diff --git a/apps/web/src/components/sme/SmeChatWorkspace.tsx b/apps/web/src/components/sme/SmeChatWorkspace.tsx
index d9c57db6c..2f888e4b4 100644
--- a/apps/web/src/components/sme/SmeChatWorkspace.tsx
+++ b/apps/web/src/components/sme/SmeChatWorkspace.tsx
@@ -1,5 +1,5 @@
 import { useCallback, useEffect, useRef, useState } from "react";
-import { BookOpenIcon, SendIcon } from "lucide-react";
+import { BookOpenIcon, ArrowUpIcon, SparklesIcon } from "lucide-react";
 import type { SmeConversationId, SmeMessage, SmeMessageId } from "@okcode/contracts";
 import { ensureNativeApi } from "~/nativeApi";
 import { useSmeStore } from "~/smeStore";
@@ -39,6 +39,14 @@ export function SmeChatWorkspace({
     messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
   }, [messages, streamingText]);
 
+  // Auto-resize textarea
+  useEffect(() => {
+    const textarea = textareaRef.current;
+    if (!textarea) return;
+    textarea.style.height = "auto";
+    textarea.style.height = `${Math.min(textarea.scrollHeight, 200)}px`;
+  }, [inputText]);
+
   const handleSend = useCallback(async () => {
     if (!conversationId || !inputText.trim() || sending) return;
 
@@ -106,11 +114,15 @@ export function SmeChatWorkspace({
 
   if (!conversationId) {
     return (
-      <div className="flex h-full items-center justify-center">
-        <div className="space-y-3 text-center">
-          <BookOpenIcon className="mx-auto size-10 text-muted-foreground/20" />
-          <p className="text-sm text-muted-foreground">
-            Select a conversation or create a new one to start chatting
+      <div className="flex h-full flex-col items-center justify-center gap-4">
+        <div className="flex size-14 items-center justify-center rounded-2xl bg-gradient-to-br from-primary/20 to-primary/5">
+          <SparklesIcon className="size-7 text-primary/60" />
+        </div>
+        <div className="space-y-2 text-center">
+          <h3 className="text-base font-medium text-foreground">SME Chat</h3>
+          <p className="max-w-xs text-sm text-muted-foreground">
+            Select a conversation or create a new one to start chatting with your subject matter
+            expert.
           </p>
         </div>
       </div>
@@ -118,17 +130,16 @@ export function SmeChatWorkspace({
   }
 
   return (
-    <div className="flex h-full flex-col">
-      {/* Header */}
-      <div className="flex items-center justify-between border-b border-border px-4 py-2">
-        <span className="text-sm font-medium text-foreground">Conversation</span>
+    <div className="flex h-full flex-col bg-background">
+      {/* Minimal Header */}
+      <div className="flex items-center justify-end px-4 py-2">
         <button
           type="button"
           onClick={onToggleKnowledge}
-          className={`flex items-center gap-1.5 rounded-md px-2 py-1 text-xs transition-colors ${
+          className={`flex items-center gap-1.5 rounded-full px-3 py-1.5 text-xs font-medium transition-colors ${
             knowledgePanelOpen
-              ? "bg-accent text-accent-foreground"
-              : "text-muted-foreground hover:bg-accent/50 hover:text-foreground"
+              ? "bg-primary/10 text-primary"
+              : "text-muted-foreground hover:bg-muted hover:text-foreground"
           }`}
         >
           <BookOpenIcon className="size-3.5" />
@@ -137,8 +148,8 @@ export function SmeChatWorkspace({
       </div>
 
