.contenedor {
  width: 90%;
  margin: 0 auto;
  background-color: lightblue;
  text-align: center;
  overflow: hidden; 
}

.caja {
  float: left;
  width: 15%;      
  height: 100px;   
  margin: 0.5%;
  display: flex;
  justify-content: center;
  align-items: center;
  color: black;    
  font-weight: bold;
  font-size: 2.5em;
  box-sizing: border-box;
}

.caja1 { 
  background: linear-gradient(to bottom, lightgreen, darkgreen); 
  justify-content: left;
  padding-left: 10px;
}

.caja2 { 
  background: radial-gradient(circle, lightyellow, orange, red); 
}

.caja3 { 
  background: linear-gradient(to bottom, skyblue, navy); 
  overflow: hidden; 
  justify-content: flex-start;
}

.caja3 img { 
  max-width: 100%; 
  max-height: 100%; 
  object-fit: contain; 
}

.caja4 { 
  background: radial-gradient(circle, lightgray, black); 
  overflow: hidden; 
  justify-content: flex-start;
}

.caja4 img { 
  max-width: 100%; 
  max-height: 100%; 
  object-fit: contain; 
}

.caja5 { 
  background: linear-gradient(to bottom, lightcoral, darkred); 
  justify-content: flex-start;
  padding-left: 10px;
}

.caja6 { 
  background: radial-gradient(circle, lightblue, darkblue); 
}