style(ui): unify components with shared Input/Button

src/App.css

@@ -12,7 +12,7 @@
 
 :root {
   /* Typography */
-  font-size: 16px;
+  font-size: 15px;
   line-height: 24px;
   font-weight: 400;
 

src/components/settings/CorrectWords.tsx

@@ -1,5 +1,7 @@
 import React, { useState } from "react";
 import { useSettings } from "../../hooks/useSettings";
+import { Input } from "../ui/Input";
+import { Button } from "../ui/Button";
 import { SettingContainer } from "../ui/SettingContainer";
 
 interface CorrectWordsProps {
@@ -44,39 +46,43 @@ export const CorrectWords: React.FC<CorrectWordsProps> = React.memo(({
         grouped={grouped}
       >
         <div className="flex items-center gap-2">
-          <input
+          <Input
             type="text"
+            className="max-w-[128px]"
             value={newWord}
             onChange={(e) => setNewWord(e.target.value)}
             onKeyPress={handleKeyPress}
             placeholder="Add a word"
-            className="px-2 py-1 text-sm border border-mid-gray/30 rounded focus:outline-none focus:ring-1 focus:ring-logo-primary focus:border-transparent bg-background"
+            variant="compact"
             disabled={isUpdating("correct_words")}
           />
-          <button
+          <Button
             onClick={handleAddWord}
             disabled={!newWord.trim() || newWord.includes(' ') || newWord.trim().length > 50 || isUpdating("correct_words")}
-            className="px-3 py-1 text-xs font-medium text-white bg-logo-primary rounded hover:bg-logo-primary/90 focus:outline-none focus:ring-1 focus:ring-logo-primary disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+            variant="primary"
+            size="md"
           >
             Add
-          </button>
+          </Button>
         </div>
       </SettingContainer>
       {correctWords.length > 0 && (
         <div className={`px-4 p-2 ${grouped ? "" : "rounded-lg border border-mid-gray/20"} flex flex-wrap gap-1`}>
           {correctWords.map((word) => (
-            <button
+            <Button
               key={word}
               onClick={() => handleRemoveWord(word)}
               disabled={isUpdating("correct_words")}
-              className="inline-flex items-center gap-1 px-2 py-1 bg-mid-gray/10 rounded text-xs hover:bg-red-100 hover:text-red-700 focus:outline-none disabled:opacity-50 cursor-pointer transition-colors"
+              variant="secondary"
+              size="sm"
+              className="inline-flex items-center gap-1 cursor-pointer"
               aria-label={`Remove ${word}`}
             >
               <span>{word}</span>
               <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={3} d="M6 18L18 6M6 6l12 12" />
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
               </svg>
-            </button>
+            </Button>
           ))}
         </div>
       )}

src/components/settings/MicrophoneSelector.tsx

@@ -33,10 +33,13 @@ export const MicrophoneSelector: React.FC<MicrophoneSelectorProps> = React.memo(
     await resetSetting("selected_microphone");
   };
 
-  const microphoneOptions = audioDevices.map(device => ({
-    value: device.name,
-    label: device.name
-  }));
+  const microphoneOptions = [
+    { value: "Default", label: "Default" },
+    ...audioDevices.map(device => ({
+      value: device.name,
+      label: device.name
+    }))
+  ];
 
   return (
     <SettingContainer
@@ -50,7 +53,7 @@ export const MicrophoneSelector: React.FC<MicrophoneSelectorProps> = React.memo(
           options={microphoneOptions}
           selectedValue={selectedMicrophone}
           onSelect={handleMicrophoneSelect}
-          placeholder={isLoading ? "Loading..." : "Select microphone..."}
+          placeholder={isLoading ? "Loading..." : ""}
           disabled={isUpdating("selected_microphone") || isLoading}
           onRefresh={refreshAudioDevices}
         />

src/components/settings/OutputDeviceSelector.tsx

@@ -34,10 +34,13 @@ export const OutputDeviceSelector: React.FC<OutputDeviceSelectorProps> = React.m
     await resetSetting("selected_output_device");
   };
 
