refactor: deduplicate modal/button styles and enforce global utility usage

- Consolidated all modal-related styles into Modal.module.css; ValidationModal.module.css is now deprecated
- All main action/navigation buttons in NewGame and GameDetail use global .btn/.nav-buttons utility classes
- Removed duplicate utility classes from component CSS files
- Fixed .fullscreenToggle class naming for consistency
- Cleaned up component CSS to only contain component-specific styles
- Updated GameCompletionModal to use shared modal styles

This ensures DRY, maintainable, and consistent styling across the app.

src/components/FullscreenToggle.module.css

@@ -1,3 +1,4 @@
+/* FullscreenToggle-specific styles only. */
 .fullscreenToggle {
     position: fixed;
     bottom: 20px;

src/components/GameCompletionModal.jsx

@@ -1,4 +1,5 @@
 import { h } from 'preact';
+import modalStyles from './Modal.module.css';
 import styles from './GameCompletionModal.module.css';
 
 /**
@@ -21,13 +22,13 @@ const GameCompletionModal = ({ open, game, onConfirm, onClose }) => {
     ? `Unentschieden zwischen ${winners.join(' und ')}`
     : `${winners[0]} hat gewonnen!`;
   return (
-    <div id="game-completion-modal" className="modal show" role="dialog" aria-modal="true" aria-labelledby="completion-modal-title">
+    <div id="game-completion-modal" className={modalStyles['modal'] + ' ' + modalStyles['show']} role="dialog" aria-modal="true" aria-labelledby="completion-modal-title">
-      <div className={styles['modal-content']}>
+      <div className={modalStyles['modal-content']}>
-        <div className={styles['modal-header']}>
+        <div className={modalStyles['modal-header']}>
-          <span className={styles['modal-title']} id="completion-modal-title">Spiel beendet</span>
+          <span className={modalStyles['modal-title']} id="completion-modal-title">Spiel beendet</span>
-          <button className={styles['close-button']} onClick={onClose} aria-label="Schließen">×</button>
+          <button className={modalStyles['close-button']} onClick={onClose} aria-label="Schließen">×</button>
         </div>
-        <div className={styles['modal-body']}>
+        <div className={modalStyles['modal-body']}>
           <div className={styles['final-scores']}>
             {playerNames.map((name, idx) => (
               <div className={styles['final-score']} key={name + idx}>
@@ -38,7 +39,7 @@ const GameCompletionModal = ({ open, game, onConfirm, onClose }) => {
           </div>
           <div className={styles['winner-announcement']}><h3>{winnerText}</h3></div>
         </div>
-        <div className={styles['modal-footer']}>
+        <div className={modalStyles['modal-footer']}>
           <button className={styles['btn'] + ' ' + styles['btn--warning']} onClick={onConfirm} aria-label="Bestätigen">Bestätigen</button>
           <button className={styles['btn']} onClick={onClose} aria-label="Abbrechen">Abbrechen</button>
         </div>

src/components/GameCompletionModal.module.css

@@ -1,26 +1,4 @@
-#game-completion-modal {
+/* Only GameCompletionModal-specific styles. Shared modal styles are now in Modal.module.css */
-    position: fixed;
-    top: 0;
-    left: 0;
-    width: 100vw;
-    height: 100vh;
-    background-color: rgba(0, 0, 0, 0.8);
-    z-index: 9999;
-    display: flex;
-    justify-content: center;
-    align-items: center;
-}
-.modal-content {
-    background-color: #222;
-    padding: 32px 24px 24px 24px;
-    border-radius: 16px;
-    width: 90vw;
-    max-width: 480px;
-    box-shadow: 0 4px 32px rgba(0,0,0,0.7);
-    position: relative;
-    margin: auto;
-    transform: none;
-}
 .final-scores {
     margin: 20px 0;
 }
@@ -60,14 +38,6 @@
     margin: 0;
     color: #fff;
 }
-.modal-footer {
-    display: flex;
-    flex-direction: row;
-    gap: 16px;
-    margin-top: 24px;
-    width: 100%;
-    justify-content: center;
-}
 .btn {
     flex: 1;
     padding: 18px 0;
@@ -89,25 +59,7 @@
 .btn--warning:hover {
     background: #d32f2f;
 }
-.close-button {
-    position: absolute;
-    top: 12px;
-    right: 16px;
-    background: none;
-    border: none;
-    color: #aaa;
-    font-size: 2rem;
-    cursor: pointer;
-    z-index: 2;
-}
-.close-button:hover {
-    color: #fff;
-}
 @media (max-width: 600px) {
-    .modal-content {
-        padding: 16px 4px 16px 4px;
-        max-width: 98vw;
-    }
     .btn {
         font-size: 1rem;
         padding: 14px 0;

