diff --git a/src/components/calculator/ValidationMessage.tsx b/src/components/calculator/ValidationMessage.tsx
index 30236f8..d9ce480 100644
--- a/src/components/calculator/ValidationMessage.tsx
+++ b/src/components/calculator/ValidationMessage.tsx
@@ -28,7 +28,7 @@ export function ValidationMessage({
     <p
       className={cn(
         'text-xs mt-1',
-        type === 'error' && 'text-red-500',
+        type === 'error' && 'text-red-600',
         type === 'warning' && 'text-amber-500',
         type === 'info' && 'text-slate-600',
         className
diff --git a/src/components/form/FieldError.tsx b/src/components/form/FieldError.tsx
index b264494..bf3b72b 100644
--- a/src/components/form/FieldError.tsx
+++ b/src/components/form/FieldError.tsx
@@ -33,7 +33,7 @@ export function FieldError({
       id={errorId}
       className={cn(
         'text-xs mt-1',
-        type === 'error' && 'text-red-500',
+        type === 'error' && 'text-red-600',
         type === 'warning' && 'text-amber-500',
         type === 'info' && 'text-slate-600',
         className
diff --git a/src/components/lab/SpectroscopeCalculator.tsx b/src/components/lab/SpectroscopeCalculator.tsx
index 41d2c9e..4696025 100644
--- a/src/components/lab/SpectroscopeCalculator.tsx
+++ b/src/components/lab/SpectroscopeCalculator.tsx
@@ -108,7 +108,7 @@ export function SpectroscopeCalculator() {
             placeholder="e.g., 694"
           />
           {!isValid && wavelength && (
-            <p className="text-xs text-red-500 mt-1">Valid range: 380-780nm</p>
+            <p className="text-xs text-red-600 mt-1">Valid range: 380-780nm</p>
           )}
         </div>
 
diff --git a/src/components/layout/Header.astro b/src/components/layout/Header.astro
index 7fab413..cfc2fa4 100644
--- a/src/components/layout/Header.astro
+++ b/src/components/layout/Header.astro
@@ -11,6 +11,12 @@ const navItems = [
 const currentPath = Astro.url.pathname;
 ---
 
+<a
+  href="#main-content"
+  class="sr-only focus:not-sr-only focus:fixed focus:top-2 focus:left-2 focus:z-[100] focus:rounded-lg focus:bg-white focus:px-4 focus:py-2 focus:text-sm focus:font-medium focus:text-slate-900 focus:shadow-lg focus:outline-none focus-visible:ring-2 focus-visible:ring-crystal-500 focus-visible:ring-offset-2"
+>
+  Skip to content
+</a>
 <header class="sticky top-0 z-50 border-b border-slate-200 bg-white/80 backdrop-blur-lg">
   <div class="mx-auto max-w-7xl px-4 sm:px-6 lg:px-8">
     <div class="flex h-16 items-center justify-between">
diff --git a/src/components/quiz/study/ConfidenceTap.tsx b/src/components/quiz/study/ConfidenceTap.tsx
index 5275bbf..9fbb579 100644
--- a/src/components/quiz/study/ConfidenceTap.tsx
+++ b/src/components/quiz/study/ConfidenceTap.tsx
@@ -39,24 +39,24 @@ const OPTIONS: ConfidenceOption[] = [
     value: 'unsure',
     label: 'Unsure',
     shortcut: 'Q',
-    selectedClass: 'border-red-500 bg-red-50 text-red-700 dark:bg-red-950/40 dark:text-red-300 dark:border-red-500',
-    idleClass: 'border-slate-200 text-slate-700 hover:border-red-300 hover:bg-red-50/50 dark:border-slate-700 dark:text-slate-300 dark:hover:border-red-700',
+    selectedClass: 'border-red-500 bg-red-50 text-red-700',
+    idleClass: 'border-slate-200 text-slate-700 hover:border-red-300 hover:bg-red-50/50',
     description: 'I guessed or am not confident',
   },
   {
     value: 'fairly-sure',
     label: 'Fairly sure',
     shortcut: 'W',
