feat: implement exercise filter modal and enhance filtering logic

- Added a new exercise filter modal with improved layout and styling for better user experience.
- Introduced initial filter state and logic to count active filter groups, enhancing the filtering capabilities on the ExercisesListPage.
- Updated CSS styles to support the new modal and improve overall UI consistency.
- Implemented keyboard accessibility for closing the filter modal, enhancing usability.

frontend/src/app.css

@@ -1537,6 +1537,67 @@ a.analysis-split__nav-item {
   overscroll-behavior: contain;
 }
 
+.exercise-filter-modal.admin-modal-sheet {
+  max-width: min(920px, calc(100vw - 16px));
+}
+.exercise-filter-modal .admin-modal-sheet__body.exercise-filter-modal__scroll {
+  flex: 1;
+  min-height: 0;
+}
+.exercise-filter-modal__footer {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 10px;
+  justify-content: flex-end;
+  align-items: center;
+  padding: 12px 16px;
+  padding-bottom: max(12px, env(safe-area-inset-bottom, 0px));
+  border-top: 1px solid var(--border);
+  flex-shrink: 0;
+  background: var(--surface);
+}
+.exercise-search-bar__actions {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 10px;
+  margin-top: 12px;
+}
+.exercise-filter-trigger {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+}
+.exercise-filter-badge {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 22px;
+  height: 22px;
+  padding: 0 6px;
+  border-radius: 999px;
+  font-size: 12px;
+  font-weight: 700;
+  background: var(--accent);
+  color: #fff;
+}
+.exercise-filters-modal-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
+  gap: 14px;
+}
+.exercise-filter-level-row {
+  grid-column: 1 / -1;
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 12px;
+}
+@media (max-width: 480px) {
+  .exercise-filter-level-row {
+    grid-template-columns: 1fr;
+  }
+}
+
 /* Reifegradmodell-Admin: klare Schritte, responsives Raster */
 .admin-matrix-alert {
   border: 1px solid var(--danger);

frontend/src/pages/ExercisesListPage.jsx

@@ -1,13 +1,37 @@
-import React, { useState, useEffect, useMemo } from 'react'
+import React, { useState, useEffect, useMemo, useCallback } from 'react'
 import { Link } from 'react-router-dom'
 import api from '../utils/api'
 import { SKILL_LEVEL_OPTIONS } from '../constants/skillLevels'
-import SearchableSelect from '../components/SearchableSelect'
 import MultiSelectCombo from '../components/MultiSelectCombo'
 
 const PAGE_SIZE = 100
 const LEVEL_FILTER_OPTS = SKILL_LEVEL_OPTIONS.filter((o) => o.level != null)
 
+const INITIAL_FILTERS = {
+  focus_area_ids: [],
+  style_direction_ids: [],
+  training_type_ids: [],
+  target_group_ids: [],
+  skill_ids: [],
+  skill_min_level: '',
+  skill_max_level: '',
+  visibility_any: [],
+  status_any: [],
+}
+
+function countActiveFilterGroups(f) {
+  let n = 0
+  if (f.focus_area_ids?.length) n++
+  if (f.style_direction_ids?.length) n++
+  if (f.training_type_ids?.length) n++
+  if (f.target_group_ids?.length) n++
+  if (f.skill_ids?.length) n++
+  if (f.skill_min_level || f.skill_max_level) n++
+  if (f.visibility_any?.length) n++
+  if (f.status_any?.length) n++
+  return n
+}
+
 function ExercisesListPage() {
   const [exercises, setExercises] = useState([])
   const [catalogs, setCatalogs] = useState({
@@ -26,17 +50,10 @@ function ExercisesListPage() {
   const [aiSearchInput, setAiSearchInput] = useState('')
   const [debouncedSearch, setDebouncedSearch] = useState('')
   const [debouncedAiSearch, setDebouncedAiSearch] = useState('')
-  const [filters, setFilters] = useState({
+  const [filters, setFilters] = useState(() => ({ ...INITIAL_FILTERS }))
-    focus_area_ids: [],
+  const [filterModalOpen, setFilterModalOpen] = useState(false)
-    style_direction_ids: [],
+
-    training_type_ids: [],
+  const activeFilterGroups = useMemo(() => countActiveFilterGroups(filters), [filters])
-    target_group_ids: [],
-    skill_ids: [],
-    skill_min_level: '',
-    skill_max_level: '',
-    visibility_any: [],
-    status_any: [],
-  })
 
   useEffect(() => {
     const t = setTimeout(() => setDebouncedSearch(searchInput.trim()), 400)
@@ -48,6 +65,15 @@ function ExercisesListPage() {
     return () => clearTimeout(t)
   }, [aiSearchInput])
 
