/* ============================================================
   Reverse Math Puzzle — Shared Stylesheet
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;500;600;700;800;900&display=swap');

:root {
  --navy:        #1e3a5f;
  --navy-dark:   #122438;
  --blue:        #2d6fa4;
  --gold:        #ffcb05;
  --gold-dark:   #e6b700;
  --orange:      #ff7b00;
  --surface:     #ffffff;
  --bg:          #f0f5fb;
  --bg-card:     #ffffff;
  --text:        #1a2b3c;
  --text-muted:  #5a7a9a;
  --border:      #ddeaf7;
  --radius-sm:   8px;
  --radius-md:   14px;
  --radius-lg:   22px;
  --radius-xl:   32px;
  --shadow-sm:   0 2px 8px rgba(30,58,95,0.08);
  --shadow-md:   0 8px 28px rgba(30,58,95,0.12);
  --shadow-lg:   0 20px 60px rgba(30,58,95,0.18);
  --transition:  0.25s ease;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Nunito', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ── NAV ──────────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--navy);
  white-space: nowrap;
}
.nav-logo img {
  width: 36px;
  height: 36px;
  border-radius: 9px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}
.nav-links a {
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover { color: var(--navy); background: var(--bg); }
.nav-links a.active { color: var(--navy); }
.nav-cta {
  background: var(--gold) !important;
  color: var(--navy) !important;
  border-radius: var(--radius-sm) !important;
  font-weight: 800 !important;
  padding: 8px 18px !important;
  transition: background var(--transition), transform var(--transition) !important;
}
.nav-cta:hover { background: var(--gold-dark) !important; transform: translateY(-1px) !important; }

/* Hamburger */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  margin-left: auto;
  flex-direction: column;
  gap: 5px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-menu {
  display: none;
  flex-direction: column;
  gap: 2px;
  padding: 12px 24px 20px;
  background: #fff;
  border-bottom: 1px solid var(--border);
}
.mobile-menu a {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.95rem;
}
.mobile-menu a.nav-cta {
  margin-top: 8px;
  text-align: center;
  background: var(--gold);
  color: var(--navy);
}

/* ── FOOTER ───────────────────────────────────────────────── */
.site-footer {
  background: var(--navy-dark);
  color: rgba(255,255,255,0.7);
  padding: 48px 24px 32px;
}
.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px;
  align-items: start;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 800;
  font-size: 1rem;
  margin-bottom: 10px;
}
.footer-brand img { width: 32px; height: 32px; border-radius: 8px; }
.footer-tagline { font-size: 0.85rem; margin-bottom: 0; }
.footer-links {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}
.footer-links a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.6);
  transition: color var(--transition);
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  max-width: 1120px;
  margin: 24px auto 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.82rem;
  color: rgba(255,255,255,0.4);
  text-align: center;
}

/* ── BUTTONS ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-weight: 800;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: var(--gold);
  color: var(--navy-dark);
  box-shadow: 0 4px 14px rgba(255,203,5,0.4);
}
.btn-primary:hover { background: var(--gold-dark); box-shadow: 0 6px 20px rgba(255,203,5,0.5); }
.btn-dark {
  background: var(--navy);
  color: #fff;
  box-shadow: 0 4px 14px rgba(30,58,95,0.3);
}
.btn-dark:hover { background: var(--navy-dark); }
.btn-outline {
  background: transparent;
  color: var(--navy);
  border: 2px solid var(--border);
}
.btn-outline:hover { border-color: var(--blue); background: var(--bg); }
.btn-lg { padding: 16px 36px; font-size: 1.05rem; }
.btn-sm { padding: 9px 20px; font-size: 0.85rem; }

/* Store badges */
.store-badges { display: flex; gap: 14px; flex-wrap: wrap; }
.store-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: #111;
  color: #fff;
  padding: 11px 20px;
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: 0.9rem;
  transition: background var(--transition), transform var(--transition);
  border: 1.5px solid rgba(255,255,255,0.15);
}
.store-badge:hover { background: #222; transform: translateY(-2px); }
.store-badge svg { flex-shrink: 0; }
.store-badge-sub { font-size: 0.68rem; font-weight: 500; opacity: 0.75; display: block; }
.store-badge-main { font-size: 0.92rem; font-weight: 800; display: block; line-height: 1.1; }

/* ── SECTION HELPERS ──────────────────────────────────────── */
.section { padding: 80px 24px; }
.section-inner { max-width: 1120px; margin: 0 auto; }
.section-label {
  display: inline-block;
  background: rgba(45,111,164,0.1);
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 14px;
}
.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 900;
  color: var(--navy);
  line-height: 1.2;
  margin-bottom: 16px;
}
.section-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 560px;
  line-height: 1.7;
}
.text-center { text-align: center; }
.text-center .section-sub { margin: 0 auto; }

/* ── CARDS ────────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

/* ── PAGE HERO (inner pages) ──────────────────────────────── */
.page-hero {
  background: linear-gradient(135deg, var(--navy-dark) 0%, var(--navy) 100%);
  padding: 60px 24px;
  text-align: center;
  color: #fff;
}
.page-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  margin-bottom: 12px;
}
.page-hero p {
  font-size: 1.05rem;
  opacity: 0.75;
}

/* ── PROSE (legal pages) ──────────────────────────────────── */
.prose {
  max-width: 780px;
  margin: 0 auto;
  padding: 60px 24px 80px;
}
.prose h2 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--navy);
  margin: 36px 0 10px;
}
.prose h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy);
  margin: 24px 0 8px;
}
.prose p { margin-bottom: 14px; color: var(--text); }
.prose ul {
  list-style: disc;
  padding-left: 22px;
  margin-bottom: 14px;
}
.prose ul li { margin-bottom: 6px; }
.prose a { color: var(--blue); text-decoration: underline; }
.prose .updated {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  display: block;
}
.prose .callout {
  background: rgba(45,111,164,0.08);
  border-left: 4px solid var(--blue);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px;
  margin: 24px 0;
}
.prose .callout p { margin: 0; }

/* ── ANIMATIONS ───────────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ── RESPONSIVE ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .mobile-menu.open { display: flex; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-links { align-items: flex-start; }
  .section { padding: 56px 20px; }
}