body { font-family: Arial, sans-serif; margin: 0; padding: 0; }
header { background: #333; color: #fff; padding: 10px; }
nav ul { list-style: none; margin: 0; padding: 0; }
nav li { display: inline-block; position: relative; margin-right: 10px; }
nav li ul { display: none; position: absolute; left: 0; background: #333; padding: 0; }
nav li ul li { display: block; margin: 0; }
nav li.open > ul { display: block; }
nav a { color: #fff; text-decoration: none; padding: 5px 10px; display: block; }
nav li ul li a { background: #444; white-space: nowrap; }
nav .has-submenu > a::after { content: ' ▾'; font-size: 0.8em; }
table { border-collapse: collapse; margin-top: 10px; }
th, td { border: 1px solid #ccc; padding: 5px 10px; }