/* ══════════════════════════════════════════
   SHARED STYLES — The AI Math Guy
   Used by: index.html, guest-guide.html
   ══════════════════════════════════════════ */

/* ── RESET & VARIABLES ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg-deep: #090909;
  --bg-primary: #0D0D0D;
  --bg-elevated: #141414;
  --bg-card: #1A1A1A;
  --accent: #C0392B;
  --accent-bright: #E74C3C;
  --accent-glow: rgba(192, 57, 43, 0.15);
  --gold: #D4A537;
  --white: #FFFFFF;
  --gray-100: #F0F0F0;
  --gray-200: #D0D0D0;
  --gray-300: #A0A0A0;
  --gray-400: #707070;
  --font-display: 'Bebas Neue', sans-serif;
  --font-serif: 'Cormorant Garamond', serif;
  --font-body: 'DM Sans', sans-serif;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg-deep);
  color: var(--gray-200);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── NAV ── */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(9,9,9,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.04);
  transition: all 0.4s ease;
}
nav.scrolled { padding: 0.7rem 2rem; background: rgba(9,9,9,0.95); }
.nav-brand {
  font-family: var(--font-display);
  font-size: 1.3rem;
  letter-spacing: 3px;
  color: var(--white);
  text-decoration: none;
}
.nav-brand span { color: var(--accent); }
.nav-links { display: flex; gap: 2rem; list-style: none; }
.nav-links a {
  color: var(--gray-300);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 1px;
  text-transform: uppercase;
  transition: color 0.3s;
}
.nav-links a:hover { color: var(--white); }
.nav-back {
  color: var(--gray-300);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 1px;
  text-transform: uppercase;
  transition: color 0.3s;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.nav-back:hover { color: var(--white); }

@media (max-width: 768px) {
  .nav-links { display: none; }
  nav { padding: 0.8rem 1.2rem; }
}

/* ── SHARED LAYOUT ── */
section { position: relative; }

.section-label {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 4px;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}

.section-number {
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 4px;
  color: var(--accent);
  opacity: 0.6;
  margin-bottom: 0.8rem;
}

/* ── BUTTONS ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 2rem;
  border-radius: 6px;
  text-decoration: none;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.5px;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--accent);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--accent-bright);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(192, 57, 43, 0.3);
}
.btn-outline {
  background: transparent;
  color: var(--gray-200);
  border: 1.5px solid var(--gray-400);
}
.btn-outline:hover {
  border-color: var(--white);
  color: var(--white);
  transform: translateY(-2px);
}

/* ── ANIMATIONS ── */
.fade-up {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── FOOTER ── */
footer {
  padding: 3rem 2rem;
  background: var(--bg-deep);
  border-top: 1px solid rgba(255,255,255,0.04);
  text-align: center;
}
.footer-info {
  font-size: 0.9rem;
  color: var(--gray-400);
  margin-bottom: 1.5rem;
  line-height: 1.8;
}
.footer-info strong { color: var(--gray-200); font-weight: 600; }
.footer-socials {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  margin-bottom: 1.5rem;
}
.footer-socials a {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gray-300);
  text-decoration: none;
  transition: all 0.3s;
}
.footer-socials a:hover {
  border-color: var(--accent);
  color: var(--white);
  background: rgba(192,57,43,0.1);
}
.footer-socials a svg { width: 18px; height: 18px; fill: currentColor; }
.footer-copy {
  font-size: 0.78rem;
  color: var(--gray-400);
  letter-spacing: 1px;
}

/* ── DIVIDER ── */
.section-divider {
  height: 1px;
  background: linear-gradient(to right, transparent, rgba(255,255,255,0.06), transparent);
  margin: 0 auto;
}

/* ── GRAIN OVERLAY ── */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
  opacity: 0.5;
}