diff --git a/src/EverythingToJpeg.App/App.xaml b/src/EverythingToJpeg.App/App.xaml
index 430b975..7516c02 100644
--- a/src/EverythingToJpeg.App/App.xaml
+++ b/src/EverythingToJpeg.App/App.xaml
@@ -9,6 +9,7 @@
             <ResourceDictionary.MergedDictionaries>
                 <ui:ThemesDictionary Theme="Dark"/>
                 <ui:ControlsDictionary/>
+                <ResourceDictionary Source="Views/FormatShiftTheme.xaml"/>
             </ResourceDictionary.MergedDictionaries>
 
             <!-- Spacing tokens (Fluent 8pt grid) -->
diff --git a/src/EverythingToJpeg.App/App.xaml.cs b/src/EverythingToJpeg.App/App.xaml.cs
index e005df4..6ed2c32 100644
--- a/src/EverythingToJpeg.App/App.xaml.cs
+++ b/src/EverythingToJpeg.App/App.xaml.cs
@@ -67,7 +67,7 @@ public partial class App : Application
 
     private void ShowConvertDialog(IReadOnlyList<string> files)
     {
-        var window = new ConvertWindow(Engine, files);
+        var window = new Views.MainWindow(files);
         MainWindow = window;
         window.Show();
     }
diff --git a/src/EverythingToJpeg.App/Views/ConvertWindow.xaml b/src/EverythingToJpeg.App/Views/ConvertWindow.xaml
index f896c18..8e776b4 100644
--- a/src/EverythingToJpeg.App/Views/ConvertWindow.xaml
+++ b/src/EverythingToJpeg.App/Views/ConvertWindow.xaml
@@ -3,47 +3,66 @@
                  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                  xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml"
                  Title="JPEG로 변환"
-                 Width="640" Height="780"
-                 MinWidth="520" MinHeight="560"
+                 Width="720" Height="780"
+                 MinWidth="560" MinHeight="560"
                  ExtendsContentIntoTitleBar="True"
-                 WindowBackdropType="Mica"
+                 WindowBackdropType="None"
                  WindowCornerPreference="Round"
                  WindowStartupLocation="CenterOwner"
                  AllowDrop="True"
                  Drop="OnFilesDropped"
-                 DragOver="OnDragOver">
-    <Grid>
+                 DragOver="OnDragOver"
+                 TextOptions.TextFormattingMode="Display"
+                 UseLayoutRounding="True">
+    <Window.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="FormatShiftTheme.xaml"/>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Window.Resources>
+
+    <Grid Background="{StaticResource FsBgBase}">
         <Grid.RowDefinitions>
-            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="32"/>
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="*"/>
             <RowDefinition Height="Auto"/>
         </Grid.RowDefinitions>
 
-        <!-- 0: TitleBar -->
-        <ui:TitleBar Grid.Row="0" Title="JPEG로 변환"/>
+        <!-- 0: TitleBar (window controls only) -->
+        <ui:TitleBar Grid.Row="0" Title=""/>
 
-        <!-- 1: 헤더 (제목 + 파일 카운트) -->
-        <Grid Grid.Row="1" Margin="32,8,32,12">
+        <!-- 1: 헤더 -->
+        <Grid Grid.Row="1" Margin="32,8,32,16">
             <Grid.ColumnDefinitions>
                 <ColumnDefinition Width="*"/>
                 <ColumnDefinition Width="Auto"/>
             </Grid.ColumnDefinitions>
             <StackPanel>
-                <TextBlock Text="JPEG로 변환" Style="{StaticResource TextTitle}"/>
-                <TextBlock x:Name="FilesSummaryText" Style="{StaticResource TextCaption}" Margin="0,2,0,0"/>
+                <TextBlock Text="JPEG로 변환"
+                           FontFamily="{StaticResource FsFontSans}"
+                           FontSize="20" FontWeight="SemiBold"
+                           Foreground="{StaticResource FsTextPrimary}"/>
+                <TextBlock x:Name="FilesSummaryText" Margin="0,2,0,0"
+                           Style="{StaticResource FsCaptionStyle}"/>
             </StackPanel>
             <StackPanel Grid.Column="1" Orientation="Horizontal" VerticalAlignment="Center">
-                <ui:Button Content="추가" Icon="{ui:SymbolIcon Add24}"
-                           Click="OnAddFilesClick" Margin="0,0,8,0"/>
-                <ui:Button Content="비우기" Icon="{ui:SymbolIcon Delete24}"
-                           Click="OnClearFilesClick"/>
+                <Button Content="+ 추가" Margin="0,0,8,0"
+                        Style="{StaticResource FsSecondaryButtonStyle}"
+                        Click="OnAddFilesClick"/>
+                <Button Content="비우기"
+                        Style="{StaticResource FsSecondaryButtonStyle}"
+                        Click="OnClearFilesClick"/>
             </StackPanel>
         </Grid>
 
-        <!-- 2: 옵션 바 (고정 핵심 옵션 + 고급 expander) -->
-        <ui:Card Grid.Row="2" Margin="32,0,32,12" Padding="16,12">
+        <!-- 2: 옵션 카드 -->
+        <Border Grid.Row="2" Margin="32,0,32,16"
+                Background="{StaticResource FsBgPanel}"
+                BorderBrush="{StaticResource FsBorderSubtle}"
+                BorderThickness="1" CornerRadius="8" Padding="20">
             <StackPanel>
                 <Grid>
                     <Grid.ColumnDefinitions>
@@ -53,128 +72,194 @@
                     </Grid.ColumnDefinitions>
 
                     <!-- 품질 -->
-                    <StackPanel Grid.Column="0" Margin="0,0,8,0">
-                        <TextBlock Text="JPEG 품질" Style="{StaticResource TextCaption}"/>
-                        <Grid Margin="0,2,0,0">
+                    <StackPanel Grid.Column="0" Margin="0,0,12,0">
+                        <Grid>
                             <Grid.ColumnDefinitions>
                                 <ColumnDefinition Width="*"/>
-                                <ColumnDefinition Width="32"/>
+                                <ColumnDefinition Width="Auto"/>
                             </Grid.ColumnDefinitions>
-                            <Slider x:Name="QualitySlider" Minimum="50" Maximum="100" Value="92"
-                                    SmallChange="1" LargeChange="5" VerticalAlignment="Center"/>
-                            <TextBlock Grid.Column="1" Text="{Binding ElementName=QualitySlider, Path=Value, StringFormat={}{0:0}}"
-                                       FontWeight="SemiBold" VerticalAlignment="Center" HorizontalAlignment="Right"/>
+                            <TextBlock Text="JPEG 품질" Style="{StaticResource FsLabelStyle}"/>
+                            <Border Grid.Column="1" CornerRadius="4"
+                                    Background="{StaticResource FsBgInput}"
+                                    BorderBrush="{StaticResource FsBorderSubtle}"
+                                    BorderThickness="1" Padding="6,1">
+                                <TextBlock x:Name="QualityValueText"
+                                           FontFamily="{StaticResource FsFontMono}" FontSize="11"
+                                           Foreground="{StaticResource FsAccentBlue}"
+                                           Text="92"/>
+                            </Border>
                         </Grid>
+                        <Slider x:Name="QualitySlider" Margin="0,8,0,0"
+                                Style="{StaticResource FsSliderStyle}"
+                                Minimum="50" Maximum="100" Value="92"
+                                ValueChanged="OnQualityChanged"/>
                     </StackPanel>
 
