:root{--primary:#2563eb;--primary-dark:#1d4ed8;--secondary:#f8fafc;--accent:#0ea5e9;--text-primary:#0f172a;--text-secondary:#64748b;--border:#e2e8f0;--shadow:#0000001a;--gradient:linear-gradient(135deg, #667eea 0%, #764ba2 100%);--sidebar-bg:linear-gradient(180deg, #1e293b 0%, #0f172a 100%);--card-bg:#fff}*{box-sizing:border-box;margin:0;padding:0}body{color:var(--text-primary);background-color:#f1f5f9;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;line-height:1.6}#root{min-height:100vh}a{color:inherit;text-decoration:none}button{cursor:pointer;border:none;outline:none}input,textarea{outline:none}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--secondary)}::-webkit-scrollbar-thumb{background:var(--text-secondary);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--primary)}.activity-item:hover{background:#f8fafc}