       {/* Messages */}
-      <div className="flex-1 overflow-y-auto px-4 py-4">
-        <div className="mx-auto max-w-3xl space-y-4">
+      <div className="flex-1 overflow-y-auto">
+        <div className="mx-auto max-w-3xl">
           {messages.map((msg) => (
             <SmeMessageBubble key={msg.messageId} message={msg} />
           ))}
@@ -158,39 +169,54 @@ export function SmeChatWorkspace({
             />
           ) : null}
           {sending && !streamingText ? (
-            <div className="flex items-center gap-2 py-2">
-              <div className="flex gap-1">
-                <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/40 [animation-delay:0ms]" />
-                <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/40 [animation-delay:150ms]" />
-                <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/40 [animation-delay:300ms]" />
+            <div className="flex items-center gap-4 px-4 py-5">
+              <div className="flex size-8 shrink-0 items-center justify-center rounded-lg bg-gradient-to-br from-primary/80 to-primary text-primary-foreground">
+                <SparklesIcon className="size-4" />
+              </div>
+              <div className="space-y-1">
+                <p className="text-xs font-medium text-muted-foreground">SME Assistant</p>
+                <div className="flex items-center gap-1.5">
+                  <div className="flex gap-1">
+                    <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/50 [animation-delay:0ms]" />
+                    <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/50 [animation-delay:150ms]" />
+                    <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground/50 [animation-delay:300ms]" />
+                  </div>
+                  <span className="text-xs text-muted-foreground">Thinking...</span>
+                </div>
               </div>
-              <span className="text-xs text-muted-foreground">Thinking...</span>
             </div>
           ) : null}
           <div ref={messagesEndRef} />
         </div>
       </div>
 
-      {/* Composer */}
-      <div className="border-t border-border px-4 py-3">
-        <div className="mx-auto flex max-w-3xl items-end gap-2">
-          <textarea
-            ref={textareaRef}
-            value={inputText}
-            onChange={(e) => setInputText(e.target.value)}
-            onKeyDown={handleKeyDown}
-            placeholder="Ask your subject matter expert..."
-            rows={1}
-            className="min-h-[36px] max-h-[200px] flex-1 resize-none rounded-lg border border-border bg-background px-3 py-2 text-sm outline-none focus:ring-1 focus:ring-ring"
-          />
-          <button
-            type="button"
-            onClick={() => void handleSend()}
-            disabled={!inputText.trim() || sending}
-            className="flex size-9 shrink-0 items-center justify-center rounded-lg bg-primary text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
-          >
-            <SendIcon className="size-4" />
-          </button>
+      {/* Modern Composer */}
+      <div className="px-4 pb-4 pt-2">
+        <div className="mx-auto max-w-3xl">
+          <div className="relative flex items-end rounded-2xl border border-border bg-muted/30 shadow-sm transition-colors focus-within:border-ring focus-within:bg-muted/50">
+            <textarea
+              ref={textareaRef}
+              value={inputText}
+              onChange={(e) => setInputText(e.target.value)}
+              onKeyDown={handleKeyDown}
+              placeholder="Message your SME..."
+              rows={1}
+              className="max-h-[200px] min-h-[44px] flex-1 resize-none bg-transparent px-4 py-3 text-sm leading-relaxed outline-none placeholder:text-muted-foreground/60"
+            />
+            <div className="flex items-center gap-1 p-2">
+              <button
+                type="button"
+                onClick={() => void handleSend()}
+                disabled={!inputText.trim() || sending}
+                className="flex size-8 shrink-0 items-center justify-center rounded-xl bg-primary text-primary-foreground transition-all hover:bg-primary/90 disabled:bg-muted-foreground/20 disabled:text-muted-foreground/40"
+              >
+                <ArrowUpIcon className="size-4" />
+              </button>
+            </div>
+          </div>
+          <p className="mt-1.5 text-center text-[10px] text-muted-foreground/40">
+            SME can make mistakes. Verify important information.
+          </p>
         </div>
       </div>
     </div>
diff --git a/apps/web/src/components/sme/SmeConversationRail.tsx b/apps/web/src/components/sme/SmeConversationRail.tsx
index 09451785c..0a110d0af 100644
--- a/apps/web/src/components/sme/SmeConversationRail.tsx
+++ b/apps/web/src/components/sme/SmeConversationRail.tsx
@@ -1,5 +1,5 @@
 import { useCallback, useState } from "react";
-import { MessageSquarePlusIcon, TrashIcon } from "lucide-react";
+import { PlusIcon, TrashIcon, MessageSquareIcon } from "lucide-react";
 import type { SmeConversationId } from "@okcode/contracts";
 
