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

body {
  font-family: Arial, Helvetica, sans-serif;
  background: #e5e5e5;
  color: #000;
}

/* HEADER */
#site-header {
  width: 900px;
  margin: 20px auto;
  background: #ffffff;
  border: 1px solid #999;
  padding: 15px;
}

#site-header h1 {
  font-size: 32px;
  color: #003399;
}

#site-header p {
  font-size: 14px;
  color: #444;
}

/* SECCIONES */
section {
  width: 900px;
  margin: 20px auto;
  background: #ffffff;
  border: 1px solid #999;
  padding: 15px;
}

h2 {
  font-size: 20px;
  margin-bottom: 10px;
  color: #003399;
}

/* USUARIOS */
#usuarios ul {
  list-style: none;
  display: flex;
  gap: 20px;
}

#usuarios li {
  text-align: center;
}

#usuarios img {
  width: 90px;
  height: 90px;
  border: 1px solid #666;
}

/* POSTS */
.post {
  border-top: 1px solid #ccc;
  padding: 10px 0;
}

.post:first-child {
  border-top: none;
}

.post img {
  max-width: 100%;
  border: 1px solid #666;
}

.post a {
  color: #003399;
  font-size: 13px;
}