:root {
  --primary: #2563eb;
  --dark: #0f172a;
  --light: #f8fafc;
  --card: #ffffff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: var(--light);
  color: var(--dark);
}

/* HEADER */
header {
  background: linear-gradient(135deg, #2563eb, #1e40af);
  color: white;
  padding: 40px 20px;
  text-align: center;
}

/* NAVBAR */
nav {
  background: var(--dark);
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}

nav a {
  color: white;
  text-decoration: none;
  padding: 12px 16px;
}

nav a:hover {
  background: #1e293b;
}

/* LAYOUT */
.container {
  max-width: 1100px;
  margin: auto;
  padding: 20px;
}

/* GRID */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

/* CARD */
.card {
  background: var(--card);
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.08);
  text-align: center;
  transition: 0.3s;
}

.card:hover {
  transform: translateY(-6px);
}

.card a {
  text-decoration: none;
  color: var(--dark);
  font-size: 18px;
  font-weight: 600;
}

/* BUTTON */
.btn {
  display: inline-block;
  margin-top: 10px;
  padding: 10px 18px;
  background: var(--primary);
  color: white;
  border-radius: 8px;
  text-decoration: none;
}

/* FOOTER */
footer {
  background: var(--dark);
  color: white;
  text-align: center;
  padding: 15px;
  margin-top: 40px;
}

/* MOBILE FIX */
@media (max-width: 600px) {
  header {
    padding: 30px 10px;
  }
}