diff --git a/apps/readest-app/package.json b/apps/readest-app/package.json
index abda1948..39eee759 100644
--- a/apps/readest-app/package.json
+++ b/apps/readest-app/package.json
@@ -24,6 +24,7 @@
     "@tauri-apps/plugin-os": "^2.0.0",
     "@zip.js/zip.js": "^2.7.52",
     "clsx": "^2.1.1",
+    "cssbeautify": "^0.3.1",
     "epubjs": "^0.3.93",
     "foliate-js": "workspace:*",
     "js-md5": "^0.8.3",
@@ -36,6 +37,7 @@
   },
   "devDependencies": {
     "@tauri-apps/cli": "2.0.4",
+    "@types/cssbeautify": "^0.3.5",
     "@types/node": "^20",
     "@types/react": "18.3.12",
     "@types/react-dom": "18.3.1",
diff --git a/apps/readest-app/src/app/reader/components/settings/ColorPanel.tsx b/apps/readest-app/src/app/reader/components/settings/ColorPanel.tsx
index ce198392..d584926c 100644
--- a/apps/readest-app/src/app/reader/components/settings/ColorPanel.tsx
+++ b/apps/readest-app/src/app/reader/components/settings/ColorPanel.tsx
@@ -15,18 +15,20 @@ const ColorPanel: React.FC<{ bookKey: string }> = () => {
   ];
 
   return (
-    <div>
-      <h2 className='mb-2 font-medium'>Color Settings</h2>
-      <div className='mt-4 grid grid-cols-3 gap-2'>
-        {themes.map((theme) => (
-          <button
-            key={theme}
-            className={`btn ${selectedTheme === theme ? 'btn-active' : ''}`}
-            onClick={() => setSelectedTheme(theme)}
-          >
-            {theme}
-          </button>
-        ))}
+    <div className='my-4 w-full space-y-6'>
+      <div className='w-full'>
+        <h2 className='mb-2 font-medium'>Color Settings</h2>
+        <div className='mt-4 grid grid-cols-3 gap-2'>
+          {themes.map((theme) => (
+            <button
+              key={theme}
+              className={`btn ${selectedTheme === theme ? 'btn-active' : ''}`}
+              onClick={() => setSelectedTheme(theme)}
+            >
+              {theme}
+            </button>
+          ))}
+        </div>
       </div>
     </div>
   );
diff --git a/apps/readest-app/src/app/reader/components/settings/FontPanel.tsx b/apps/readest-app/src/app/reader/components/settings/FontPanel.tsx
index 9d7936e5..b3b3213e 100644
--- a/apps/readest-app/src/app/reader/components/settings/FontPanel.tsx
+++ b/apps/readest-app/src/app/reader/components/settings/FontPanel.tsx
@@ -134,7 +134,7 @@ const FontPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
 
   return (
     <div className='my-4 w-full space-y-6'>
-      <div className='cell-font-size w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Font Size</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
@@ -143,7 +143,7 @@ const FontPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
               label='Default Font Size'
               value={defaultFontSize}
               onChange={setDefaultFontSize}
-              min={1}
+              min={minFontSize}
               max={120}
             />
             <NumberInput
@@ -158,7 +158,7 @@ const FontPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
         </div>
       </div>
 
-      <div className='cell-font-family w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Font Family</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
@@ -185,7 +185,7 @@ const FontPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
         </div>
       </div>
 
-      <div className='cell-font-family w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Font Face</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
diff --git a/apps/readest-app/src/app/reader/components/settings/LayoutPanel.tsx b/apps/readest-app/src/app/reader/components/settings/LayoutPanel.tsx
index 82b3836f..e0ecfd7b 100644
--- a/apps/readest-app/src/app/reader/components/settings/LayoutPanel.tsx
+++ b/apps/readest-app/src/app/reader/components/settings/LayoutPanel.tsx
@@ -92,7 +92,7 @@ const LayoutPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
 
   return (
     <div className='my-4 w-full space-y-6'>
-      <div className='cell-font-size w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Paragraph</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
@@ -127,7 +127,7 @@ const LayoutPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
         </div>
       </div>
 
