body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; padding: 20px; background: #f9f9f9; color: #333; }
header { margin-bottom: 30px; }
h1 { font-size: 2.5rem; color: #0055cc; }
nav a { margin-right: 15px; text-decoration: none; color: #0077ff; }
nav a:hover { text-decoration: underline; }
table { width: 100%; border-collapse: collapse; background: white; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
th, td { border: 1px solid #ddd; padding: 12px 15px; text-align: left; }
th { background: #f0f0f0; }
tr:hover { background: #f5faff; }
.error { color: red; font-weight: bold; margin-bottom: 20px; }