auto;padding:16px clamp(12px,3vw,28px) 32px;display:flex;flex-direction:column;gap:14px;user-select:none;-webkit-user-select:none}.app-header{display:flex;flex-wrap:wrap;align-items:center;gap:12px 20px}.brand{display:flex;align-items:center;gap:12px}.brand-logo{width:46px;height:46px}.brand-title{font-size:1.5rem;letter-spacing:.02em;line-height:1.1}.brand-sub{color:var(--ink-soft);font-size:.85rem}.menu-lead{color:var(--ink-soft);font-size:.95rem}.quiz-header{gap:12px}.quiz-title{font-size:1.3rem;flex:1}.app-main{display:flex;flex-direction:column;gap:14px}.app-footer{text-align:center;color:var(--ink-soft);font-size:.8rem;padding-top:6px}.quiz-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:14px}.quiz-card{display:flex;flex-direction:column;background:var(--surface);border:2px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden;transition:transform .15s,border-color .2s,box-shadow .2s}.quiz-card:hover{border-color:var(--c-b);box-shadow:0 6px 22px #1e293b1f}.quiz-card:active{transform:scale(.97)}.quiz-thumb{display:block;width:100%;height:auto;background:#fdfdfe;border-bottom:1.5px solid var(--line)}.quiz-thumb .shape{stroke-width:6}.quiz-card-meta{display:flex;align-items:center;gap:8px;padding:10px 14px;min-height:var(--tap)}.quiz-card-no{font-size:.8rem;font-weight:700;color:var(--ink-soft);background:var(--bg);border-radius:8px;padding:2px 8px}.quiz-card-title{font-weight:600;flex:1;text-align:left;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.quiz-card-diff{font-size:.7rem;padding:2px 8px;border-radius:999px;color:#fff;flex-shrink:0}.diff-基礎{background:#22c55e}.diff-中等{background:var(--c-hint)}.diff-進階{background:var(--c-a)}.stage-tabs{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.stage-tab{min-height:var(--tap);display:flex;align-items:center;justify-content:center;gap:8px;padding:8px 6px;background:var(--surface);border:2px solid var(--line);border-radius:14px;box-shadow:var(--shadow);transition:border-color .2s,background .2s,transform .15s}.stage-tab:active{transform:scale(.98)}.stage-tab.active{border-color:var(--c-b);background:#eff6ff}.stage-tab-index{width:26px;height:26px;border-radius:50%;background:var(--bg);color:var(--ink-soft);font-size:.85rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0}.stage-tab.active .stage-tab-index{background:var(--c-b);color:#fff}.stage-tab-name{font-weight:700;font-size:.95rem}.board-wrap{background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);padding:10px}.board{display:block;width:100%;height:auto;touch-action:none;border-radius:12px}.board-drawing{cursor:crosshair}.board-bg{fill:#fdfdfe;stroke:var(--line);stroke-width:2}.grid-minor{stroke:#eef2f7;stroke-width:1}.grid-major{stroke:#e3e9f2;stroke-width:1.5}.shape{stroke-width:4;stroke-linejoin:round}.shape.shape-a{fill:#ef444452;stroke:var(--c-a)}.shape.shape-b{fill:#3b82f652;stroke:var(--c-b)}.shape-outline{fill:none;stroke-width:4;stroke-linejoin:round}.shape-outline.shape-a{stroke:var(--c-a)}.shape-outline.shape-b{stroke:var(--c-b)}.trace-guide{fill:none;stroke-width:4;stroke-linejoin:round;stroke-dasharray:14 12;pointer-events:none}.trace-guide.guide-a{stroke:var(--c-a)}.trace-guide.guide-b{stroke:var(--c-b)}.union-outline{fill:none;stroke:var(--ink);stroke-width:5;stroke-linejoin:round}.answer-region{stroke-width:3.5;stroke-dasharray:12 10;animation:fade-in .3s ease-out;pointer-events:none}.answer-region.ink-a{fill:#ef444426;stroke:var(--c-a)}.answer-region.ink-b{fill:#3b82f626;stroke:var(--c-b)}.answer-region.ink-x{fill:#22c55e2e;stroke:var(--c-ok)}.diff-layer{animation:fade-in .4s ease-out;pointer-events:none}.missed-edge{fill:none;stroke:var(--c-a);stroke-width:6;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:14 12}.stray-ink{fill:none;stroke:var(--c-hint);stroke-width:6;stroke-linecap:round;stroke-linejoin:round;opacity:.85}.ink{fill:none;stroke-width:5;stroke-linecap:round;stroke-linejoin:round;pointer-events:none}.ink.ink-a{stroke:var(--c-a)}.ink.ink-b{stroke:var(--c-b)}.ink.ink-x{stroke:var(--c-ok)}.ink.ink-dim{stroke:#94a3b8;opacity:.55}.passed-region{fill:#22c55e47;stroke:var(--c-ok);stroke-width:4;animation:pop .45s ease-out;pointer-events:none}@keyframes pop{0%{transform:scale(.985);transform-origin:center}60%{transform:scale(1.01)}to{transform:scale(1)}}.toolbar{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}.btn{display:inline-flex;align-items:center;gap:8px;min-height:var(--tap);padding:10px 20px;border-radius:14px;background:var(--surface);border:2px solid var(--line);font-weight:600;box-shadow:var(--shadow);transition:transform .15s,border-color .2s,background .2s,opacity .2s}.btn:active:not(:disabled){transform:scale(.96)}.btn:disabled{opacity:.4;cursor:default}.btn-active{border-color:var(--c-hint);background:#fffbeb}.btn-primary{background:var(--c-b);border-color:var(--c-b);color:#fff}.btn-primary:disabled{background:var(--c-b)}.btn-back{padding:10px 14px}.feedback{background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);border:2px solid var(--line);padding:16px 20px;display:flex;align-items:center;gap:18px;flex-wrap:wrap;transition:border-color .3s,background .3s}.feedback-pass{border-color:var(--c-ok);background:#f0fdf4}.feedback-retry{border-color:var(--c-hint);background:#fffbeb}.feedback-message{flex:1;min-width:220px;line-height:1.65;font-size:1rem}.score-block{display:flex;flex-direction:column;align-items:center;gap:4px;min-width:110px}.score-number{font-size:2rem;font-weight:800;line-height:1;animation:fade-in .4s ease-out}.score-unit{font-size:1rem;font-weight:600;color:var(--ink-soft)}.score-bar{width:100px;height:8px;background:var(--line);border-radius:999px;overflow:hidden}.score-bar-fill{height:100%;background:var(--c-hint);border-radius:999px;transition:width .6s cubic-bezier(.22,1,.36,1)}.score-bar-fill.pass{background:var(--c-ok)}.score-caption{font-size:.75rem;color:var(--ink-soft)}.diff-legend{display:flex;gap:14px;font-size:.85rem;color:var(--ink-soft)}.legend-item{display:inline-flex;align-items:center;gap:6px}.legend-swatch{width:16px;height:16px;border-radius:4px;display:inline-block}.swatch-missed{background:#ef444473;border:1.5px dashed var(--c-a)}.swatch-stray{background:#f59e0b73;border:1.5px solid var(--c-hint)}@keyframes fade-in{0%{opacity:0}to{opacity:1}}@media(max-width:640px){.stage-tabs{grid-template-columns:repeat(2,1fr)}.stage-tab-name{font-size:.88rem}.quiz-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr))}.feedback{flex-direction:column;align-items:stretch;text-align:center}.score-block{align-self:center}.diff-legend{justify-content:center}}