-      <div className='cell-font-family w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Page</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
diff --git a/apps/readest-app/src/app/reader/components/settings/MiscPanel.tsx b/apps/readest-app/src/app/reader/components/settings/MiscPanel.tsx
index b34acd4c..1de6ae10 100644
--- a/apps/readest-app/src/app/reader/components/settings/MiscPanel.tsx
+++ b/apps/readest-app/src/app/reader/components/settings/MiscPanel.tsx
@@ -1,5 +1,10 @@
 import React, { useEffect, useState } from 'react';
 import { useReaderStore } from '@/store/readerStore';
+import cssbeautify from 'cssbeautify';
+import { getStyles } from '@/utils/style';
+
+const cssRegex =
+  /((?:\s*)([\w#.@*,:\-.:>+~\[\]\"=(),*\s]+)\s*{(?:[\s]*)((?:[A-Za-z\- \s]+[:]\s*['"0-9\w .,\/\()\-!#%]+;?)*)*\s*}(?:\s*))/gim;
 
 const MiscPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
   const { books, settings, setSettings, setConfig, getFoliateView } = useReaderStore();
@@ -8,6 +13,48 @@ const MiscPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
   const config = bookState.config!;
 
   const [animated, setAnimated] = useState(config.viewSettings!.animated!);
+  const [userStylesheet, setUserStylesheet] = useState(config.viewSettings!.userStylesheet!);
+  const [error, setError] = useState<string | null>(null);
+
+  let cssInput = userStylesheet;
+
+  const validateCSS = (css: string) => {
+    return cssRegex.test(css);
+  };
+
+  const handleUserStylesheetChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
+    cssInput = e.target.value;
+
+    try {
+      const formattedCSS = cssbeautify(cssInput, {
+        indent: '  ',
+        openbrace: 'end-of-line',
+        autosemicolon: true,
+      });
+      setUserStylesheet(formattedCSS);
+
+      if (cssInput && !validateCSS(cssInput)) {
+        throw new Error('Invalid CSS');
+      }
+      setError(null);
+
+      config.viewSettings!.userStylesheet = formattedCSS;
+      setConfig(bookKey, config);
+      if (isFontLayoutSettingsGlobal) {
+        settings.globalViewSettings.userStylesheet = formattedCSS;
+        setSettings(settings);
+      }
+      getFoliateView(bookKey)?.renderer.setStyles?.(getStyles(config));
+    } catch (err) {
+      setError('Invalid CSS: Please check your input.');
+      console.log('CSS Error:', err);
+    }
+  };
+
+  const handleInput = (e: React.FormEvent<HTMLTextAreaElement>) => {
+    e.stopPropagation();
+    e.nativeEvent.stopImmediatePropagation();
+  };
 
   useEffect(() => {
     config.viewSettings!.animated = animated;
@@ -25,7 +72,7 @@ const MiscPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
 
   return (
     <div className='my-4 w-full space-y-6'>
-      <div className='cell-font-size w-full'>
+      <div className='w-full'>
         <h2 className='mb-2 font-medium'>Animation</h2>
         <div className='card bg-base-100 border shadow'>
           <div className='divide-y'>
@@ -41,6 +88,26 @@ const MiscPanel: React.FC<{ bookKey: string }> = ({ bookKey }) => {
           </div>
         </div>
       </div>
+
+      <div className='w-full'>
+        <h2 className='mb-2 font-medium'>Custom CSS</h2>
+        <div className={`card bg-base-100 border shadow ${error ? 'border-red-500' : ''}`}>
+          <div className='divide-y'>
+            <div className='css-text-area config-item-top config-item-bottom p-1'>
+              <textarea
+                className='textarea textarea-ghost h-48 w-full border-0 p-3 !outline-none'
+                placeholder='Enter your custom CSS here...'
+                spellCheck='false'
+                value={cssInput}
+                onInput={handleInput}
+                onKeyDown={handleInput}
+                onKeyUp={handleInput}
+                onChange={handleUserStylesheetChange}
+              />
+            </div>
+          </div>
+        </div>
+      </div>
     </div>
   );
 };
diff --git a/apps/readest-app/src/app/reader/components/settings/NumberInput.tsx b/apps/readest-app/src/app/reader/components/settings/NumberInput.tsx
index ccbaa0f9..67015c16 100644
--- a/apps/readest-app/src/app/reader/components/settings/NumberInput.tsx
+++ b/apps/readest-app/src/app/reader/components/settings/NumberInput.tsx
@@ -30,10 +30,10 @@ const NumberInput: React.FC<NumberInputProps> = ({
   };
 
