diff --git a/src/view/atoms/ConfirmDialog.tsx b/src/view/atoms/ConfirmDialog.tsx
index 083c210..4761d98 100644
--- a/src/view/atoms/ConfirmDialog.tsx
+++ b/src/view/atoms/ConfirmDialog.tsx
@@ -40,11 +40,15 @@ const ConfirmDialog = ({
 
   return (
     <Dialog open={open} onClose={onCancel} fullScreen={fullScreen} maxWidth="xs" fullWidth>
-      <DialogTitle>{title}</DialogTitle>
+      <DialogTitle sx={{ textAlign: "center", fontSize: "1.1rem", fontWeight: 600 }}>
+        {title}
+      </DialogTitle>
       <DialogContent>
-        <DialogContentText component="div">{message}</DialogContentText>
+        <DialogContentText component="div" sx={{ textAlign: "center" }}>
+          {message}
+        </DialogContentText>
       </DialogContent>
-      <DialogActions>
+      <DialogActions sx={{ justifyContent: "center", pb: 3, gap: 1 }}>
         <Button onClick={onCancel} disabled={loading}>
           {cancelLabel}
         </Button>
diff --git a/src/view/moles/Header.tsx b/src/view/moles/Header.tsx
index 4266722..25353b4 100644
--- a/src/view/moles/Header.tsx
+++ b/src/view/moles/Header.tsx
@@ -10,9 +10,6 @@ import {
   Avatar,
   Tooltip,
 } from "@mui/material";
-import { useColorScheme } from "@mui/material/styles";
-import DarkModeOutlinedIcon from "@mui/icons-material/DarkModeOutlined";
-import LightModeOutlinedIcon from "@mui/icons-material/LightModeOutlined";
 import { useNavigate } from "react-router-dom";
 import { useAccount } from "../../nonview/core/AccountContext";
 import { getInitials } from "../_constants/avatarUtils";
@@ -31,8 +28,6 @@ const Header = ({
   const isMobile = useMediaQuery(theme.breakpoints.down("md"));
   const navigate = useNavigate();
   const { activeAccount } = useAccount();
-  const { mode, systemMode, setMode } = useColorScheme();
-  const resolvedMode = (mode === "system" ? systemMode : mode) || "light";
 
   const TitleIcon = titleIcon;
 
@@ -124,20 +119,6 @@ const Header = ({
             );
           })}
 
-          <Tooltip title={resolvedMode === "dark" ? "Light mode" : "Dark mode"}>
-            <IconButton
-              onClick={() => setMode(resolvedMode === "dark" ? "light" : "dark")}
-              aria-label="toggle color scheme"
-              sx={{ color: "text.secondary" }}
-            >
-              {resolvedMode === "dark" ? (
-                <LightModeOutlinedIcon />
-              ) : (
-                <DarkModeOutlinedIcon />
-              )}
-            </IconButton>
-          </Tooltip>
-
           <IconButton
             onClick={() => navigate("/profile")}
             aria-label="profile"
diff --git a/src/view/moles/ManageAccountDialog.tsx b/src/view/moles/ManageAccountDialog.tsx
new file mode 100644
index 0000000..e677585
--- /dev/null
+++ b/src/view/moles/ManageAccountDialog.tsx
@@ -0,0 +1,314 @@
+import React, { useState } from "react";
+import {
+  Dialog,
+  DialogTitle,
+  DialogContent,
+  IconButton,
+  List,
+  ListItemButton,
+  ListItemIcon,
+  ListItemText,
+  Box,
+  Avatar,
+  TextField,
+  Button,
+  Divider,
+  Typography,
+  Link,
+  useMediaQuery,
+  useTheme,
+} from "@mui/material";
+import { useColorScheme } from "@mui/material/styles";
+import CloseIcon from "@mui/icons-material/Close";
+import PersonOutlineIcon from "@mui/icons-material/PersonOutline";
+import PaletteOutlinedIcon from "@mui/icons-material/PaletteOutlined";
+import DeleteOutlineIcon from "@mui/icons-material/DeleteOutline";
+import ChevronRightIcon from "@mui/icons-material/ChevronRight";
+import { useAccount } from "../../nonview/core/AccountContext";
+import { getInitials } from "../_constants/avatarUtils";
+import ErrorMessage from "../atoms/ErrorMessage";
+import ConfirmDialog from "../atoms/ConfirmDialog";
+
+interface ManageAccountDialogProps {
+  open: boolean;
+  onClose: () => void;
+}
+
+const THEME_OPTIONS = ["light", "dark"] as const;
+const NAV_ITEMS = [
+  { key: "profile", label: "Profile", icon: PersonOutlineIcon },
+  { key: "appearance", label: "Appearance", icon: PaletteOutlinedIcon },
+] as const;
+
+const ManageAccountDialog = ({ open, onClose }: ManageAccountDialogProps) => {
+  const theme = useTheme();
+  const fullScreen = useMediaQuery(theme.breakpoints.down("md"));
+  const { activeAccount, updateAccount, removeAccount } = useAccount();
+  const { mode, systemMode, setMode } = useColorScheme();
+  const resolvedMode = (mode === "system" ? systemMode : mode) || "light";
+
+  const [section, setSection] = useState<(typeof NAV_ITEMS)[number]["key"]>("profile");
+  const [name, setName] = useState(activeAccount?.name || "");
