Give cards the surface look of the PM app

Cards had a 3px petrol bar on the top edge, and Bootstrap's shadow-sm
class overrode their own shadow with !important. They now use the PM app
surface: a 1px border all around, a 16px radius and a soft diffuse shadow
with a faint inner highlight, with a stronger shadow and a weaker highlight
in dark mode. The shadow-sm classes are removed from the cards so the
shared rule applies. Menus, drawers and dialogs keep their shadows.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -171,6 +171,10 @@ Support Ctrl+Plus and Ctrl+Shift+Plus for insertion.
 
 Bootstrap may be used for the general application UI, such as navigation, page layout, buttons, forms, cards, alerts and modals.
 
+Cards follow the PM app look: 1px border all around, 16px radius and the
+soft shadow defined on `.card` in `globals.css` (own dark-mode value). Do
+not add Bootstrap `shadow-*` classes or a colored top border to cards.
+
 Do not use Bootstrap as the core table/grid framework for the circuit list editor.
 
 The circuit list editor must remain a custom spreadsheet-like component with controlled cell selection, inline edit mode, row grouping, drag-and-drop indicators and keyboard behavior.

src/app/globals.css

@@ -431,12 +431,26 @@ a.kpi:hover {
   color: var(--color-accent-pale);
 }
 
+/* Flächen-Look wie in der PM-App (Vorbild grow-monitor): gleichmäßiger
+   1-px-Rahmen statt farbigem Balken an der Oberkante, größerer Radius und ein
+   weicher Streuschatten mit feiner heller Innenkante oben. Der Akzent kommt
+   über Kopfzeile und Inhalt, nicht über die Kante. Karten tragen deshalb keine
+   Bootstrap-Klasse shadow-*, die den Schatten mit !important überschreiben
+   würde. */
 .card {
-  border-radius: var(--radius);
-  border-top: 3px solid var(--color-primary);
+  --bs-card-border-radius: 16px;
+  --bs-card-border-color: var(--color-border);
   box-shadow:
-    0 1px 2px var(--shadow-soft),
-    0 10px 24px -14px var(--shadow-strong);
+    0 4px 24px var(--shadow-soft),
+    0 1px 0 rgba(255, 255, 255, 0.7) inset;
+}
+
+/* Auf dunklem Grund ein kräftigerer Streuschatten und nur eine schwache
+   Innenkante, sonst wirkt sie wie ein harter weißer Strich. */
+:root[data-bs-theme="dark"] .card {
+  box-shadow:
+    0 4px 24px rgba(0, 0, 0, 0.4),
+    0 1px 0 rgba(255, 255, 255, 0.05) inset;
 }
 
 .card-header {

src/app/projects/[projectId]/page.tsx

@@ -904,7 +904,7 @@ export default function ProjectDetailPage() {
         ) : null}
 
         <section className="col-12" id="verteilungen">
-          <div className="card shadow-sm">
+          <div className="card">
             <div className="card-header d-flex justify-content-between align-items-center">
               <div>
                 <span>Verteilungen</span>
@@ -997,7 +997,7 @@ export default function ProjectDetailPage() {
         </section>
 
         <section className="col-12 col-lg-5" id="etagen">
-          <div className="card shadow-sm h-100">
+          <div className="card h-100">
             <div className="card-header d-flex justify-content-between align-items-center">
               <div>
                 <span>Etagen</span>
@@ -1028,7 +1028,7 @@ export default function ProjectDetailPage() {
         </section>
 
         <section className="col-12 col-lg-7" id="raeume">
-          <div className="card shadow-sm">
+          <div className="card">
             <div className="card-header d-flex justify-content-between align-items-center">
               <div>
                 <span>Räume</span>
@@ -1079,7 +1079,7 @@ export default function ProjectDetailPage() {
         </section>
       </div>
 
-      <section className="card shadow-sm mt-4" id="projektgeraete">
+      <section className="card mt-4" id="projektgeraete">
         <div className="card-header d-flex flex-wrap justify-content-between align-items-center gap-2">
           <div>
             <span>Projektgeräte</span>

src/app/projects/page.tsx

@@ -238,7 +238,7 @@ export default function ProjectsPage() {
       {error ? <div className="alert alert-warning">{error}</div> : null}
 
       <div className="d-flex flex-column gap-4">
-        <section className="card shadow-sm">
+        <section className="card">
           <div className="card-header">Neues Projekt</div>
           <div className="card-body" style={{ maxWidth: 480 }}>
             <form className="vstack gap-3" onSubmit={handleCreateProject}>
@@ -271,7 +271,7 @@ export default function ProjectsPage() {
           </div>
         </section>
 
-        <section className="card shadow-sm">
+        <section className="card">
           <div className="card-header">Projekt importieren</div>
           <div className="card-body" style={{ maxWidth: 480 }}>
             <p className="text-secondary small">
@@ -326,7 +326,7 @@ export default function ProjectsPage() {
           </div>
         </section>
 
-        <section className="card shadow-sm">
+        <section className="card">
           <div className="card-header">Globale Geräte / Verbraucher</div>
         <div className="card-body border-bottom">
           <form className="row g-2" onSubmit={handleCreateGlobalDevice}>

src/frontend/components/project-version-history.tsx

@@ -227,7 +227,7 @@ export function ProjectVersionHistory({
     history?.currentRevision === currentRevision;
 
   return (
-    <section className="card shadow-sm">
+    <section className="card">
       <div className="card-header d-flex flex-wrap justify-content-between align-items-center gap-2">
         <span>Versionen und Sicherungspunkte</span>
         <div className="d-flex align-items-center gap-2">