body {
  margin: 0;
  font-family: Verdana, Geneva, Tahoma, sans-serif;
  font-size: 1.1em;
}

/* Page Header Styles */
.page-header {
  max-width: 1200px;   
  margin: 0 auto;      
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 1em 0 1em;
}

.page-header h1 {
  font-family: 'Courier New', Courier, monospace;
}

.page-header img {
  max-width: 50%;
}
/* End Page Header Styles */

/* Main Container Styles */
.container {
  max-width: 1200px;   /* 960, 1100, 1200, 1280 */
  margin: 0 auto;       
  display: grid;
  /*  grid-template-columns: auto auto auto; */
  grid-template-columns: auto;
  background-color: white;
  padding: .3em;
  gap: 1em;
}

.container article {
  background-color: #f1f1f1;
  padding: 1em;
  font-size: 1em;
}

/* Standard item styles */
.page-article {
  text-align  : left;
}

.page-picture {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 1em 0 1em;
  gap: 1em;
}

.picture {
  margin: 0 1em 0 1em;
}

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

/*spceific item styles*/
#equilibrium {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  object-fit: contain;
}

/* Footer Styles */
footer {
  border-top: 1px solid black;
  background: #ddd;
  text-align: center;
  padding: 1em;
  margin-top: 1em;
}

@media (max-width: 768px) {

  .header {
    flex-direction: column;
    gap: .3em;
  }

  .page-picture {
    flex-direction: column;
  }
}