Add some CSS fixes for navigation instructions

Author: WebCoder49

code-input.css

@@ -187,7 +187,7 @@ code-input .code-input_dialog-container {
   text-align: inherit;
 }
 code-input.code-input_pre-element-styled .code-input_dialog-container {
-  width: calc(100% + 2 * var(--padding, 16px) - 2px);
+  width: calc(100% + 2 * var(--padding, 16px));
 }
 
 [dir=rtl] code-input .code-input_dialog-container, code-input[dir=rtl] .code-input_dialog-container {

plugins/prism-line-numbers.css

@@ -25,6 +25,6 @@ code-input .line-numbers .line-numbers-rows {
   top: var(--padding);
 }
 /* Things with padding when instructions are present */
-code-input:not(:has(.code-input_keyboard-navigation-instructions:empty)):has(textarea:focus):not(.code-input_mouse-focused) .line-numbers .line-numbers-rows {
+code-input:not(:has(.code-input_keyboard-navigation-instructions:empty)):has(textarea:not([data-code-input-fallback]):focus):not(.code-input_mouse-focused) .line-numbers .line-numbers-rows {
   top: calc(var(--padding) + 3em);
 }