fix styling on login + signup page

frontend/src/screens/Login.tsx

@@ -3,15 +3,17 @@ import "../styles/Login.css"
 export default function Login() {
     return (
         <main>
-            <form>
+            <form className="login-container">
                 <h1>Login</h1>
-                <div className="form-inputs">
+                <div className="form-input">
                     <label htmlFor="username">Username</label>
                     <input type="text" name="username" id="username" />
+                </div>
+                <div className="form-input">
                     <label htmlFor="password">Password</label>
                     <input type="password" name="password" id="password" />
                 </div>
-                <button>Login</button>
+                <button className="submit-button">Login</button>
                 <p>or <Link to="/signup">Sign up</Link></p>
             </form>
         </main>