@import "https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700;800&display=swap";:root{--brand-primary:#1b2559;--brand-secondary:#4318ff;--brand-accent:#05cd99;--brand-bg:#f4f7fe;--brand-card:#fff;color:#2d3748;background-color:var(--brand-bg);font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-family:Nunito,sans-serif;font-weight:400;line-height:1.5}body{box-sizing:border-box;margin:0;padding:0}*,:before,:after{box-sizing:inherit}:root{--primary:#0d9488;--primary-hover:#0f766e;--bg-color:#f4f7fe;--card-bg:#fff;--text-main:#2b3674;--text-muted:#a3aed0;--border-color:#e2e8f0;--success:#05cd99;--danger:#ee5d50;--warning:#ffce20;--radius-sm:8px;--radius-md:16px;--radius-lg:24px;--shadow-soft:0px 4px 20px #7090b014}body{background-color:var(--bg-color);color:var(--text-main)}.app-container{flex-direction:column;min-height:100vh;display:flex}.app-header{background:var(--card-bg);box-shadow:var(--shadow-soft);z-index:10;justify-content:space-between;align-items:center;padding:1rem 2rem;display:flex}.app-header h1{color:var(--primary);text-transform:uppercase;letter-spacing:.5px;margin:0;font-size:1.5rem;font-weight:800}.main-layout{flex:1;gap:2rem;width:100%;max-width:1400px;margin:0 auto;padding:2rem;display:flex}.content-area{flex-direction:column;flex:1;gap:1.5rem;display:flex}.card{background:var(--card-bg);border-radius:var(--radius-md);box-shadow:var(--shadow-soft);padding:2rem}.problem-view{background:var(--card-bg);border-radius:var(--radius-lg);box-shadow:var(--shadow-soft);padding:2.5rem}.problem-title{color:var(--text-main);margin:0 0 1rem;font-size:1.25rem;font-weight:700}.problem-description{border-radius:var(--radius-sm);color:#4a5568;background:#f4f7fe;margin-bottom:2rem;padding:1.5rem;font-size:1.1rem}.right-nav{flex-direction:column;gap:1.5rem;width:320px;display:flex}.stats-card{background:var(--primary);color:#fff;border-radius:var(--radius-md);padding:1.5rem;box-shadow:0 10px 20px #524ee133}.stats-card h3{text-transform:uppercase;letter-spacing:1px;margin:0 0 1rem;font-size:.9rem}.stats-grid{justify-content:space-between;display:flex}.stat-box{flex-direction:column;display:flex}.stat-value{font-size:2.5rem;font-weight:800;line-height:1}.stat-label{opacity:.8;text-transform:uppercase;margin-top:.5rem;font-size:.8rem}.tips-card{background:var(--card-bg);border-radius:var(--radius-md);box-shadow:var(--shadow-soft);padding:1.5rem}.tips-card h4{color:#eab308;align-items:center;gap:.5rem;margin:0 0 .5rem;display:flex}.tips-card p{color:var(--text-muted);margin:0;font-size:.9rem;line-height:1.6}.nav-items{flex-wrap:wrap;gap:.5rem;display:flex}.nav-item{border:2px solid var(--border-color);width:40px;height:40px;color:var(--text-muted);cursor:pointer;background:0 0;border-radius:50%;justify-content:center;align-items:center;font-weight:700;transition:all .2s;display:flex}.nav-item.active{background:var(--primary);border-color:var(--primary);color:#fff}.nav-item.status-finished{background:var(--success);border-color:var(--success);color:#fff}.btn-primary{background:var(--primary);color:#fff;border-radius:var(--radius-sm);cursor:pointer;border:none;padding:.75rem 1.5rem;font-weight:700;transition:background .2s}.btn-primary:hover{background:var(--primary-hover)}.math-input,.text-input{border:1px solid var(--border-color);border-radius:var(--radius-sm);background:#f8fafc;width:100%;padding:1rem;font-size:1rem;transition:border-color .2s}.math-input:focus-within,.text-input:focus{border-color:var(--primary);background:#fff;outline:none}.step-item{border-radius:var(--radius-sm);border:1px solid var(--border-color);background:#f8fafc;margin-bottom:1rem;padding:1.5rem}.add-step-btn{color:var(--primary);border:2px dashed var(--primary);border-radius:var(--radius-sm);cursor:pointer;background:0 0;width:100%;padding:1rem;font-weight:700}.add-step-btn:hover{background:#524ee10d}.final-answer-container{border-radius:var(--radius-md);background:#eef2ff;border:1px solid #c7d2fe;margin-top:2rem;padding:2rem}table{border-collapse:collapse;width:100%}th,td{text-align:left;border-bottom:1px solid var(--border-color);padding:1rem}th{color:var(--text-muted);text-transform:uppercase;font-size:.85rem;font-weight:600}tr:hover{background:#f8fafc}.graphical-input-container{background:var(--card-bg);border:1px solid var(--border-color);border-radius:var(--radius-sm);padding:1rem}.drawing-toolbar button{color:var(--text-main);cursor:pointer;background:#f1f5f9;border:none;border-radius:4px;padding:.5rem 1rem;font-weight:600}.drawing-toolbar button.active{background:var(--primary);color:#fff}.factor-tree-content{border:2px solid var(--primary);background:#f1f5f9;border-radius:8px}.factor-tree-lines{background-color:var(--primary)}.factor-tree-children{border-color:var(--primary)}.factor-tree-children:before,.factor-tree-children:after{background-color:var(--primary)}