:root {
  --bg: #0a0c0f;
  --surface: #111318;
  --surface2: #181c23;
  --border: rgba(255,255,255,0.07);
  --text: #e8eaf0;
  --muted: #8a8f9e;
  --accent: #4fffb0;
  --accent2: #38bdf8;
  --accent3: #f472b6;
  --gold: #f5c842;
  --red: #ff6b6b;
  --yellow: #fbbf24;
  --nav-bg: rgb(10,12,15);
}

[data-theme="light"] {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface2: #f1f5f9;
  --border: rgba(0,0,0,0.08);
  --text: #0f172a;
  --muted: #64748b;
  --accent: #059669;
  --accent2: #0284c7;
  --accent3: #db2777;
  --nav-bg: rgb(248,250,252);
}

* { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-weight: 300;
  overflow-x: hidden;
}

/* ── CANVAS BG ── */
#bg-canvas {
  position: fixed;
  top:0; left:0;
  width:100%; height:100%;
  z-index: 0;
  pointer-events: none;
}

/* ── NAV ── */
nav {
  position: fixed;
  top:0; left:0; right:0;
  z-index: 100;
  padding: 1.2rem 4rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--nav-bg);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
/* hamburger toggle (hidden on desktop) */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  font-size: 1.5rem;
  color: var(--text);
}
.nav-toggle .hamburger,
.nav-toggle .hamburger::before,
.nav-toggle .hamburger::after {
  content: '';
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: transform 0.3s ease, opacity 0.3s ease;
  position: relative;
}
.nav-toggle .hamburger::before,
.nav-toggle .hamburger::after {
  position: absolute;
}
.nav-toggle .hamburger::before {
  top: -6px;
}
.nav-toggle .hamburger::after {
  top: 6px;
}
.nav-toggle.active .hamburger {
  background: transparent;
}
.nav-toggle.active .hamburger::before {
  transform: translateY(6px) rotate(45deg);
}
.nav-toggle.active .hamburger::after {
  transform: translateY(-6px) rotate(-45deg);
}
.theme-toggle {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.2s;
  margin-right: 1.5rem;
}
.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.nav-logo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--accent);
  letter-spacing: 0.05em;
}
.nav-logo h6 { text-align: center;}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
}
.nav-links .link {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 400;
  transition: color 0.2s;
}
.nav-links .link:hover { color: var(--text); }
.nav-cta {
  background: var(--accent);
  color: #0a0c0f;
  padding: 0.55rem 1.4rem;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.2s;
}
.nav-cta:hover { opacity: 0.85; transform: translateY(-1px); }

.nav-back {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: color 0.2s;
}
.nav-back:hover { color: var(--text); }

/* ── BUTTONS ── */
.btn-primary {
  background: var(--accent);
  color: #0a0c0f;
  padding: 0.85rem 2.2rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 0 24px rgba(79,255,176,0.25);
  display: inline-block;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 36px rgba(79,255,176,0.4);
}
.btn-secondary {
  background: transparent;
  color: var(--text);
  padding: 0.85rem 2.2rem;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.95rem;
  text-decoration: none;
  border: 1px solid var(--border);
  transition: border-color 0.2s, background 0.2s;
}
.btn-secondary:hover {
  border-color: rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.04);
}

/* ── BACK TO TOP ── */
#back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
  width: 44px;
  height: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  text-decoration: none;
  transition: all 0.3s;
  opacity: 0;
  visibility: hidden;
  cursor: pointer;
}
#back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
#back-to-top:hover {
  background: var(--accent);
  color: #0a0c0f;
  box-shadow: 0 0 20px rgba(79,255,176,0.3);
  transform: translateY(-3px);
}

/* ── RESPONSIVE NAV ── */
@media (max-width: 768px) {
  nav { padding: 1rem 1.5rem; }
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    flex-direction: column;
    align-items: center;
    padding: 1rem 0;
    gap: 1rem;
  }
  .nav-links.open {
    display: flex;
  }
  .theme-toggle { margin-right: 1rem; }
}

/* ── GRID SECTIONS (Benefits/Bonus) ── */
.grid-section {
  position: relative;
  z-index: 1;
  padding: 6rem 4rem;
  max-width: 1100px;
  margin: 0 auto;
}
.grid-header {
  margin-bottom: 3rem;
  text-align: center;
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.grid-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  transition: border-color 0.2s, transform 0.3s;
}
.grid-card:hover { 
  border-color: var(--accent); 
  transform: translateY(-5px); 
}
.card-icon { font-size: 2rem; margin-bottom: 1.2rem; display: block; }
.card-title { font-family: 'DM Serif Display', serif; font-size: 1.25rem; margin-bottom: 0.75rem; color: var(--text); }
.card-desc { font-size: 0.9rem; color: var(--muted); line-height: 1.6; font-weight: 400; }

@media (max-width: 992px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .grid-section { padding: 4rem 1.5rem; }
  .card-grid { grid-template-columns: 1fr; }
}