:root {
  --primary: #0f172a;
  --accent: #2563eb;
  --bg: #f8fafc;
  --text: #334155;
  --white: #ffffff;
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: system-ui, -apple-system, sans-serif; }
body { background-color: var(--bg); color: var(--text); line-height: 1.6; }

/* Header & Navigation */
header { background: var(--white); border-bottom: 1px solid #e2e8f0; padding: 1rem 5%; display: flex; justify-content: space-between; align-items: center; position: sticky; top: 0; z-index: 100; }
.logo { font-size: 1.25rem; font-weight: 700; color: var(--primary); text-decoration: none; }
nav a { margin-left: 1.5rem; text-decoration: none; color: var(--text); font-weight: 500; transition: color 0.2s; }
nav a:hover { color: var(--accent); }

/* Hero Section */
.hero { background: var(--primary); color: var(--white); padding: 5rem 5%; text-align: center; }
.hero h1 { font-size: 2.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.1rem; color: #cbd5e1; max-width: 600px; margin: 0 auto 2rem; }
.btn { display: inline-block; background: var(--accent); color: var(--white); padding: 0.75rem 1.75rem; border-radius: 6px; text-decoration: none; font-weight: 600; }

/* Sections & Grid */
.container { max-width: 1100px; margin: 0 auto; padding: 4rem 5%; }
.section-title { text-align: center; font-size: 1.8rem; color: var(--primary); margin-bottom: 2.5rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }
.card { background: var(--white); padding: 2rem; border-radius: 8px; border: 1px solid #e2e8f0; }
.card h3 { color: var(--primary); margin-bottom: 0.75rem; }

/* Footer */
footer { background: var(--primary); color: #94a3b8; text-align: center; padding: 2rem 5%; margin-top: 3rem; font-size: 0.9rem; }