+  const [nameError, setNameError] = useState("");
+  const [saved, setSaved] = useState(false);
+  const [confirmOpen, setConfirmOpen] = useState(false);
+  const [removing, setRemoving] = useState(false);
+
+  if (!activeAccount) return null;
+
+  const handleSave = () => {
+    if (!name.trim()) {
+      setNameError("Name is required");
+      return;
+    }
+    updateAccount(activeAccount.id, { name: name.trim() });
+    setSaved(true);
+  };
+
+  const handleRemove = async () => {
+    setRemoving(true);
+    await removeAccount(activeAccount.id);
+    setRemoving(false);
+    setConfirmOpen(false);
+    onClose();
+  };
+
+  const filledFieldSx = {
+    "& .MuiFilledInput-root": {
+      borderRadius: 2,
+      bgcolor: "action.hover",
+      "&::before, &::after": { display: "none" },
+    },
+  };
+
+  return (
+    <>
+      <Dialog
+        open={open}
+        onClose={onClose}
+        fullScreen={fullScreen}
+        keepMounted={false}
+        slotProps={{
+          paper: {
+            sx: fullScreen
+              ? undefined
+              : {
+                  width: 650,
+                  height: 560,
+                  maxWidth: "95vw",
+                  maxHeight: "90vh",
+                  display: "flex",
+                  flexDirection: "column",
+                },
+          },
+        }}
+      >
+        <DialogTitle sx={{ display: "flex", alignItems: "center", gap: 1.5, py: 2, flexShrink: 0 }}>
+          <Avatar
+            sx={{
+              width: 40,
+              height: 40,
+              fontSize: "1rem",
+              bgcolor: "primary.main",
+              color: "primary.contrastText",
+            }}
+          >
+            {getInitials(activeAccount.name)}
+          </Avatar>
+          <Box sx={{ flex: 1, minWidth: 0 }}>
+            <Typography variant="subtitle1" sx={{ fontWeight: 600, lineHeight: 1.2 }} noWrap>
+              {activeAccount.name}
+            </Typography>
+            <Typography variant="body2" color="text.secondary" noWrap>
+              {activeAccount.email}
+            </Typography>
+          </Box>
+          <IconButton onClick={onClose} aria-label="close">
+            <CloseIcon />
+          </IconButton>
+        </DialogTitle>
+
+        <Divider sx={{ flexShrink: 0 }} />
+
+        <Box sx={{ display: "flex", flexDirection: fullScreen ? "column" : "row", flex: 1, minHeight: 0 }}>
+          <List
+            sx={
+              fullScreen
+                ? {
+                    display: "flex",
+                    flexDirection: "row",
+                    width: "100%",
+                    flexShrink: 0,
+                    borderBottom: 1,
+                    borderColor: "divider",
+                    py: 1,
+                  }
+                : {
+                    width: 200,
+                    flexShrink: 0,
+                    borderRight: 1,
+                    borderColor: "divider",
+                    py: 2,
+                    overflowY: "auto",
+                  }
+            }
+          >
+            {NAV_ITEMS.map(({ key, label, icon: Icon }) => (
+              <ListItemButton
+                key={key}
+                selected={section === key}
+                onClick={() => setSection(key)}
+                sx={fullScreen ? { flex: 1, justifyContent: "center", mx: 0.5, borderRadius: 1.5 } : { mx: 1, borderRadius: 1.5 }}
+              >
+                <ListItemIcon sx={{ minWidth: fullScreen ? 0 : 36, mr: fullScreen ? 1 : 0 }}>
+                  <Icon fontSize="small" color={section === key ? "primary" : "inherit"} />
+                </ListItemIcon>
+                <ListItemText
+                  primary={label}
+                  sx={fullScreen ? { flexGrow: 0 } : undefined}
+                  slotProps={{
+                    primary: { color: section === key ? "primary" : "text.primary" },
+                  }}
+                />
+              </ListItemButton>
+            ))}
+          </List>
+
+          <DialogContent sx={{ flex: 1, overflowY: "auto" }}>
+            {section === "profile" && (
+              <Box sx={{ maxWidth: fullScreen ? "100%" : 420 }}>
+                <Box sx={{ display: "flex", alignItems: "center", gap: 2, mb: 3 }}>
+                  <Avatar
+                    sx={{
+                      width: 64,
+                      height: 64,
+                      fontSize: "1.5rem",
+                      bgcolor: "primary.main",
+                      color: "primary.contrastText",
+                    }}
+                  >