                     <!-- 출력 위치 -->
-                    <StackPanel Grid.Column="1" Margin="8,0,8,0">
-                        <TextBlock Text="출력 위치" Style="{StaticResource TextCaption}"/>
-                        <ComboBox x:Name="OutputModeCombo" SelectedIndex="0" Margin="0,2,0,0">
-                            <ComboBoxItem Content="원본 폴더 안 _jpeg 하위 폴더"/>
-                            <ComboBoxItem Content="원본과 같은 폴더"/>
-                            <ComboBoxItem Content="사용자 지정 폴더…"/>
-                        </ComboBox>
+                    <StackPanel Grid.Column="1" Margin="6,0,6,0">
+                        <TextBlock Text="출력 위치" Style="{StaticResource FsLabelStyle}"/>
+                        <Border Margin="0,8,0,0"
+                                Background="{StaticResource FsBgInput}"
+                                BorderBrush="{StaticResource FsBorderSubtle}"
+                                BorderThickness="1" CornerRadius="6" Padding="2">
+                            <UniformGrid Rows="1" Columns="3">
+                                <ToggleButton x:Name="OutputSubBtn" Content="하위"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              IsChecked="True"
+                                              Click="OnOutputSegmentClick" Tag="Sub"
+                                              ToolTip="원본 폴더 안 _jpeg 하위 폴더"/>
+                                <ToggleButton x:Name="OutputSameBtn" Content="동일"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              Click="OnOutputSegmentClick" Tag="Same"
+                                              ToolTip="원본과 같은 폴더"/>
+                                <ToggleButton x:Name="OutputCustomBtn" Content="지정"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              Click="OnOutputSegmentClick" Tag="Custom"
+                                              ToolTip="사용자 지정 폴더"/>
+                            </UniformGrid>
+                        </Border>
                     </StackPanel>
 
-                    <!-- 충돌 -->
-                    <StackPanel Grid.Column="2" Margin="8,0,0,0">
-                        <TextBlock Text="이름 충돌" Style="{StaticResource TextCaption}"/>
-                        <ComboBox x:Name="CollisionCombo" SelectedIndex="0" Margin="0,2,0,0">
-                            <ComboBoxItem Content="번호 붙여 새 파일"/>
-                            <ComboBoxItem Content="덮어쓰기"/>
-                            <ComboBoxItem Content="건너뛰기"/>
-                        </ComboBox>
+                    <!-- 이름 충돌 -->
+                    <StackPanel Grid.Column="2" Margin="12,0,0,0">
+                        <TextBlock Text="이름 충돌" Style="{StaticResource FsLabelStyle}"/>
+                        <Border Margin="0,8,0,0"
+                                Background="{StaticResource FsBgInput}"
+                                BorderBrush="{StaticResource FsBorderSubtle}"
+                                BorderThickness="1" CornerRadius="6" Padding="2">
+                            <UniformGrid Rows="1" Columns="3">
+                                <ToggleButton x:Name="ConflictRenameBtn" Content="번호"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              IsChecked="True"
+                                              Click="OnConflictSegmentClick" Tag="Rename"/>
+                                <ToggleButton x:Name="ConflictReplaceBtn" Content="덮어쓰기"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              Click="OnConflictSegmentClick" Tag="Replace"/>
+                                <ToggleButton x:Name="ConflictSkipBtn" Content="건너뛰기"
+                                              Style="{StaticResource FsSegmentStyle}"
+                                              Click="OnConflictSegmentClick" Tag="Skip"/>
+                            </UniformGrid>
+                        </Border>
                     </StackPanel>
                 </Grid>
 
-                <!-- 사용자 지정 폴더 (옵션) -->
-                <Grid Margin="0,8,0,0" x:Name="CustomFolderRow" Visibility="Collapsed">
+                <!-- 사용자 지정 폴더 -->
+                <Grid Margin="0,12,0,0" x:Name="CustomFolderRow" Visibility="Collapsed">
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="*"/>
                         <ColumnDefinition Width="Auto"/>
                     </Grid.ColumnDefinitions>
-                    <TextBox x:Name="CustomFolderTextBox"/>
-                    <ui:Button Grid.Column="1" Content="찾아보기" Margin="6,0,0,0" Click="OnBrowseClick"/>
+                    <TextBox x:Name="CustomFolderTextBox"
+                             Style="{StaticResource FsPathInputStyle}"/>
+                    <Button Grid.Column="1" Margin="8,0,0,0" Width="40"
+                            Content="…" Style="{StaticResource FsSecondaryButtonStyle}"
+                            Click="OnBrowseClick"/>
                 </Grid>
 
-                <!-- 고급 옵션 expander -->
-                <Expander Header="고급 옵션" Margin="0,8,0,0" IsExpanded="False"
-                          Foreground="{DynamicResource TextFillColorSecondaryBrush}">
-                    <Grid Margin="0,8,0,0">
+                <!-- 고급 옵션 -->
+                <Expander Margin="0,12,0,0" IsExpanded="False"
+                          Foreground="{StaticResource FsTextSecondary}">
+                    <Expander.Header>
+                        <TextBlock Text="고급 옵션" Style="{StaticResource FsLabelStyle}"/>
+                    </Expander.Header>
+                    <Grid Margin="0,12,0,0">
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="*"/>
                             <ColumnDefinition Width="*"/>
-                            <ColumnDefinition Width="*"/>
+                            <ColumnDefinition Width="Auto"/>
                         </Grid.ColumnDefinitions>
 
-                        <StackPanel Grid.Column="0" Margin="0,0,8,0">
-                            <TextBlock Text="긴 변 최대 픽셀" Style="{StaticResource TextCaption}"
+                        <StackPanel Grid.Column="0" Margin="0,0,12,0">
+                            <TextBlock Text="긴 변 최대 픽셀" Style="{StaticResource FsLabelStyle}"
                                        ToolTip="비워 두면 원본 크기 유지"/>
-                            <TextBox x:Name="MaxLongEdgeTextBox" Margin="0,2,0,0"
-                                     ToolTip="비워 두면 원본 크기 유지"/>
+                            <TextBox x:Name="MaxLongEdgeTextBox" Margin="0,8,0,0"
+                                     Style="{StaticResource FsPathInputStyle}"/>
                         </StackPanel>
 
-                        <StackPanel Grid.Column="1" Margin="8,0,8,0">
-                            <TextBlock Text="PDF 렌더 DPI" Style="{StaticResource TextCaption}"/>
-                            <Grid Margin="0,2,0,0">
+                        <StackPanel Grid.Column="1" Margin="6,0,12,0">
+                            <Grid>
                                 <Grid.ColumnDefinitions>
                                     <ColumnDefinition Width="*"/>
-                                    <ColumnDefinition Width="32"/>
+                                    <ColumnDefinition Width="Auto"/>
                                 </Grid.ColumnDefinitions>
-                                <Slider x:Name="DpiSlider" Minimum="72" Maximum="450" Value="200"
-                                        VerticalAlignment="Center"/>
-                                <TextBlock Grid.Column="1" Text="{Binding ElementName=DpiSlider, Path=Value, StringFormat={}{0:0}}"
-                                           VerticalAlignment="Center" HorizontalAlignment="Right" FontWeight="SemiBold"/>
+                                <TextBlock Text="PDF 렌더 DPI" Style="{StaticResource FsLabelStyle}"/>
+                                <TextBlock Grid.Column="1"
+                                           FontFamily="{StaticResource FsFontMono}" FontSize="11"
+                                           Foreground="{StaticResource FsAccentBlue}"
+                                           Text="{Binding ElementName=DpiSlider, Path=Value, StringFormat={}{0:0}}"/>
                             </Grid>
+                            <Slider x:Name="DpiSlider" Margin="0,8,0,0"
+                                    Style="{StaticResource FsSliderStyle}"
+                                    Minimum="72" Maximum="450" Value="200"/>
                         </StackPanel>
 
-                        <StackPanel Grid.Column="2" Margin="8,0,0,0" VerticalAlignment="Bottom">
-                            <CheckBox x:Name="FlattenCheckBox" Content="투명을 흰색으로"
-                                      IsChecked="True" Margin="0,0,0,4"/>
-                        </StackPanel>
+                        <CheckBox Grid.Column="2" x:Name="FlattenCheckBox"
+                                  Content="투명을 흰색으로"
+                                  IsChecked="True" VerticalAlignment="Bottom"
+                                  Foreground="{StaticResource FsTextSecondary}"
+                                  FontFamily="{StaticResource FsFontSans}"
+                                  FontSize="12"/>
                     </Grid>
                 </Expander>
             </StackPanel>
-        </ui:Card>
+        </Border>
 
