* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: Arial, sans-serif;
  background-color: #F6F6F6;
}

.center {
  text-align: center;
}

h1 {
  font-size: 2em;
  margin-bottom: 20px;
}

img {
  max-width: 100%;
  height: auto;
}