* {
  box-sizing: border-box;
}

#arithapp {
  margin: 10px;
  padding: 5px;
  width: 90vw;
  border: 2px solid #777;
  background-color: #efe;
}


#arithapp table {
  border-collapse: collapse;
}

#arithapp tr.answer td {
  border-top: 2px black solid;
  padding-bottom: 5px;
}

#arithapp td {
  text-align: right;
  vertical-align: bottom;
}

#arithapp ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

#arithapp input {
  background-color: inherit;
  width: 5em;
  text-align: right;
  border: none;
  outline: none;
  padding: 0;
  margin: 0;
  font-size: inherit;
  font-family: inherit;
}

#arithapp .correct {
  color: red;
}

#multapp {
  margin: 10px;
  padding: 5px;
  width: 90vw;
  border: 2px solid #777;
  background-color: #fee;
}

#multable {
  border: none;
}

#multable td {
  padding: 3px;
  border: none;
  width: 2em;
  height: 1.6em;
}

#multable td div {
  width: 100%;
  height: 100%;
  background-color: #ccf;
  color: #000;
  text-align: center;
}