-        <!-- 3: 파일 리스트 (메인 — 세로로 끝까지) -->
-        <ui:Card Grid.Row="3" Margin="32,0,32,0" Padding="0">
+        <!-- 3: 파일 리스트 -->
+        <Border Grid.Row="3" Margin="32,0,32,0"
+                Background="{StaticResource FsBgPanel}"
+                BorderBrush="{StaticResource FsBorderSubtle}"
+                BorderThickness="1" CornerRadius="8">
             <DockPanel>
-                <Border DockPanel.Dock="Top" Padding="20,12,20,8"
-                        BorderBrush="{DynamicResource ControlStrokeColorDefaultBrush}"
+                <Border DockPanel.Dock="Top" Padding="20,14,20,10"
+                        BorderBrush="{StaticResource FsBorderSubtle}"
                         BorderThickness="0,0,0,1">
-                    <TextBlock Text="대상 파일" Style="{StaticResource TextBodyStrong}"/>
+                    <TextBlock Text="대상 파일" Style="{StaticResource FsLabelStyle}"/>
                 </Border>
-                <ScrollViewer VerticalScrollBarVisibility="Auto" Padding="20,8,20,16">
+                <ScrollViewer VerticalScrollBarVisibility="Auto" Padding="20,12,20,16">
                     <ItemsControl x:Name="FilesList">
                         <ItemsControl.ItemTemplate>
                             <DataTemplate>
-                                <Border Margin="0,0,0,6" Padding="12,8" CornerRadius="6"
-                                        Background="{DynamicResource SubtleFillColorTransparentBrush}"
-                                        BorderBrush="{DynamicResource ControlStrokeColorDefaultBrush}"
+                                <Border Margin="0,0,0,8" Padding="12,10" CornerRadius="6"
+                                        Background="{StaticResource FsBgSurface}"
+                                        BorderBrush="{StaticResource FsBorderSubtle}"
                                         BorderThickness="1">
                                     <Grid>
                                         <Grid.ColumnDefinitions>
-                                            <ColumnDefinition Width="44"/>
+                                            <ColumnDefinition Width="40"/>
                                             <ColumnDefinition Width="*"/>
                                             <ColumnDefinition Width="Auto"/>
                                         </Grid.ColumnDefinitions>
-                                        <Border Width="40" Height="40" CornerRadius="4"
-                                                Background="{DynamicResource ControlFillColorDefaultBrush}">
-                                            <Image Source="{Binding Thumbnail}" Stretch="UniformToFill"/>
+
+                                        <Border Width="32" Height="32" CornerRadius="4"
+                                                Background="{Binding FormatBrush}"
+                                                VerticalAlignment="Center">
+                                            <Grid>
+                                                <Image Source="{Binding Thumbnail}" Stretch="UniformToFill"/>
+                                                <TextBlock Text="{Binding FormatLabel}"
+                                                           Foreground="White" FontSize="9"
+                                                           FontWeight="SemiBold"
+                                                           HorizontalAlignment="Center"
+                                                           VerticalAlignment="Center"
+                                                           Visibility="{Binding ShowFormatLabel}"/>
+                                            </Grid>
                                         </Border>
-                                        <StackPanel Grid.Column="1" Margin="12,0,8,0" VerticalAlignment="Center">
-                                            <TextBlock Text="{Binding FileName}" FontWeight="SemiBold"
+
+                                        <StackPanel Grid.Column="1" Margin="14,0,8,0"
+                                                    VerticalAlignment="Center">
+                                            <TextBlock Text="{Binding FileName}"
+                                                       FontFamily="{StaticResource FsFontSans}"
+                                                       FontSize="13" FontWeight="Medium"
+                                                       Foreground="{StaticResource FsTextPrimary}"
                                                        TextTrimming="CharacterEllipsis"/>
-                                            <TextBlock Text="{Binding SubText}" FontSize="11"
-                                                       Foreground="{DynamicResource TextFillColorSecondaryBrush}"
+                                            <TextBlock Text="{Binding SubText}"
+                                                       FontSize="11" Margin="0,2,0,0"
+                                                       Foreground="{StaticResource FsTextTertiary}"
                                                        TextTrimming="CharacterEllipsis"/>
                                             <TextBlock Text="{Binding State}" FontSize="11" Margin="0,2,0,0">
                                                 <TextBlock.Style>
                                                     <Style TargetType="TextBlock">
                                                         <Setter Property="Foreground"
-                                                                Value="{DynamicResource TextFillColorTertiaryBrush}"/>
+                                                                Value="{StaticResource FsTextTertiary}"/>
                                                         <Style.Triggers>
                                                             <DataTrigger Binding="{Binding IsFailed}" Value="True">
                                                                 <Setter Property="Foreground" Value="#F87171"/>
@@ -184,9 +269,19 @@
                                                 </TextBlock.Style>
                                             </TextBlock>
                                         </StackPanel>
-                                        <ui:Button Grid.Column="2" Icon="{ui:SymbolIcon Dismiss20}"
-                                                   Appearance="Transparent" Click="OnRemoveEntry"
-                                                   ToolTip="목록에서 제거"/>
+
+                                        <Button Grid.Column="2"
+                                                Style="{StaticResource FsSecondaryButtonStyle}"
+                                                Background="Transparent"
+                                                BorderThickness="0"
+                                                Padding="6"
+                                                Click="OnRemoveEntry"
+                                                ToolTip="목록에서 제거">
+                                            <Path Width="14" Height="14" Stretch="Uniform"
+                                                  Stroke="{StaticResource FsTextTertiary}"
+                                                  StrokeThickness="2"
+                                                  Data="M18,6 L6,18 M6,6 L18,18"/>
+                                        </Button>
                                     </Grid>
                                 </Border>
                             </DataTemplate>
@@ -194,31 +289,33 @@
                     </ItemsControl>
                 </ScrollViewer>
             </DockPanel>
-        </ui:Card>
+        </Border>
 
-        <!-- 4: 액션 바 (하단 고정) -->
-        <Border Grid.Row="4" Background="{DynamicResource LayerOnAcrylicFillColorDefaultBrush}"
-                BorderThickness="0,1,0,0"
-                BorderBrush="{DynamicResource ControlStrokeColorDefaultBrush}"
-                Padding="32,16" Margin="0,16,0,0">
+        <!-- 4: 액션바 -->
+        <Border Grid.Row="4" Padding="32,16,32,20" Margin="0,16,0,0"
+                BorderBrush="{StaticResource FsBorderSubtle}" BorderThickness="0,1,0,0"
+                Background="{StaticResource FsBgPanel}">
             <Grid>
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="*"/>
                     <ColumnDefinition Width="Auto"/>
                 </Grid.ColumnDefinitions>
                 <StackPanel VerticalAlignment="Center">
-                    <ProgressBar x:Name="OverallProgress" Height="6" Minimum="0" Maximum="1"
-                                 IsIndeterminate="False"/>
-                    <TextBlock x:Name="ProgressStatusText" Style="{StaticResource TextCaption}"
-                               Margin="0,6,0,0" TextTrimming="CharacterEllipsis"/>
+                    <ProgressBar x:Name="OverallProgress" Height="3"
+                                 Background="{StaticResource FsBgInput}"
+                                 Foreground="{StaticResource FsAccentBlue}"
+                                 Minimum="0" Maximum="1"/>
+                    <TextBlock x:Name="ProgressStatusText" Margin="0,8,0,0"
+                               Style="{StaticResource FsCaptionStyle}"
+                               TextTrimming="CharacterEllipsis"/>
                 </StackPanel>
                 <StackPanel Grid.Column="1" Orientation="Horizontal" Margin="20,0,0,0">
-                    <ui:Button x:Name="CancelButton" Content="닫기" Click="OnCancelClick"
-                               Margin="0,0,8,0" Padding="20,6"/>
-                    <ui:Button x:Name="ConvertButton" Content="변환 시작"
-                               Icon="{ui:SymbolIcon ArrowRight24}"
-                               Appearance="Primary" Click="OnConvertClick"
-                               Padding="24,6"/>
+                    <Button x:Name="CancelButton" Content="닫기" Click="OnCancelClick"
+                            Margin="0,0,8,0" MinWidth="80"
+                            Style="{StaticResource FsSecondaryButtonStyle}"/>
+                    <Button x:Name="ConvertButton" Content="→ 변환 시작"
+                            Click="OnConvertClick" MinWidth="120"
+                            Style="{StaticResource FsPrimaryButtonStyle}"/>
                 </StackPanel>
             </Grid>
         </Border>
diff --git a/src/EverythingToJpeg.App/Views/ConvertWindow.xaml.cs b/src/EverythingToJpeg.App/Views/ConvertWindow.xaml.cs
index e3ede57..8670321 100644
--- a/src/EverythingToJpeg.App/Views/ConvertWindow.xaml.cs
+++ b/src/EverythingToJpeg.App/Views/ConvertWindow.xaml.cs
@@ -1,35 +1,46 @@
 using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Globalization;
+using System.Runtime.CompilerServices;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
 using System.Windows.Input;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using EverythingToJpeg.Core;
-using EverythingToJpeg.Core.Providers;
 using Wpf.Ui.Controls;
 