 import type { Project } from "~/types";
@@ -55,14 +55,28 @@ export function SmeConversationRail({
   );
 
   return (
-    <div className="flex w-56 shrink-0 flex-col border-r border-border bg-sidebar">
+    <div className="flex w-64 shrink-0 flex-col bg-muted/30">
+      {/* Header with new chat button */}
+      <div className="flex items-center justify-between px-4 py-3">
+        <span className="text-sm font-semibold text-foreground">Chats</span>
+        <button
+          type="button"
+          onClick={handleNewConversation}
+          disabled={creating}
+          className="flex size-8 items-center justify-center rounded-lg text-muted-foreground transition-colors hover:bg-muted hover:text-foreground disabled:opacity-50"
+          title="New conversation"
+        >
+          <PlusIcon className="size-4" />
+        </button>
+      </div>
+
       {/* Project selector */}
       {projects.length > 1 ? (
-        <div className="border-b border-border px-3 py-2">
+        <div className="px-3 pb-2">
           <select
             value={selectedProjectId ?? ""}
             onChange={(e) => onProjectChange(e.target.value)}
-            className="w-full rounded-md border border-border bg-background px-2 py-1 text-xs"
+            className="w-full rounded-lg border border-border bg-background px-2.5 py-1.5 text-xs"
           >
             {projects.map((p) => (
               <option key={p.id} value={p.id}>
@@ -73,25 +87,13 @@ export function SmeConversationRail({
         </div>
       ) : null}
 
-      {/* New conversation button */}
-      <div className="px-3 py-2">
-        <button
-          type="button"
-          onClick={handleNewConversation}
-          disabled={creating}
-          className="flex w-full items-center gap-2 rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
-        >
-          <MessageSquarePlusIcon className="size-3.5" />
-          <span>New Conversation</span>
-        </button>
-      </div>
-
       {/* Conversation list */}
-      <div className="flex-1 overflow-y-auto px-1.5">
+      <div className="flex-1 overflow-y-auto px-2">
         {conversations.length === 0 ? (
-          <p className="px-2 py-4 text-center text-xs text-muted-foreground">
-            No conversations yet
-          </p>
+          <div className="flex flex-col items-center gap-2 px-2 py-8 text-center">
+            <MessageSquareIcon className="size-5 text-muted-foreground/30" />
+            <p className="text-xs text-muted-foreground">No conversations yet</p>
+          </div>
         ) : (
           <div className="space-y-0.5 py-1">
             {conversations.map((conv) => (
@@ -100,17 +102,17 @@ export function SmeConversationRail({
                 type="button"
                 onClick={() => setActiveConversationId(conv.conversationId)}
                 className={cn(
-                  "group flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-left text-xs transition-colors",
+                  "group flex w-full items-center gap-2.5 rounded-lg px-3 py-2 text-left text-[13px] transition-colors",
                   activeConversationId === conv.conversationId
-                    ? "bg-accent text-accent-foreground"
-                    : "text-muted-foreground hover:bg-accent/50 hover:text-foreground",
+                    ? "bg-muted text-foreground"
+                    : "text-muted-foreground hover:bg-muted/60 hover:text-foreground",
                 )}
               >
                 <span className="min-w-0 flex-1 truncate">{conv.title}</span>
                 <button
                   type="button"
                   onClick={(e) => void handleDeleteConversation(e, conv.conversationId)}
-                  className="shrink-0 opacity-0 transition-opacity group-hover:opacity-100"
+                  className="shrink-0 rounded-md p-0.5 opacity-0 transition-opacity hover:bg-background group-hover:opacity-100"
                 >
                   <TrashIcon className="size-3 text-muted-foreground hover:text-destructive" />
                 </button>
diff --git a/apps/web/src/components/sme/SmeKnowledgePanel.tsx b/apps/web/src/components/sme/SmeKnowledgePanel.tsx
index 9dd4ba3de..72effce92 100644
--- a/apps/web/src/components/sme/SmeKnowledgePanel.tsx
+++ b/apps/web/src/components/sme/SmeKnowledgePanel.tsx
@@ -86,21 +86,21 @@ export function SmeKnowledgePanel({ project, onClose }: SmeKnowledgePanelProps)
   );
 
