diff --git a/webapp/js/dayDetail.js b/webapp/js/dayDetail.js
index 62ce691..04e6e69 100644
--- a/webapp/js/dayDetail.js
+++ b/webapp/js/dayDetail.js
@@ -17,6 +17,8 @@ let panelEl = null;
 let overlayEl = null;
 /** @type {((e: MouseEvent) => void)|null} */
 let popoverCloseHandler = null;
+/** Scroll position saved when sheet opens (for restore on close). */
+let sheetScrollY = 0;
 
 /**
  * Parse JSON from data attribute (values are stored with " for safety).
@@ -172,6 +174,11 @@ function showAsBottomSheet() {
   panelEl.style.right = "";
   panelEl.style.bottom = "0";
   panelEl.hidden = false;
+
+  sheetScrollY = window.scrollY;
+  document.body.classList.add("day-detail-sheet-open");
+  document.body.style.top = "-" + sheetScrollY + "px";
+
   const closeBtn = panelEl.querySelector(".day-detail-close");
   if (closeBtn) closeBtn.focus();
 }
@@ -204,6 +211,11 @@ export function hideDayDetail() {
     document.removeEventListener("click", popoverCloseHandler);
     popoverCloseHandler = null;
   }
+  if (document.body.classList.contains("day-detail-sheet-open")) {
+    document.body.classList.remove("day-detail-sheet-open");
+    document.body.style.top = "";
+    window.scrollTo(0, sheetScrollY);
+  }
   if (panelEl) panelEl.hidden = true;
   if (overlayEl) overlayEl.hidden = true;
 }
diff --git a/webapp/js/main.js b/webapp/js/main.js
index 1e02a02..3a7b351 100644
--- a/webapp/js/main.js
+++ b/webapp/js/main.js
@@ -178,6 +178,7 @@ async function loadMonth() {
 
 if (prevBtn) {
   prevBtn.addEventListener("click", () => {
+    if (document.body.classList.contains("day-detail-sheet-open")) return;
     if (accessDeniedEl && !accessDeniedEl.hidden) return;
     state.current.setMonth(state.current.getMonth() - 1);
     loadMonth();
@@ -185,6 +186,7 @@ if (prevBtn) {
 }
 if (nextBtn) {
   nextBtn.addEventListener("click", () => {
+    if (document.body.classList.contains("day-detail-sheet-open")) return;
     if (accessDeniedEl && !accessDeniedEl.hidden) return;
     state.current.setMonth(state.current.getMonth() + 1);
     loadMonth();
@@ -211,6 +213,7 @@ if (nextBtn) {
     "touchend",
     (e) => {
       if (e.changedTouches.length === 0) return;
+      if (document.body.classList.contains("day-detail-sheet-open")) return;
       if (accessDeniedEl && !accessDeniedEl.hidden) return;
       const t = e.changedTouches[0];
       const deltaX = t.clientX - startX;
diff --git a/webapp/style.css b/webapp/style.css
index a4756a3..8f1bcdd 100644
--- a/webapp/style.css
+++ b/webapp/style.css
@@ -212,6 +212,14 @@ body {
 }
 
 /* === Day detail panel (popover / bottom sheet) */
+/* Блокировка фона при открытом bottom sheet: прокрутка и свайпы отключены */
+body.day-detail-sheet-open {
+  position: fixed;
+  left: 0;
+  right: 0;
+  overflow: hidden;
+}
+
 .day-detail-overlay {
   position: fixed;
   inset: 0;