:root {
  color-scheme: light dark;
  --background: #f4f7fb;
  --surface: #ffffff;
  --surface-muted: #eef3f8;
  --text: #111820;
  --muted: #627080;
  --line: #d8e0e8;
  --accent: #07598a;
  --accent-bright: #178ee6;
  --accent-soft: #dcecf7;
  --red: #ef4148;
  --green: #148a5b;
  --shadow: 0 22px 70px rgba(24, 49, 72, 0.14);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-size: 16px;
  line-height: 1.55;
}
a { color: inherit; }
.site-header {
  position: relative;
  z-index: 10;
  width: min(1180px, calc(100% - 40px));
  min-height: 82px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 720;
  text-decoration: none;
}
.brand img {
  border-radius: 9px;
  box-shadow: 0 4px 14px rgba(12, 75, 115, 0.18);
}
nav { display: flex; align-items: center; gap: 28px; }
nav a {
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 650;
  text-decoration: none;
}
nav a:hover, nav a[aria-current="page"] { color: var(--accent); }

.hero {
  position: relative;
  min-height: calc(100vh - 82px);
  padding: clamp(44px, 7vh, 76px) 24px clamp(64px, 8vw, 104px);
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(244,247,251,0.25), var(--background) 96%),
    radial-gradient(circle at 50% 44%, rgba(23,142,230,0.16), transparent 48%);
}
.hero-copy {
  position: relative;
  z-index: 2;
  width: min(840px, 100%);
  margin: 0 auto;
  text-align: center;
}
.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.77rem;
  font-weight: 760;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
h1, h2, h3, p { letter-spacing: 0; }
h1 {
  margin: 0;
  font-size: clamp(3rem, 7vw, 6.6rem);
  line-height: 0.98;
}
.hero-summary {
  max-width: 680px;
  margin: 24px auto 0;
  color: var(--muted);
  font-size: clamp(1.06rem, 2vw, 1.32rem);
}
.hero-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 28px;
}
.button {
  min-height: 46px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 7px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  text-decoration: none;
}
.button.primary { background: var(--accent); color: #fff; }
.button.secondary { border-color: var(--line); background: var(--surface); color: var(--accent); }
.button:hover { transform: translateY(-1px); }

.product-preview {
  position: relative;
  z-index: 1;
  width: min(930px, calc(100% - 16px));
  height: 570px;
  margin: clamp(42px, 7vh, 68px) auto 0;
  padding: 24px;
  border: 1px solid rgba(170, 187, 202, 0.8);
  border-radius: 8px 8px 0 0;
  background: rgba(249, 251, 253, 0.94);
  box-shadow: var(--shadow);
}
.preview-topbar, .preview-brand, .panel-heading, .chart-heading, .trend-panel {
  display: flex;
  align-items: center;
}
.preview-topbar { justify-content: space-between; margin-bottom: 18px; }
.preview-brand { gap: 13px; }
.preview-brand img { border-radius: 11px; }
.preview-brand strong, .preview-brand span { display: block; }
.preview-brand strong { font-size: 1.12rem; }
.preview-brand span { color: var(--muted); font-size: 0.86rem; }
.logging-status {
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}
.logging-status i {
  width: 8px;
  height: 8px;
  margin-right: 7px;
  border-radius: 50%;
  display: inline-block;
  background: var(--red);
}
.preview-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.8fr;
  gap: 14px;
}
.pressure-panel, .trend-panel, .chart-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}
.pressure-panel { min-height: 222px; padding: 20px; }
.panel-heading { justify-content: space-between; }
.panel-heading span, .panel-heading small { display: block; }
.panel-heading span { font-weight: 720; }
.panel-heading small { margin-top: 2px; color: var(--muted); }
.info-mark {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  text-align: center;
  line-height: 28px;
  font-family: Georgia, serif;
  font-weight: 800;
}
.pressure-reading {
  margin: 20px 0 15px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.pressure-reading strong {
  font-size: clamp(3.2rem, 7vw, 5.3rem);
  font-weight: 630;
  line-height: 1;
}
.pressure-reading span { color: var(--muted); font-size: 1.25rem; font-weight: 700; }
.reading-meta { display: flex; gap: 10px; }
.reading-meta span {
  padding: 6px 9px;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--muted);
  font-size: 0.78rem;
}
.reading-meta strong { color: var(--accent); }
.trend-panel {
  gap: 14px;
  min-height: 222px;
  padding: 20px;
}
.trend-panel div:last-child > * { display: block; }
.trend-icon {
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  border-radius: 7px;
  display: grid;
  place-items: center;
  background: var(--surface-muted);
  color: var(--muted);
  font-size: 1.4rem;
}
.trend-panel small, .trend-panel span { color: var(--muted); }
.trend-panel strong { margin: 4px 0; font-size: 1.18rem; }
.chart-panel { grid-column: 1 / -1; height: 250px; padding: 17px 20px; }
.chart-heading { justify-content: space-between; }
.chart-heading small, .chart-heading strong { display: block; }
.chart-heading small, .chart-heading > span { color: var(--muted); font-size: 0.77rem; }
.chart { position: relative; height: 170px; margin-top: 7px; overflow: hidden; }
.chart svg { position: absolute; inset: 0 0 18px; width: 100%; height: calc(100% - 18px); overflow: visible; }
.chart-line { fill: none; stroke: var(--accent-bright); stroke-width: 4; stroke-linecap: round; }
.chart-area { fill: rgba(23, 142, 230, 0.08); }
.grid-line { position: absolute; left: 0; right: 0; border-top: 1px solid var(--line); }
.line-one { top: 32px; } .line-two { top: 79px; } .line-three { top: 126px; }
.chart-times {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.69rem;
}