   return (
-    <div className="flex w-72 shrink-0 flex-col border-l border-border bg-sidebar">
+    <div className="flex w-72 shrink-0 flex-col border-l border-border bg-muted/30">
       {/* Header */}
-      <div className="flex items-center justify-between border-b border-border px-3 py-2">
-        <span className="text-xs font-medium text-foreground">Knowledge Base</span>
+      <div className="flex items-center justify-between px-4 py-3">
+        <span className="text-sm font-semibold text-foreground">Knowledge Base</span>
         <button
           type="button"
           onClick={onClose}
-          className="rounded p-0.5 text-muted-foreground hover:text-foreground"
+          className="flex size-8 items-center justify-center rounded-lg text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
         >
-          <XIcon className="size-3.5" />
+          <XIcon className="size-4" />
         </button>
       </div>
 
       {/* Upload button */}
-      <div className="px-3 py-2">
+      <div className="px-3 pb-2">
         <input
           ref={fileInputRef}
           type="file"
@@ -112,12 +112,12 @@ export function SmeKnowledgePanel({ project, onClose }: SmeKnowledgePanelProps)
           type="button"
           onClick={() => fileInputRef.current?.click()}
           disabled={uploading}
-          className="flex w-full items-center justify-center gap-2 rounded-md border border-dashed border-border px-3 py-2 text-xs text-muted-foreground transition-colors hover:border-foreground/30 hover:text-foreground disabled:opacity-50"
+          className="flex w-full items-center justify-center gap-2 rounded-xl border border-dashed border-border/60 px-3 py-3 text-xs text-muted-foreground transition-colors hover:border-primary/40 hover:bg-primary/5 hover:text-foreground disabled:opacity-50"
         >
-          <UploadIcon className="size-3.5" />
+          <UploadIcon className="size-4" />
           <span>{uploading ? "Uploading..." : "Upload Document"}</span>
         </button>
-        <p className="mt-1 text-center text-[10px] text-muted-foreground/60">
+        <p className="mt-1.5 text-center text-[10px] text-muted-foreground/50">
           .txt, .md, .json, .csv, .yaml, .html, .xml
         </p>
       </div>
@@ -125,29 +125,32 @@ export function SmeKnowledgePanel({ project, onClose }: SmeKnowledgePanelProps)
       {/* Document list */}
       <div className="flex-1 overflow-y-auto px-2">
         {documents.length === 0 ? (
-          <p className="px-2 py-6 text-center text-xs text-muted-foreground">
-            No documents uploaded yet.
-            <br />
-            Upload reference docs to give your SME context.
-          </p>
+          <div className="flex flex-col items-center gap-2 px-2 py-8 text-center">
+            <FileTextIcon className="size-5 text-muted-foreground/30" />
+            <p className="text-xs text-muted-foreground">
+              No documents uploaded yet.
+              <br />
+              Upload reference docs to give your SME context.
+            </p>
+          </div>
         ) : (
-          <div className="space-y-1 py-1">
+          <div className="space-y-0.5 py-1">
             {documents.map((doc) => (
               <div
                 key={doc.documentId}
-                className="group flex items-start gap-2 rounded-md px-2 py-1.5 hover:bg-accent/50"
+                className="group flex items-start gap-2.5 rounded-lg px-3 py-2 transition-colors hover:bg-muted/60"
               >
-                <FileTextIcon className="mt-0.5 size-3.5 shrink-0 text-muted-foreground" />
+                <FileTextIcon className="mt-0.5 size-4 shrink-0 text-muted-foreground" />
                 <div className="min-w-0 flex-1">
-                  <p className="truncate text-xs font-medium text-foreground">{doc.title}</p>
-                  <p className="truncate text-[10px] text-muted-foreground">
+                  <p className="truncate text-[13px] font-medium text-foreground">{doc.title}</p>
+                  <p className="truncate text-[11px] text-muted-foreground">
                     {doc.fileName} &middot; {formatBytes(doc.sizeBytes)}
                   </p>
                 </div>
                 <button
                   type="button"
                   onClick={() => void handleDelete(doc.documentId)}
-                  className="mt-0.5 shrink-0 opacity-0 transition-opacity group-hover:opacity-100"
+                  className="mt-0.5 shrink-0 rounded-md p-0.5 opacity-0 transition-opacity hover:bg-background group-hover:opacity-100"
                 >
                   <TrashIcon className="size-3 text-muted-foreground hover:text-destructive" />
                 </button>
diff --git a/apps/web/src/components/sme/SmeMessageBubble.tsx b/apps/web/src/components/sme/SmeMessageBubble.tsx
index ac1ed4551..585631a33 100644
--- a/apps/web/src/components/sme/SmeMessageBubble.tsx
+++ b/apps/web/src/components/sme/SmeMessageBubble.tsx
@@ -1,4 +1,4 @@
-import { UserIcon, BotIcon } from "lucide-react";
+import { UserIcon, SparklesIcon } from "lucide-react";
 import type { SmeMessage } from "@okcode/contracts";
 
