diff --git a/components/BookInfoInput.tsx b/components/BookInfoInput.tsx
index 394e5eb..40cd543 100644
--- a/components/BookInfoInput.tsx
+++ b/components/BookInfoInput.tsx
@@ -85,7 +85,7 @@ function BookInfoInput({ handleSubmit }: { handleSubmit: (info: { frontmatter: F
             <input multiple={false} ref={coverRef} className="form-control" type="file" id="cover-file" accept="image/jpeg,image/png"/>
         </div>
         {fields.map((field) => (
-            <div className="mb-2">
+            <div className="mb-2" key={field}>
                 <label htmlFor={field} className="form-label d-flex flex-row align-items-center">
                     {!requiredFields.includes(field) && <span className="me-2">
                         <button type="button" className="btn btn-sm btn-outline-secondary" onClick={() => handleRemoveField(field)}>
@@ -110,7 +110,7 @@ function BookInfoInput({ handleSubmit }: { handleSubmit: (info: { frontmatter: F
           options={availableFieldsOptions}
         />
         <LanguageSelect value={state.lang} onChange={handleLanguageChange} />
-        <button onClick={submit} type="button" className="btn btn-primary my-4">Create .epub</button>
+        <button onClick={submit} type="button" className="btn btn-lg btn-primary my-4">Create .epub</button>
     </div>
 }
 
diff --git a/components/LanguageSelect.tsx b/components/LanguageSelect.tsx
index 9a12d9b..27d4dab 100644
--- a/components/LanguageSelect.tsx
+++ b/components/LanguageSelect.tsx
@@ -44,7 +44,7 @@ function LanguageSelect({ value, onChange }: {
         />
         {showingOther && <div className="my-2">
             <label htmlFor="otherLang" className="form-label d-flex flex-row align-items-center">
-                <span>Custom <a href="https://www.w3.org/International/articles/language-tags/" target="_blank">IETF BCP 47</a> Language Code</span>
+                <span>Custom <a href="https://www.w3.org/International/articles/language-tags/" target="_blank" rel="noreferrer">IETF BCP 47</a> Language Code</span>
             </label>
             {/* TODO: for some reason can't use value={value} with this - but it still works */}
             <input onChange={(e) => onChange(e.target.value)} type="text" className="form-control" id="otherLang" />