add board buttons row for mobile and desktop, global styling for button

src/components/post-form/post-form.module.css

@@ -4,36 +4,9 @@
   text-align: center;
 }
 
-.postFormButtonDesktop span {
-  color: var(--button-text-color);
-  text-decoration: var(--button-text-decoration);
-}
-
-.postFormButtonDesktop span:hover {
-  cursor: pointer;
-  color: var(--button-text-color-hover);
-}
-
 .postFormButtonMobile {
   text-align: center;
-  padding-top: 5px;
-}
-
-.postFormButtonMobile span {
-  font-size: var(--button-font-size-mobile);
-  font-weight: var(--button-font-weight-mobile);
-  font-family: var(--button-font-family-mobile);
-  border-radius: 3px;
-  padding: 5px 10px 5px;
-  background-color: var(--button-background-color-mobile);
-  color: var(--button-text-color-mobile);
-  border: var(--button-border-mobile);
-  background-image: var(--button-background-image-mobile);
-  background: var(--button-background-mobile);
-  background-repeat: var(--button-background-repeat-mobile);
-  text-decoration: var(--button-text-decoration-mobile);
-  user-select: none;
-  display: inline-block;
+  padding-top: 9px;
 }
 
 @media (max-width: 640px) {

src/components/post-form/post-form.tsx

@@ -11,10 +11,10 @@ const PostForm = ({ address }: PostFormProps) => {
   return (
     <>
       <div className={styles.postFormButtonDesktop}>
-        [<span>{t('start_new_thread')}</span>]
+        [<button className='button'>{t('start_new_thread')}</button>]
       </div>
       <div className={styles.postFormButtonMobile}>
-        <span>{t('start_new_thread')}</span>
+        <button className='button'>{t('start_new_thread')}</button>
       </div>
     </>
   );