💄 Add new tool buttons in page side.

assets/css/_common/components/tool-buttons.scss

@@ -0,0 +1,88 @@
+.tool-buttons {
+
+  @include sidebar-toggle();
+  background: var(--body-bg-color);
+  bottom: 55px;
+  z-index: 100;
+  filter: alpha(opacity=0);
+  font-size: 12px;
+
+  .button {
+    display: block;
+    margin-bottom: 5px;
+    width: 36px;
+    height: 36px;
+    border-radius: 5px;
+    background-color: $tool-btn-bg;
+    color: $tool-btn-color;
+    text-align: center;
+    font-size: $font-size-larger;
+    line-height: 35px;
+    padding: 0;
+    outline: 0;
+    border: none;
+    text-transform: none;
+    cursor: pointer;
+    opacity: $tool-btn-opacity;
+    touch-action: manipulation;
+
+    &:hover {
+      color: $tool-btn-hover-fore-color;
+      opacity: $tool-btn-opacity-hover;
+    }
+  }
+
+  .goto-comments {
+      display: none;
+  }
+
+  .goto-comments-on {
+    display: block;
+  }
+}
+
+@if $back2top_enable {
+  .back-to-top {
+    font-size: $font-size-smaller;
+
+    @if not $back2top_scrollpercent {
+      span {
+        display: none;
+      }
+    }
+
+    @if $back2top_sidebar {
+      margin: 20px - $sidebar-offset -10px -20px;
+      opacity: 0;
+      transition: opacity $transition-ease;
+
+      &.back-to-top-on {
+        cursor: pointer;
+        opacity: $b2t-opacity;
+
+        &:hover {
+          opacity: $b2t-opacity-hover;
+        }
+      }
+    } @else {
+      bottom: $b2t-position-bottom;
+      box-sizing: border-box;
+      color: $b2t-color;
+      padding: 0 6px;
+      transition: bottom $transition-ease;
+      @include sidebar-toggle();
+
+      @if not $back2top_scrollpercent {
+        width: 24px;
+      }
+
+      &:hover {
+        color: $sidebar-highlight;
+      }
+
+      &.back-to-top-on {
+        bottom: $b2t-position-bottom-on;
+      }
+    }
+  }
+}