-    selectedClass: 'border-amber-500 bg-amber-50 text-amber-700 dark:bg-amber-950/40 dark:text-amber-300 dark:border-amber-500',
-    idleClass: 'border-slate-200 text-slate-700 hover:border-amber-300 hover:bg-amber-50/50 dark:border-slate-700 dark:text-slate-300 dark:hover:border-amber-700',
+    selectedClass: 'border-amber-500 bg-amber-50 text-amber-700',
+    idleClass: 'border-slate-200 text-slate-700 hover:border-amber-300 hover:bg-amber-50/50',
     description: 'I am reasonably confident',
   },
   {
     value: 'certain',
     label: 'Certain',
     shortcut: 'E',
-    selectedClass: 'border-emerald-500 bg-emerald-50 text-emerald-700 dark:bg-emerald-950/40 dark:text-emerald-300 dark:border-emerald-500',
-    idleClass: 'border-slate-200 text-slate-700 hover:border-emerald-300 hover:bg-emerald-50/50 dark:border-slate-700 dark:text-slate-300 dark:hover:border-emerald-700',
+    selectedClass: 'border-emerald-500 bg-emerald-50 text-emerald-700',
+    idleClass: 'border-slate-200 text-slate-700 hover:border-emerald-300 hover:bg-emerald-50/50',
     description: 'I am very confident in this answer',
   },
 ];
@@ -96,7 +96,7 @@ export function ConfidenceTap({ value, onChange, disabled = false }: ConfidenceT
     >
       <legend
         id="confidence-legend"
-        className="text-sm font-medium text-slate-700 dark:text-slate-300 mb-2"
+        className="text-sm font-medium text-slate-700 mb-2"
       >
         How confident are you?
       </legend>
@@ -128,7 +128,7 @@ export function ConfidenceTap({ value, onChange, disabled = false }: ConfidenceT
               <span>{opt.label}</span>
               <kbd
                 aria-hidden="true"
-                className="text-xs opacity-50 font-sans not-italic"
+                className="hidden sm:inline text-xs opacity-50 font-sans not-italic"
               >
                 [{opt.shortcut}]
               </kbd>
diff --git a/src/components/quiz/study/ExportImportPanel.tsx b/src/components/quiz/study/ExportImportPanel.tsx
index e953f6d..f30f290 100644
--- a/src/components/quiz/study/ExportImportPanel.tsx
+++ b/src/components/quiz/study/ExportImportPanel.tsx
@@ -104,7 +104,7 @@ export function ExportImportPanel({ store }: ExportImportPanelProps) {
 
   return (
     <Card padding="none" className="overflow-hidden">
-      <CardHeader className="px-6 pt-6 pb-4 mb-0 border-b border-slate-100 dark:border-slate-800">
+      <CardHeader className="px-6 pt-6 pb-4 mb-0 border-b border-slate-100">
         <CardTitle as="h2">Export &amp; Import</CardTitle>
         <CardDescription>
           Back up your study history, schedule, and settings to a JSON file, or
@@ -158,11 +158,11 @@ export function ExportImportPanel({ store }: ExportImportPanelProps) {
           className={cn(
             'mx-6 mb-4 rounded-lg px-4 py-3 text-sm flex items-start gap-2',
             toast.kind === 'success' &&
-              'bg-emerald-50 text-emerald-800 border border-emerald-200 dark:bg-emerald-950/40 dark:text-emerald-300 dark:border-emerald-800',
+              'bg-emerald-50 text-emerald-800 border border-emerald-200',
             (toast.kind === 'warning') &&
-              'bg-amber-50 text-amber-800 border border-amber-200 dark:bg-amber-950/40 dark:text-amber-300 dark:border-amber-800',
+              'bg-amber-50 text-amber-800 border border-amber-200',
             toast.kind === 'error' &&
