:root {
  --fondo-principal: linear-gradient(
    to right,
    #f1f509 0%,
    #dd2b2b 50%,
    #fcf700 100%
  );

  --fondo-footer: linear-gradient(
    to right,
    #f1f509 0%,
    #dd2b2b 50%,
    #fcf700 100%
  );
}

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

html {
  font-size: 62, 5%;
}

header {
  position: sticky;
  top: 0;
  z-index: 1;
  
}

nav {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  background: var(--fondo-principal);
  
}

nav img {
  height: 10rem;
}

main {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  
}

.container {
  margin: 3rem;
  width: 10rem;
  height: 20rem;
  border-radius: 2rem;
  box-shadow: 3px 2px 15px -1px #000000;
  
  
  
}

.container:hover {
  transform: scale(1.1);
}

.container img {
  width: 100%;
  height: 100%;
  border-radius: 1rem;
  filter: grayscale(100%);
  transition-property: filter;
  transition-duration: 1s;
}


.container:hover img {
  filter: grayscale(0%);
}


.footer {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 15rem;
  background: var(--fondo-footer);
  position: relative;
  display: inline-block;
  
}

.footer img {
  display: flex;
  justify-content: center;
  width: 100%;
  height: 15rem;
  
}

.footer small {
  position: absolute;
  top: 90%;
  left: 5%;
  color: rgb(7, 7, 7);
  font-size: large;
}