:root{--color-primary: #1e40af;--color-secondary: #eff6ff;--color-accent: #f59e0b;--color-background: #ffffff;--color-text: #1e293b;--color-primary-dark: #1e3a8a;--color-secondary-dark: #dbeafe;--color-border: #e2e8f0;--color-surface-hover: #f8fafc;--font-base: "Open Sans", "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;--font-weight-base: 400;--font-heading: "Poppins", sans-serif;--font-weight-heading: 700;--size-base: 16px;--line-height: 1.5;--letter-spacing: -.5px;--radius-input: 12px;--radius-card: 16px;--radius-button: 8px;--shadow-button: 0 4px 4px rgba(30, 64, 175, .2);--shadow-card: 0 4px 6px -1px rgba(0, 0, 0, .1), 0 2px 4px -1px rgba(0, 0, 0, .06);--shadow-card-hover: 0 10px 15px -3px rgba(0, 0, 0, .1), 0 4px 6px -2px rgba(0, 0, 0, .05);--nav-padding-y: 16px;--nav-links-spacing: 40px}*{margin:0;padding:0;box-sizing:border-box}html{font-size:var(--size-base);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:var(--font-base);font-weight:var(--font-weight-base);background-color:var(--color-background);color:var(--color-text);line-height:var(--line-height);letter-spacing:var(--letter-spacing);min-height:100vh}h1,h2,h3,h4,h5,h6{font-family:var(--font-heading);font-weight:var(--font-weight-heading);color:var(--color-text);transform:none}.app-container{display:flex;flex-direction:column;min-height:100vh}.app-header{position:sticky;top:0;z-index:100;background-color:var(--color-background);border-bottom:1px solid var(--color-border);padding:var(--nav-padding-y) 0;width:100%}.header-content{max-width:1400px;margin:0 auto;padding:0 2rem;display:flex;justify-content:space-between;align-items:center}.logo-section{display:flex;align-items:center;gap:12px}.logo-img{width:40px;height:40px;object-fit:contain}.logo-text h1{font-size:1.25rem;color:var(--color-primary);margin:0}.subtitle{font-size:.8rem;color:#64748b;font-family:var(--font-base);font-weight:400;margin-top:2px}.header-actions{display:flex;gap:var(--nav-links-spacing);align-items:center}.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.75rem 1.5rem;font-family:var(--font-base);font-weight:600;border-radius:var(--radius-button);border:none;cursor:pointer;transition:transform .2s ease,box-shadow .2s ease,background-color .2s ease;text-decoration:none;font-size:.95rem}.btn-primary{background-color:var(--color-primary);color:#fff;box-shadow:var(--shadow-button)}.btn-primary:hover{background-color:var(--color-primary-dark);transform:translateY(-2px);box-shadow:0 6px 8px #1e40af4d}.btn-secondary{background-color:var(--color-secondary);color:var(--color-primary);box-shadow:none}.btn-secondary:hover{background-color:var(--color-secondary-dark);transform:translateY(-2px);color:var(--color-primary-dark)}.header-actions .btn-secondary{background:transparent;color:var(--color-text);font-weight:500;padding:4px 8px;box-shadow:none}.header-actions .btn-secondary:hover{color:var(--color-primary);background-color:var(--color-secondary);transform:none}.header-actions .btn-secondary .icon{margin-right:4px}.main-content{flex:1;display:grid;grid-template-columns:350px 1fr;gap:2rem;max-width:1400px;margin:2rem auto;padding:0 2rem;width:100%}.control-panel,.puzzle-display{background-color:#fff;border-radius:var(--radius-card);border:none;box-shadow:var(--shadow-card);padding:2rem}.control-group{margin-bottom:1.5rem}.control-group label{display:block;margin-bottom:.5rem;font-weight:600;color:var(--color-text)}.select-input,.range-input{width:100%;border-radius:var(--radius-input);background-color:#f1f5f9;border:1px solid transparent;padding:.75rem 1rem;font-family:var(--font-base);color:var(--color-text);font-size:1rem;transition:all .2s ease}.select-input:focus{outline:none;background-color:#fff;border-color:var(--color-primary);box-shadow:0 0 0 3px #1e40af1a}.range-input-wrapper{display:flex;align-items:center;gap:1rem}.range-input{-webkit-appearance:none;-moz-appearance:none;appearance:none;height:8px;background:#e2e8f0;border-radius:4px;padding:0}.range-input::-webkit-slider-thumb{-webkit-appearance:none;width:20px;height:20px;border-radius:50%;background:var(--color-primary);cursor:pointer;box-shadow:0 2px 4px #0003;transition:transform .1s}.range-input::-webkit-slider-thumb:hover{transform:scale(1.1)}.range-value{background-color:var(--color-primary);color:#fff;font-weight:700;border-radius:8px;min-width:32px;height:32px;display:flex;align-items:center;justify-content:center}.help-text{font-size:.85rem;color:#64748b;margin-top:.5rem}.panel-title{font-size:1.25rem;margin-bottom:1.5rem;padding-bottom:1rem;border-bottom:2px solid var(--color-secondary)}.puzzle-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem}.badge{background-color:var(--color-secondary);color:var(--color-primary);padding:.5rem 1rem;border-radius:20px;font-weight:600;font-size:.85rem}.welcome-message{text-align:center;padding:3rem 1rem}.welcome-icon{font-size:3rem;margin-bottom:1rem;color:var(--color-primary)}.welcome-features{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem;margin-top:2rem}.feature-item{background-color:#f8fafc;padding:1rem;border-radius:12px;display:flex;flex-direction:column;align-items:center;gap:.5rem}.feature-icon{font-size:1.5rem}.tutorial-container{width:100%;max-width:600px;height:300px;background:#f8fafc;border-radius:16px;margin:0 auto 2rem;position:relative;overflow:hidden;display:flex;justify-content:center;align-items:center;box-shadow:inset 0 2px 4px #0000000d}.tutorial-equation{font-size:2.5rem;font-family:Poppins,sans-serif;font-weight:600;display:flex;gap:1rem;align-items:center;opacity:0;transform:translateY(20px);transition:all .5s ease;position:absolute}.tutorial-equation.active{opacity:1;transform:translateY(0)}.tut-icon{display:inline-block;transition:all .8s cubic-bezier(.4,0,.2,1)}.tut-text{color:var(--color-primary)}.tut-operator{color:var(--color-text)}.move-right{transform:translate(120px) scale(.9);opacity:.5}.fade-out{opacity:0;transform:scale(.8)}.highlight{color:var(--color-accent);transform:scale(1.1)}.tutorial-caption{position:absolute;bottom:2rem;font-size:1.25rem;color:var(--color-primary);font-weight:600;background:#fff;padding:.5rem 1.5rem;border-radius:50px;box-shadow:0 4px 6px #0000001a;opacity:0;transform:translateY(20px);transition:all .5s ease}.tutorial-caption.show{opacity:1;transform:translateY(0)}.toast-container{position:fixed;bottom:2rem;right:2rem;z-index:1000;display:flex;flex-direction:column;gap:1rem}.toast{background:#fff;border-left:4px solid var(--color-primary);padding:1rem 1.5rem;border-radius:var(--radius-md);box-shadow:var(--shadow-lg);display:flex;align-items:center;gap:1rem;min-width:300px;transform:translate(120%);transition:transform .3s cubic-bezier(.16,1,.3,1)}.toast.show{transform:translate(0)}.toast.error{border-left-color:#ef4444}.toast.success{border-left-color:#10b981}.toast-icon{font-size:1.5rem}.toast-message{font-weight:500;color:var(--color-text)}.puzzle-equations{display:flex;flex-direction:column;gap:1.5rem}.equation-row{background-color:#f8fafc;border-radius:12px;padding:1.5rem;display:flex;align-items:center;gap:1rem;transition:background-color .2s}.equation-row:hover{background-color:var(--color-secondary)}.equation-row.final-equation{background-color:#fffbeb;border:2px solid var(--color-accent)}.icon-symbol{font-size:2rem;width:3rem;height:3rem;display:flex;align-items:center;justify-content:center;background:#fff;border-radius:8px;box-shadow:0 1px 3px #0000000d}.operator,.equals{font-size:1.5rem;font-weight:700;color:#94a3b8}.result{font-size:1.5rem;font-weight:700;color:var(--color-primary)}.unknown{font-size:1.5rem;font-weight:700;color:var(--color-accent);background:#fff;padding:0 1rem;border-radius:8px;border:2px dashed var(--color-accent)}@media print{body{display:none}}@media (max-width: 900px){.main-content{grid-template-columns:1fr}.control-panel{order:-1}}