-              'bg-red-50 text-red-800 border border-red-200 dark:bg-red-950/40 dark:text-red-300 dark:border-red-900',
+              'bg-red-50 text-red-800 border border-red-200',
           )}
         >
           {toast.kind === 'success' && (
diff --git a/src/components/quiz/study/LearnQuizWidget.tsx b/src/components/quiz/study/LearnQuizWidget.tsx
index 672682a..6901a22 100644
--- a/src/components/quiz/study/LearnQuizWidget.tsx
+++ b/src/components/quiz/study/LearnQuizWidget.tsx
@@ -153,20 +153,20 @@ export function LearnQuizWidget({
       >
         <Card
           padding="md"
-          className="border-emerald-200 dark:border-emerald-900/50 bg-emerald-50/40 dark:bg-emerald-950/30"
+          className="border-emerald-200 bg-emerald-50/40"
         >
           <CardContent className="flex items-start gap-4">
             <span aria-hidden="true">
-              <CheckCircle2 className="w-7 h-7 text-emerald-600 dark:text-emerald-400 flex-shrink-0 mt-0.5" />
+              <CheckCircle2 className="w-7 h-7 text-emerald-600 flex-shrink-0 mt-0.5" />
             </span>
             <div>
-              <p className="font-semibold text-slate-900 dark:text-slate-100 text-sm tracking-tight">
+              <p className="font-semibold text-slate-900 text-sm tracking-tight">
                 Pretest complete
-                <span className="ml-2 font-mono text-xs font-normal text-emerald-700 dark:text-emerald-400">
+                <span className="ml-2 font-mono text-xs font-normal text-emerald-700">
                   {correctCount} / {visibleQuestions.length}
                 </span>
               </p>
-              <p className="text-sm text-slate-600 dark:text-slate-400 mt-1.5 leading-relaxed">
+              <p className="text-sm text-slate-600 mt-1.5 leading-relaxed">
                 The article below covers each of these topics in depth. Pay particular
                 attention to any questions you got wrong; the pretesting effect makes
                 the content that follows measurably stickier.
@@ -195,10 +195,10 @@ export function LearnQuizWidget({
     <aside className="my-6" aria-label={`Pretest, question ${currentIndex + 1} of ${visibleQuestions.length}`}>
       <Card
         padding="none"
-        className="overflow-hidden border-slate-200 dark:border-slate-800 dark:bg-slate-900"
+        className="overflow-hidden border-slate-200"
       >
         {/* Widget header — instrument-label strip */}
-        <div className="px-5 py-2.5 bg-slate-900 dark:bg-slate-950 border-b border-slate-900 dark:border-slate-800 flex items-center justify-between">
+        <div className="px-5 py-2.5 bg-slate-900 border-b border-slate-900 flex items-center justify-between">
           <span
             id={legendId}
             className="flex items-baseline gap-2 text-sm font-semibold tracking-tight text-slate-50"
@@ -219,7 +219,7 @@ export function LearnQuizWidget({
         <CardContent className="px-5 py-5">
           {/* Helper line — guidance, not body */}
           {currentIndex === 0 && !isSubmitted && (
-            <p className="text-sm text-slate-600 dark:text-slate-400 mb-4 leading-relaxed">
+            <p className="text-sm text-slate-600 mb-4 leading-relaxed">
               <span aria-hidden="true" className="text-crystal-500 mr-1.5">—</span>
               Try these before reading. Getting them wrong here makes the article
               that follows stick better in memory.
