/* Sentez landing page
   Minimal, spacious, research-appropriate UI
   No external assets or trackers.
*/

:root{
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-alt: #fafafa;
  --text: #111318;        /* deep charcoal */
  --muted: #5a606b;       /* neutral gray */
  --border: #e6e8ee;      /* thin dividers */
  --accent: #4a4aa6;      /* muted indigo/violet */
  --accent-weak: rgba(74, 74, 166, 0.12);
  --focus: rgba(74, 74, 166, 0.35);

  --radius: 16px;
  --radius-sm: 12px;
  --shadow: 0 1px 0 rgba(17, 19, 24, 0.04), 0 8px 24px rgba(17, 19, 24, 0.06);

  --container: 1080px;
  --gutter: 24px;
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.5;
  letter-spacing: -0.01em;
}

a{ color: inherit; text-decoration: none; }
a:hover{ text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }

img{ max-width: 100%; display: block; }

.container{
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.skip-link{
  position: absolute;
  left: -999px;
  top: 10px;
  padding: 10px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: var(--shadow);
}
.skip-link:focus{ left: 10px; z-index: 999; outline: 3px solid var(--focus); }

/* Header */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,0.88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
  gap: 14px;
}
.brand{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 650;
  letter-spacing: -0.02em;
}
.brand-mark{
  width: 24px;
  height: 24px;
  color: var(--accent);
  flex-shrink: 0;
}
.brand-name{ font-size: 15px; }

.nav{
  display: flex;
  gap: 16px;
  align-items: center;
  color: var(--muted);
  font-size: 14px;
}
.nav a{ padding: 8px 8px; border-radius: 10px; }
.nav a:focus{ outline: 3px solid var(--focus); outline-offset: 2px; }
.nav-cta{
  color: var(--text);
  border: 1px solid var(--border);
  background: var(--surface);
}
.nav-cta:hover{ background: var(--surface-alt); text-decoration: none; }

/* Sections */
.section{
  padding: 72px 0;
}
.section.alt{
  background: var(--surface-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.section-header{
  max-width: 760px;
  margin-bottom: 28px;
}
.section-subtitle{
  color: var(--muted);
  font-size: 18px;
  margin: 10px 0 0;
}
h1,h2,h3{ margin: 0; line-height: 1.15; letter-spacing: -0.03em; }
h1{ font-size: clamp(34px, 4vw, 48px); }
h2{ font-size: clamp(24px, 2.6vw, 32px); }
h3{ font-size: 18px; }

/* Hero */
.hero{
  padding: 76px 0 54px;
}
.hero-grid{
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 34px;
  align-items: start;
}
.eyebrow{
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 10px;
}
.lead{
  color: var(--muted);
  font-size: 18px;
  max-width: 48ch;
  margin: 14px 0 0;
}
.cta-row{
  display: flex;
  gap: 12px;
  margin-top: 22px;
  flex-wrap: wrap;
}
.note{
  margin-top: 16px;
  color: var(--muted);
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.pill{
  display: inline-flex;
  align-items: center;
  padding: 5px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: 12px;
}

/* Buttons */
.button{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}
.button:hover{ text-decoration: none; background: var(--surface-alt); }
.button:active{ transform: translateY(1px); }
.button:focus{ outline: 3px solid var(--focus); outline-offset: 2px; }

.button.primary{
  border-color: rgba(74,74,166,0.35);
  background: var(--accent-weak);
}
.button.primary:hover{
  background: rgba(74,74,166,0.16);
}

.button.secondary{
  background: var(--surface);
}

/* Hero visual */
.hero-visual .visual-frame{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 16px;
}
.visual-caption{
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 13px;
}

/* Cards */
.cards{
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.card{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 18px 18px 16px;
  box-shadow: 0 1px 0 rgba(17, 19, 24, 0.02);
}
.card p{
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
}

/* Bullets */
.bullets{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  padding: 0;
  margin: 0;
  list-style: none;
}
.bullets li{
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 16px;
}
.bullet-title{
  display: block;
  font-weight: 650;
  margin-bottom: 6px;
}
.bullet-body{
  color: var(--muted);
  font-size: 14px;
}

/* Why panels */
.two-col{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.panel{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 18px;
}
.panel.accent{
  border-color: rgba(74,74,166,0.35);
  background: linear-gradient(to bottom, rgba(74,74,166,0.08), rgba(74,74,166,0.04));
}
.checklist{
  padding-left: 18px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
}
.checklist li{ margin: 8px 0; }

/* Steps */
.steps{
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
}
.step{
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 16px;
}
.step-num{
  width: 36px;
  height: 36px;
  border-radius: 999px;
  border: 1px solid rgba(74,74,166,0.35);
  background: rgba(74,74,166,0.08);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}
.step-body p{
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

/* Callout */
.callout{
  border: 1px solid rgba(74,74,166,0.35);
  background: rgba(74,74,166,0.06);
  border-radius: var(--radius);
  padding: 18px;
}
.callout p{ margin: 10px 0 0; color: var(--muted); }

/* CTA */
.section.cta{
  padding: 76px 0;
}
.cta-grid{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  align-items: start;
}
.form{
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.field{ display: block; margin-bottom: 12px; }
.label{
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}
input{
  width: 100%;
  padding: 11px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
  font-size: 14px;
  color: var(--text);
}
input:focus{ outline: 3px solid var(--focus); outline-offset: 2px; border-color: rgba(74,74,166,0.35); }
.form-note{
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 12.5px;
}
.form-note.subtle{ opacity: 0.85; }

/* Footer */
.site-footer{
  border-top: 1px solid var(--border);
  padding: 22px 0;
  background: var(--surface);
}
.footer-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.footer-muted{
  color: var(--muted);
  font-size: 13px;
  margin: 6px 0 0;
}
.footer-right{
  display: inline-flex;
  gap: 10px;
  align-items: center;
  color: var(--muted);
  font-size: 13px;
}
.footer-right a{ color: var(--text); }
.footer-dot{ color: var(--muted); }

.quiet{
  margin-top: 16px;
  color: var(--muted);
}

/* Responsive */
@media (max-width: 940px){
  .hero-grid{ grid-template-columns: 1fr; }
  .cards{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .bullets{ grid-template-columns: 1fr; }
  .two-col{ grid-template-columns: 1fr; }
  .cta-grid{ grid-template-columns: 1fr; }
  .nav{ display: none; }
}

@media (max-width: 520px){
  .section{ padding: 56px 0; }
  .hero{ padding: 64px 0 44px; }
  .cards{ grid-template-columns: 1fr; }
}