/* ---------- Reset ---------- */
* { margin:0; padding:0; box-sizing:border-box; }
html, body {
  height:100%;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height:1.5;
  transition: background .3s, color .3s;
}

/* ---------- Light theme (default) ---------- */
:root {
  --bg: #ffffff;
  --text: #111827;
  --nav-bg: #f3f4f6;
  --card-bg: #f9fafb;
  --muted: #6b7280;
  --primary: #2563eb;
  --hero-bg: linear-gradient(135deg, #f0f4ff, #ffffff);
}

/* ---------- Dark theme overrides ---------- */
body.dark {
  --bg: #0b1220;
  --text: #f9fafb;
  --nav-bg: #0b1220;
  --card-bg: #1f2937;
  --muted: #9ca3af;
  --primary: #3b82f6;
  --hero-bg: linear-gradient(135deg, #0b1220, #1a2238);
}

/* ---------- General ---------- */
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
section { padding: 60px 0; }
.container { width: min(1100px, 92%); margin-inline: auto; }

/* ---------- Navbar ---------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  box-shadow: 0 2px 6px rgba(0,0,0,.12);
  transition: background .3s;
}
.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo img { height: 64px; width: auto; display:block; }
.nav-links { display: flex; gap: 24px; list-style: none; }
.nav-links a { color: var(--text); font-weight: 500; }
.nav-links a:hover { color: var(--primary); }
.toggle-btn {
  background:none; border:none; color:var(--text);
  font-size:1.5rem; cursor:pointer; margin-left:20px;
}

/* ---------- Hero Section ---------- */
.hero {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 60px 20px;
  background: var(--hero-bg);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background-image: radial-gradient(rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}
.hero h1 {
  font-size: 3rem;
  color: var(--text);
  margin-bottom: 16px;
  position: relative;
}
.hero p {
  font-size: 1.25rem;
  color: var(--muted);
  max-width: 700px;
  margin: 0 auto 24px;
  position: relative;
}
.hero .btn-group {
  display: flex;
  gap: 16px;
  justify-content: center;
  position: relative;
}

/* ---------- Features Section ---------- */
.features {
  padding: 80px 20px;
  background: var(--bg);
  color: var(--text);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 30px 20px;
  text-align: center;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  transition: transform .2s ease, box-shadow .2s ease;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.12);
}
.feature-card .icon {
  margin-bottom: 16px;
  color: var(--primary);
}
.feature-card svg {
  width: 40px;
  height: 40px;
  stroke: currentColor;
}
.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}
.feature-card p {
  font-size: 0.95rem;
  color: var(--muted);
}

/* ---------- Buttons ---------- */
.btn { display:inline-block; padding:10px 16px; border-radius:8px; font-weight:600; text-align:center; }
.btn-primary { background:var(--primary); color:#fff; }
.btn-primary:hover { filter:brightness(1.05); }
.btn-outline { border:1px solid var(--muted); color:var(--text); background:transparent; }
.btn-outline:hover { background:var(--card-bg); }

/* ---------- Section headers ---------- */
.section-head { text-align:center; margin-bottom:32px; }
.section-head h2 { font-size:2rem; margin-bottom:8px; }
.section-head p { color: var(--muted); }

/* ---------- Footer ---------- */
.footer { background: var(--nav-bg); color: var(--text); padding-top: 40px; }
.footer__wrap {
  display:grid; grid-template-columns:1fr 2fr; gap:24px;
  max-width:1100px; margin:0 auto; padding:0 20px 40px;
}
.footer__logo { font-weight:700; font-size:20px; }
.footer__links { display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.footer__links h4 { margin-bottom:10px; font-size:14px; text-transform:uppercase; color:var(--muted); }
.footer__links a { display:block; padding:4px 0; color:var(--text); }
.footer__links a:hover { color:var(--primary); }
.footer__bar { border-top:1px solid var(--muted); padding:14px 20px; text-align:center; font-size:14px; color:var(--muted); }

/* ---------- Responsive ---------- */
@media (max-width:768px){
  .nav-links{ display:none; }
  .footer__wrap{ grid-template-columns:1fr; }
  .footer__links{ grid-template-columns:repeat(2,1fr); }
}
@media (max-width:480px){
  .footer__links{ grid-template-columns:1fr; }
}