@@ -228,7 +228,7 @@ export function LearnQuizWidget({
 
           {/* Question stem */}
           <p
-            className="text-base font-medium text-slate-900 dark:text-slate-100 leading-relaxed mb-4 tracking-tight"
+            className="text-base font-medium text-slate-900 leading-relaxed mb-4 tracking-tight"
             aria-live="polite"
           >
             {currentQuestion.questionText}
@@ -260,15 +260,15 @@ export function LearnQuizWidget({
                     'focus:outline-none focus-visible:ring-2 focus-visible:ring-crystal-500 focus-visible:ring-offset-2',
                     'disabled:pointer-events-none',
                     isIdle &&
-                      'border-slate-200 text-slate-800 hover:border-slate-300 hover:bg-slate-50 dark:border-slate-800 dark:text-slate-200 dark:hover:border-slate-700 dark:hover:bg-slate-800/40',
+                      'border-slate-200 text-slate-800 hover:border-slate-300 hover:bg-slate-50',
                     isPickedIdle &&
-                      'border-crystal-600 bg-crystal-50 text-crystal-900 ring-1 ring-crystal-600 dark:bg-crystal-950/40 dark:text-crystal-100 dark:border-crystal-500 dark:ring-crystal-500',
+                      'border-crystal-600 bg-crystal-50 text-crystal-900 ring-1 ring-crystal-600',
                     isCorrectReveal &&
-                      'border-emerald-600 bg-emerald-50 text-emerald-900 dark:bg-emerald-950/40 dark:text-emerald-100 dark:border-emerald-500',
+                      'border-emerald-600 bg-emerald-50 text-emerald-900',
                     isWrongChosen &&
-                      'border-red-500 bg-red-50 text-red-900 dark:bg-red-950/40 dark:text-red-100 dark:border-red-500',
+                      'border-red-500 bg-red-50 text-red-900',
                     showCorrectness && !isThisCorrect && !isSelected &&
-                      'border-slate-200 text-slate-500 dark:border-slate-800 dark:text-slate-500',
+                      'border-slate-200 text-slate-500',
                   )}
                 >
                   <span className="inline-flex items-center gap-3">
@@ -277,15 +277,15 @@ export function LearnQuizWidget({
                       className={cn(
                         'inline-flex h-6 w-6 items-center justify-center rounded font-mono text-[11px] tracking-wider transition-colors duration-150 flex-shrink-0',
                         isIdle &&
-                          'bg-slate-100 text-slate-600 group-hover:bg-slate-200 dark:bg-slate-800 dark:text-slate-400 dark:group-hover:bg-slate-700',
+                          'bg-slate-100 text-slate-600 group-hover:bg-slate-200',
                         isPickedIdle &&
-                          'bg-crystal-600 text-white dark:bg-crystal-500',
+                          'bg-crystal-600 text-white',
                         isCorrectReveal &&
-                          'bg-emerald-600 text-white dark:bg-emerald-500',
+                          'bg-emerald-600 text-white',
                         isWrongChosen &&
-                          'bg-red-600 text-white dark:bg-red-500',
+                          'bg-red-600 text-white',
                         showCorrectness && !isThisCorrect && !isSelected &&
-                          'bg-slate-100 text-slate-400 dark:bg-slate-800 dark:text-slate-600',
+                          'bg-slate-100 text-slate-400',
                       )}
                     >
                       {letter}
diff --git a/src/components/quiz/study/RationalePanel.tsx b/src/components/quiz/study/RationalePanel.tsx
index e6cc178..7cf0e68 100644
--- a/src/components/quiz/study/RationalePanel.tsx
+++ b/src/components/quiz/study/RationalePanel.tsx
@@ -67,9 +67,7 @@ export function RationalePanel({
     <div
       className={cn(
         'mt-4 rounded-xl border-2 overflow-hidden',
-        correct
-          ? 'border-emerald-200 dark:border-emerald-800'
-          : 'border-red-200 dark:border-red-900',
+        correct ? 'border-emerald-200' : 'border-red-200',
       )}
       role="region"
       aria-label="Answer explanation"
@@ -83,17 +81,13 @@ export function RationalePanel({
         className={cn(
           'w-full flex items-center justify-between px-4 py-3 text-left',
           'focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-crystal-500',
-          correct
-            ? 'bg-emerald-50 dark:bg-emerald-950/40'
-            : 'bg-red-50 dark:bg-red-950/30',
+          correct ? 'bg-emerald-50' : 'bg-red-50',
         )}
       >
         <span
