body {
  font-family: Inter, system-ui, sans-serif;
  margin: 0;
  background: #f5f7fa;
  color: #222;
}

header {
  background: #1e293b;
  color: white;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header h1 {
  margin: 0;
  font-size: 20px;
}
header h1 a {
  color: white;
  text-decoration: none;
}
header nav a {
  color: #e2e8f0;
  margin-left: 16px;
  text-decoration: none;
}
header nav a:hover {
  text-decoration: underline;
}

main {
  max-width: 1600px;
  margin: 40px auto;
  padding: 0 20px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
}

.tool-card {
  background: white;
  padding: 16px;
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, box-shadow 0.2s;
}
.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.12);
}

footer {
  background: #f1f5f9;
  text-align: center;
  padding: 20px;
  font-size: 13px;
  color: #64748b;
  margin-top: 40px;
}