:root {
  --primary: #4f6df5;
  --text: #1a1a2e;
  --bg: #fdfdfd;
  --muted: #5a5a6e;
  --radius: 12px;
}

* { box-sizing: border-box; margin: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

/* ---------- header ---------- */

#siteHeader {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, .06);
}

#siteHeader nav {
  max-width: 900px; margin: 0 auto; padding: .9rem 1.5rem;
  display: flex; align-items: center; justify-content: space-between;
}

#brandName {
  font-weight: 700; font-size: 1.05rem;
  color: var(--text); text-decoration: none;
}

#navLinks a {
  color: var(--muted); text-decoration: none;
  margin-left: 1.4rem; font-size: .92rem;
  transition: color .18s ease;
}
#navLinks a:hover { color: var(--primary); }

/* ---------- sections ---------- */

main { max-width: 900px; margin: 0 auto; padding: 0 1.5rem; }

section { padding: 4.5rem 0; border-bottom: 1px solid rgba(0, 0, 0, .05); }
section:last-child { border-bottom: none; }

h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; letter-spacing: -.02em; }
h2 { font-size: 1.6rem; margin-bottom: 1.4rem; letter-spacing: -.01em; }

/* ---------- hero ---------- */

#hero { padding: 6.5rem 0 5.5rem; }

#heroSubtitle {
  font-size: 1.15rem; color: var(--muted);
  max-width: 34rem; margin: 1.1rem 0 2rem;
}

.btn {
  display: inline-block; padding: .7rem 1.5rem;
  background: var(--primary); color: #fff;
  border-radius: 999px; text-decoration: none; font-weight: 600;
  transition: transform .18s ease, box-shadow .18s ease;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px color-mix(in srgb, var(--primary) 35%, transparent);
}

/* ---------- about ---------- */

#aboutBody p { max-width: 40rem; margin-bottom: 1rem; color: var(--muted); }

/* ---------- faq ---------- */

#faqList details {
  border: 1px solid rgba(0, 0, 0, .08);
  border-radius: var(--radius);
  margin-bottom: .8rem;
  overflow: hidden;
  transition: box-shadow .18s ease;
}
#faqList details:hover { box-shadow: 0 2px 10px rgba(0, 0, 0, .05); }

#faqList summary {
  padding: 1rem 1.2rem;
  font-weight: 600; cursor: pointer;
  list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
#faqList summary::-webkit-details-marker { display: none; }
#faqList summary::after {
  content: "+";
  font-size: 1.3rem; color: var(--primary);
  transition: transform .25s ease;
}
#faqList details[open] summary::after { transform: rotate(45deg); }

#faqList .faq-answer {
  padding: 0 1.2rem 1.1rem; color: var(--muted);
}

/* ---------- contact ---------- */

#contactList {
  display: grid; gap: .35rem 1.5rem;
  grid-template-columns: max-content 1fr;
}
#contactList dt { font-weight: 600; }
#contactList dd { color: var(--muted); }

/* ---------- footer ---------- */

footer {
  text-align: center; padding: 2.5rem 1.5rem;
  color: var(--muted); font-size: .88rem;
}

/* ---------- reveal animation ---------- */

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}