           className={cn(
             'flex items-center gap-2 font-semibold text-sm',
-            correct
-              ? 'text-emerald-700 dark:text-emerald-300'
-              : 'text-red-700 dark:text-red-300',
+            correct ? 'text-emerald-700' : 'text-red-700',
           )}
         >
           {correct ? (
@@ -116,16 +110,16 @@ export function RationalePanel({
       <div
         id="rationale-body"
         hidden={!expanded}
-        className="bg-white dark:bg-slate-900"
+        className="bg-white"
       >
         {/* Main rationale */}
-        <div className="px-4 py-3 text-sm text-slate-700 dark:text-slate-300 border-b border-slate-100 dark:border-slate-800">
+        <div className="px-4 py-3 text-sm text-slate-700 border-b border-slate-100">
           {cleanCorrect}
         </div>
 
         {/* Per-option breakdown */}
         {cleanOptions.length > 0 && (
-          <ul className="divide-y divide-slate-100 dark:divide-slate-800" aria-label="Option breakdown">
+          <ul className="divide-y divide-slate-100" aria-label="Option breakdown">
             {cleanOptions.map((opt, idx) => {
               const wasChosen = userPickedIndex === idx;
               const isCorrect = opt.isCorrect;
@@ -134,23 +128,21 @@ export function RationalePanel({
                   key={idx}
                   className={cn(
                     'px-4 py-3 text-sm',
-                    isCorrect && 'bg-emerald-50/50 dark:bg-emerald-950/20',
-                    wasChosen && !isCorrect && 'bg-red-50/50 dark:bg-red-950/20',
+                    isCorrect && 'bg-emerald-50/50',
+                    wasChosen && !isCorrect && 'bg-red-50/50',
                   )}
                 >
                   <div className="flex items-start gap-2">
                     {isCorrect ? (
                       <CheckCircle2
-                        className="w-4 h-4 text-emerald-600 dark:text-emerald-400 flex-shrink-0 mt-0.5"
+                        className="w-4 h-4 text-emerald-600 flex-shrink-0 mt-0.5"
                         aria-label="Correct option"
                       />
                     ) : (
                       <XCircle
                         className={cn(
                           'w-4 h-4 flex-shrink-0 mt-0.5',
-                          wasChosen
-                            ? 'text-red-600 dark:text-red-400'
-                            : 'text-slate-600 dark:text-slate-600',
+                          wasChosen ? 'text-red-600' : 'text-slate-600',
                         )}
                         aria-label={wasChosen ? 'Your choice, incorrect' : 'Incorrect option'}
                       />
@@ -160,10 +152,10 @@ export function RationalePanel({
                         className={cn(
                           'font-medium',
                           isCorrect
-                            ? 'text-emerald-700 dark:text-emerald-300'
+                            ? 'text-emerald-700'
                             : wasChosen
-                            ? 'text-red-700 dark:text-red-300'
-                            : 'text-slate-600 dark:text-slate-400',
+                            ? 'text-red-700'
+                            : 'text-slate-600',
                         )}
                       >
                         {opt.text}
@@ -172,7 +164,7 @@ export function RationalePanel({
                         )}
                       </p>
                       {opt.rationale && (
-                        <p className="mt-0.5 text-slate-600 dark:text-slate-400">{opt.rationale}</p>
+                        <p className="mt-0.5 text-slate-600">{opt.rationale}</p>
                       )}
                     </div>
                   </div>
@@ -185,15 +177,15 @@ export function RationalePanel({
         {/* Sources footer — single deduped citation line at the foot of the body */}
         {sources.length > 0 && (
           <p
-            className="px-4 py-2.5 text-xs text-slate-500 dark:text-slate-500 border-t border-slate-100 dark:border-slate-800 bg-slate-50/50 dark:bg-slate-900/40"
+            className="px-4 py-2.5 text-xs text-slate-500 border-t border-slate-100 bg-slate-50/50"
             aria-label="Sources"
           >
-            <span className="font-medium uppercase tracking-wider text-slate-600 dark:text-slate-400 mr-2">
+            <span className="font-medium uppercase tracking-wider text-slate-600 mr-2">
               Sources
             </span>
             {sources.map((slug, idx) => (
               <span key={slug}>
