:root{--primary:#2563eb;--primary-dark:#1d4ed8;--secondary:#64748b;--success:#10b981;--danger:#ef4444;--warning:#f59e0b;--light:#f8fafc;--dark:#0f172a;--border:#e2e8f0;--shadow:#0000001a;--radius:8px;--spacing:1rem;--max-width:1200px;--transition:.2s ease}*{box-sizing:border-box;margin:0;padding:0}html{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-size:16px}body{color:var(--dark);background:var(--light);min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,sans-serif;line-height:1.6}h1,h2,h3,h4,h5,h6{margin-bottom:var(--spacing);font-weight:700;line-height:1.2}h1{font-size:2rem}h2{font-size:1.75rem}h3{font-size:1.5rem}h4{font-size:1.25rem}h5{font-size:1.1rem}h6{font-size:1rem}p{margin-bottom:var(--spacing)}a{color:var(--primary);transition:color var(--transition);text-decoration:none}a:hover{color:var(--primary-dark);text-decoration:underline}header,main,footer,section,article,aside{width:100%}header{border-bottom:1px solid var(--border);padding:var(--spacing);z-index:100;box-shadow:0 2px 4px var(--shadow);background:#fff;position:sticky;top:0}header>nav{max-width:var(--max-width);justify-content:space-between;align-items:center;gap:var(--spacing);margin:0 auto;display:flex}header h1{margin:0;font-size:1.5rem}main{max-width:var(--max-width);padding:var(--spacing);min-height:calc(100vh - 200px);margin:0 auto}footer{background:var(--dark);color:#fff;padding:calc(var(--spacing)*2)var(--spacing);text-align:center;margin-top:calc(var(--spacing)*3)}footer p{margin:0}section>ul,article>ul{gap:var(--spacing);grid-template-columns:1fr;margin:0;padding:0;list-style:none;display:grid}button,input[type=button],input[type=submit],input[type=reset]{background:var(--primary);color:#fff;border-radius:var(--radius);cursor:pointer;transition:background var(--transition),transform var(--transition);text-align:center;border:none;padding:.75rem 1.5rem;font-size:1rem;font-weight:600;display:inline-block}button:hover,input[type=button]:hover,input[type=submit]:hover{background:var(--primary-dark);transform:translateY(-1px)}button:active{transform:translateY(0)}button:disabled{opacity:.6;cursor:not-allowed}input[type=text],input[type=email],input[type=number],input[type=search],select,textarea{border:1px solid var(--border);border-radius:var(--radius);width:100%;transition:border-color var(--transition);padding:.75rem;font-family:inherit;font-size:1rem}input:focus,select:focus,textarea:focus{border-color:var(--primary);outline:none;box-shadow:0 0 0 3px #2563eb1a}label{color:var(--dark);margin-bottom:.5rem;font-weight:600;display:block}article{border:1px solid var(--border);border-radius:var(--radius);padding:var(--spacing);transition:box-shadow var(--transition),transform var(--transition);background:#fff}article:hover{box-shadow:0 4px 12px var(--shadow);transform:translateY(-2px)}article img{border-radius:var(--radius);width:100%;height:auto;margin-bottom:var(--spacing);display:block}article h3{margin-bottom:.5rem}article p{color:var(--secondary);margin-bottom:.75rem}img{max-width:100%;height:auto;display:block}table{border-collapse:collapse;width:100%;margin-bottom:var(--spacing);background:#fff}th,td{text-align:left;border-bottom:1px solid var(--border);padding:.75rem}th{background:var(--light);font-weight:600}tr:hover{background:var(--light)}mark{background:var(--primary);color:#fff;border-radius:calc(var(--radius)/2);padding:.25rem .5rem;font-size:.875rem;font-weight:600}hr{border:none;border-top:1px solid var(--border);margin:calc(var(--spacing)*2)0}@media (min-width:640px){section>ul,article>ul{grid-template-columns:repeat(2,1fr)}h1{font-size:2.5rem}h2{font-size:2rem}}@media (min-width:768px){:root{--spacing:1.5rem}main{padding:calc(var(--spacing)*2)}}@media (min-width:1024px){section>ul,article>ul{grid-template-columns:repeat(3,1fr)}h1{font-size:3rem}}@media (min-width:1280px){section>ul,article>ul{grid-template-columns:repeat(4,1fr)}}[role=button]{cursor:pointer}nav ul{gap:var(--spacing);flex-wrap:wrap;align-items:center;list-style:none;display:flex}nav a{white-space:nowrap;font-weight:600}strong{color:var(--primary);font-size:1.25rem;font-weight:700}sup{background:var(--danger);color:#fff;border-radius:10px;margin-left:.25rem;padding:.125rem .375rem;font-size:.75rem;font-weight:700}[aria-busy=true]{opacity:.6;pointer-events:none}[aria-label=empty]{text-align:center;padding:calc(var(--spacing)*3);color:var(--secondary)}details{transition:all var(--transition)}details summary{cursor:pointer;-webkit-user-select:none;user-select:none;list-style:none}details summary::-webkit-details-marker{display:none}details summary:before{content:"▼";transition:transform var(--transition);margin-right:.5rem;font-size:.875rem;display:inline-block}details:not([open]) summary:before{transform:rotate(-90deg)}details summary:hover{color:var(--primary)}input[type=number]::-webkit-inner-spin-button{opacity:1}input[type=number]::-webkit-outer-spin-button{opacity:1}small{color:var(--secondary);font-size:.875rem;display:block}input[type=checkbox]{cursor:pointer;width:1.25rem;height:1.25rem;accent-color:var(--primary)}