:root{--bg-color:#0f172a;--surface-color:#1e293b;--surface-hover:#334155;--text-primary:#f8fafc;--text-secondary:#94a3b8;--accent-color:#3b82f6;--accent-hover:#60a5fa;--success-color:#22c55e;--danger-color:#ef4444;--font-main:"Outfit", sans-serif;--font-mono:"Roboto Mono", monospace;--border-radius:12px;--transition:all .2s cubic-bezier(.4, 0, .2, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-primary);font-family:var(--font-main);justify-content:center;min-height:100vh;display:flex}#app-container{background-color:var(--surface-color);flex-direction:column;width:100%;max-width:600px;height:100vh;min-height:500px;display:flex;position:relative;overflow:hidden;box-shadow:0 0 20px #00000080}header{text-align:center;background:linear-gradient(135deg,#1e293b 0%,#0f172a 100%);border-bottom:1px solid #ffffff0d;padding:24px;position:relative}h1{letter-spacing:-.5px;background:-webkit-linear-gradient(45deg, var(--accent-color), #8b5cf6);-webkit-text-fill-color:transparent;-webkit-background-clip:text;font-size:1.8rem;font-weight:800}h2{text-align:center;margin-bottom:24px;font-weight:600}.view{flex-direction:column;flex:1;min-height:0;padding:32px 24px;display:none;overflow:hidden}.view.active{animation:.3s ease-out fadeIn;display:flex}button{font-family:var(--font-main);cursor:pointer;transition:var(--transition);border:none;outline:none}.mode-btn{border-radius:var(--border-radius);text-align:left;background-color:#ffffff08;border:1px solid #ffffff1a;flex-direction:column;width:100%;margin-bottom:16px;padding:16px;display:flex}.mode-btn:hover{background-color:var(--surface-hover);border-color:var(--accent-color);transform:translateY(-2px);box-shadow:0 4px 12px #3b82f633}.mode-title{color:var(--text-primary);margin-bottom:4px;font-size:1.2rem;font-weight:600}.mode-desc{color:var(--text-secondary);font-size:.9rem}.settings{text-align:left}.settings label{color:var(--text-secondary);justify-content:center;align-items:center;gap:12px;font-weight:600;display:flex}.settings input{background:var(--bg-color);color:var(--text-primary);font-family:var(--font-main);text-align:center;border:1px solid #ffffff1a;border-radius:8px;width:80px;padding:8px 12px;font-size:1rem}.top-bar{color:var(--text-secondary);justify-content:space-between;align-items:center;margin-bottom:32px;font-size:.9rem;font-weight:600;display:flex}.icon-btn{color:var(--text-secondary);background:0 0;padding:8px;font-size:1.2rem;line-height:1}.icon-btn:hover{color:var(--danger-color);transform:scale(1.1)}.burger-btn{font-size:1.5rem;position:absolute;top:50%;right:24px;transform:translateY(-50%)}.burger-btn:hover{color:var(--accent-hover)}.strikes-container{flex-direction:column;gap:12px;display:flex;position:absolute;left:24px}.strike-icon{color:var(--surface-hover);font-size:1.5rem;line-height:1;transition:color .3s}.strike-icon.active{color:var(--danger-color)}#question-container{flex-direction:column;flex-shrink:0;justify-content:center;align-items:center;margin-bottom:24px;display:flex}.tablature-line{font-family:var(--font-mono);color:var(--text-secondary);letter-spacing:2px;white-space:pre;font-size:1.5rem}#staff-container{background:#fff;border-radius:8px;padding:16px;box-shadow:inset 0 0 10px #0000001a}.target-string{color:var(--accent-color);margin-top:16px;font-size:1.2rem;font-weight:600}#answer-container{flex:1;gap:12px;min-height:0;display:grid;overflow-y:auto}.answer-btn{background:var(--bg-color);color:var(--text-primary);border:1px solid #ffffff1a;border-radius:8px;padding:16px 8px;font-size:1.1rem;font-weight:600;box-shadow:0 4px 6px #0000001a}.answer-btn:hover{background:var(--surface-hover);border-color:#ffffff4d;transform:translateY(-2px)}.answer-btn:active{transform:translateY(1px)}.answer-btn.correct{background:var(--success-color);color:#fff;border-color:var(--success-color);transform:scale(1.05);box-shadow:0 0 15px #22c55e80}.answer-btn.wrong{background:var(--danger-color);color:#fff;border-color:var(--danger-color);animation:.4s cubic-bezier(.36,.07,.19,.97) both