 import { cn } from "~/lib/utils";
@@ -11,31 +11,44 @@ export function SmeMessageBubble({ message }: SmeMessageBubbleProps) {
   const isUser = message.role === "user";
 
   return (
-    <div className={cn("flex gap-3", isUser && "flex-row-reverse")}>
+    <div
+      className={cn(
+        "group flex w-full gap-4 px-4 py-5",
+        isUser ? "flex-row-reverse" : "flex-row",
+      )}
+    >
       {/* Avatar */}
       <div
         className={cn(
-          "flex size-7 shrink-0 items-center justify-center rounded-full",
-          isUser ? "bg-primary/10 text-primary" : "bg-muted text-muted-foreground",
+          "flex size-8 shrink-0 items-center justify-center rounded-lg",
+          isUser
+            ? "bg-primary text-primary-foreground"
+            : "bg-gradient-to-br from-primary/80 to-primary text-primary-foreground",
         )}
       >
-        {isUser ? <UserIcon className="size-3.5" /> : <BotIcon className="size-3.5" />}
+        {isUser ? <UserIcon className="size-4" /> : <SparklesIcon className="size-4" />}
       </div>
 
-      {/* Bubble */}
-      <div
-        className={cn(
-          "max-w-[80%] rounded-xl px-3.5 py-2.5 text-sm leading-relaxed",
-          isUser ? "bg-primary text-primary-foreground" : "bg-muted text-foreground",
-        )}
-      >
-        {/* Render text with basic whitespace preservation */}
-        <div className="whitespace-pre-wrap break-words">{message.text}</div>
+      {/* Content */}
+      <div className={cn("min-w-0 max-w-[85%] space-y-1", isUser && "text-right")}>
+        <p className="text-xs font-medium text-muted-foreground">
+          {isUser ? "You" : "SME Assistant"}
+        </p>
+        <div
+          className={cn(
+            "rounded-2xl px-4 py-3 text-sm leading-relaxed",
+            isUser
+              ? "bg-primary text-primary-foreground"
+              : "bg-muted/60 text-foreground",
+          )}
+        >
+          <div className="whitespace-pre-wrap break-words">{message.text}</div>
 
-        {/* Streaming indicator */}
-        {message.isStreaming ? (
-          <span className="mt-1 inline-block size-2 animate-pulse rounded-full bg-current opacity-60" />
-        ) : null}
+          {/* Streaming cursor */}
+          {message.isStreaming ? (
+            <span className="ml-0.5 inline-block h-4 w-0.5 animate-pulse bg-current align-text-bottom opacity-70" />
+          ) : null}
+        </div>
       </div>
     </div>
   );