fix: improve button transition smoothness in Firefox

- Address laggy appearance of button transitions in Firefox
- Adjust cubic-bezier and duration for smoother transition effects

Changes summary:
    - Improved the smoothness of button transitions in Firefox by adjusting cubic-bezier and duration.

extension-dev/manifest-moz.json

@@ -0,0 +1,30 @@
+{
+	"name": "GPThemes - ChatGPT 3.5 Restyled",
+	"description": "Instantly refresh ChatGPT's UI with a modern and enhanced look using custom CSS",
+	"author": "Marta Bires",
+	"homepage_url": "https://github.com/itsmartashub/GPThemes",
+	"version": "1.2.0",
+	"manifest_version": 3,
+	"host_permissions": ["https://chat.openai.com/*", "http://chat.openai.com/*"],
+	"icons": {
+		"16": "./assets/icons/16.png",
+		"19": "./assets/icons/19.png",
+		"32": "./assets/icons/32.png",
+		"38": "./assets/icons/38.png",
+		"48": "./assets/icons/48.png",
+		"128": "./assets/icons/128.png"
+	},
+	"content_scripts": [
+		{
+			"matches": ["https://chat.openai.com/*", "http://chat.openai.com/*"],
+			"css": ["./css/index.css"],
+			"run_at": "document_start"
+		}
+	],
+	"browser_specific_settings": {
+		"gecko": {
+			"id": "gpthemes@itsmarta",
+			"strict_min_version": "121.0"
+		}
+	}
+}

extension-dev/manifest.json

@@ -0,0 +1,24 @@
+{
+	"name": "GPThemes - ChatGPT 3.5 Restyled",
+	"description": "Instantly refresh ChatGPT's UI with a modern and enhanced look using custom CSS",
+	"author": "Marta Bires",
+	"homepage_url": "https://github.com/itsmartashub/GPThemes",
+	"version": "1.2.0",
+	"manifest_version": 3,
+	"host_permissions": ["https://chat.openai.com/*", "http://chat.openai.com/*"],
+	"icons": {
+		"16": "./assets/icons/16.png",
+		"19": "./assets/icons/19.png",
+		"32": "./assets/icons/32.png",
+		"38": "./assets/icons/38.png",
+		"48": "./assets/icons/48.png",
+		"128": "./assets/icons/128.png"
+	},
+	"content_scripts": [
+		{
+			"matches": ["https://chat.openai.com/*", "http://chat.openai.com/*"],
+			"css": ["./css/index.css"],
+			"run_at": "document_start"
+		}
+	]
+}

src/sass/elements/_transitions.scss

@@ -64,7 +64,8 @@ button:not(
 .btn {
 	will-change: transform, opacity;
 
-	transition: transform 0.4s $easeOutBack, opacity 0.3s ease-in-out, background-color 0.3s ease-in-out,
+	// transition: transform 0.4s $easeOutBack, opacity 0.3s ease-in-out, background-color 0.3s ease-in-out, color 0.3s ease-in-out !important;
+	transition: transform 0.2s $easeInOutQuad, opacity 0.3s ease-in-out, background-color 0.3s ease-in-out,
 		color 0.3s ease-in-out !important;
 
 	&:is(:hover, :active) {
@@ -254,7 +255,8 @@ main:has(.sticky [href='/gpts/editor']) {
 		/* Sticky header with tags aka "Top Picks", "DALLE", "Writing", etc */
 		[class*='md:rounded-none'],
 		[class*='md:rounded-lg'] {
-			transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s $easeInCirc;
+			// transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s $easeInCirc;
+			transition: background-color 0.3s $easeInOutSine, color 0.3s $easeInOutSine, transform 0.3s $easeInOutSine;
 		}
 		/* Non-active pill-tag */
 		[class*='md:rounded-lg']:hover {