input.css

.copilotKitInput {
  border-top: 1px solid var(--copilot-kit-input-separator-color);
  padding-left: 2rem;
  padding-right: 2.5rem;
  padding-top: 1rem;
  padding-bottom: 1rem;
  display: flex;
  align-items: center;
  cursor: text;
  position: relative;
  border-bottom-left-radius: 0.75rem;
  border-bottom-right-radius: 0.75rem;
  background-color: var(--copilot-kit-input-background-color);
}

.copilotKitInput > button {
  position: absolute;
  right: 0.5rem;
  padding: 0.25rem;
  cursor: pointer;
  transition-property: transform;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
  transition-duration: 200ms;
  transform: scale(1);
  color: rgba(0, 0, 0, 0.25);
  -webkit-appearance: button;
  appearance: button;
  background-color: transparent;
  background-image: none;
  text-transform: none;
  font-family: inherit;
  font-size: 100%;
  font-weight: inherit;
  line-height: inherit;
  border: 0;
  margin: 0;
  text-indent: 0px;
  text-shadow: none;
  display: inline-block;
  text-align: center;
}

.copilotKitInput > button:not([disabled]) {
  color: var(--copilot-kit-input-send-button-color);
}

.copilotKitInput > button:not([disabled]):hover {
  transform: scale(1.1);
}

.copilotKitInput > button[disabled] {
  color: var(--copilot-kit-input-send-button-disabled-color);
}

.copilotKitInput > textarea {
  width: 100%;
  outline: 2px solid transparent;
  outline-offset: 2px;
  resize: none;
  white-space: pre-wrap;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  cursor: text;
  font-size: 0.875rem;
  line-height: 1.25rem;
  margin: 0;
  padding: 0;
  font-family: inherit;
  font-weight: inherit;
  color: var(--copilot-kit-input-color);
  border: 0px;
  background-color: var(--copilot-kit-input-background-color);
}

.copilotKitInput > textarea::placeholder {
  color: var(--copilot-kit-input-placeholder-color);
  opacity: 1;
}