Upd code viewer

static/styles.css

@@ -1077,67 +1077,172 @@
 /* Code blocks with copy button */
 .code-block-wrapper {
   position: relative;
-  margin: 16px 0;
-  border-radius: var(--radius);
+  margin: 20px 0;
+  border-radius: 12px;
   overflow: hidden;
   border: 1px solid var(--border);
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
+  background: var(--card);
 }
 
 .code-block-header {
   display: flex;
   justify-content: space-between;
   align-items: center;
-  padding: 8px 12px;
-  background: var(--bg-secondary);
+  padding: 12px 16px;
+  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--card) 100%);
   border-bottom: 1px solid var(--border);
   font-size: 12px;
   color: var(--muted);
+  font-weight: 500;
 }
 
 .code-block-language {
-  font-weight: 600;
+  font-weight: 700;
   text-transform: uppercase;
+  letter-spacing: 0.5px;
+  color: var(--accent);
+  display: flex;
+  align-items: center;
+  gap: 6px;
+}
+
+.code-block-language::before {
+  content: '';
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  background: var(--accent);
+  display: inline-block;
 }
 
 .copy-code-btn {
   display: flex;
   align-items: center;
-  gap: 4px;
-  padding: 4px 8px;
+  gap: 6px;
+  padding: 6px 12px;
   background: var(--card);
   border: 1px solid var(--border);
-  border-radius: var(--radius-sm);
+  border-radius: 8px;
   color: var(--text-secondary);
   font-size: 11px;
+  font-weight: 500;
   cursor: pointer;
-  transition: all 0.2s ease;
+  transition: all 0.3s ease;
+  position: relative;
+  overflow: hidden;
+}
+
+.copy-code-btn::before {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: -100%;
+  width: 100%;
+  height: 100%;
+  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
+  transition: left 0.5s ease;
 }
 
 .copy-code-btn:hover {
   background: var(--card-hover);
-  border-color: var(--border-light);
+  border-color: var(--accent);
   color: var(--text);
+  transform: translateY(-1px);
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+}
+
+.copy-code-btn:hover::before {
+  left: 100%;
 }
 
 .copy-code-btn.copied {
   background: var(--success);
   color: white;
   border-color: var(--success);
+  transform: scale(1.05);
 }
 
 .copy-code-btn svg {
-  width: 12px;
-  height: 12px;
+  width: 14px;
+  height: 14px;
+  transition: transform 0.2s ease;
+}
+
+.copy-code-btn:hover svg {
+  transform: scale(1.1);
 }
 
 .code-block-content {
-  background: var(--code-bg, #1e1e1e);
-  color: var(--code-text, #d4d4d4);
-  padding: 16px;
+  background: linear-gradient(135deg, #1a1a1a 0%, #1e1e1e 100%);
+  color: #e6e6e6;
+  padding: 20px;
   overflow-x: auto;
-  font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
+  font-family: 'JetBrains Mono', 'Fira Code', 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
   font-size: 14px;
-  line-height: 1.5;
+  line-height: 1.6;
+  position: relative;
+}
+
+.code-block-content::before {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  height: 1px;
+  background: linear-gradient(90deg, transparent, var(--accent), transparent);
+}
+
+/* Enhanced syntax highlighting for code blocks */
+.code-block-content .hljs {
+  background: transparent !important;
+  color: inherit !important;
+}
+
+.code-block-content .hljs-keyword {
+  color: #ff7b72;
+  font-weight: 600;
+}
+
+.code-block-content .hljs-string {
+  color: #a5d6ff;
+}
+
+.code-block-content .hljs-comment {
+  color: #8b949e;
+  font-style: italic;
+}
+
+.code-block-content .hljs-number {
+  color: #79c0ff;
+}
+
+.code-block-content .hljs-function {
+  color: #d2a8ff;
+}
+
+.code-block-content .hljs-variable {
+  color: #ffa657;
+}
+
+/* Scrollbar styling for code blocks */
+.code-block-content::-webkit-scrollbar {
+  height: 8px;
+}
+
+.code-block-content::-webkit-scrollbar-track {
+  background: #2d2d2d;
+  border-radius: 4px;
+}
+
+.code-block-content::-webkit-scrollbar-thumb {
+  background: var(--accent);
+  border-radius: 4px;
+}
+
+.code-block-content::-webkit-scrollbar-thumb:hover {
+  background: var(--accent-hover);
 }
 
 /* Download PDF button */

utils/api/router.py

@@ -94,25 +94,39 @@ async def generate_answer_with_model(selection: Dict[str, Any], system_prompt: s
     model = selection["model"]
 
     if provider == "gemini":
-        key = gemini_rotator.get_key() or ""
-        url = f"https://generativelanguage.googleapis.com/v1beta/models/{model}:generateContent?key={key}"
-        payload = {
-            "contents": [
-                {"role": "user", "parts": [{"text": f"{system_prompt}\n\n{user_prompt}"}]}
-            ],
-            "generationConfig": {"temperature": 0.2}
-        }
-        headers = {"Content-Type": "application/json"}
-        data = await robust_post_json(url, headers, payload, gemini_rotator)
+        # Try Gemini first
         try:
+            key = gemini_rotator.get_key() or ""
+            url = f"https://generativelanguage.googleapis.com/v1beta/models/{model}:generateContent?key={key}"
+            payload = {
+                "contents": [
+                    {"role": "user", "parts": [{"text": f"{system_prompt}\n\n{user_prompt}"}]}
+                ],
+                "generationConfig": {"temperature": 0.2}
+            }
+            headers = {"Content-Type": "application/json"}
+            data = await robust_post_json(url, headers, payload, gemini_rotator)
+            
             content = data["candidates"][0]["content"]["parts"][0]["text"]
             if not content or content.strip() == "":
                 logger.warning(f"Empty content from Gemini model: {data}")
-                return "I received an empty response from the model."
+                raise Exception("Empty content from Gemini")
             return content
         except Exception as e:
-            logger.warning(f"Unexpected Gemini response: {data}, error: {e}")
-            return "I couldn't parse the model response."
+            logger.warning(f"Gemini model {model} failed: {e}. Attempting fallback...")
+            
+            # Fallback logic: GEMINI_PRO/MED → NVIDIA_LARGE, GEMINI_SMALL → NVIDIA_SMALL
+            if model in [GEMINI_PRO, GEMINI_MED]:
+                logger.info(f"Falling back from {model} to NVIDIA_LARGE")
+                fallback_selection = {"provider": "nvidia_large", "model": NVIDIA_LARGE}
+                return await generate_answer_with_model(fallback_selection, system_prompt, user_prompt, gemini_rotator, nvidia_rotator)
+            elif model == GEMINI_SMALL:
+                logger.info(f"Falling back from {model} to NVIDIA_SMALL")
+                fallback_selection = {"provider": "nvidia", "model": NVIDIA_SMALL}
+                return await generate_answer_with_model(fallback_selection, system_prompt, user_prompt, gemini_rotator, nvidia_rotator)
+            else:
+                logger.error(f"No fallback defined for Gemini model: {model}")
+                return "I couldn't parse the model response."
 
     elif provider == "nvidia":
         # Many NVIDIA endpoints are OpenAI-compatible. Adjust if using a different path.