.feature-band {
  padding: clamp(76px, 10vw, 140px) max(24px, calc((100vw - 1180px) / 2));
  background: var(--surface);
}
.section-intro { max-width: 670px; }
.section-intro h2, .privacy-callout h2, .note-band h2, .contact-panel h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.7rem);
  line-height: 1.08;
}
.section-intro > p:last-child { color: var(--muted); font-size: 1.08rem; }
.feature-list {
  margin-top: 64px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.feature-list article {
  min-height: 260px;
  padding: 28px 24px 20px 0;
  border-right: 1px solid var(--line);
}
.feature-list article + article { padding-left: 24px; }
.feature-list article:last-child { border-right: 0; }
.feature-number { color: var(--accent); font-size: 0.78rem; font-weight: 800; }
.feature-list h3 { margin: 36px 0 10px; font-size: 1.25rem; }
.feature-list p { margin: 0; color: var(--muted); font-size: 0.94rem; }
.privacy-callout {
  padding: clamp(72px, 10vw, 130px) max(24px, calc((100vw - 1180px) / 2));
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: clamp(50px, 10vw, 150px);
  background: #102a3a;
  color: #fff;
}
.privacy-callout .eyebrow { color: #82c8f4; }
.privacy-callout p:not(.eyebrow) { color: #c4d2db; font-size: 1.08rem; }
.text-link { color: #91d1f8; font-weight: 720; text-decoration: none; }
.note-band { padding: 72px 24px; text-align: center; }
.note-band h2 { font-size: clamp(1.7rem, 3vw, 2.7rem); }
.note-band p { max-width: 740px; margin: 14px auto 0; color: var(--muted); }

.document-page { width: min(900px, calc(100% - 40px)); margin: 0 auto; padding: 68px 0 110px; }
.document-header { max-width: 760px; margin-bottom: 64px; }
.document-header h1 { font-size: clamp(2.8rem, 7vw, 5.2rem); }
.document-header > p:last-child { color: var(--muted); }
.document-content { border-top: 1px solid var(--line); }
.document-content section {
  padding: 30px 0;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 40px;
}
.document-content h2 { margin: 0; font-size: 1.03rem; }
.document-content p { margin: 0; color: var(--muted); }
.document-content a { color: var(--accent); }
.support-header .button { margin-top: 18px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary {
  padding: 25px 44px 25px 0;
  cursor: pointer;
  font-size: 1.08rem;
  font-weight: 720;
  list-style: none;
  position: relative;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 8px;
  color: var(--accent);
  font-size: 1.4rem;
}
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { max-width: 720px; margin: -8px 0 26px; color: var(--muted); }
.contact-panel {
  margin-top: 76px;
  padding: 36px;
  border-radius: 8px;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 40px;
  background: var(--surface);
  border: 1px solid var(--line);
}
.contact-panel h2 { font-size: 2rem; }
.contact-panel p:not(.eyebrow) { margin-bottom: 0; color: var(--muted); }

footer {
  min-height: 110px;
  padding: 28px max(24px, calc((100vw - 1180px) / 2));
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.88rem;
}
footer div { display: flex; gap: 24px; }
footer a { text-decoration: none; }

@media (max-width: 760px) {
  .site-header { width: min(100% - 28px, 1180px); min-height: 70px; }
  .brand span { display: none; }
  nav { gap: 16px; }
  nav a { font-size: 0.84rem; }
  .hero { min-height: calc(100vh - 70px); padding: 42px 12px 64px; }
  .hero-actions { flex-wrap: wrap; }
  .product-preview { width: 100%; height: 510px; padding: 14px; }
  .preview-brand strong { font-size: 0.92rem; }
  .preview-brand span { font-size: 0.72rem; }
  .preview-brand img { width: 42px; height: 42px; }
  .preview-grid { grid-template-columns: 1fr; gap: 10px; }
  .pressure-panel { min-height: 185px; padding: 15px; }
  .pressure-reading { margin: 16px 0 12px; }
  .pressure-reading strong { font-size: clamp(3rem, 15vw, 4.3rem); }
  .trend-panel { min-height: 90px; padding: 14px; }
  .chart-panel { height: 190px; padding: 12px 14px; }
  .chart { height: 120px; }
  .chart-heading > span { display: none; }
  .feature-list { grid-template-columns: 1fr; margin-top: 42px; }
  .feature-list article, .feature-list article + article {
    min-height: 0;
    padding: 24px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .feature-list h3 { margin: 14px 0 7px; }
  .privacy-callout { grid-template-columns: 1fr; gap: 28px; }
  .document-page { padding-top: 48px; }
  .document-header { margin-bottom: 44px; }
  .document-content section { grid-template-columns: 1fr; gap: 10px; }
  .contact-panel { padding: 26px; align-items: stretch; flex-direction: column; }
  footer { align-items: flex-start; flex-direction: column; justify-content: center; gap: 12px; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0d141a;
    --surface: #151f27;
    --surface-muted: #1d2a34;
    --text: #f4f7f9;
    --muted: #a9b5bf;
    --line: #2e3c47;
    --accent: #69bff4;
    --accent-bright: #55b8f5;
    --accent-soft: #183b50;
    --shadow: 0 22px 70px rgba(0, 0, 0, 0.35);
  }
  .hero {
    background:
      linear-gradient(180deg, rgba(13,20,26,0.2), var(--background) 96%),
      radial-gradient(circle at 50% 44%, rgba(30,140,205,0.22), transparent 48%);
  }
  .product-preview { background: rgba(17, 27, 35, 0.95); border-color: #344652; }
  .privacy-callout { background: #071e2b; }
  .button.primary { background: #1682c5; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button:hover { transform: none; }
}