use $theme-pack variable for direct css file

src/themes/classic/_theme_bloodlust.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "classic" {
 body[data-th-main="bloodlust"] {
 	--themeName:"Bloodlust";
 	--bg-300: #333;
@@ -86,3 +87,4 @@ body[data-th-main="bloodlust"] {
 	--button-text-hover: #fff;
 	--button-text-hover-secondary: #fff;
 }
+}

src/themes/classic/_theme_hexagon.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "classic" {
 body {
 	--themeName: "Hexagon";
 	--thin-scrollbar: var(--true);
@@ -93,3 +94,4 @@ body {
 	scrollbar-width: var(--thin-scrollbar);
 	scrollbar-color: #3c3c3c #222;
 }
+}

src/themes/classic/_theme_hotdog.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "classic" {
 body[data-th-main="hotdog"] {
 	--themeName:"Hotdog";
 	--bg: #f00;
@@ -86,3 +87,4 @@ body[data-th-main="hotdog"] {
 	--button-text-hover: #222;
 	--button-text-hover-secondary: #222;
 }
+}

src/themes/classic/_theme_pony.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "classic" {
 body[data-th-main="pony"] {
 	--themeName:"Pony";
 	--bg-300: #2f175c;
@@ -86,3 +87,4 @@ body[data-th-main="pony"] {
 	--button-text-hover: #fff;
 	--button-text-hover-secondary: #fff;
 }
+}

src/themes/classic/_theme_serpent.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "classic" {
 body[data-th-main="serpent"] {
 	--themeName:"Serpent";
 	--bg: #f6eb86;
@@ -86,3 +87,4 @@ body[data-th-main="serpent"] {
 	--button-text-hover: #222;
 	--button-text-hover-secondary: #222;
 }
+}

src/themes/muted/_theme_bloodlust.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "muted" {
 body[data-th-main="bloodlust"] {
 	--themeName: "Discord-esque";
 	--bg-300: #36393e;
@@ -82,3 +83,4 @@ body[data-th-main="bloodlust"] {
 	--button-text-hover: #c3ccd4;
 	--button-text-hover-secondary: #fff;
 }
+}

src/themes/muted/_theme_hexagon.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "muted" {
 body {
 	--themeName: "Classic blue";
 	--thin-scrollbar: var(--true);
@@ -93,3 +94,4 @@ body {
 	scrollbar-width: var(--thin-scrollbar);
 	scrollbar-color: #3c3c3c #222;
 }
+}

src/themes/muted/_theme_hotdog.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "muted" {
 body[data-th-main="hotdog"] {
 	--themeName: "Hot Coffee";
 	--bg-300: #3c3836;
@@ -82,3 +83,4 @@ body[data-th-main="hotdog"] {
 	--button-text-hover: #d6bbae;
 	--button-text-hover-secondary: #f0cfc0;
 }
+}

src/themes/muted/_theme_pony.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "muted" {
 body[data-th-main="pony"] {
 	--themeName: "Pony";
 	--bg-300: #604a67;
@@ -82,3 +83,4 @@ body[data-th-main="pony"] {
 	--button-text-hover: #c3ccd4;
 	--button-text-hover-secondary: #fff;
 }
+}

src/themes/muted/_theme_serpent.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "muted" {
 body[data-th-main="serpent"] {
 	--themeName: "Forest";
 	--bg-300: #3e5341;
@@ -84,3 +85,4 @@ body[data-th-main="serpent"] {
 	--true: thin;
 	scrollbar-width: var(--thin-scrollbar);
 }
+}

src/themes/popular/_theme_bloodlust.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "popular" {
 body[data-th-main="bloodlust"] {
 	--themeName: "Sonokai - Shusia";
 	--bg-300: #37343a;
@@ -82,3 +83,4 @@ body[data-th-main="bloodlust"] {
 	--button-text-hover: #c3ccd4;
 	--button-text-hover-secondary: #fafafb;
 }
+}

src/themes/popular/_theme_hexagon.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "popular" {
 body {
 	--themeName: "Nord";
 	--thin-scrollbar: var(--true);
@@ -93,3 +94,4 @@ body {
 	scrollbar-width: var(--thin-scrollbar);
 	scrollbar-color: #3c3c3c #222;
 }
+}

src/themes/popular/_theme_hotdog.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "popular" {
 body[data-th-main="hotdog"] {
 	--themeName: "Gruvbox";
 	--bg-300: #47403d;
@@ -82,3 +83,4 @@ body[data-th-main="hotdog"] {
 	--button-text-hover: #d6bbae;
 	--button-text-hover-secondary: #fbf1c7;
 }
+}

src/themes/popular/_theme_pony.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "popular" {
 body[data-th-main="pony"] {
 	--themeName: "Rosé Pine";
 	--bg-300: #393552;
@@ -82,3 +83,4 @@ body[data-th-main="pony"] {
 	--button-text-hover: #c3ccd4;
 	--button-text-hover-secondary: #f5f4ff;
 }
+}

src/themes/popular/_theme_serpent.scss

@@ -1,3 +1,4 @@
+@if $theme-pack == "popular" {
 body[data-th-main="serpent"] {
 	--themeName: "Everforest";
 	--bg-300: #3d484d;
@@ -84,3 +85,4 @@ body[data-th-main="serpent"] {
 	--true: thin;
 	scrollbar-width: var(--thin-scrollbar);
 }
+}