style: change css color functions to use modern notation

- `rgba()` → `rgb()`

_sass/base/_base.scss

@@ -103,7 +103,7 @@ main {
     width: 100%;
     height: 100%;
     position: absolute;
-    background-color: var(--card-hovor-bg);
+    background-color: var(--card-hover-bg);
     opacity: 0;
     transition: opacity 0.35s ease-in-out;
   }
@@ -349,7 +349,7 @@ main {
 }
 
 .disabled {
-  color: rgb(206, 196, 196);
+  color: rgb(206 196 196);
   pointer-events: auto;
   cursor: not-allowed;
 }

_sass/base/_syntax.scss

@@ -66,7 +66,7 @@ code {
   &.highlighter-rouge {
     font-size: v.$code-font-size;
     padding: 3px 5px;
-    word-break: break-word;
+    overflow-wrap: break-word;
     border-radius: v.$radius-sm;
     background-color: var(--inline-code-bg);
   }
@@ -243,7 +243,7 @@ div {
     }
 
     &:not([timeout]):hover {
-      background-color: rgba(128, 128, 128, 0.37);
+      background-color: rgb(128 128 128 / 37%);
 
       i {
         color: white;

_sass/base/_typography.scss

@@ -238,7 +238,7 @@ main {
     border-spacing: 0;
 
     thead {
-      border-bottom: solid 2px rgba(210, 215, 217, 0.75);
+      border-bottom: solid 2px rgb(210 215 217 / 75%);
 
       th {
         @extend %table-cell;