-                {idx > 0 && <span aria-hidden="true" className="mx-1.5 text-slate-400 dark:text-slate-700">·</span>}
+                {idx > 0 && <span aria-hidden="true" className="mx-1.5 text-slate-400">·</span>}
                 {citationLabel(slug)}
               </span>
             ))}
diff --git a/src/components/quiz/study/StudySettingsPanel.tsx b/src/components/quiz/study/StudySettingsPanel.tsx
index 1666511..8129eb3 100644
--- a/src/components/quiz/study/StudySettingsPanel.tsx
+++ b/src/components/quiz/study/StudySettingsPanel.tsx
@@ -36,11 +36,11 @@ function ToggleRow({ id, label, description, checked, onToggle }: ToggleRowProps
       <div className="flex-1 min-w-0">
         <label
           htmlFor={id}
-          className="block text-sm font-medium text-slate-800 dark:text-slate-200 cursor-pointer"
+          className="block text-sm font-medium text-slate-800 cursor-pointer"
         >
           {label}
         </label>
-        <p className="text-sm text-slate-600 dark:text-slate-400 mt-0.5">{description}</p>
+        <p className="text-sm text-slate-600 mt-0.5">{description}</p>
       </div>
       {/* Toggle switch */}
       <button
@@ -54,9 +54,7 @@ function ToggleRow({ id, label, description, checked, onToggle }: ToggleRowProps
           'relative inline-flex h-6 w-11 flex-shrink-0 rounded-full border-2 border-transparent',
           'cursor-pointer transition-colors duration-200',
           'focus:outline-none focus-visible:ring-2 focus-visible:ring-crystal-500 focus-visible:ring-offset-2',
-          checked
-            ? 'bg-crystal-600 dark:bg-crystal-500'
-            : 'bg-slate-200 dark:bg-slate-700',
+          checked ? 'bg-crystal-600' : 'bg-slate-200',
         )}
       >
         <span
@@ -77,11 +75,11 @@ export function StudySettingsPanel({ value, onChange }: StudySettingsPanelProps)
 
   return (
     <Card padding="none" className="overflow-hidden">
-      <CardHeader className="px-6 pt-6 pb-4 mb-0 border-b border-slate-100 dark:border-slate-800">
+      <CardHeader className="px-6 pt-6 pb-4 mb-0 border-b border-slate-100">
         <CardTitle as="h2">Study settings</CardTitle>
       </CardHeader>
 
-      <CardContent className="px-6 py-2 divide-y divide-slate-100 dark:divide-slate-800">
+      <CardContent className="px-6 py-2 divide-y divide-slate-100">
         {/* Require confidence */}
         <ToggleRow
           id="setting-require-confidence"
@@ -104,14 +102,14 @@ export function StudySettingsPanel({ value, onChange }: StudySettingsPanelProps)
         <div className="py-3">
           <label
             htmlFor="setting-review-mix"
-            className="block text-sm font-medium text-slate-800 dark:text-slate-200"
+            className="block text-sm font-medium text-slate-800"
           >
             Review mix
-            <span className="ml-2 text-xs font-normal text-slate-600 dark:text-slate-400">
+            <span className="ml-2 text-xs font-normal text-slate-600">
               {reviewMixPercent}% review / {100 - reviewMixPercent}% new
             </span>
           </label>
-          <p className="text-sm text-slate-600 dark:text-slate-400 mt-0.5 mb-2">
+          <p className="text-sm text-slate-600 mt-0.5 mb-2">
             Fraction of due (spaced-repetition) items vs new questions in each session.
           </p>
           <input
@@ -130,8 +128,8 @@ export function StudySettingsPanel({ value, onChange }: StudySettingsPanelProps)
             aria-valuetext={`${reviewMixPercent}% review`}
             className={cn(
               'w-full h-2 rounded-full appearance-none cursor-pointer',
-              'bg-slate-200 dark:bg-slate-700',
-              'accent-crystal-600 dark:accent-crystal-500',
+              'bg-slate-200',
+              'accent-crystal-600',
             )}
           />
           <div className="flex justify-between text-xs text-slate-600 mt-1">
@@ -144,11 +142,11 @@ export function StudySettingsPanel({ value, onChange }: StudySettingsPanelProps)
         <div className="py-3">
           <label
             htmlFor="setting-question-count"
-            className="block text-sm font-medium text-slate-800 dark:text-slate-200"
+            className="block text-sm font-medium text-slate-800"
           >
             Default question count
           </label>
-          <p className="text-sm text-slate-600 dark:text-slate-400 mt-0.5 mb-2">
+          <p className="text-sm text-slate-600 mt-0.5 mb-2">
             Pre-filled in the quiz setup screen.
