diff --git a/frontend/src/pages/CalendarPage.jsx b/frontend/src/pages/CalendarPage.jsx
index f33a23d..8a90aea 100644
--- a/frontend/src/pages/CalendarPage.jsx
+++ b/frontend/src/pages/CalendarPage.jsx
@@ -1416,7 +1416,7 @@ const CalendarPage = () => {
                 }}
               >
                 <div
-                  className="grid w-full min-w-0 border-l border-t border-border"
+                  className="grid w-full min-w-0"
                   style={{
                     height: calendarViewportHeight === null
                       ? '100%'
@@ -1459,16 +1459,17 @@ const CalendarPage = () => {
                     (monthIndex) => (
                       <div
                         key={MONTHS[monthIndex]}
-                        className="
+                        className={`
                           sticky top-0 z-[2]
                           flex items-center justify-center
-                          border-b border-r border-border
+                          border-b border-border
+                          ${monthIndex !== displayedMonthIndices[displayedMonthIndices.length - 1] ? 'border-r' : ''}
                           bg-background
                           px-3
                           text-center
                           text-sm
                           font-medium
-                        "
+                        `}
                         style={{
                           height: `${HEADER_HEIGHT}px`,
                         }}
@@ -1491,15 +1492,16 @@ const CalendarPage = () => {
                         >
                           {/* NUMÉRO DU JOUR */}
                           <div
-                            className="
+                            className={`
                               sticky left-0 z-[1]
                               flex items-center justify-center
-                              border-b border-r border-border
+                              border-r border-border
+                              ${dayIndex < rowCount - 1 ? 'border-b' : ''}
                               bg-card
                               px-2
                               text-xs font-medium
                               text-muted-foreground
-                            "
+                            `}
                           >
                             {day}
                           </div>
@@ -1523,10 +1525,12 @@ const CalendarPage = () => {
                                 return (
                                   <div
                                     key={`${monthIndex}-${day}`}
-                                    className="
-                                      border-b border-r border-border
+                                    className={`
+                                      border-border
+                                      ${dayIndex < rowCount - 1 ? 'border-b' : ''}
+                                      ${monthIndex !== displayedMonthIndices[displayedMonthIndices.length - 1] ? 'border-r' : ''}
                                       bg-transparent
-                                    "
+                                    `}
                                   />
                                 );
                               }
@@ -1571,7 +1575,9 @@ const CalendarPage = () => {
                                   key={`${monthIndex}-${day}`}
                                   className={`
                                     relative isolate
-                                    border-b border-r border-border
+                                    border-border
+                                    ${dayIndex < rowCount - 1 ? 'border-b' : ''}
+                                    ${monthIndex !== displayedMonthIndices[displayedMonthIndices.length - 1] ? 'border-r' : ''}
                                     bg-card
                                     px-2
                                     transition-colors