src/components/GameDetail.jsx

@@ -45,8 +45,8 @@ const GameDetail = ({ game, onFinishGame, onUpdateScore, onBack }) => {
         ))}
       </div>
       <div className={styles['game-detail-controls']}>
-        <button className={styles['nav-button']} onClick={onBack} aria-label="Zurück zur Liste">Zurück zur Liste</button>
+        <button className="btn" onClick={onBack} aria-label="Zurück zur Liste">Zurück zur Liste</button>
-        <button className={styles['nav-button']} disabled={isCompleted} onClick={onFinishGame} aria-label={isCompleted ? 'Abgeschlossen' : 'Spiel beenden'}>{isCompleted ? 'Abgeschlossen' : 'Spiel beenden'}</button>
+        <button className="btn" disabled={isCompleted} onClick={onFinishGame} aria-label={isCompleted ? 'Abgeschlossen' : 'Spiel beenden'}>{isCompleted ? 'Abgeschlossen' : 'Spiel beenden'}</button>
       </div>
     </div>
   );

src/components/GameDetail.module.css

@@ -1,3 +1,4 @@
+/* GameDetail-specific styles only. Shared utility classes are now in global CSS. */
 .screen {
     position: absolute;
     top: 0;
@@ -121,22 +122,4 @@
     margin: 40px 0 0 0;
     width: 100%;
     justify-content: center;
-}
-.nav-button {
-    flex: 1;
-    min-width: 200px;
-    padding: 24px 0;
-    color: #fff;
-    background: #333;
-    border: none;
-    border-radius: 8px;
-    font-size: 1.4rem;
-    font-weight: 600;
-    cursor: pointer;
-    transition: background 0.2s, color 0.2s;
-    margin-bottom: 0;
-    margin-top: 0;
-}
-.nav-button:hover:enabled {
-    background: #444;
 } 

src/components/GameHistory.module.css

@@ -1,3 +1,4 @@
+/* GameHistory-specific styles only. Shared utility classes are now in global CSS. */
 .screen {
     position: absolute;
     top: 0;
@@ -20,21 +21,4 @@
 .screen-title {
     font-size: 24px;
     margin-bottom: 20px;
-}
-.nav-buttons {
-    display: flex;
-    flex-direction: column;
-    gap: 10px;
-    margin: 20px 0 40px 0;
-}
-.btn {
-    flex: 1;
-    min-width: 100px;
-    padding: 20px;
-    color: white;
-    border: none;
-    border-radius: 0;
-    font-size: 20px;
-    cursor: pointer;
-    touch-action: manipulation;
 } 

src/components/GameList.module.css

@@ -1,3 +1,4 @@
+/* GameList-specific styles only. Shared utility classes are now in global CSS. */
 .screen.active {
     display: block;
     opacity: 1;
@@ -21,23 +22,6 @@
     flex: 1;
     overflow-y: auto;
 }
-.nav-buttons {
-    display: flex;
-    flex-direction: column;
-    gap: 10px;
-    margin: 20px 0 40px 0;
-}
-.btn {
-    flex: 1;
-    min-width: 100px;
-    padding: 20px;
-    color: white;
-    border: none;
-    border-radius: 0;
-    font-size: 20px;
-    cursor: pointer;
-    touch-action: manipulation;
-}
 .filter-buttons {
     display: flex;
     gap: 8px;

src/components/Modal.module.css

@@ -1,3 +1,4 @@
+/* Consolidated modal styles for all modals */
 .modal {
     display: none;
     position: fixed;
@@ -31,6 +32,8 @@
     font-size: 24px;
     cursor: pointer;
     color: #888;
+    background: none;
+    border: none;
 }
 .close-button:hover {
     color: white;