 namespace EverythingToJpeg.App.Views;
 
 public partial class ConvertWindow : FluentWindow
 {
+    private static readonly string DialogLogPath =
+        Path.Combine(Path.GetTempPath(), "EverythingToJpeg_dialog.log");
+
     private readonly ConversionEngine _engine;
-    private readonly ObservableCollection<FileEntry> _entries = new();
+    private readonly ObservableCollection<ConvertFileEntry> _entries = new();
     private CancellationTokenSource? _cts;
+    private OutputLocation _outputMode = OutputLocation.SubfolderBesideSource;
+    private NameCollision _conflictRule = NameCollision.AppendNumber;
 
     public ConvertWindow(ConversionEngine engine, IReadOnlyList<string> initialFiles)
     {
         _engine = engine;
         InitializeComponent();
-
         FilesList.ItemsSource = _entries;
-
         AddFiles(initialFiles);
-
-        OutputModeCombo.SelectionChanged += (_, _) =>
-            CustomFolderRow.Visibility = OutputModeCombo.SelectedIndex == 2
-                ? Visibility.Visible : Visibility.Collapsed;
     }
 
+    private static void DiagLog(string line)
+    {
+        try { File.AppendAllText(DialogLogPath,
+            $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}] {line}{Environment.NewLine}"); }
+        catch { }
+    }
+
+    // ============== Files ==============
+
     private void AddFiles(IEnumerable<string> paths)
     {
         var existing = new HashSet<string>(_entries.Select(e => e.Path), StringComparer.OrdinalIgnoreCase);
@@ -38,7 +49,7 @@ public partial class ConvertWindow : FluentWindow
             if (!File.Exists(p)) continue;
             if (existing.Contains(p)) continue;
 
-            var entry = new FileEntry(p, _engine);
+            var entry = ConvertFileEntry.From(p, _engine);
             _entries.Add(entry);
             _ = entry.LoadThumbnailAsync();
         }
@@ -85,7 +96,7 @@ public partial class ConvertWindow : FluentWindow
 
     private void OnRemoveEntry(object sender, RoutedEventArgs e)
     {
-        if (sender is FrameworkElement fe && fe.DataContext is FileEntry entry)
+        if (sender is FrameworkElement fe && fe.DataContext is ConvertFileEntry entry)
         {
             _entries.Remove(entry);
             UpdateSummary();
@@ -105,33 +116,74 @@ public partial class ConvertWindow : FluentWindow
         {
             if (File.Exists(p)) yield return p;
             else if (Directory.Exists(p))
-            {
                 foreach (var f in Directory.EnumerateFiles(p, "*", SearchOption.TopDirectoryOnly))
                     yield return f;
-            }
         }
     }
 
-    private static readonly string DialogLogPath =
-        Path.Combine(Path.GetTempPath(), "EverythingToJpeg_dialog.log");
+    // ============== Segments ==============
 
-    private static void DiagLog(string line)
+    private void OnQualityChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
     {
-        try
-        {
-            File.AppendAllText(DialogLogPath,
-                $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}] {line}{Environment.NewLine}");
-        }
-        catch { }
+        if (QualityValueText is null) return;
+        QualityValueText.Text = ((int)e.NewValue).ToString(CultureInfo.InvariantCulture);
     }
 
+    private void OnOutputSegmentClick(object sender, RoutedEventArgs e)
+    {
+        if (sender is not ToggleButton clicked) return;
+        OutputSubBtn.IsChecked = clicked == OutputSubBtn;
+        OutputSameBtn.IsChecked = clicked == OutputSameBtn;
+        OutputCustomBtn.IsChecked = clicked == OutputCustomBtn;
+
+        _outputMode = (clicked.Tag as string) switch
+        {
+            "Same" => OutputLocation.SameFolderAsSource,
+            "Custom" => OutputLocation.Custom,
+            _ => OutputLocation.SubfolderBesideSource,
+        };
+        CustomFolderRow.Visibility = _outputMode == OutputLocation.Custom
+            ? Visibility.Visible : Visibility.Collapsed;
+    }
+
+    private void OnConflictSegmentClick(object sender, RoutedEventArgs e)
+    {
+        if (sender is not ToggleButton clicked) return;
+        ConflictRenameBtn.IsChecked = clicked == ConflictRenameBtn;
+        ConflictReplaceBtn.IsChecked = clicked == ConflictReplaceBtn;
+        ConflictSkipBtn.IsChecked = clicked == ConflictSkipBtn;
+        _conflictRule = (clicked.Tag as string) switch
+        {
+            "Skip" => NameCollision.Skip,
+            "Replace" => NameCollision.Overwrite,
+            _ => NameCollision.AppendNumber,
+        };
+    }
+
+    private ConvertOptions BuildOptions()
+    {
+        var opts = new ConvertOptions
+        {
+            Quality = (int)QualitySlider.Value,
+            PdfDpi = (int)DpiSlider.Value,
+            FlattenTransparency = FlattenCheckBox.IsChecked == true,
+            OutputLocation = _outputMode,
+            OnCollision = _conflictRule,
+        };
+        if (_outputMode == OutputLocation.Custom)
+            opts.CustomOutputDirectory = CustomFolderTextBox.Text;
+        if (int.TryParse(MaxLongEdgeTextBox.Text, out var maxEdge) && maxEdge > 0)
+            opts.MaxLongEdgePixels = maxEdge;
+        return opts;
+    }
+
+    // ============== Convert ==============
+
     private async void OnConvertClick(object sender, RoutedEventArgs e)
     {
         DiagLog($"OnConvertClick: entries={_entries.Count}");
-
         if (_entries.Count == 0)
         {
-            DiagLog("  → no entries, showing info");
             ShowInfo("변환할 파일이 없습니다.");
             return;
         }
@@ -145,7 +197,7 @@ public partial class ConvertWindow : FluentWindow
         try
         {
             options = BuildOptions();
-            DiagLog($"  options: Quality={options.Quality} OutputLocation={options.OutputLocation} Custom={options.CustomOutputDirectory} Collision={options.OnCollision} MaxLong={options.MaxLongEdgePixels} PdfDpi={options.PdfDpi}");
+            DiagLog($"  options: Quality={options.Quality} OutputLocation={options.OutputLocation} Custom={options.CustomOutputDirectory} Collision={options.OnCollision}");
         }
         catch (Exception ex)
         {
@@ -171,24 +223,19 @@ public partial class ConvertWindow : FluentWindow
             DiagLog($"  starting ConvertManyAsync, {sources.Count} files");
             var results = await _engine.ConvertManyAsync(sources, options, reporter, _cts.Token);
             DiagLog($"  finished, {results.Count} results");
-            foreach (var r in results)
-                DiagLog($"    [{r.Status}] {Path.GetFileName(r.SourcePath)} msg={r.Message}");
             ApplyResults(results);
             ProgressStatusText.Text = SummarizeResults(results);
         }
         catch (OperationCanceledException)
         {
-            DiagLog("  canceled");
             ProgressStatusText.Text = "변환이 취소되었습니다.";
         }
         catch (Exception ex)
         {
             DiagLog("  EXCEPTION: " + ex);
             ProgressStatusText.Text = "오류: " + ex.Message;
-            MessageBox.Show(this,
-                "변환 중 오류가 발생했습니다:\n\n" + ex.Message + "\n\n로그: " + DialogLogPath,
-                "EverythingToJpeg",
-                MessageBoxButton.OK, MessageBoxImage.Error);
+            MessageBox.Show(this, "변환 중 오류:\n\n" + ex.Message + "\n\n로그: " + DialogLogPath,
+                "EverythingToJpeg", MessageBoxButton.OK, MessageBoxImage.Error);
         }
         finally
         {
@@ -241,84 +288,68 @@ public partial class ConvertWindow : FluentWindow
         Close();
     }
 