-  const outputDeviceOptions = outputDevices.map(device => ({
-    value: device.name,
-    label: device.name
-  }));
+  const outputDeviceOptions = [
+    { value: "Default", label: "Default" },
+    ...outputDevices.map(device => ({
+      value: device.name,
+      label: device.name
+    }))
+  ];
 
   return (
     <SettingContainer
@@ -51,7 +54,7 @@ export const OutputDeviceSelector: React.FC<OutputDeviceSelectorProps> = React.m
           options={outputDeviceOptions}
           selectedValue={selectedOutputDevice}
           onSelect={handleOutputDeviceSelect}
-          placeholder={isLoading ? "Loading..." : "Select output device..."}
+          placeholder={isLoading ? "Loading..." : ""}
           disabled={isUpdating("selected_output_device") || isLoading}
           onRefresh={refreshOutputDevices}
         />

src/components/ui/Button.tsx

@@ -0,0 +1,38 @@
+import React from "react";
+
+interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: "primary" | "secondary" | "danger" | "ghost";
+  size?: "sm" | "md" | "lg";
+}
+
+export const Button: React.FC<ButtonProps> = ({
+  children,
+  className = "",
+  variant = "primary",
+  size = "md",
+  ...props
+}) => {
+  const baseClasses = "font-medium rounded focus:outline-none transition-colors disabled:opacity-50 disabled:cursor-not-allowed";
+  
+  const variantClasses = {
+    primary: "text-white bg-background-ui hover:bg-background-ui/90 focus:ring-1 focus:ring-background-ui",
+    secondary: "bg-mid-gray/10 hover:bg-background-ui/30 focus:outline-none",
+    danger: "text-white bg-red-600 hover:bg-red-700 focus:ring-1 focus:ring-red-500",
+    ghost: "text-current hover:bg-mid-gray/10 focus:bg-mid-gray/20"
+  };
+
+  const sizeClasses = {
+    sm: "px-2 py-1 text-xs",
+    md: "px-3 py-1 text-sm", 
+    lg: "px-4 py-2 text-base"
+  };
+
+  return (
+    <button
+      className={`${baseClasses} ${variantClasses[variant]} ${sizeClasses[size]} ${className}`}
+      {...props}
+    >
+      {children}
+    </button>
+  );
+};

src/components/ui/Dropdown.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useRef, useEffect } from "react";
+import React, { useEffect, useRef, useState } from "react";
 
 export interface DropdownOption {
   value: string;
@@ -95,7 +95,7 @@ export const Dropdown: React.FC<DropdownProps> = ({
                 type="button"
                 className={`w-full px-2 py-1 text-sm text-left hover:bg-logo-primary/10 transition-colors duration-150 ${
                   selectedValue === option.value
-                    ? "bg-logo-primary/20 text-logo-primary font-semibold"
+                    ? "bg-logo-primary/20 font-semibold"
                     : ""
                 }`}
                 onClick={() => handleSelect(option.value)}

src/components/ui/Input.tsx

@@ -0,0 +1,25 @@
+import React from "react";
+
+interface InputProps extends React.InputHTMLAttributes<HTMLInputElement> {
+  variant?: "default" | "compact";
+}
+
+export const Input: React.FC<InputProps> = ({
+  className = "",
+  variant = "default",
+  ...props
+}) => {
+  const baseClasses = "px-2 py-1 text-sm font-semibold bg-mid-gray/10 border border-mid-gray/80 rounded text-left flex items-center justify-between transition-all duration-150 hover:bg-logo-primary/10 cursor-pointer hover:border-logo-primary focus:outline-none focus:bg-logo-primary/20 focus:border-logo-primary";
+  
+  const variantClasses = {
+    default: "px-3 py-2",
+    compact: "px-2 py-1"
+  };
+
+  return (
+    <input
+      className={`${baseClasses} ${variantClasses[variant]} ${className}`}
+      {...props}
+    />
+  );
+};

src/components/ui/SettingContainer.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useEffect, useRef } from "react";
+import React, { useEffect, useRef, useState } from "react";
 
 interface SettingContainerProps {
   title: string;