src/components/NewGame.jsx

@@ -60,7 +60,7 @@ const NewGame = ({ onCreateGame, playerNameHistory, onCancel, onGameCreated, ini
     <form className={styles['new-game-form']} onSubmit={handleSubmit} aria-label="Neues Spiel Formular">
       <div className={styles['screen-title']}>Neues Spiel</div>
       <div style={{ display: 'flex', justifyContent: 'flex-end', marginBottom: 16 }}>
-        <button type="button" className={styles['btn']} onClick={handleClear} aria-label="Felder leeren">Felder leeren</button>
+        <button type="button" className="btn" onClick={handleClear} aria-label="Felder leeren">Felder leeren</button>
       </div>
       <div className={styles['player-inputs']}>
         <div className={styles['player-input']}>
@@ -106,9 +106,9 @@ const NewGame = ({ onCreateGame, playerNameHistory, onCancel, onGameCreated, ini
         </div>
       </div>
       {error && <div className={styles['validation-error']}>{error}</div>}
-      <div className={styles['nav-buttons']}>
+      <div className="nav-buttons">
-        <button type="button" className={styles['btn']} onClick={onCancel} aria-label="Abbrechen">Abbrechen</button>
+        <button type="button" className="btn" onClick={onCancel} aria-label="Abbrechen">Abbrechen</button>
-        <button type="submit" className={styles['btn']} aria-label="Spiel starten">Spiel starten</button>
+        <button type="submit" className="btn" aria-label="Spiel starten">Spiel starten</button>
       </div>
     </form>
   );

src/components/NewGame.module.css

@@ -1,3 +1,4 @@
+/* NewGame-specific styles only. Shared utility classes are now in global CSS. */
 .screen {
     position: absolute;
     top: 0;
@@ -97,29 +98,6 @@
     font-size: 1.1rem;
     text-align: center;
 }
-.nav-buttons {
-    display: flex;
-    flex-direction: column;
-    gap: 12px;
-    margin: 16px 0 0 0;
-}
-.btn {
-    flex: 1;
-    min-width: 100px;
-    padding: 18px;
-    color: white;
-    background: #333;
-    border: none;
-    border-radius: 6px;
-    font-size: 1.2rem;
-    font-weight: 600;
-    cursor: pointer;
-    touch-action: manipulation;
-    transition: background 0.2s, color 0.2s;
-}
-.btn:hover {
-    background: #444;
-}
 .new-game-form {
     width: 100%;
     max-width: 700px;

src/components/ValidationModal.jsx

@@ -1,5 +1,5 @@
 import { h } from 'preact';
-import styles from './ValidationModal.module.css';
+import styles from './Modal.module.css';
 
 /**
  * Modal for displaying validation errors.

src/components/ValidationModal.module.css

@@ -1,63 +1 @@
-.modal {
+/* DEPRECATED: All modal styles are now in Modal.module.css */ 
-    display: none;
-    position: fixed;
-    top: 0;
-    left: 0;
-    width: 100%;
-    height: 100%;
-    background-color: rgba(0, 0, 0, 0.7);
-    z-index: 1000;
-}
-.modal.show {
-    display: flex;
-    justify-content: center;
-    align-items: center;
-}
-.modal-content {
-    background-color: #2a2a2a;
-    padding: 20px;
-    border-radius: 10px;
-    width: 90%;
-    max-width: 500px;
-    position: relative;
-}
-.modal-header {
-    display: flex;
-    justify-content: space-between;
-    align-items: center;
-    margin-bottom: 20px;
-}
-.close-button {
-    font-size: 24px;
-    cursor: pointer;
-    color: #888;
-}
-.close-button:hover {
-    color: white;
-}
-.modal-body {
-    margin-bottom: 20px;
-}
-.modal-footer {
-    display: flex;
-    justify-content: flex-end;
-    gap: 10px;
-}
-.modal-button {
-    padding: 8px 16px;
-    border: none;
-    border-radius: 5px;
-    cursor: pointer;
-    font-size: 16px;
-}
-.modal-button.cancel {
-    background-color: #444;
-    color: white;
-}
-.modal-button.confirm {
-    background-color: #e74c3c;
-    color: white;
-}
-.modal-button:hover {
-    opacity: 0.9;
-} 

src/styles/index.css

@@ -26,7 +26,7 @@ input, select {
 
 /* Responsive adjustments for fullscreen toggle button */
 @media screen and (max-width: 480px) {
-    .fullscreen-toggle {
+    .fullscreenToggle {
         bottom: 15px;
         right: 15px;
         width: 40px;
@@ -55,6 +55,31 @@ input, select {
     background: #333;
 }
 
+/* Shared utility classes for buttons and layout */
+.btn {
+    flex: 1;
+    min-width: 100px;
+    padding: 18px;
+    color: white;
+    background: #333;
+    border: none;
+    border-radius: 6px;
+    font-size: 1.2rem;
+    font-weight: 600;
+    cursor: pointer;
+    touch-action: manipulation;
+    transition: background 0.2s, color 0.2s;
+}
+.btn:hover {
+    background: #444;
+}
+.nav-buttons {
+    display: flex;
+    flex-direction: column;
+    gap: 12px;
+    margin: 16px 0 0 0;
+}
+
 /* Modal overlay (global, not component-specific) */
 .modal {
     position: fixed;