/* Frontier Labs — light minimal style.
   Inspired by Linear, Vercel, Stripe. Sharp typography, generous
   whitespace, single accent color. */

:root {
  --bg: #ffffff;
  --bg-soft: #fafafa;
  --bg-tint: #f4f4f5;
  --border: #e6e6e8;
  --border-strong: #d4d4d8;

  --text: #0a0a0a;
  --text-muted: #5a5a63;
  --text-soft: #8a8a92;

  --accent: #1f2937;
  --accent-hover: #0a0f1a;

  --radius: 10px;
  --radius-lg: 16px;

  --max: 1080px;
  --pad: 24px;

  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", system-ui, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Inter", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--text); text-decoration: none; }
a:hover { color: var(--accent-hover); }

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

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding-left: var(--pad);
  padding-right: var(--pad);
}

/* Top nav */

.nav {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 16px;
  letter-spacing: -0.01em;
}

.brand .dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent);
  margin-right: 10px;
  vertical-align: middle;
  transform: translateY(-1px);
}

.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
  transition: color 0.15s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

/* Hero */

.hero {
  padding: 96px 0 64px;
}

.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-soft);
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-soft);
  margin-bottom: 20px;
}

.h-display {
  font-family: var(--font-display);
  font-size: clamp(36px, 6vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  font-weight: 700;
  margin: 0 0 24px;
  max-width: 22ch;
}

.h-subhead {
  font-size: 18px;
  line-height: 1.55;
  color: var(--text-muted);
  max-width: 62ch;
  margin: 0 0 32px;
}

.cta-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 14px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.1s;
  font-family: var(--font);
}

.btn:active { transform: scale(0.98); }

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-strong);
}
.btn-ghost:hover {
  background: var(--bg-soft);
}

/* Section */

.section {
  padding: 72px 0;
  border-top: 1px solid var(--border);
}

.section-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-soft);
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  font-weight: 700;
  margin: 0 0 20px;
  max-width: 24ch;
}

.section-lede {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 60ch;
  margin: 0 0 32px;
}

/* Card grid */

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color 0.15s, transform 0.15s;
}

.card:hover {
  border-color: var(--border-strong);
}

.card h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

.card p {
  font-size: 15px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.55;
}

.card .icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--bg-tint);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  margin-bottom: 16px;
}

/* Product feature row */

.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
  padding: 56px 0;
  border-top: 1px solid var(--border);
}

.feature-row:first-of-type {
  border-top: none;
}

.feature-row.flip > .feature-text { order: 2; }
.feature-row.flip > .feature-visual { order: 1; }

.feature-text h3 {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.015em;
  margin: 0 0 12px;
}

.feature-text p {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.6;
  margin: 0;
}

.feature-visual {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  aspect-ratio: 4 / 3;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 44px;
  color: var(--text-soft);
}

@media (max-width: 760px) {
  .feature-row {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .feature-row.flip > .feature-text { order: 1; }
  .feature-row.flip > .feature-visual { order: 0; }
}

/* Prose (about/legal) */

.prose {
  max-width: 68ch;
  margin: 0 auto;
}

.prose h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 48px);
  letter-spacing: -0.02em;
  font-weight: 700;
  line-height: 1.1;
  margin: 0 0 12px;
}

.prose .lede {
  font-size: 19px;
  color: var(--text-muted);
  margin: 0 0 40px;
}

.prose h2 {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 40px 0 12px;
}

.prose h3 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  margin: 28px 0 8px;
}

.prose p, .prose li {
  font-size: 16px;
  line-height: 1.65;
  color: #1f1f23;
  margin: 0 0 14px;
}

.prose ul, .prose ol {
  padding-left: 24px;
  margin: 0 0 14px;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 40px 0;
}

.prose a {
  color: var(--accent);
  border-bottom: 1px solid var(--border-strong);
}

.prose a:hover {
  border-bottom-color: var(--accent);
}

/* Contact form */

.form {
  max-width: 560px;
  margin: 0 auto;
}

.form label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin: 16px 0 6px;
}

.form input,
.form textarea {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font: inherit;
  color: var(--text);
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.form input:focus,
.form textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(31, 41, 55, 0.1);
}

.form textarea {
  min-height: 140px;
  resize: vertical;
  font-family: var(--font);
}

.form button {
  margin-top: 20px;
}

/* Footer */

.footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 48px 0 64px;
  margin-top: 96px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 32px;
  font-size: 14px;
  color: var(--text-muted);
}

.footer-inner a {
  color: var(--text-muted);
  margin-right: 20px;
  font-weight: 500;
}

.footer-inner a:hover {
  color: var(--text);
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text);
}

.footer-meta {
  font-size: 13px;
  color: var(--text-soft);
}

/* Tiny utilities */

.muted { color: var(--text-muted); }
.center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-8 { margin-top: 8px; }
.mt-24 { margin-top: 24px; }

@media (max-width: 600px) {
  .nav-links { gap: 16px; }
  .hero { padding: 56px 0 32px; }
  .section { padding: 48px 0; }
}