Обновил стили CSS, так как в отображение в разных браузерах - разное

html/css/course.css

@@ -272,7 +272,7 @@ hr {
 
 main {
     height: 1200px;
-    max-width: 1000px;
+    max-width: 1200px;
     margin: 0 auto;
     margin-top: 20px;
     display: flex;
@@ -287,11 +287,12 @@ main {
 main .this_course {
     display: flex;
     justify-content: space-evenly;
-    max-width: 900px;
+    max-width: 1100px;
     margin: 0 auto;
-    height: 980px;
+    height: 1100px;
     flex-direction: column;
     font-family: 'monsterrat_regular';
+    padding: 0 10px;
 }
 
 .teacher_first {
@@ -309,13 +310,13 @@ main .this_course #btn_order {
     border-radius: 17px;
     font-family: 'monsterrat_regular';
     font-size: 16px;
-    margin-top: 40px;
 }
 
 main #btn_back {
     width: 50px;
     height: 50px;
     margin-left: 100px;
+    margin-top: 15px;
 }
 
 #img2 {
@@ -327,8 +328,7 @@ main #btn_back, #btn_back button {
     width: 70px;
     height: 50px;
     border-radius: 17px;
-    position: absolute;
-    bottom: 30px;
+    position: relative;
 }
 
 #btn_back button {
@@ -549,13 +549,14 @@ footer {
     }
     main {
         margin-top: 10px;
+        height: 1300px;
         justify-content: space-between;
     }
     .this_course {
         padding: 0 10px;
     }
     #btn_back {
-        margin-bottom: 0px;
+        margin-bottom: 20px;
         margin-left: 20px !important;
     }
     #right {
@@ -664,9 +665,13 @@ footer {
     .fa-map {
         margin-right: 10px;
     }
+    main {
+        height: 1800px !important;
+    }
     .this_course {
         max-width: 250px !important;
         text-align: justify;
+        height: 1700px !important;
     }
     #img2 {
         margin-left: 0;

html/css/index.css

@@ -278,9 +278,14 @@ main {
     background-color: #ffffff;
     border-radius: 10px;
     overflow: scroll;
+    -ms-overflow-style: none;
     scrollbar-width: none;
 }
 
+main::-webkit-scrollbar {
+    display: none;
+}
+
 main > .course {
     height: 350px;
     width: 250px;