diff --git a/cimery/crates/viewer/src/lib.rs b/cimery/crates/viewer/src/lib.rs
index f53df9b..a80d866 100644
--- a/cimery/crates/viewer/src/lib.rs
+++ b/cimery/crates/viewer/src/lib.rs
@@ -429,13 +429,12 @@ impl RenderState {
                     ui.heading("교량 속성");
                     ui.separator();
 
-                    // Helper: slider that auto-applies on drag release
                     macro_rules! param_slider {
                         ($label:expr, $val:expr, $range:expr, $step:expr) => {{
                             ui.label($label);
-                            let r = ui.add(egui::Slider::new($val, $range).step_by($step));
-                            if r.drag_released() || r.lost_focus() { apply = true; dirty = true; }
-                            if r.changed() { dirty = true; }
+                            if ui.add(egui::Slider::new($val, $range).step_by($step)).changed() {
+                                dirty = true;
+                            }
                         }};
                     }
 
@@ -446,11 +445,9 @@ impl RenderState {
                     param_slider!("슬래브 두께(mm)",&mut p.slab_thickness, 150.0..=400.0,    10.0);
 
                     ui.separator();
-                    if dirty && !apply {
-                        // Manual apply button as fallback
+                    if dirty {
                         if ui.button("▶ 적용 (Apply)").clicked() { apply = true; }
-                        ui.small("* 슬라이더를 놓으면 자동 적용");
-                    } else if !dirty {
+                    } else {
                         ui.label("✓ 최신 상태");
                     }