Fix SCSS deprecation warnings

Frontend/src/features/interview/style/home.scss

@@ -1,3 +1,4 @@
+@use "sass:color";
 // ── Variables ────────────────────────────────────────────────────────────────
 $bg-page:        #0d1117;
 $bg-card:        #161b22;
@@ -384,7 +385,7 @@ $font-stack:     system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Robot
     align-items: center;
     gap: 0.5rem;
     padding: 0.75rem 1.5rem;
-    background: linear-gradient(135deg, $accent 0%, darken($accent, 10%) 100%);
+    background: linear-gradient(135deg, $accent 0%, color.adjust($accent, $lightness: -10%) 100%);
     color: #fff;
     font-size: 0.9rem;
     font-weight: 600;

Frontend/src/features/interview/style/interview.scss

@@ -1,3 +1,4 @@
+@use "sass:color";
 // ── Shared Variables (mirrors home.scss theme) ────────────────────────────────
 $bg-page: #0d1117;
 $bg-card: #161b22;
@@ -172,7 +173,7 @@ $severity-low: #3fb950;
     transition: border-color 0.2s;
 
     &:hover {
-        border-color: lighten($border-color, 8%);
+        border-color: color.adjust($border-color, $lightness: 8%);
     }
 
     &__header {
@@ -234,7 +235,7 @@ $severity-low: #3fb950;
         p {
             margin: 0;
             font-size: 0.835rem;
-            color: lighten($text-muted, 15%);
+            color: color.adjust($text-muted, $lightness: 15%);
             line-height: 1.6;
         }
     }
@@ -329,7 +330,7 @@ $severity-low: #3fb950;
 
     p {
         margin: 0;
-        color: lighten($text-muted, 15%);
+        color: color.adjust($text-muted, $lightness: 15%);
     }
 
     &--user {
@@ -363,7 +364,7 @@ $severity-low: #3fb950;
     ul {
         margin: 0.5rem 0 0;
         padding-left: 1.25rem;
-        color: lighten($text-muted, 15%);
+        color: color.adjust($text-muted, $lightness: 15%);
         font-size: 0.8rem;
         
         li {
@@ -481,7 +482,7 @@ $severity-low: #3fb950;
             align-items: flex-start;
             gap: 0.5rem;
             font-size: 0.845rem;
-            color: lighten($text-muted, 12%);
+            color: color.adjust($text-muted, $lightness: 12%);
             line-height: 1.5;
         }
     }