Proceed implementing responsive theme

The responsive theme is almost ready; most pages and elements now render correctly on the vast majority of screens. There are some known issues which are in the works.

Also, a <h4> "Paragraphs" title has been aded on the left navbar.

assets/css/screen.css

@@ -244,14 +244,14 @@ is applied by the script on scroll.
 
 .mind-global-navbar_primary li.nav-services {
     /* TODO: choose if background should be colorful or white */
-    background: linear-gradient(to right, #33ffc5 20%, #fc33ff, #ff3370, #ff3333, #3dff33, #33ffc5);
     /*background: white;*/
+    /*background: linear-gradient(to right, #33ffc5 20%, #fc33ff, #ff3370, #ff3333, #3dff33, #33ffc5);
     background-size: 800px, 800px;
     color: aquamarine;
     text-fill-color: transparent;
     animation: gradient 2s linear infinite;
     -webkit-background-clip: text;
-    -webkit-text-fill-color: transparent;
+    -webkit-text-fill-color: transparent;*/
 }
 
 .mind-global-navbar_secondary {
@@ -1112,15 +1112,50 @@ div.mind-policy-popup {
     }
 }
 
+@media only screen and (max-width: 2000px)
+{
+    ul {
+        margin: 15px 0;
+    }
+}
 
 @media only screen and (max-width: 1300px) {
 
+    h1 {
+        font-size: 60px;
+    }
+
+    h2 {
+        font-size: 32px;
+    }
+
+    h3 {
+        font-size: 26px;
+    }
+
+    .mind-post-header p {
+        font-size: 13px;
+    }
+
     .mind-content_main {
         min-width: calc(100% - 40px);
         width: calc(100% - 40px);
         padding: 20px;
     }
 
+    .mind-post_central-column {
+        padding: 0 40px;
+        font-size: 17px;
+    }
+
+    .kg-gallery-image {
+        margin: 10px 10px;
+    }
+
+    .kg-gallery-row {
+        margin: 0 20px;
+    }
+
     .mind-post-card-big_main {
         margin: auto;
     }
@@ -1128,6 +1163,18 @@ div.mind-policy-popup {
 
 @media only screen and (max-width: 1000px) {
 
+    h1 {
+        font-size: 50px;
+    }
+
+    h2 {
+        font-size: 30px;
+    }
+
+    h3 {
+        font-size: 24px;
+    }
+
     h4 {
         font-size: 18px;
     }
@@ -1136,6 +1183,28 @@ div.mind-policy-popup {
         grid-template-columns: 1fr 1fr;
     }
 
+    .mind-post_main {
+        grid-template-columns: 1fr;
+    }
+
+    .mind-post_central-column {
+        padding: 0 20px;
+    }
+
+    .kg-gallery-image {
+        margin: 10px 5px;
+    }
+    .kg-gallery-row {
+        margin: 0 40px;
+    }
+
+    .mind-post_sidebar {
+        visibility: hidden;
+        height: 0;
+        max-height: 0;
+        overflow: hidden;
+    }
+
     .mind-policy-popup {
         width: 50vw;
         bottom: 10px;
@@ -1149,17 +1218,45 @@ div.mind-policy-popup {
 
 @media only screen and (max-width: 650px) {
 
+    h1 {
+        font-size: 40px;
+    }
+
+    h2 {
+        font-size: 26px;
+    }
+
+    h3 {
+        font-size: 21px;
+    }
+
+    .mind-post-header p {
+        font-size: 11px;
+    }
+
     ul {
         margin: 10px 0 10px auto;
         transition: .5s;
     }
 
-    .mind-global-navbar_primary li {
-        font-size: 20px;
+    .mind-global-navbar_primary li, .mind-global-navbar_secondary li {
+        font-size: 18px;
     }
 
     .mind-feed-content_main {
         grid-template-columns: 1fr;
+        min-width: calc(100% - 40px);
+        width: calc(100% - 40px);
+        padding: 20px;
+    }
+
+    .mind-content_main {
+        width: 100%;
+        padding: 0;
+    }
+
+    .mind-post_central-column {
+        font-size: 15px;
     }
 
     .mind-global-navbar_primary img {
@@ -1190,4 +1287,16 @@ div.mind-policy-popup {
     .mind-index-header_main h1 {
         font-size: 16vw;
     }
+
+    h2 {
+        font-size: 23px;
+    }
+
+    h3 {
+        font-size: 19px;
+    }
+
+    .mind-post_central-column {
+        font-size: 14px;
+    }
 }