:root {
  --bt-blue: #3171de;
  --bt-blue-dark: #1f4fae;
  --bt-grey: #b4b6b6;
  --ink: #0f172a;
  --ink-soft: #475569;
  --bg: #ffffff;
  --bg-soft: #f6f8fc;
  --border: #e2e8f0;
  --radius: 16px;
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--bt-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); }
.brand img { width: 28px; height: 28px; display: block; }
.brand:hover { text-decoration: none; }
.nav { display: flex; align-items: center; gap: 22px; }
.nav a { color: var(--ink-soft); font-size: 15px; font-weight: 500; }
.nav a:hover { color: var(--ink); text-decoration: none; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bt-blue);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  padding: 10px 18px;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.15s ease;
}
.btn:hover { background: var(--bt-blue-dark); text-decoration: none; transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--bt-blue); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--bg-soft); }

/* Hero */
.hero { padding: 96px 0 64px; text-align: center; }
.hero h1 { font-size: clamp(34px, 5vw, 56px); line-height: 1.1; letter-spacing: -0.02em; margin: 0 0 18px; }
.hero p.lead { font-size: clamp(17px, 2.2vw, 21px); color: var(--ink-soft); max-width: 620px; margin: 0 auto 32px; }
.hero .cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* Ticks demo */
.ticks-demo {
  margin: 56px auto 0;
  max-width: 520px;
  display: grid;
  gap: 14px;
}
.tick-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 22px;
  text-align: left;
}
.tick-mark { font-size: 22px; letter-spacing: -2px; color: var(--bt-blue); font-weight: 700; min-width: 48px; }
.tick-card b { display: block; font-size: 16px; }
.tick-card div span { color: var(--ink-soft); font-size: 14px; }

/* Sections */
section { padding: 64px 0; }
section.alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-title { text-align: center; font-size: clamp(26px, 3.5vw, 36px); letter-spacing: -0.02em; margin: 0 0 12px; }
.section-sub { text-align: center; color: var(--ink-soft); max-width: 560px; margin: 0 auto 44px; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}
.card h3 { margin: 0 0 8px; font-size: 17px; }
.card p { margin: 0; color: var(--ink-soft); font-size: 15px; }

/* Privacy highlights */
.privacy-list { list-style: none; padding: 0; margin: 0; max-width: 760px; }
.privacy-list li {
  position: relative;
  padding: 14px 0 14px 36px;
  border-bottom: 1px solid var(--border);
  color: var(--ink-soft);
}
.privacy-list li:last-child { border-bottom: none; }
.privacy-list li::before {
  content: "✓";
  position: absolute;
  left: 4px;
  top: 14px;
  color: var(--bt-blue);
  font-weight: 700;
}
.privacy-list b { color: var(--ink); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 40px 0; color: var(--ink-soft); font-size: 14px; }
.site-footer .container { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.site-footer .links { display: flex; gap: 20px; flex-wrap: wrap; }
.site-footer a { color: var(--ink-soft); }
.site-footer a:hover { color: var(--ink); }

/* Legal / article pages */
.legal { padding: 56px 0 80px; }
.legal .container { max-width: 760px; }
.legal h1 { font-size: clamp(28px, 4vw, 40px); letter-spacing: -0.02em; margin: 0 0 8px; }
.legal .updated { color: var(--ink-soft); font-size: 14px; margin: 0 0 36px; }
.legal h2 { font-size: 20px; margin: 40px 0 10px; letter-spacing: -0.01em; }
.legal p, .legal li { color: var(--ink-soft); }
.legal ul { padding-left: 22px; }
.legal li { margin: 6px 0; }
.legal a { font-weight: 500; }

@media (max-width: 640px) {
  .nav a:not(.btn) { display: none; }
  .hero { padding: 64px 0 48px; }
}