File to change fill in the blanks field width

Are you sure that I can do it just with css in this case? Cause a programmer told me I need a js file.

I think I need to change the script in the blanks file?

What should I do to make th efiled shorter?

var self = this;
    var fontSize = parseInt($input.css('font-size'), 10);
    var minEm = 3;
    var minPx = fontSize * minEm;
    var rightPadEm = 3.25;
    var rightPadPx = fontSize * rightPadEm;
    var static_min_pad = 0.5 * fontSize;
// Adjust width of text input field to match value
      self.autoGrowTextField($this);

      var $inputs, isLastInput;
      var enterPressed = (event.keyCode === 13);
      var tabPressedAutoCheck = (event.keyCode === 9 && self.params.behaviour.autoCheck);

      if (enterPressed || tabPressedAutoCheck) {
        // Figure out which inputs are left to answer
        $inputs = self.$questions.find('.h5p-input-wrapper:not(.h5p-correct) .h5p-text-input');

        // Figure out if this is the last input
        isLastInput = $this.is($inputs[$inputs.length - 1]);
      }

      if ((tabPressedAutoCheck && isLastInput && !self.shiftPressed) ||
          (enterPressed && isLastInput)) {
        // Focus first button on next tick
        setTimeout(function () {
          self.focusButton();
        }, 10);
      }

      if (enterPressed) {
        if (isLastInput) {
          // Check answers
          $this.trigger('blur');
        }
        else {
          // Find next input to focus
          $inputs.eq($inputs.index($this) + 1).focus();
        }

        return false; // Prevent form submission on enter key
      }
    }).on('change', function () {
      self.answered = true;
      self.triggerXAPI('interacted');
    });

    self.on('resize', function () {
      self.resetGrowTextField();
    });

    return this.$questions;
  };

  /**
   *
   */
  Blanks.prototype.autoGrowTextField = function ($input) {
    // Do not set text field size when separate lines is enabled
    if (this.params.behaviour.separateLines) {
      return;
    }

    var self = this;
    var fontSize = parseInt($input.css('font-size'), 10);
    var minEm = 3;
    var minPx = fontSize * minEm;
    var rightPadEm = 3.25;
    var rightPadPx = fontSize * rightPadEm;
    var static_min_pad = 0.5 * fontSize;

    setTimeout(function(){
      var tmp = $('<div>', {
        'html': $input.val()
      });
      tmp.css({
        'position': 'absolute',
        'white-space': 'nowrap',
        'font-size': $input.css('font-size'),
        'font-family': $input.css('font-family'),
        'padding': $input.css('padding'),
        'width': 'initial'
      });
      $input.parent().append(tmp);
      var width = tmp.width();
      var parentWidth = self.$questions.width();
      tmp.remove();
      if (width <= minPx) {
        // Apply min width
        $input.width(minPx + static_min_pad);
      }
      else if (width + rightPadPx >= parentWidth) {
        // Apply max width of parent
        $input.width(parentWidth - rightPadPx);
      }
      else {
        // Apply width that wraps input
        $input.width(width + static_min_pad);
      }
    }, 1);
  };

  /**
   * Resize all text field growth to current size.
   */
  Blanks.prototype.resetGrowTextField = function () {
    var self = this;

    this.$questions.find('input').each(function () {
      self.autoGrowTextField($(this));
    });
  };

  /**
   * Toggle buttons dependent of state.
   *
   * Using CSS-rules to conditionally show/hide using the data-attribute [data-state]
   */
  Blanks.prototype.toggleButtonVisibility = function (state) {
    // The show solutions button is hidden if all answers are correct
    var allCorrect = (this.getScore() === this.getMaxScore());
    if (this.params.behaviour.autoCheck && allCorrect) {
      // We are viewing the solutions
      state = STATE_FINISHED;
    }

    if (this.params.behaviour.enableSolutionsButton) {
      if (state === STATE_CHECKING && !allCorrect) {
        this.showButton('show-solution');
      }
      else {
        this.hideButton('show-solution');
      }
    }

    if (this.params.behaviour.enableRetry) {
      if ((state === STATE_CHECKING && !allCorrect) || state === STATE_SHOWING_SOLUTION) {
        this.showButton('try-again');
      }
      else {
        this.hideButton('try-again');
      }
    }

    if (state === STATE_ONGOING) {
      this.showButton('check-answer');
    }
    else {
      this.hideButton('check-answer');
    }

    this.trigger('resize');
  };