diff --git a/src/components/layout/AppShell.tsx b/src/components/layout/AppShell.tsx
index f58ce1a..b886472 100644
--- a/src/components/layout/AppShell.tsx
+++ b/src/components/layout/AppShell.tsx
@@ -147,7 +147,6 @@ const SIDEBAR_BG = '#0f1923'
 const DIVIDER_COLOR = 'rgba(255,255,255,0.08)'
 const TEXT_MUTED = '#94a3b8'
 const TEXT_WHITE = '#ffffff'
-const ACTIVE_BG = 'rgba(255,255,255,0.1)'
 const NAV_ACTIVE_BG = 'rgba(255,255,255,0.12)'
 const NAV_HOVER_BG = 'rgba(255,255,255,0.06)'
 
@@ -173,7 +172,7 @@ function Sidebar({
   orgName,
 }: SidebarProps) {
   const config = WORKSPACE_CONFIG[activeWorkspace]
-  const width = collapsed ? 60 : 240
+  const width = collapsed ? 60 : 264
   const visibleWorkspaces = WORKSPACE_ORDER.filter((ws) => allowedWorkspaces.includes(ws))
 
   return (
@@ -234,16 +233,16 @@ function Sidebar({
         )}
       </Box>
 
-      {/* Workspace tabs */}
+      {/* Workspace tabs — side-by-side segmented control */}
       <Box
         sx={{
           borderBottom: `1px solid ${DIVIDER_COLOR}`,
-          py: 0.5,
-          px: 0.5,
+          display: 'grid',
+          gridTemplateColumns: collapsed ? '1fr' : `repeat(${visibleWorkspaces.length}, 1fr)`,
           flexShrink: 0,
         }}
       >
-        {visibleWorkspaces.map((ws) => {
+        {visibleWorkspaces.map((ws, idx) => {
           const wsConfig = WORKSPACE_CONFIG[ws]
           const Icon = wsConfig.icon
           const isActive = ws === activeWorkspace
@@ -253,29 +252,32 @@ function Sidebar({
               onClick={() => { onWorkspaceClick(ws); onClose?.() }}
               sx={{
                 display: 'flex',
+                flexDirection: collapsed ? 'row' : 'column',
                 alignItems: 'center',
-                gap: 1.25,
-                px: collapsed ? 0 : 1.5,
-                py: 0.75,
-                borderRadius: 1,
+                justifyContent: 'center',
+                gap: collapsed ? 0 : 0.5,
+                py: collapsed ? 1 : 1.25,
                 cursor: 'pointer',
-                justifyContent: collapsed ? 'center' : 'flex-start',
-                backgroundColor: isActive ? ACTIVE_BG : 'transparent',
-                '&:hover': {
-                  backgroundColor: isActive ? ACTIVE_BG : NAV_HOVER_BG,
-                },
+                backgroundColor: isActive ? wsConfig.chipColor : 'transparent',
+                borderRight: !collapsed && idx < visibleWorkspaces.length - 1
+                  ? `1px solid ${DIVIDER_COLOR}`
+                  : 'none',
                 transition: 'background-color 0.15s ease',
+                '&:hover': {
+                  backgroundColor: isActive ? wsConfig.chipColor : NAV_HOVER_BG,
+                },
               }}
             >
-              <Icon size={16} color={isActive ? TEXT_WHITE : TEXT_MUTED} />
+              <Icon size={15} color={isActive ? TEXT_WHITE : TEXT_MUTED} />
               {!collapsed && (
                 <Typography
-                  variant="body2"
+                  variant="caption"
                   sx={{
                     color: isActive ? TEXT_WHITE : TEXT_MUTED,
-                    fontWeight: isActive ? 600 : 400,
-                    fontSize: '0.8125rem',
-                    whiteSpace: 'nowrap',
+                    fontWeight: isActive ? 700 : 400,
+                    fontSize: '0.6875rem',
+                    lineHeight: 1,
+                    letterSpacing: 0.2,
                   }}
                 >
                   {wsConfig.label}
@@ -557,7 +559,7 @@ export function AppShell() {
           onClose={() => setMobileOpen(false)}
           variant="temporary"
           ModalProps={{ keepMounted: true }}
-          slotProps={{ paper: { sx: { width: 240, bgcolor: 'transparent', boxShadow: 'none' } } }}
+          slotProps={{ paper: { sx: { width: 264, bgcolor: 'transparent', boxShadow: 'none' } } }}
         >
           {sidebarContent}
         </Drawer>