@import "https://fonts.googleapis.com/css2?family=Outfit:wght@400;600;800&family=Nunito:wght@400;600;700;800;900&display=swap";:root{--bg-gradient-start:#ff9a9e;--bg-gradient-end:#fecfef;--card-bg:#ffffffd9;--card-border:#fff6;--primary:#ff6b6b;--primary-hover:#ff5252;--secondary:#4ecdc4;--secondary-hover:#45b7aa;--text-main:#2d3436;--text-light:#636e72;--shadow-sm:0 4px 6px #0000000d;--shadow-md:0 10px 20px #0000001a;--shadow-lg:0 15px 35px #00000026;--border-radius-lg:24px;--border-radius-md:16px;--border-radius-sm:12px}*{box-sizing:border-box;margin:0;padding:0}body{background:linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);min-height:100vh;color:var(--text-main);font-family:Nunito,sans-serif;overflow-x:hidden}#root{flex-direction:column;min-height:100vh;display:flex}h1,h2,h3,h4,h5,h6{color:var(--text-main);font-family:Outfit,sans-serif;font-weight:800}.title{text-align:center;color:#fff;text-shadow:2px 4px 8px #00000026;letter-spacing:-1px;margin:2rem 0;font-size:3rem}.subtitle{text-align:center;color:#fff;opacity:.9;margin-top:-1rem;margin-bottom:2rem;font-size:1.2rem;font-weight:600}.container{flex:1;max-width:1000px;margin:0 auto;padding:0 20px 40px}.glass-card{background:var(--card-bg);-webkit-backdrop-filter:blur(16px);border:1px solid var(--card-border);border-radius:var(--border-radius-lg);box-shadow:var(--shadow-md);padding:2rem;transition:transform .3s,box-shadow .3s}.table-grid{grid-template-columns:repeat(auto-fit,minmax(80px,1fr));gap:15px;margin-bottom:2rem;display:grid}.table-btn{border-radius:var(--border-radius-md);color:var(--primary);cursor:pointer;box-shadow:var(--shadow-sm);background:#fff;border:3px solid #0000;padding:15px 10px;font-family:Outfit,sans-serif;font-size:1.5rem;font-weight:800;transition:all .2s cubic-bezier(.175,.885,.32,1.275)}.table-btn:hover{box-shadow:var(--shadow-md);border-color:var(--primary-hover);transform:translateY(-5px)scale(1.05)}.table-btn.active{background:var(--primary);color:#fff;border-color:var(--primary-hover);box-shadow:var(--shadow-md);transform:scale(1.1)}.lesson-container{flex-direction:column;gap:1.5rem;display:flex}.equation-row{border-radius:var(--border-radius-md);box-shadow:var(--shadow-sm);background:#fff;justify-content:center;align-items:center;gap:1rem;padding:1.5rem;display:flex}.math-text{color:var(--text-main);align-items:center;gap:.5rem;font-family:Outfit,sans-serif;font-size:2rem;font-weight:800;display:flex}.operator{color:var(--secondary);font-weight:900}.equals{color:var(--primary);margin:0 .5rem;font-weight:900}.result{color:#fff;background:var(--primary);border-radius:var(--border-radius-sm);box-shadow:0 4px 0 var(--primary-hover);padding:.2rem 1rem}.visual-groups{border-radius:var(--border-radius-md);background:#ffffff80;border:2px dashed #0000001a;flex-wrap:wrap;justify-content:center;align-items:center;gap:1rem;margin-top:1rem;padding:1.5rem;display:flex}.group{border-radius:var(--border-radius-sm);box-shadow:var(--shadow-sm);background:#fff;gap:4px;padding:10px;display:flex}.group-icon{color:var(--primary);width:24px;height:24px}.nav-buttons{justify-content:space-between;margin-top:2rem;display:flex}.btn-icon{background:var(--secondary);color:#fff;border-radius:var(--border-radius-lg);cursor:pointer;box-shadow:0 6px 0 var(--secondary-hover);border:none;align-items:center;gap:.5rem;padding:1rem 1.5rem;font-family:Nunito,sans-serif;font-size:1.2rem;font-weight:700;transition:all .1s;display:flex}.btn-icon:hover{box-shadow:0 4px 0 var(--secondary-hover);transform:translateY(2px)}.btn-icon:active{box-shadow:none;transform:translateY(6px)}.btn-icon:disabled{cursor:not-allowed;background:#ccc;box-shadow:0 6px #aaa}.btn-icon.active{background:var(--secondary-hover);box-shadow:0 4px 0 var(--secondary-hover), 0 0 15px #4ecdc466;border:2px solid #fff;transform:translateY(2px)scale(1.05)}@media (width<=768px){.title{font-size:2.2rem}.table-grid{grid-template-columns:repeat(5,1fr)}.math-text{font-size:1.5rem}.equation-row{flex-direction:column}}.number-line-wrapper{border-radius:var(--border-radius-md);background:#ffffff80;border:2px dashed #0000001a;margin-top:1rem;padding:2.5rem 1.5rem 1rem}.number-line-container{align-items:flex-end;height:60px;margin:0 10px;display:flex;position:relative}.line-base{background:var(--text-light);border-radius:2px;height:4px;position:absolute;bottom:0;left:0;right:0}.line-segment{justify-content:space-between;align-items:flex-end;height:100%;display:flex;position:relative}.minor-ticks{justify-content:space-evenly;width:100%;height:10px;display:flex}.tick-minor{background:#636e7266;width:2px;height:10px}.tick-major-container{flex-direction:column;align-items:center;display:flex;position:absolute;bottom:0;right:0;transform:translate(50%)}.tick-zero{flex-direction:column;align-items:center;display:flex;position:absolute;bottom:0;left:0;transform:translate(-50%)}.tick-major{background:var(--text-main);border-radius:2px;width:4px;height:16px}.tick-label{color:var(--text-main);margin-top:8px;font-family:Outfit,sans-serif;font-weight:800}.jump-arc{width:100%;height:50px;position:absolute;bottom:12px;left:0}.jump-arc svg{width:100%;height:100%;overflow:visible}.jump-label{background:var(--primary);color:#fff;border-radius:12px;padding:2px 8px;font-size:.9rem;font-weight:700;position:absolute;top:-20px;left:50%;transform:translate(-50%)}