body {
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.5;
  margin: 0;
  padding: 0 1rem;
}
header { padding: 1rem 0; }
nav a { margin-right: 1rem; text-decoration: none; color: #1a5a7a; }
img.thumbnail { height: 100px; width: 200px; }
.container { max-width: 900px; margin: 0 auto; }
h1, h2, h3 { color: #1a5a7a; }
hr { border: none; border-top: 1px solid #ddd; margin: 1.5rem 0; }
.step img { display:block;  width: 200px;  height:150px; margin-top:0.5rem; }
.result-image { width: 500px; max-width: 100%; height: auto; }
.back-link { display:inline-flex; align-items:center; gap:0.4rem; margin-bottom:1rem; }
footer { margin: 2rem 0; font-size:0.9rem; color:#666; }

.index-img {
  height: 100px;
  width: auto;
  display: block;
  margin: 10px auto;
}

.primer-pas-img {
    width: auto;
    height: 200px;
    display: block;
    margin: 10px;
}