-    private ConvertOptions BuildOptions()
-    {
-        var opts = new ConvertOptions
-        {
-            Quality = (int)QualitySlider.Value,
-            PdfDpi = (int)DpiSlider.Value,
-            FlattenTransparency = FlattenCheckBox.IsChecked == true,
-        };
-        opts.OutputLocation = OutputModeCombo.SelectedIndex switch
-        {
-            1 => OutputLocation.SameFolderAsSource,
-            2 => OutputLocation.Custom,
-            _ => OutputLocation.SubfolderBesideSource,
-        };
-        if (opts.OutputLocation == OutputLocation.Custom)
-            opts.CustomOutputDirectory = CustomFolderTextBox.Text;
-
-        opts.OnCollision = CollisionCombo.SelectedIndex switch
-        {
-            1 => NameCollision.Overwrite,
-            2 => NameCollision.Skip,
-            _ => NameCollision.AppendNumber,
-        };
-
-        if (int.TryParse(MaxLongEdgeTextBox.Text, out var maxEdge) && maxEdge > 0)
-            opts.MaxLongEdgePixels = maxEdge;
-
-        return opts;
-    }
-
     private void ShowInfo(string message)
         => MessageBox.Show(this, message, "EverythingToJpeg",
             MessageBoxButton.OK, MessageBoxImage.Information);
-
 }
 
-public sealed class FileEntry : System.ComponentModel.INotifyPropertyChanged
+public sealed class ConvertFileEntry : INotifyPropertyChanged
 {
-    private readonly ConversionEngine _engine;
     private string _state = "대기";
     private bool _isFailed;
     private ImageSource? _thumbnail;
 
-    public FileEntry(string path, ConversionEngine engine)
+    public required string Path { get; init; }
+    public required string FileName { get; init; }
+    public required string SubText { get; init; }
+    public required string FormatLabel { get; init; }
+    public required Brush FormatBrush { get; init; }
+
+    public string State
     {
-        Path = path;
-        _engine = engine;
+        get => _state;
+        set { _state = value; Raise(nameof(State)); }
     }
 
-    public string Path { get; }
-    public string FileName => System.IO.Path.GetFileName(Path);
-
-    public string SubText
+    public bool IsFailed
     {
-        get
+        get => _isFailed;
+        set { _isFailed = value; Raise(nameof(IsFailed)); }
+    }
+
+    public ImageSource? Thumbnail
+    {
+        get => _thumbnail;
+        set { _thumbnail = value; Raise(nameof(Thumbnail)); Raise(nameof(ShowFormatLabel)); }
+    }
+
+    public Visibility ShowFormatLabel => _thumbnail is null ? Visibility.Visible : Visibility.Collapsed;
+
+    public static ConvertFileEntry From(string path, ConversionEngine engine)
+    {
+        var ext = System.IO.Path.GetExtension(path).TrimStart('.').ToLowerInvariant();
+        var (label, brushKey) = FormatPalette.For(ext);
+
+        string handler;
+        if (engine.Providers.TryGetForFile(path, out var provider) && provider is not null)
+            handler = provider.Capability.DisplayName;
+        else
+            handler = "지원되지 않음";
+
+        long size = 0;
+        try { size = new FileInfo(path).Length; } catch { }
+        var sub = $".{ext}  ·  {handler}  ·  {MainWindow.HumanizeBytes(size)}";
+
+        return new ConvertFileEntry
         {
-            var ext = System.IO.Path.GetExtension(Path).ToLowerInvariant();
-            string handler;
-            if (_engine.Providers.TryGetForFile(Path, out var provider) && provider is not null)
-                handler = provider.Capability.DisplayName;
-            else
-                handler = "지원되지 않음";
-            try
-            {
-                var size = new FileInfo(Path).Length;
-                return $"{ext}  ·  {handler}  ·  {FormatBytes(size)}";
-            }
-            catch
-            {
-                return $"{ext}  ·  {handler}";
-            }
-        }
+            Path = path,
+            FileName = System.IO.Path.GetFileName(path),
+            SubText = sub,
+            FormatLabel = label,
+            FormatBrush = (Brush)Application.Current.FindResource(brushKey),
+        };
     }
 
-    public string State { get => _state; set { _state = value; Raise(nameof(State)); } }
-    public bool IsFailed { get => _isFailed; set { _isFailed = value; Raise(nameof(IsFailed)); } }
-    public ImageSource? Thumbnail { get => _thumbnail; set { _thumbnail = value; Raise(nameof(Thumbnail)); } }
-
     public Task LoadThumbnailAsync() => Task.Run(() =>
     {
         try
@@ -333,21 +364,13 @@ public sealed class FileEntry : System.ComponentModel.INotifyPropertyChanged
                 bmp.CacheOption = BitmapCacheOption.OnLoad;
                 bmp.EndInit();
                 bmp.Freeze();
-                System.Windows.Application.Current.Dispatcher.Invoke(() => Thumbnail = bmp);
+                Application.Current.Dispatcher.Invoke(() => Thumbnail = bmp);
             }
         }
         catch { }
     });
 
-    private static string FormatBytes(long bytes)
-    {
-        string[] units = { "B", "KB", "MB", "GB" };
-        double size = bytes;
-        var unit = 0;
-        while (size >= 1024 && unit < units.Length - 1) { size /= 1024; unit++; }
-        return $"{size:0.#} {units[unit]}";
-    }
-
-    public event System.ComponentModel.PropertyChangedEventHandler? PropertyChanged;
-    private void Raise(string n) => PropertyChanged?.Invoke(this, new System.ComponentModel.PropertyChangedEventArgs(n));
+    public event PropertyChangedEventHandler? PropertyChanged;
+    private void Raise([CallerMemberName] string? n = null)
+        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(n));
 }
diff --git a/src/EverythingToJpeg.App/Views/MainWindow.xaml b/src/EverythingToJpeg.App/Views/MainWindow.xaml
index 6816237..87b191d 100644
--- a/src/EverythingToJpeg.App/Views/MainWindow.xaml
+++ b/src/EverythingToJpeg.App/Views/MainWindow.xaml
@@ -246,18 +246,6 @@
                                         </Border>
                                     </StackPanel>
                                 </ToggleButton>
-                                <ToggleButton x:Name="TabPreviewBtn" Margin="8,0,0,0"
-                                              Style="{StaticResource FsTabPillStyle}"
-                                              Click="OnTabClick" Tag="Preview">
-                                    <StackPanel Orientation="Horizontal">
-                                        <TextBlock Text="Preview" VerticalAlignment="Center"/>
-                                        <Border Margin="8,0,0,0" Style="{StaticResource FsTabBadgeStyle}">
-                                            <TextBlock x:Name="TabPreviewBadge" Text="0"
-                                                       FontSize="10" FontWeight="SemiBold"
-                                                       Foreground="{StaticResource FsTextTertiary}"/>
-                                        </Border>
-                                    </StackPanel>
-                                </ToggleButton>
                                 <ToggleButton x:Name="TabPastBtn" Margin="8,0,0,0"
                                               IsChecked="True"
                                               Style="{StaticResource FsTabPillStyle}"
@@ -292,8 +280,15 @@
                     </Grid>
                 </Border>
 
-                <!-- View content -->
+                <!-- View content (좌측: 탭 컨텐츠 / 우측: Preview 컬럼) -->
                 <Grid Grid.Row="1">
+                    <Grid.ColumnDefinitions>
+                        <ColumnDefinition Width="*" MinWidth="360"/>
+                        <ColumnDefinition Width="380"/>
+                    </Grid.ColumnDefinitions>
+
+                    <!-- 좌측: Active Queue OR Past Results -->
+                    <Grid Grid.Column="0">
                     <!-- Active Queue view -->
                     <Grid x:Name="ActiveQueueView" Visibility="Collapsed">
                         <Grid x:Name="DropZoneEmpty">
@@ -323,7 +318,7 @@
                                                 BorderBrush="{StaticResource FsBorderSubtle}"
                                                 BorderThickness="1"
                                                 Cursor="Hand"
-                                                MouseLeftButtonUp="OnQueueRowClick"
+                                                PreviewMouseLeftButtonUp="OnQueueRowClick"
                                                 Tag="{Binding}">
                                             <Grid>
                                                 <Grid.ColumnDefinitions>
@@ -381,129 +376,6 @@
                         </ScrollViewer>
                     </Grid>
 
