feat: Implement marketing page layout, core sections, and shared UI components.

src/components/ui/Input.tsx

@@ -7,7 +7,10 @@ interface InputProps extends React.InputHTMLAttributes<HTMLInputElement> {
 }
 
 export const Input = React.forwardRef<HTMLInputElement, InputProps>(
-  ({ className, type, label, error, onInvalid, ...props }, ref) => {
+  ({ className, type, label, error, onInvalid, id, ...props }, ref) => {
+    // Generate a unique id for accessibility if not provided
+    const inputId = id || (label ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+
     // Default English validation message
     const handleInvalid = (e: React.InvalidEvent<HTMLInputElement>) => {
       e.target.setCustomValidity('Please fill out this field.');
@@ -21,11 +24,12 @@ export const Input = React.forwardRef<HTMLInputElement, InputProps>(
     return (
       <div className="space-y-1">
         {label && (
-          <label className="block text-sm font-medium text-gray-700">
+          <label htmlFor={inputId} className="block text-sm font-medium text-gray-700">
             {label}
           </label>
         )}
         <input
+          id={inputId}
           type={type}
           className={cn(
             'flex h-10 w-full rounded-lg border border-gray-300 bg-white px-3 py-2 text-sm ring-offset-white file:border-0 file:bg-transparent file:text-sm file:font-medium placeholder:text-gray-500 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary-500 focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50',

src/components/ui/ScrollToTop.tsx

@@ -41,6 +41,7 @@ export function ScrollToTop() {
             stroke="currentColor"
             viewBox="0 0 24 24"
             xmlns="http://www.w3.org/2000/svg"
+            aria-hidden="true"
           >
             <path
               strokeLinecap="round"

src/components/ui/Select.tsx

@@ -8,15 +8,19 @@ interface SelectProps extends React.SelectHTMLAttributes<HTMLSelectElement> {
 }
 
 export const Select = React.forwardRef<HTMLSelectElement, SelectProps>(
-  ({ className, label, error, options, ...props }, ref) => {
+  ({ className, label, error, options, id, ...props }, ref) => {
+    // Generate a unique id for accessibility if not provided
+    const selectId = id || (label ? `select-${label.toLowerCase().replace(/\s+/g, '-')}` : undefined);
+
     return (
       <div className="space-y-1">
         {label && (
-          <label className="block text-sm font-medium text-gray-700">
+          <label htmlFor={selectId} className="block text-sm font-medium text-gray-700">
             {label}
           </label>
         )}
         <select
+          id={selectId}
           className={cn(
             'flex h-10 w-full rounded-lg border border-gray-300 bg-white px-3 py-2 text-sm ring-offset-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary-500 focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50',
             error && 'border-red-500 focus-visible:ring-red-500',