+                    {getInitials(activeAccount.name)}
+                  </Avatar>
+                  <Box>
+                    <Typography variant="body2" color="text.secondary">
+                      Profile photo
+                    </Typography>
+                    {/* No avatar-upload backend yet — inert placeholder. */}
+                    <Link component="button" type="button" variant="body2" underline="hover" disabled>
+                      Change photo
+                    </Link>
+                  </Box>
+                </Box>
+
+                {saved && (
+                  <Box sx={{ mb: 2 }}>
+                    <ErrorMessage
+                      message="Profile updated successfully"
+                      variant="success"
+                      onDismiss={() => setSaved(false)}
+                    />
+                  </Box>
+                )}
+
+                <TextField
+                  label="Name"
+                  fullWidth
+                  variant="filled"
+                  value={name}
+                  onChange={(e) => {
+                    setName(e.target.value);
+                    setNameError("");
+                    setSaved(false);
+                  }}
+                  error={!!nameError}
+                  helperText={nameError}
+                  sx={{ mb: 2, ...filledFieldSx }}
+                />
+                <TextField
+                  label="Email Address"
+                  fullWidth
+                  variant="filled"
+                  value={activeAccount.email}
+                  disabled
+                  sx={{ mb: 3, ...filledFieldSx }}
+                />
+                <Button
+                  variant="contained"
+                  onClick={handleSave}
+                  disabled={!name.trim() || name.trim() === activeAccount.name}
+                  sx={{ mb: 4 }}
+                >
+                  Save changes
+                </Button>
+
+                <Divider sx={{ mb: 2 }} />
+                <Typography variant="subtitle2" color="text.secondary" sx={{ mb: 1 }}>
+                  Account management
+                </Typography>
+                <ListItemButton
+                  disabled={removing}
+                  onClick={() => setConfirmOpen(true)}
+                  sx={{
+                    border: 1,
+                    borderColor: "divider",
+                    borderRadius: 2,
+                  }}
+                >
+                  <ListItemIcon sx={{ minWidth: 36 }}>
+                    <DeleteOutlineIcon fontSize="small" />
+                  </ListItemIcon>
+                  <ListItemText primary="Remove this account" />
+                  <ChevronRightIcon fontSize="small" color="action" />
+                </ListItemButton>
+              </Box>
+            )}
+
+            {section === "appearance" && (
+              <Box sx={{ maxWidth: fullScreen ? "100%" : 420 }}>
+                <Typography variant="subtitle2" color="text.secondary" sx={{ mb: 2 }}>
+                  Theme
+                </Typography>
+                <Box sx={{ display: "flex", gap: 2 }}>
+                  {THEME_OPTIONS.map((option) => (
+                    <Box
+                      key={option}
+                      onClick={() => setMode(option)}
+                      sx={{
+                        flex: 1,
+                        cursor: "pointer",
+                        border: 2,
+                        borderColor: resolvedMode === option ? "primary.main" : "divider",
+                        borderRadius: 2,
+                        p: 2,
+                        textAlign: "center",
+                        bgcolor: option === "dark" ? "grey.900" : "grey.50",
+                        color: option === "dark" ? "grey.50" : "grey.900",
+                      }}
+                    >
+                      <Typography variant="body2" sx={{ textTransform: "capitalize" }}>
+                        {option}
+                      </Typography>
+                    </Box>
+                  ))}
+                </Box>
+              </Box>
+            )}
+          </DialogContent>
+        </Box>
+      </Dialog>
+
+      <ConfirmDialog
+        open={confirmOpen}
+        title="Are you sure you want to remove this account?"
+        message="You'll need to sign in again to add it later."
+        confirmLabel="Remove"
+        confirmColor="error"
+        loading={removing}
+        onConfirm={handleRemove}
+        onCancel={() => setConfirmOpen(false)}
+      />
+    </>
+  );
+};
+
+export default ManageAccountDialog;