           </p>
           <input
@@ -168,9 +166,8 @@ export function StudySettingsPanel({ value, onChange }: StudySettingsPanelProps)
             aria-valuemax={50}
             className={cn(
               'block w-24 rounded-lg border border-slate-300 px-3 py-1.5 text-sm',
-              'text-slate-800 dark:text-slate-200',
-              'bg-white dark:bg-slate-900',
-              'dark:border-slate-700',
+              'text-slate-800',
+              'bg-white',
               'focus:outline-none focus:ring-2 focus:ring-crystal-500 focus:border-crystal-500',
             )}
           />
diff --git a/src/components/quiz/study/UnvettedFlag.tsx b/src/components/quiz/study/UnvettedFlag.tsx
index 7052ae0..f7ff942 100644
--- a/src/components/quiz/study/UnvettedFlag.tsx
+++ b/src/components/quiz/study/UnvettedFlag.tsx
@@ -62,7 +62,6 @@ export function UnvettedFlag({ unvetted }: UnvettedFlagProps) {
           'absolute bottom-full left-0 mb-2 z-50',
           'w-56 rounded-lg border border-amber-200 bg-amber-50 px-3 py-2',
           'text-xs text-amber-800 shadow-md',
-          'dark:border-amber-800 dark:bg-amber-950/80 dark:text-amber-200',
           'transition-opacity duration-150',
           tooltipVisible ? 'opacity-100' : 'opacity-0 pointer-events-none',
         )}
diff --git a/src/layouts/BaseLayout.astro b/src/layouts/BaseLayout.astro
index ff611bc..24fd649 100644
--- a/src/layouts/BaseLayout.astro
+++ b/src/layouts/BaseLayout.astro
@@ -93,7 +93,7 @@ const fullTitle = isHome
   </head>
   <body class="min-h-screen flex flex-col">
     {!noHeader && <Header />}
-    <main class="flex-1">
+    <main id="main-content" class="flex-1">
       <slot />
     </main>
     {!noFooter && <Footer />}
diff --git a/src/pages/index.astro b/src/pages/index.astro
index 8be46a1..916723d 100644
--- a/src/pages/index.astro
+++ b/src/pages/index.astro
@@ -141,7 +141,7 @@ const iconPaths: Record<string, string> = {
             </div>
           </div>
           <div class="absolute right-2 -bottom-3 sm:-right-2 sm:-bottom-4 bg-white rounded-lg shadow-lg border border-slate-200 px-3 py-1.5 sm:px-4 sm:py-2 max-w-[calc(100%-1rem)]">
-            <code class="text-xs sm:text-sm font-mono text-slate-700 whitespace-nowrap overflow-hidden text-ellipsis block">cubic[m3m]:{'{'}{'{'}111{'}'}</code>
+            <code class="text-xs sm:text-sm font-mono text-slate-700 whitespace-nowrap overflow-hidden text-ellipsis block">cubic[m3m]:{'{'}111{'}'}</code>
           </div>
         </div>
       </div>
diff --git a/src/pages/quiz/index.astro b/src/pages/quiz/index.astro
index 51af37e..a429598 100644
--- a/src/pages/quiz/index.astro
+++ b/src/pages/quiz/index.astro
@@ -142,15 +142,6 @@ const quizSchema = {
           items with no setup screen, making it easy to fit a focused five-minute review into any
           break between study sessions.
         </p>
-
-        <h2 class="text-xl font-semibold text-slate-800 mt-8 mb-3">Quiz categories</h2>
-        <ul class="space-y-1">
-          {categories.map(cat => (
-            <li class="text-slate-700">
-              <strong>{cat.name}:</strong> {cat.description}
-            </li>
-          ))}
-        </ul>
       </section>
 
       <QuizPage client:idle learnEntries={entries} curatedQuestions={curatedQuestions} />
diff --git a/src/styles/global.css b/src/styles/global.css
index a1cf5c2..c97ed94 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -35,6 +35,15 @@
     scroll-behavior: smooth;
   }
 
+  /*
+   * The sticky header (h-16 + border = ~65px) hides anchor-jump targets
+   * (citation backlinks, jump-nav) without this. 5rem (80px) covers the
+   * header height plus a small visual buffer.
+   */
+  [id] {
+    scroll-margin-top: 5rem;
+  }
+
   body {
     @apply bg-white text-slate-900 antialiased;
     font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';