simple-keyboard/src/demo/css/FullKeyboardDemo.css

input {
  width: 100%;
  height: 100px;
  padding: 20px;
  font-size: 20px;
  border: none;
  box-sizing: border-box;
}

.keyboardContainer {
  display: flex;
  background-color: rgba(0, 0, 0, 0.1);
  justify-content: center;
  width: 1024px;
  border-radius: 5px;
}

.simple-keyboard.hg-theme-default {
  display: inline-block;
}

.simple-keyboard-main.simple-keyboard {
  width: 640px;
  min-width: 640px;
  background: none;
}

.simple-keyboard-main.simple-keyboard .hg-row:first-child {
  margin-bottom: 10px;
}

.simple-keyboard-arrows.simple-keyboard {
  align-self: flex-end;
  background: none;
}

.simple-keyboard .hg-button.selectedButton {
  background: rgba(5, 25, 70, 0.53);
  color: white;
}

.simple-keyboard .hg-button.emptySpace {
  pointer-events: none;
  background: none;
  border: none;
  box-shadow: none;
}

.simple-keyboard-arrows .hg-row {
  justify-content: center;
}

.simple-keyboard-arrows .hg-button {
  width: 50px;
  flex-grow: 0;
  justify-content: center;
  display: flex;
  align-items: center;
}

.controlArrows {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-flow: column;
}

.simple-keyboard-control.simple-keyboard {
  background: none;
}

.simple-keyboard-control.simple-keyboard .hg-row:first-child {
  margin-bottom: 10px;
}

.simple-keyboard-control .hg-button {
  width: 50px;
  flex-grow: 0;
  justify-content: center;
  display: flex;
  align-items: center;
}

.numPad {
  display: flex;
  align-items: flex-end;
}

.simple-keyboard-numpad.simple-keyboard {
  background: none;
}

.simple-keyboard-numpad.simple-keyboard {
  width: 160px;
}

.simple-keyboard-numpad.simple-keyboard .hg-button {
  width: 50px;
  justify-content: center;
  display: flex;
  align-items: center;
}

.simple-keyboard-numpadEnd.simple-keyboard {
  width: 50px;
  background: none;
  margin: 0;
  padding: 5px 5px 5px 0;
}

.simple-keyboard-numpadEnd.simple-keyboard .hg-button {
  align-items: center;
  justify-content: center;
  display: flex;
}

.simple-keyboard-numpadEnd .hg-button.hg-standardBtn.hg-button-plus {
  height: 85px;
}

.simple-keyboard-numpadEnd.simple-keyboard .hg-button.hg-button-enter {
  height: 85px;
}

.simple-keyboard.hg-theme-default .hg-button.hg-selectedButton {
  background: rgba(5, 25, 70, 0.53);
  color: white;
}

.hg-button.hg-functionBtn.hg-button-space {
  width: 350px;
}