-                    <!-- Preview view -->
-                    <Grid x:Name="PreviewView" Visibility="Collapsed" Background="{StaticResource FsBgBase}">
-                        <Grid Margin="32">
-                            <Grid.ColumnDefinitions>
-                                <ColumnDefinition Width="*"/>
-                                <ColumnDefinition Width="320"/>
-                            </Grid.ColumnDefinitions>
-
-                            <!-- Image area -->
-                            <Border Background="{StaticResource FsBgPanel}"
-                                    BorderBrush="{StaticResource FsBorderSubtle}"
-                                    BorderThickness="1" CornerRadius="8">
-                                <Grid>
-                                    <!-- Empty state -->
-                                    <StackPanel x:Name="PreviewEmpty" HorizontalAlignment="Center" VerticalAlignment="Center">
-                                        <Path Width="40" Height="40" Stretch="Uniform"
-                                              Stroke="{StaticResource FsTextTertiary}" StrokeThickness="1.5"
-                                              Data="M1,12 C1,12 5,4 12,4 C19,4 23,12 23,12 C23,12 19,20 12,20 C5,20 1,12 1,12 Z M12,9 A3,3 0 1,1 12,15 A3,3 0 1,1 12,9 Z"/>
-                                        <TextBlock Margin="0,12,0,0" FontSize="14" FontWeight="SemiBold"
-                                                   Foreground="{StaticResource FsTextSecondary}"
-                                                   HorizontalAlignment="Center"
-                                                   Text="No preview selected"/>
-                                        <TextBlock Margin="0,4,0,0" Style="{StaticResource FsCaptionStyle}"
-                                                   HorizontalAlignment="Center" TextAlignment="Center"
-                                                   Text="Active Queue 항목을 클릭하면&#x0a;여기에 미리보기가 표시됩니다."/>
-                                    </StackPanel>
-
-                                    <!-- Loading -->
-                                    <StackPanel x:Name="PreviewLoading" Visibility="Collapsed"
-                                                HorizontalAlignment="Center" VerticalAlignment="Center">
-                                        <ProgressBar IsIndeterminate="True" Width="200" Height="3"
-                                                     Foreground="{StaticResource FsAccentBlue}"
-                                                     Background="{StaticResource FsBgInput}"/>
-                                        <TextBlock Margin="0,12,0,0" Style="{StaticResource FsCaptionStyle}"
-                                                   HorizontalAlignment="Center"
-                                                   Text="미리보기 생성 중…"/>
-                                    </StackPanel>
-
-                                    <!-- Image -->
-                                    <Image x:Name="PreviewImage" Stretch="Uniform" Margin="24"
-                                           Visibility="Collapsed"/>
-
-                                    <!-- Reason / fallback -->
-                                    <StackPanel x:Name="PreviewReason" Visibility="Collapsed"
-                                                HorizontalAlignment="Center" VerticalAlignment="Center">
-                                        <Path Width="36" Height="36" Stretch="Uniform"
-                                              Stroke="{StaticResource FsAccentAmber}" StrokeThickness="1.5"
-                                              Data="M12,2 L22,20 L2,20 Z M12,9 L12,14 M12,17 L12,17.01"/>
-                                        <TextBlock x:Name="PreviewReasonText" Margin="0,12,0,0"
-                                                   Style="{StaticResource FsBodyStyle}"
-                                                   HorizontalAlignment="Center" TextAlignment="Center"
-                                                   TextWrapping="Wrap" MaxWidth="360"/>
-                                    </StackPanel>
-                                </Grid>
-                            </Border>
-
-                            <!-- Meta panel -->
-                            <Border Grid.Column="1" Margin="16,0,0,0"
-                                    Background="{StaticResource FsBgPanel}"
-                                    BorderBrush="{StaticResource FsBorderSubtle}"
-                                    BorderThickness="1" CornerRadius="8" Padding="20">
-                                <StackPanel>
-                                    <TextBlock Text="FILE DETAIL" Style="{StaticResource FsLabelStyle}"/>
-                                    <TextBlock x:Name="PreviewFileName" Margin="0,8,0,0"
-                                               Style="{StaticResource FsBodyStyle}"
-                                               FontWeight="SemiBold" TextWrapping="Wrap"
-                                               Text="—"/>
-                                    <TextBlock x:Name="PreviewFilePath" Margin="0,4,0,0"
-                                               FontFamily="{StaticResource FsFontMono}" FontSize="11"
-                                               Foreground="{StaticResource FsTextTertiary}"
-                                               TextWrapping="Wrap"/>
-
-                                    <Border Margin="0,16,0,16" Height="1" Background="{StaticResource FsBorderSubtle}"/>
-
-                                    <Grid>
-                                        <Grid.RowDefinitions>
-                                            <RowDefinition Height="Auto"/>
-                                            <RowDefinition Height="Auto"/>
-                                            <RowDefinition Height="Auto"/>
-                                            <RowDefinition Height="Auto"/>
-                                        </Grid.RowDefinitions>
-                                        <Grid.ColumnDefinitions>
-                                            <ColumnDefinition Width="*"/>
-                                            <ColumnDefinition Width="Auto"/>
-                                        </Grid.ColumnDefinitions>
-
-                                        <TextBlock Grid.Row="0" Grid.Column="0" Text="Format"
-                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,6"/>
-                                        <TextBlock x:Name="PreviewFormatText" Grid.Row="0" Grid.Column="1"
-                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
-                                                   Foreground="{StaticResource FsTextPrimary}" Margin="0,0,0,6"/>
-
-                                        <TextBlock Grid.Row="1" Grid.Column="0" Text="Size"
-                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,6"/>
-                                        <TextBlock x:Name="PreviewSizeText" Grid.Row="1" Grid.Column="1"
-                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
-                                                   Foreground="{StaticResource FsTextPrimary}" Margin="0,0,0,6"/>
-
-                                        <TextBlock Grid.Row="2" Grid.Column="0" Text="Dimensions"
-                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,6"/>
-                                        <TextBlock x:Name="PreviewDimText" Grid.Row="2" Grid.Column="1"
-                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
-                                                   Foreground="{StaticResource FsTextPrimary}" Text="—"
-                                                   Margin="0,0,0,6"/>
-
-                                        <TextBlock Grid.Row="3" Grid.Column="0" Text="Pages"
-                                                   Style="{StaticResource FsCaptionStyle}"/>
-                                        <TextBlock x:Name="PreviewPageText" Grid.Row="3" Grid.Column="1"
-                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
-                                                   Foreground="{StaticResource FsTextPrimary}" Text="—"/>
-                                    </Grid>
-
-                                    <Border Margin="0,20,0,16" Height="1" Background="{StaticResource FsBorderSubtle}"/>
-
-                                    <Button Content="Open in Explorer"
-                                            Style="{StaticResource FsSecondaryButtonStyle}"
-                                            Click="OnPreviewOpenFolder"
-                                            HorizontalAlignment="Stretch"/>
-                                </StackPanel>
-                            </Border>
-                        </Grid>
-                    </Grid>
-
                     <!-- Past Results view (default) -->
                     <ScrollViewer x:Name="PastResultsView" VerticalScrollBarVisibility="Auto"
                                   Padding="24">
@@ -537,7 +409,11 @@
                                             <ItemsControl.ItemTemplate>
                                                 <DataTemplate>
                                                     <Border BorderBrush="#0DFFFFFF"
-                                                            BorderThickness="0,0,0,1" Padding="0,12">
+                                                            BorderThickness="0,0,0,1" Padding="0,12"
+                                                            Cursor="Hand"
+                                                            Background="Transparent"
+                                                            PreviewMouseLeftButtonUp="OnPastRowClick"
+                                                            Tag="{Binding}">
                                                         <Grid>
                                                             <Grid.ColumnDefinitions>
                                                                 <ColumnDefinition Width="40"/>
@@ -617,8 +493,154 @@
                         </ItemsControl>
                     </ScrollViewer>
 