+  useEffect(() => {
+    if (!filterModalOpen) return
+    const onKey = (e) => {
+      if (e.key === 'Escape') setFilterModalOpen(false)
+    }
+    window.addEventListener('keydown', onKey)
+    return () => window.removeEventListener('keydown', onKey)
+  }, [filterModalOpen])
+
   const focusOptions = useMemo(
     () =>
       catalogs.focusAreas.map((fa) => ({
@@ -72,10 +98,6 @@ function ExercisesListPage() {
     () => catalogs.skills.map((s) => ({ id: s.id, label: s.name || String(s.id) })),
     [catalogs.skills]
   )
-  const levelFilterOptions = useMemo(
-    () => LEVEL_FILTER_OPTS.map((o) => ({ id: o.level, label: o.label })),
-    []
-  )
   const visibilityOptions = useMemo(
     () => [
       { id: 'private', label: 'Privat' },
@@ -204,6 +226,8 @@ function ExercisesListPage() {
     }
   }
 
+  const resetAllFilters = useCallback(() => setFilters({ ...INITIAL_FILTERS }), [])
+
   if (!catalogsReady || loading) {
     return (
       <div style={{ padding: '2rem', textAlign: 'center' }}>
@@ -231,12 +255,7 @@ function ExercisesListPage() {
         </Link>
       </div>
 
