html {
  /* The number of cells in the width of the grid */
  --grid-width: 10;
}

body {
  margin: 0;
  background: #458;
  display: flex;
  justify-content: center;
  font-family: sans-serif;
}

main {
  display: flex;
  flex-flow: column;
  --content-width: 750px;
  width: var(--content-width);
  --page-padding: 40px;
  min-height: 100vh;
  background: white;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
}

#page-title {
  background: #ddd;
  padding: 10px var(--page-padding);
  margin: 0;
  font-size: 1.5rem;
}

@media print {
  #page-title {
    display: none;
  }
}

#options {
  display: flex;
  background: #ddd;
  padding: 12px var(--page-padding);
}

@media print {
  #options {
    display: none;
  }
}

#amount-filled-in-label {
  font-size: 1.05rem;
  padding-top: 5px;
}

#refresh, #print {
  background: none;
  border: 1px solid transparent;
  opacity: 0.8;
  cursor: pointer;
  border-radius: 2px;
  padding-top: 3px;
}

#refresh:hover, #print:hover {
  background: #eee;
  border: 1px solid #555;
}

#refresh:active, #print:active {
  box-shadow: 0 0 14px rgba(0, 0, 0, 0.15) inset, 0 0 2px rgba(0, 0, 0, 0.5) inset;
}

#refresh>img, #print>img {
  width: 20px;
}

#content-title {
  margin: 30px var(--page-padding);
  color: #222;
  font-size: 1.8rem;
}

#grid {
  display: grid;
  grid-template-columns: repeat(var(--grid-width), 1fr);
  margin-left: var(--page-padding);
  --grid-size: calc(var(--content-width) - calc(var(--page-padding) * 2));
  --border-settings: 1px solid black;
  width: var(--grid-size);
  height: var(--grid-size);
  border-bottom: var(--border-settings);
  border-right: var(--border-settings);
  margin-bottom: 30px;
}

#grid .cell {
  display: flex;
  justify-content: center;
  align-items: center;
  border-top: var(--border-settings);
  border-left: var(--border-settings);
  font-size: 2rem;
}

#grid .cell.hidden {
  color: transparent;
  user-select: none;
}

.hoz-spacer {
  flex: 1;
}