:root {
  --blue: #0f3d91;
  --green: #1db954;
  --dark: #0f172a;
  --light-bg: #ffffff;
}

body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: var(--light-bg);
  color: var(--dark);
  text-align: center;
}

header {
  padding: 2rem;
  background: #f8fafc;
}

header h1 {
  font-size: 2rem;
  color: var(--blue);
}

img.mockup {
  max-width: 1000px;   /* limit maximum size */
  width: 100%;         /* responsive */
  height: auto;
  display: block;
  margin: 0 auto;
  box-shadow: 0 4px 10px rgba(0,0,0,.1);
}

.counter {
  margin: 2rem 0;
  font-size: 1.2rem;
  color: var(--green);
}