feat: update admin page to use banner image upload and modify button styles for better UI

src/app/admin/page.tsx

@@ -499,16 +499,10 @@ export default function AdminPage() {
                             </div>
 
                             <div>
-                                <label style={{ fontSize: '13px', fontWeight: 500, marginBottom: '4px', display: 'block' }}>Banner / Logo URL</label>
-                                <input
-                                    className="input"
-                                    value={nodeSettings.bannerUrl}
-                                    onChange={e => setNodeSettings({ ...nodeSettings, bannerUrl: e.target.value })}
-                                    placeholder="https://"
-                                />
-                                <div style={{ marginTop: '8px', display: 'flex', gap: '8px', alignItems: 'center', flexWrap: 'wrap' }}>
+                                <label style={{ fontSize: '13px', fontWeight: 500, marginBottom: '4px', display: 'block' }}>Banner image</label>
+                                <div style={{ display: 'flex', gap: '8px', alignItems: 'center', flexWrap: 'wrap' }}>
                                     <label className="btn btn-ghost btn-sm">
-                                        {isUploadingBanner ? 'Uploading...' : 'Upload image'}
+                                        {isUploadingBanner ? 'Uploading...' : 'Upload banner'}
                                         <input
                                             type="file"
                                             accept="image/*"

src/app/globals.css

@@ -118,8 +118,8 @@ a.btn-primary:visited {
 }
 
 .btn-ghost {
-  background: transparent;
-  border-color: transparent;
+  background: var(--background-tertiary);
+  border-color: var(--border);
 }
 
 .btn-ghost:hover {
@@ -1308,4 +1308,3 @@ a.btn-primary:visited {
   -webkit-line-clamp: 2;
   -webkit-box-orient: vertical;
 }
-