How to customise React-Day-Picker input?

Here is my code

<DayPickerInput 
   placeholder={"Date..."} 
   onDayChange={day => setNewDate(day)}
   className="day"
/>

.day {
  text-align: center;
  text-size-adjust: 100;
  border-radius: 30px;
  background: var(--bg-accent);
  color: var(--text-color);
  width: 120px;
  height: 40px;
  border: none;
  margin-top: 50px;
  margin-right: 10px;
  margin-left: 10px;
}

but all of this isn't affecting the day picker input. How would I for example change the background of the day picker?

There is no specific class defined for the input field from the package react-day-picker, but we could get the DOM structure as you could see that it's right down the class DayPickerInput

<div class="DayPickerInput">
  <input placeholder="YYYY-M-D" value="">
</div>

so the only thing left to do is to use a CSS element selector

.DayPickerInput > input {
  background-color: lightblue;
}