-      <div className="card exercise-filters-compact" style={{ marginBottom: '12px' }}>
+      <div className="card exercise-search-bar" style={{ marginBottom: '12px' }}>
-        <p style={{ gridColumn: '1 / -1', fontSize: '12px', color: 'var(--text3)', margin: '0 0 4px' }}>
-          Filter untereinander werden mit <strong>UND</strong> kombiniert. Mehrere Einträge in einem Feld mit{' '}
-          <strong>ODER</strong> (die Übung muss mindestens eine der gewählten Zuordnungen erfüllen).
-        </p>
-        <div style={{ gridColumn: '1 / -1' }}>
         <label className="form-label">Volltextsuche (Titel, Ziel, …)</label>
         <input
           type="search"
@@ -245,25 +264,72 @@ function ExercisesListPage() {
           value={searchInput}
           onChange={(e) => setSearchInput(e.target.value)}
           autoComplete="off"
+          style={{ marginBottom: '10px' }}
         />
-        </div>
-        <div style={{ gridColumn: '1 / -1' }}>
         <label className="form-label">Ergänzende Suche / KI-Vorbereitung (Beta)</label>
         <input
           type="search"
           className="form-input"
-            placeholder="zweiter Begriff — aktuell zusätzliche Volltextsuche (ODER); später KI"
+          placeholder="zweiter Begriff — zusätzliche Volltextsuche (ODER)"
           value={aiSearchInput}
           onChange={(e) => setAiSearchInput(e.target.value)}
           autoComplete="off"
         />
-          <p style={{ fontSize: '12px', color: 'var(--text3)', marginTop: '6px' }}>
+        <div className="exercise-search-bar__actions">
-            Standardfilter aus Verein und Trainerrolle folgen später; die KI-Nutzung der zweiten Zeile
+          <button type="button" className="btn btn-secondary exercise-filter-trigger" onClick={() => setFilterModalOpen(true)}>
-            kommt mit einem eigenen Endpunkt.
+            Filter
+            {activeFilterGroups > 0 ? (
+              <span className="exercise-filter-badge" aria-hidden>
+                {activeFilterGroups}
+              </span>
+            ) : null}
+          </button>
+          {activeFilterGroups > 0 ? (
+            <button type="button" className="btn" onClick={resetAllFilters}>
+              Filter löschen
+            </button>
+          ) : null}
+        </div>
+        <p style={{ fontSize: '12px', color: 'var(--text3)', marginTop: '10px', marginBottom: 0 }}>
+          Vereins-/Trainerfilter folgen später. Fachliche Filter über „Filter“ – zwischen Feldern UND, Auswahl mehrerer Werte je Feld mit ODER.
         </p>
       </div>
+
+      {filterModalOpen && (
+        <div
+          className="admin-modal-backdrop"
+          role="presentation"
+          onClick={(e) => {
+            if (e.target === e.currentTarget) setFilterModalOpen(false)
+          }}
+        >
+          <div
+            className="admin-modal-sheet exercise-filter-modal"
+            role="dialog"
+            aria-modal="true"
+            aria-labelledby="exercise-filter-modal-title"
+            onClick={(e) => e.stopPropagation()}
+          >
+            <div className="admin-modal-sheet__header">
+              <h3 id="exercise-filter-modal-title" className="admin-modal-sheet__title">
+                Übungen filtern
+              </h3>
+              <button
+                type="button"
+                className="btn btn-secondary admin-modal-sheet__close"
+                onClick={() => setFilterModalOpen(false)}
+              >
+                Schließen
+              </button>
+            </div>
+            <div className="admin-modal-sheet__body exercise-filter-modal__scroll">
+              <p style={{ fontSize: '13px', color: 'var(--text2)', marginTop: 0, marginBottom: '14px' }}>
+                Zwischen den Bereichen gilt <strong>UND</strong>. Innerhalb eines Bereichs werden mehrere Einträge mit{' '}
+                <strong>ODER</strong> verknüpft (die Übung muss mindestens eine gewählte Zuordnung erfüllen).
+              </p>
+              <div className="exercise-filters-modal-grid">
                 <div>
-          <label className="form-label">Fokus (mehrere möglich)</label>
+                  <label className="form-label">Fokus</label>
                   <MultiSelectCombo
                     value={filters.focus_area_ids}
                     onChange={(v) => setFilters({ ...filters, focus_area_ids: v })}
@@ -272,7 +338,7 @@ function ExercisesListPage() {
                   />
                 </div>
                 <div>
-          <label className="form-label">Stilrichtung (mehrere möglich)</label>
+                  <label className="form-label">Stilrichtung</label>
                   <MultiSelectCombo
                     value={filters.style_direction_ids}
                     onChange={(v) => setFilters({ ...filters, style_direction_ids: v })}
@@ -281,7 +347,7 @@ function ExercisesListPage() {
                   />
                 </div>
                 <div>
-          <label className="form-label">Trainingsstil (mehrere möglich)</label>
+                  <label className="form-label">Trainingsstil</label>
                   <MultiSelectCombo
                     value={filters.training_type_ids}
                     onChange={(v) => setFilters({ ...filters, training_type_ids: v })}
@@ -290,7 +356,7 @@ function ExercisesListPage() {
                   />
                 </div>
                 <div>
-          <label className="form-label">Zielgruppe (mehrere möglich)</label>
+                  <label className="form-label">Zielgruppe</label>
                   <MultiSelectCombo
                     value={filters.target_group_ids}
                     onChange={(v) => setFilters({ ...filters, target_group_ids: v })}
@@ -299,7 +365,7 @@ function ExercisesListPage() {
                   />
                 </div>
                 <div>
-          <label className="form-label">Fähigkeit (mehrere möglich)</label>
+                  <label className="form-label">Fähigkeit</label>
                   <MultiSelectCombo
                     value={filters.skill_ids}
                     onChange={(v) => setFilters({ ...filters, skill_ids: v })}
@@ -307,28 +373,40 @@ function ExercisesListPage() {
                     placeholder="Fähigkeit suchen …"
                   />
                 </div>
+                <div className="exercise-filter-level-row">
                   <div>
                     <label className="form-label">Fähigkeit Stufe von</label>
-          <SearchableSelect
+                    <select
+                      className="form-input"
                       value={filters.skill_min_level}
-            onChange={(v) => setFilters({ ...filters, skill_min_level: v })}
+                      onChange={(e) => setFilters({ ...filters, skill_min_level: e.target.value })}
-            options={levelFilterOptions}
+                    >
-            allLabel="egal (min)"
+                      <option value="">egal</option>
-            filterPlaceholder="Stufe suchen…"
+                      {LEVEL_FILTER_OPTS.map((o) => (
-          />
+                        <option key={o.value} value={String(o.level)}>
+                          {o.label}
+                        </option>
+                      ))}
+                    </select>
                   </div>
                   <div>
-          <label className="form-label">Fähigkeit Stufe bis</label>
+                    <label className="form-label">bis</label>
-          <SearchableSelect
+                    <select
+                      className="form-input"
                       value={filters.skill_max_level}
-            onChange={(v) => setFilters({ ...filters, skill_max_level: v })}
+                      onChange={(e) => setFilters({ ...filters, skill_max_level: e.target.value })}
-            options={levelFilterOptions}
+                    >
-            allLabel="egal (max)"
+                      <option value="">egal</option>
-            filterPlaceholder="Stufe suchen…"
+                      {LEVEL_FILTER_OPTS.map((o) => (
-          />
+                        <option key={`m-${o.value}`} value={String(o.level)}>
+                          {o.label}
+                        </option>
+                      ))}
+                    </select>
+                  </div>
                 </div>
                 <div>
-          <label className="form-label">Sichtbarkeit (mehrere möglich)</label>
+                  <label className="form-label">Sichtbarkeit</label>
                   <MultiSelectCombo
                     value={filters.visibility_any}
                     onChange={(v) => setFilters({ ...filters, visibility_any: v })}
@@ -337,7 +415,7 @@ function ExercisesListPage() {
                   />
                 </div>
                 <div>
-          <label className="form-label">Status (mehrere möglich)</label>
+                  <label className="form-label">Status</label>
                   <MultiSelectCombo
                     value={filters.status_any}
                     onChange={(v) => setFilters({ ...filters, status_any: v })}
@@ -346,6 +424,18 @@ function ExercisesListPage() {
                   />
                 </div>
               </div>
+            </div>
+            <div className="exercise-filter-modal__footer">
+              <button type="button" className="btn" onClick={resetAllFilters}>
+                Alle Filter zurücksetzen
+              </button>
+              <button type="button" className="btn btn-primary" onClick={() => setFilterModalOpen(false)}>
+                Fertig
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
 
       {exercises.length === 0 ? (
         <div className="card">