Scrollbar jumps up on backspace hiding current line

If the console window grows so that the input is at the bottom of the screen, pressing backspace causes the scrollbars to jump up one line thus hiding the current input behind the footer
.

This appears to be caused by a calc in the following section of the css:

```
.split {
display: flex;
flex-direction: column;
min-height: calc(100vh - 64px - 40px); }
@media screen and (max-width: 1024px) {
.split {
min-height: calc(100vh - 56px - 40px); } }
.split .flex {
flex: 1 1 calc(50vh - 64px - 40px);
/* IE */
/* FF scroll */
min-height: 0; }
@media screen and (max-width: 1024px) {
.split .flex {
flex: 1 1 calc(50vh - 56px - 40px); } }
@media all and (-ms-high-contrast: none), (-ms-high-contrast: active) {
.split .flex {
height: calc(50vh - 64px - 40px); } }
```

Start with the cited CSS section for .split and .split .flex, then reproduce the issue with the console input at the bottom of the window. Check the calc-based sizing while pressing backspace. Done means the scrollbar no longer jumps up and the current input remains visible above the footer.

Written by the indexing model from the issue text.