-                    <!-- Drop hint overlay -->
-                    <Border x:Name="DropHintOverlay" Visibility="Collapsed"
+                    </Grid>
+                    <!-- /좌측 컬럼 끝 -->
+
+                    <!-- 우측: Preview 컬럼 (항상 보임) -->
+                    <Border Grid.Column="1"
+                            Background="{StaticResource FsBgPanel}"
+                            BorderBrush="{StaticResource FsBorderSubtle}"
+                            BorderThickness="1,0,0,0">
+                        <Grid>
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto"/>
+                                <RowDefinition Height="*"/>
+                                <RowDefinition Height="Auto"/>
+                            </Grid.RowDefinitions>
+
+                            <!-- 헤더 -->
+                            <Border Grid.Row="0" Padding="20,16,20,12"
+                                    BorderBrush="{StaticResource FsBorderSubtle}"
+                                    BorderThickness="0,0,0,1">
+                                <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
+                                    <Path Width="14" Height="14" Stretch="Uniform"
+                                          Stroke="{StaticResource FsTextSecondary}" StrokeThickness="2"
+                                          Data="M1,12 C1,12 5,4 12,4 C19,4 23,12 23,12 C23,12 19,20 12,20 C5,20 1,12 1,12 Z M12,9 A3,3 0 1,1 12,15 A3,3 0 1,1 12,9 Z"/>
+                                    <TextBlock Text="PREVIEW" Margin="8,0,0,0"
+                                               Style="{StaticResource FsLabelStyle}"
+                                               VerticalAlignment="Center"/>
+                                </StackPanel>
+                            </Border>
+
+                            <!-- 이미지 영역 -->
+                            <Grid Grid.Row="1" Margin="20,16,20,16" x:Name="PreviewImageArea">
+                                <Border Background="{StaticResource FsBgInput}"
+                                        BorderBrush="{StaticResource FsBorderSubtle}"
+                                        BorderThickness="1" CornerRadius="6">
+                                    <Grid>
+                                        <!-- Empty state -->
+                                        <StackPanel x:Name="PreviewEmpty" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="20">
+                                            <Path Width="36" Height="36" Stretch="Uniform"
+                                                  Stroke="{StaticResource FsTextTertiary}" StrokeThickness="1.5"
+                                                  Data="M1,12 C1,12 5,4 12,4 C19,4 23,12 23,12 C23,12 19,20 12,20 C5,20 1,12 1,12 Z M12,9 A3,3 0 1,1 12,15 A3,3 0 1,1 12,9 Z"/>
+                                            <TextBlock Margin="0,12,0,0" FontSize="13" FontWeight="SemiBold"
+                                                       Foreground="{StaticResource FsTextSecondary}"
+                                                       HorizontalAlignment="Center"
+                                                       Text="No selection"/>
+                                            <TextBlock Margin="0,4,0,0" Style="{StaticResource FsCaptionStyle}"
+                                                       HorizontalAlignment="Center" TextAlignment="Center"
+                                                       TextWrapping="Wrap" MaxWidth="240"
+                                                       Text="Active Queue 항목을 클릭하면 여기에 미리보기가 표시됩니다."/>
+                                        </StackPanel>
+
+                                        <!-- Loading -->
+                                        <StackPanel x:Name="PreviewLoading" Visibility="Collapsed"
+                                                    HorizontalAlignment="Center" VerticalAlignment="Center">
+                                            <ProgressBar IsIndeterminate="True" Width="180" Height="3"
+                                                         Foreground="{StaticResource FsAccentBlue}"
+                                                         Background="{StaticResource FsBgSurface}"/>
+                                            <TextBlock Margin="0,12,0,0" Style="{StaticResource FsCaptionStyle}"
+                                                       HorizontalAlignment="Center"
+                                                       Text="미리보기 생성 중…"/>
+                                        </StackPanel>
+
+                                        <!-- Image -->
+                                        <Image x:Name="PreviewImage" Stretch="Uniform" Margin="16"
+                                               Visibility="Collapsed"/>
+
+                                        <!-- Reason -->
+                                        <StackPanel x:Name="PreviewReason" Visibility="Collapsed"
+                                                    HorizontalAlignment="Center" VerticalAlignment="Center" Margin="20">
+                                            <Path Width="32" Height="32" Stretch="Uniform"
+                                                  Stroke="{StaticResource FsAccentAmber}" StrokeThickness="1.5"
+                                                  Data="M12,2 L22,20 L2,20 Z M12,9 L12,14 M12,17 L12,17.01"/>
+                                            <TextBlock x:Name="PreviewReasonText" Margin="0,12,0,0"
+                                                       Style="{StaticResource FsBodyStyle}"
+                                                       FontSize="12"
+                                                       HorizontalAlignment="Center" TextAlignment="Center"
+                                                       TextWrapping="Wrap" MaxWidth="280"/>
+                                        </StackPanel>
+                                    </Grid>
+                                </Border>
+                            </Grid>
+
+                            <!-- 메타 -->
+                            <Border Grid.Row="2" Padding="20,12,20,20"
+                                    BorderBrush="{StaticResource FsBorderSubtle}"
+                                    BorderThickness="0,1,0,0">
+                                <StackPanel>
+                                    <TextBlock x:Name="PreviewFileName"
+                                               Style="{StaticResource FsBodyStyle}"
+                                               FontWeight="SemiBold" TextWrapping="NoWrap"
+                                               TextTrimming="CharacterEllipsis"
+                                               Text="—"/>
+                                    <TextBlock x:Name="PreviewFilePath" Margin="0,4,0,0"
+                                               FontFamily="{StaticResource FsFontMono}" FontSize="11"
+                                               Foreground="{StaticResource FsTextTertiary}"
+                                               TextTrimming="CharacterEllipsis" MaxHeight="32"/>
+
+                                    <Border Margin="0,12,0,12" Height="1"
+                                            Background="{StaticResource FsBorderSubtle}"/>
+
+                                    <Grid>
+                                        <Grid.RowDefinitions>
+                                            <RowDefinition Height="Auto"/>
+                                            <RowDefinition Height="Auto"/>
+                                            <RowDefinition Height="Auto"/>
+                                            <RowDefinition Height="Auto"/>
+                                        </Grid.RowDefinitions>
+                                        <Grid.ColumnDefinitions>
+                                            <ColumnDefinition Width="*"/>
+                                            <ColumnDefinition Width="Auto"/>
+                                        </Grid.ColumnDefinitions>
+
+                                        <TextBlock Grid.Row="0" Grid.Column="0" Text="Format"
+                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,4"/>
+                                        <TextBlock x:Name="PreviewFormatText" Grid.Row="0" Grid.Column="1"
+                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                                                   Foreground="{StaticResource FsTextPrimary}" Margin="0,0,0,4"/>
+
+                                        <TextBlock Grid.Row="1" Grid.Column="0" Text="Size"
+                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,4"/>
+                                        <TextBlock x:Name="PreviewSizeText" Grid.Row="1" Grid.Column="1"
+                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                                                   Foreground="{StaticResource FsTextPrimary}" Margin="0,0,0,4"/>
+
+                                        <TextBlock Grid.Row="2" Grid.Column="0" Text="Dimensions"
+                                                   Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,4"/>
+                                        <TextBlock x:Name="PreviewDimText" Grid.Row="2" Grid.Column="1"
+                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                                                   Foreground="{StaticResource FsTextPrimary}" Text="—"
+                                                   Margin="0,0,0,4"/>
+
+                                        <TextBlock Grid.Row="3" Grid.Column="0" Text="Pages"
+                                                   Style="{StaticResource FsCaptionStyle}"/>
+                                        <TextBlock x:Name="PreviewPageText" Grid.Row="3" Grid.Column="1"
+                                                   FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                                                   Foreground="{StaticResource FsTextPrimary}" Text="—"/>
+                                    </Grid>
+
+                                    <Button Content="Open in Explorer" Margin="0,16,0,0"
+                                            Style="{StaticResource FsSecondaryButtonStyle}"
+                                            Click="OnPreviewOpenFolder"
+                                            HorizontalAlignment="Stretch"/>
+                                </StackPanel>
+                            </Border>
+                        </Grid>
+                    </Border>
+
+                    <!-- Drop hint overlay (전체 덮음) -->
+                    <Border x:Name="DropHintOverlay" Visibility="Collapsed" Grid.ColumnSpan="2"
                             Background="#CC090A0C" IsHitTestVisible="False">
                         <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
                             <Path Width="64" Height="64" Stretch="Uniform"
diff --git a/src/EverythingToJpeg.App/Views/MainWindow.xaml.cs b/src/EverythingToJpeg.App/Views/MainWindow.xaml.cs
index 3cd3ee6..ad1c9c7 100644
--- a/src/EverythingToJpeg.App/Views/MainWindow.xaml.cs
+++ b/src/EverythingToJpeg.App/Views/MainWindow.xaml.cs
@@ -20,7 +20,9 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
     private CancellationTokenSource? _cts;
     private NameCollision _conflictRule = NameCollision.AppendNumber;
 