shake}.fret-marker-single.answer-btn,.fret-marker-double.answer-btn{padding-top:20px;position:relative}.fret-marker-single.answer-btn:before{content:"";background-color:var(--text-secondary);opacity:.6;border-radius:50%;width:5px;height:5px;position:absolute;top:6px;left:50%;transform:translate(-50%)}.fret-marker-double.answer-btn:before,.fret-marker-double.answer-btn:after{content:"";background-color:var(--text-secondary);opacity:.6;border-radius:50%;width:5px;height:5px;position:absolute;top:6px}.fret-marker-double.answer-btn:before{left:calc(50% - 8px)}.fret-marker-double.answer-btn:after{right:calc(50% - 8px)}.modal{-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:100;opacity:0;background:#0f172acc;justify-content:center;align-items:center;width:100%;height:100%;transition:opacity .2s;display:none;position:absolute;top:0;left:0}.modal.active{opacity:1;display:flex}.modal-content{background:var(--surface-color);border-radius:var(--border-radius);text-align:center;border:1px solid #ffffff1a;padding:32px;box-shadow:0 25px 50px -12px #00000080}.modal-content p{margin-bottom:24px;font-size:1.2rem}.modal-actions{justify-content:center;gap:16px;display:flex}.primary-btn{background:var(--accent-color);color:#fff;border-radius:8px;padding:12px 24px;font-weight:600}.primary-btn:hover{background:var(--accent-hover)}.danger-btn{color:var(--danger-color);border:1px solid var(--danger-color);background:#ef444433;border-radius:8px;padding:12px 24px;font-weight:600}.danger-btn:hover{background:var(--danger-color);color:#fff}.secondary-btn{color:var(--text-primary);background:#ffffff0d;border-radius:8px;padding:12px 24px;font-weight:600}.secondary-btn:hover{background:#ffffff1a}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}@keyframes shake{10%,90%{transform:translate(-1px)}20%,80%{transform:translate(2px)}30%,50%,70%{transform:translate(-4px)}40%,60%{transform:translate(4px)}}.stats-box{text-align:center;background:#ffffff08;border-radius:12px;margin-bottom:24px;padding:24px}.stats-box p{margin:8px 0;font-size:1.2rem}.vertical-neck-container{background:var(--bg-color);scroll-behavior:smooth;border:1px solid #ffffff1a;border-radius:8px;flex:1;justify-content:center;width:100%;padding:20px 0;display:flex;position:relative;overflow-y:auto;box-shadow:inset 0 0 20px #000c}.vertical-neck{flex-direction:column;flex-shrink:0;width:200px;display:flex;position:relative}.neck-fret-row{background:#33211c;border-bottom:3px solid #64748b;flex-shrink:0;display:flex;position:relative}.neck-nut{border-top:8px solid #cbd5e1;height:30px}.neck-fret-label{width:20px;color:var(--text-secondary);text-align:right;font-size:.9rem;font-weight:700;position:absolute;top:50%;left:-30px;transform:translateY(-50%)}.neck-marker{opacity:.7;z-index:1;background:#f1f5f9;border-radius:50%;width:12px;height:12px;position:absolute;top:50%;transform:translateY(-50%)}.neck-marker-single{left:50%;transform:translate(-50%,-50%)}.neck-marker-double.left{left:28%}.neck-marker-double.right{right:28%}.neck-cell{z-index:2;flex:1;justify-content:center;align-items:center;display:flex;position:relative}.neck-string-line{z-index:2;background:#94a3b8;height:100%;box-shadow:1px 0 2px #000c}.target-string-cell{background:#3b82f626}.target-string-cell .neck-string-line{background:var(--accent-color);box-shadow:0 0 8px var(--accent-color)}.neck-cell.interactable{cursor:pointer;transition:background .1s}.neck-cell.interactable:hover{background:#3b82f666}.neck-cell.interactable:active{background:#3b82f699}.neck-cell.correct{background:var(--success-color)!important}.neck-cell.correct .neck-string-line{background:#fff;box-shadow:0 0 10px #fff}.neck-cell.wrong{animation:.4s cubic-bezier(.36,.07,.19,.97) both shake;background:var(--danger-color)!important}@keyframes flashGreenPulse{0%,to{filter:brightness();opacity:1}50%{filter:brightness(1.3);opacity:.6;box-shadow:0 0 30px var(--success-color)}}.flash-correct{animation:.6s ease-in-out infinite flashGreenPulse!important}