body { margin: 0; font-family: Arial, sans-serif; background: #f4f6f8; color: #1f2937; }
main { max-width: 900px; margin: 0 auto; padding: 28px; }
section { margin: 16px 0; padding: 18px; background: #fff; border: 1px solid #d7dde5; border-radius: 6px; }
h1 { margin: 0 0 18px 0; font-size: 28px; }
h2 { margin: 0 0 14px 0; font-size: 18px; }
nav { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }
nav a { display: inline-block; padding: 8px 12px; border: 1px solid #2563eb; border-radius: 4px; color: #2563eb; text-decoration: none; background: #fff; }
label { display: block; margin: 10px 0 6px 0; font-weight: 700; }
input { box-sizing: border-box; width: 100%; padding: 9px; border: 1px solid #c7ced8; border-radius: 4px; font-size: 14px; }
button { padding: 9px 13px; border: 0; border-radius: 4px; background: #2563eb; color: #fff; cursor: pointer; font-size: 14px; }
button:hover { background: #1d4ed8; }
pre { min-height: 120px; overflow: auto; padding: 12px; border-radius: 4px; background: #111827; color: #e5e7eb; white-space: pre-wrap; }
.row { display: flex; gap: 8px; align-items: center; margin: 8px 0; }
.row input { flex: 1; }