* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: #f4f6f8;
  color: #222;
  line-height: 1.5;
}
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px;
  background: #1f2d3d; color: #fff;
}
.topbar .logo { color: #fff; text-decoration: none; font-weight: 700; font-size: 1.1rem; }
.topbar nav a { color: #cbd5e1; text-decoration: none; margin-left: 18px; }
.topbar nav a:hover { color: #fff; }
.container { max-width: 960px; margin: 24px auto; padding: 0 16px; }
h1 { margin-top: 0; }
section { margin: 32px 0; }
.form { display: flex; flex-direction: column; gap: 12px; max-width: 360px; }
.form label { display: flex; flex-direction: column; font-size: 0.9rem; color: #444; }
.form input {
  margin-top: 4px; padding: 8px 10px; border: 1px solid #cbd5e1; border-radius: 6px;
  font-size: 1rem;
}
.btn {
  display: inline-block; padding: 10px 18px;
  background: #2563eb; color: #fff; border: none; border-radius: 6px;
  text-decoration: none; font-size: 1rem; cursor: pointer;
}
.btn:hover { background: #1d4ed8; }
.btn-secondary { background: #475569; }
.btn-secondary:hover { background: #334155; }
.error { background: #fee2e2; color: #991b1b; padding: 8px 12px; border-radius: 6px; }
.info { background: #dbeafe; color: #1e3a8a; padding: 8px 12px; border-radius: 6px; }
.muted { color: #64748b; }
.code-box {
  background: #fff; border: 1px solid #cbd5e1; border-radius: 8px;
  padding: 16px; max-width: 480px;
}
.code {
  font-family: ui-monospace, "SF Mono", Consolas, monospace;
  font-size: 1.6rem; letter-spacing: 4px; font-weight: 700;
  background: #f1f5f9; padding: 8px 12px; border-radius: 6px; display: inline-block;
}
pre {
  background: #0f172a; color: #e2e8f0; padding: 10px 14px; border-radius: 6px;
  font-size: 1rem;
}
.shop-card {
  background: #fff; border: 1px solid #e2e8f0; border-radius: 8px;
  padding: 16px; margin-bottom: 16px;
}
.shop-card h3 { margin: 0 0 8px; }
.shop-card h3 small { color: #64748b; font-weight: 400; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 6px 10px; border-bottom: 1px solid #e2e8f0; font-size: 0.95rem; }
th { background: #f8fafc; color: #475569; font-weight: 600; }
tr.buying td { background: #ecfdf5; }
tr.selling td { background: #fff7ed; }
.footer { text-align: center; padding: 24px; color: #64748b; }