/* ...existing styles... */
:root {
  --bg: #ffffff;
  --text: #0a0a0a;
  --muted: #666;
  --border: #e6e6e6;
  --accent: #111; /* subtle for buttons */
  --success: #0a7f43;
  --warn: #b36b00;
  --danger: #b00020;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font-family: "Noto Sans", system-ui, -apple-system, Segoe UI, Roboto, sans-serif; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.site-header { border-bottom: 1px solid var(--border); position: sticky; top: 0; background: var(--bg); z-index: 10; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { height: 28px; width: auto; display: block; }
.nav a { color: var(--text); text-decoration: none; margin-left: 18px; font-weight: 600; }
.nav .btn { border: 1px solid var(--border); padding: 8px 12px; border-radius: 8px; }

.hero { padding: 64px 0 32px; }
.hero-inner { text-align: left; }
h1 { font-size: 40px; line-height: 1.1; margin: 0 0 12px; }
.subhead { color: var(--muted); font-size: 18px; margin: 0 0 20px; }
.hero-cta .btn { margin-right: 10px; }

.section { padding: 56px 0; border-top: 1px solid var(--border); }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card { border: 1px solid var(--border); border-radius: 10px; padding: 16px; }
.callout { border-left: 4px solid var(--border); padding: 12px; background: #fafafa; border-radius: 6px; }

.checklist { padding-left: 18px; }
.checklist li { margin: 8px 0; }

.demo-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 20px; align-items: start; }
.panel { border: 1px solid var(--border); border-radius: 10px; padding: 16px; background: #fff; }
.controls label { display: block; margin-bottom: 12px; font-weight: 600; }
.controls input[type="range"], .controls input[type="number"] { width: 100%; margin-top: 6px; }
.row { display: flex; gap: 12px; align-items: center; }
.readouts { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; margin: 16px 0; }
.readout { border: 1px solid var(--border); border-radius: 8px; padding: 10px; }
.readout .label { color: var(--muted); font-size: 12px; }
.readout .value { font-size: 18px; font-weight: 700; }

.badge { align-self: stretch; display: flex; align-items: center; justify-content: center; border: 1px solid var(--border); border-radius: 8px; font-weight: 700; }
.badge.safe { color: var(--success); }
.badge.warn { color: var(--warn); }
.badge.danger { color: var(--danger); }

#trendChart { width: 100%; height: 280px; }

.log-list { list-style: none; padding: 0; margin: 0; max-height: 360px; overflow: auto; border: 1px solid var(--border); border-radius: 8px; }
.log-list li { padding: 10px 12px; border-bottom: 1px solid var(--border); font-size: 14px; }
.log-list li:last-child { border-bottom: none; }

.tips { margin-top: 16px; font-size: 14px; color: var(--muted); }
.tips ul { padding-left: 18px; }

.pricing { display: grid; grid-template-columns: 1fr; }
.price-card { border: 1px solid var(--border); border-radius: 10px; padding: 20px; text-align: left; }
.price { font-size: 32px; font-weight: 700; margin: 8px 0 16px; }

.contact-form .row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
.contact-form .row .full { grid-column: 1 / -1; }
.contact-form input, .contact-form textarea { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 8px; }
.form-status { margin-top: 8px; color: var(--muted); }

.btn { display: inline-block; padding: 10px 14px; border-radius: 8px; border: 1px solid var(--border); color: var(--text); text-decoration: none; transition: transform 120ms ease, box-shadow 120ms ease; }
.btn.primary { background: var(--text); color: #fff; border-color: var(--text); }
.btn:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,0,0,0.06); }

.site-footer { border-top: 1px solid var(--border); padding: 20px 0; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; }
.footer-links a { color: var(--muted); text-decoration: none; margin-left: 16px; }

@media (max-width: 900px) {
  .grid-2, .cards, .demo-grid, .contact-form .row { grid-template-columns: 1fr; }
  .nav a { display: none; }
  .nav .btn { display: inline-block; }
}
/* ...existing styles... */