-    public MainWindow()
+    public MainWindow() : this(null) { }
+
+    public MainWindow(IReadOnlyList<string>? initialFiles)
     {
         InitializeComponent();
 
@@ -30,9 +32,18 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
         SeedDemoHistory();
         UpdateBadges();
         UpdateProcessQueueButton();
-        ShowTab("Past");
-        UpdateActiveQueueVisibility();
 
+        if (initialFiles is { Count: > 0 })
+        {
+            AddToQueue(initialFiles);
+            ShowTab("Active");
+        }
+        else
+        {
+            ShowTab("Past");
+        }
+
+        UpdateActiveQueueVisibility();
         ApplyAppDataStats();
     }
 
@@ -49,11 +60,9 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
     private void ShowTab(string tag)
     {
         TabActiveBtn.IsChecked = tag == "Active";
-        TabPreviewBtn.IsChecked = tag == "Preview";
         TabPastBtn.IsChecked = tag == "Past";
 
         ActiveQueueView.Visibility = tag == "Active" ? Visibility.Visible : Visibility.Collapsed;
-        PreviewView.Visibility = tag == "Preview" ? Visibility.Visible : Visibility.Collapsed;
         PastResultsView.Visibility = tag == "Past" ? Visibility.Visible : Visibility.Collapsed;
     }
 
@@ -98,6 +107,7 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
 
     private void AddToQueue(IEnumerable<string> paths)
     {
+        var wasEmpty = _activeQueue.Count == 0;
         var existing = new HashSet<string>(_activeQueue.Select(q => q.SourcePath), StringComparer.OrdinalIgnoreCase);
         foreach (var path in paths)
         {
@@ -107,6 +117,12 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
         UpdateBadges();
         UpdateProcessQueueButton();
         UpdateActiveQueueVisibility();
+
+        if (wasEmpty && _activeQueue.Count > 0 && _selectedPreviewItem is null)
+        {
+            _selectedPreviewItem = _activeQueue[0];
+            _ = LoadPreviewAsync(_selectedPreviewItem);
+        }
     }
 
     private void OnRemoveQueueItem(object sender, RoutedEventArgs e)
@@ -130,7 +146,6 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
     private void UpdateBadges()
     {
         TabActiveBadge.Text = _activeQueue.Count.ToString(CultureInfo.InvariantCulture);
-        TabPreviewBadge.Text = "0";
         var count = _pastResults.Sum(g => g.Entries.Count);
         TabPastBadge.Text = count.ToString(CultureInfo.InvariantCulture);
     }
@@ -211,37 +226,74 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
     // ============== Preview ==============
 
     private QueueItem? _selectedPreviewItem;
+    private string? _selectedPreviewPath;
     private CancellationTokenSource? _previewCts;
 
     private async void OnQueueRowClick(object sender, MouseButtonEventArgs e)
     {
+        if (e.OriginalSource is DependencyObject src && IsInsideButton(src)) return;
         if (sender is not FrameworkElement fe || fe.Tag is not QueueItem item) return;
+
         _selectedPreviewItem = item;
-        ShowTab("Preview");
         await LoadPreviewAsync(item);
+        e.Handled = true;
     }
 
-    private async Task LoadPreviewAsync(QueueItem item)
+    private async void OnPastRowClick(object sender, MouseButtonEventArgs e)
+    {
+        if (e.OriginalSource is DependencyObject src && IsInsideButton(src)) return;
+        if (sender is not FrameworkElement fe || fe.Tag is not HistoryRow row) return;
+
+        if (row.SourcePath == "<demo>")
+        {
+            SetPreviewMeta(row.FileName, row.SourcePath, row.FormatLabel, row.SizeText);
+            ShowPreviewReason("샘플 데모 항목입니다. 원본 파일이 없으므로 미리보기를 만들 수 없습니다.");
+            _selectedPreviewPath = null;
+        }
+        else if (!File.Exists(row.SourcePath))
+        {
+            SetPreviewMeta(row.FileName, row.SourcePath, row.FormatLabel, row.SizeText);
+            ShowPreviewReason("원본 파일을 찾을 수 없습니다. 파일이 이동·삭제되었을 수 있습니다.");
+            _selectedPreviewPath = null;
+        }
+        else
+        {
+            _selectedPreviewItem = null;
+            _selectedPreviewPath = row.SourcePath;
+            await LoadPreviewByPathAsync(row.SourcePath, row.FileName, row.FormatLabel, row.SizeText);
+        }
+        e.Handled = true;
+    }
+
+    private static bool IsInsideButton(DependencyObject? node)
+    {
+        while (node is not null)
+        {
+            if (node is Button) return true;
+            node = System.Windows.Media.VisualTreeHelper.GetParent(node)
+                   ?? (node is FrameworkElement fe ? fe.Parent : null);
+        }
+        return false;
+    }
+
+    private Task LoadPreviewAsync(QueueItem item)
+    {
+        _selectedPreviewPath = item.SourcePath;
+        return LoadPreviewByPathAsync(item.SourcePath, item.FileName, item.FormatLabel, item.SizeText);
+    }
+
+    private async Task LoadPreviewByPathAsync(string sourcePath, string fileName, string formatLabel, string sizeText)
     {
         _previewCts?.Cancel();
         _previewCts = new CancellationTokenSource();
         var token = _previewCts.Token;
 
-        PreviewEmpty.Visibility = Visibility.Collapsed;
-        PreviewImage.Visibility = Visibility.Collapsed;
-        PreviewReason.Visibility = Visibility.Collapsed;
-        PreviewLoading.Visibility = Visibility.Visible;
-
-        PreviewFileName.Text = item.FileName;
-        PreviewFilePath.Text = item.SourcePath;
-        PreviewFormatText.Text = item.FormatLabel;
-        PreviewSizeText.Text = item.SizeText;
-        PreviewDimText.Text = "—";
-        PreviewPageText.Text = "—";
+        SetPreviewMeta(fileName, sourcePath, formatLabel, sizeText);
+        ShowPreviewLoading();
 
         try
         {
-            var result = await PreviewService.CreateAsync(item.SourcePath, 720, token);
+            var result = await PreviewService.CreateAsync(sourcePath, 720, token);
             if (token.IsCancellationRequested) return;
 
             PreviewLoading.Visibility = Visibility.Collapsed;
@@ -264,20 +316,47 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
         catch (Exception ex)
         {
             PreviewLoading.Visibility = Visibility.Collapsed;
-            PreviewReasonText.Text = "미리보기 오류: " + ex.Message;
-            PreviewReason.Visibility = Visibility.Visible;
+            ShowPreviewReason("미리보기 오류: " + ex.Message);
         }
     }
 
+    private void SetPreviewMeta(string fileName, string filePath, string formatLabel, string sizeText)
+    {
+        PreviewFileName.Text = fileName;
+        PreviewFilePath.Text = filePath;
+        PreviewFormatText.Text = formatLabel;
+        PreviewSizeText.Text = sizeText;
+        PreviewDimText.Text = "—";
+        PreviewPageText.Text = "—";
+    }
+
+    private void ShowPreviewLoading()
+    {
+        PreviewEmpty.Visibility = Visibility.Collapsed;
+        PreviewImage.Visibility = Visibility.Collapsed;
+        PreviewReason.Visibility = Visibility.Collapsed;
+        PreviewLoading.Visibility = Visibility.Visible;
+    }
+
+    private void ShowPreviewReason(string reason)
+    {
+        PreviewEmpty.Visibility = Visibility.Collapsed;
+        PreviewImage.Visibility = Visibility.Collapsed;
+        PreviewLoading.Visibility = Visibility.Collapsed;
+        PreviewReasonText.Text = reason;
+        PreviewReason.Visibility = Visibility.Visible;
+    }
+
     private void OnPreviewOpenFolder(object sender, RoutedEventArgs e)
     {
-        if (_selectedPreviewItem is null) return;
+        var path = _selectedPreviewPath ?? _selectedPreviewItem?.SourcePath;
+        if (string.IsNullOrEmpty(path) || !File.Exists(path)) return;
         try
         {
             System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
             {
                 FileName = "explorer.exe",
-                Arguments = $"/select,\"{_selectedPreviewItem.SourcePath}\"",
+                Arguments = $"/select,\"{path}\"",
                 UseShellExecute = true,
             });
         }