   const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
-    const newValue = e.target.value === '' ? 0 : parseInt(e.target.value);
+    const newValue = e.target.value === '' ? 0 : parseFloat(e.target.value);
+    setLocalValue(newValue);
     if (!isNaN(newValue)) {
       const roundedValue = Math.round(newValue * 10) / 10;
-      setLocalValue(roundedValue);
       onChange(Math.max(min, Math.min(max, roundedValue)));
     }
   };
@@ -70,7 +70,7 @@ const NumberInput: React.FC<NumberInputProps> = ({
           onKeyDown={handleInput}
           onKeyUp={handleInput}
           onBlur={handleOnBlur}
-          className='input input-ghost settings-content w-20 max-w-xs rounded px-3 py-1 text-right'
+          className='input input-ghost settings-content w-20 max-w-xs rounded border-0 bg-transparent px-3 py-1 text-right !outline-none'
           onFocus={(e) => e.target.select()}
         />
         <button
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index efd16d46..3bd6df1b 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -59,6 +59,9 @@ importers:
       clsx:
         specifier: ^2.1.1
         version: 2.1.1
+      cssbeautify:
+        specifier: ^0.3.1
+        version: 0.3.1
       epubjs:
         specifier: ^0.3.93
         version: 0.3.93
@@ -90,6 +93,9 @@ importers:
       '@tauri-apps/cli':
         specifier: 2.0.4
         version: 2.0.4
+      '@types/cssbeautify':
+        specifier: ^0.3.5
+        version: 0.3.5
       '@types/node':
         specifier: ^20
         version: 20.16.6
@@ -700,6 +706,9 @@ packages:
   '@tsconfig/node16@1.0.4':
     resolution: {integrity: sha512-vxhUy4J8lyeyinH7Azl1pdd43GJhZH/tP2weN8TntQblOY+A0XbT8DJk1/oCPuOOyg/Ja757rG0CgHcWC8OfMA==}
 
+  '@types/cssbeautify@0.3.5':
+    resolution: {integrity: sha512-bkxuJdUu7Liw14EouI8IFNvJXvd5IioAZdDvlCFBXv+Sel8uPK9rcxfvOchQKqw2AtppxRvcYaWmimi0t0Yuow==}
+
   '@types/estree@1.0.6':
     resolution: {integrity: sha512-AYnb1nQyY49te+VRAVgmzfcgjYS91mY5P0TKUDCLEM+gNnA+3T6rWITXRLYCpahpqSQbN5cE+gHpnPyXjHWxcw==}
 
@@ -1382,6 +1391,10 @@ packages:
   css-selector-tokenizer@0.8.0:
     resolution: {integrity: sha512-Jd6Ig3/pe62/qe5SBPTN8h8LeUg/pT4lLgtavPf7updwwHpvFzxvOQBHYj2LZDMjUnBzgvIUSjRcf6oT5HzHFg==}
 
+  cssbeautify@0.3.1:
+    resolution: {integrity: sha512-ljnSOCOiMbklF+dwPbpooyB78foId02vUrTDogWzu6ca2DCNB7Kc/BHEGBnYOlUYtwXvSW0mWTwaiO2pwFIoRg==}
+    hasBin: true
+
   cssesc@3.0.0:
     resolution: {integrity: sha512-/Tb/JcjK111nNScGob5MNtsntNM1aCNUDipB/TkwZFhyDrrE47SOx/18wF2bbjgc3ZzCSKW1T5nt5EbFoAz/Vg==}
     engines: {node: '>=4'}
@@ -3863,6 +3876,8 @@ snapshots:
   '@tsconfig/node16@1.0.4':
     optional: true
 
+  '@types/cssbeautify@0.3.5': {}
+
   '@types/estree@1.0.6': {}
 
   '@types/json-schema@7.0.15': {}
@@ -4933,6 +4948,8 @@ snapshots:
       cssesc: 3.0.0
       fastparse: 1.1.2
 
+  cssbeautify@0.3.1: {}
+
   cssesc@3.0.0: {}
 
   csstype@3.1.3: {}