ui: card-surface utility, rounded corners, calendar polish, banner layout

- Add .card-surface utility (@layer components): rounded-sm border shadow-sm
- Card.svelte, CalendarBlock, SearchableTextBlock, BlogOverview use card-surface
- OrganisationsBlock: logo h-12 rounded-sm, description style cleanup, pt-1 for hover clip fix
- DeadlineBanner: container-custom width constraint, text left-aligned
- WindAreaPanel stats: card-surface
- CalendarBlock: rounded-sm day headers, past days opacity-20 + diagonal strike
- Add .day-past pseudo-element utility for diagonal line

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app.css

@@ -10,6 +10,32 @@
 
 @import "tailwindcss";
 
+/* ==========================================================================
+   Component Utilities
+   ========================================================================== */
+
+@layer components {
+  /* Shared card surface: border, background, shadow, radius */
+  .card-surface {
+    @apply rounded-sm border border-stein-200 bg-white shadow-sm;
+  }
+
+  /* Diagonal strikethrough for past calendar days */
+  .day-past::after {
+    content: '';
+    position: absolute;
+    inset: 2px;
+    background: linear-gradient(
+      to top right,
+      transparent calc(50% - 0.5px),
+      rgba(0, 0, 0, 0.12) calc(50% - 0.5px),
+      rgba(0, 0, 0, 0.12) calc(50% + 0.5px),
+      transparent calc(50% + 0.5px)
+    );
+    pointer-events: none;
+  }
+}
+
 /* ==========================================================================
    Design Tokens – Windwiderstand (01-colors, 02-typography, 06-tokens.json)
    ========================================================================== */

src/lib/components/BlogOverview.svelte

@@ -235,7 +235,7 @@
                 {#each filteredResults as hit}
                     <a
                         href={searchResultHref(hit.slug)}
-                        class="flex flex-col overflow-hidden border border-stein-200 bg-white text-stein-900 no-underline transition-colors"
+                        class="card-surface flex flex-col overflow-hidden text-stein-900 no-underline transition-colors hover:-translate-y-0.5 hover:shadow-md hover:border-wald-300 transition-[transform,box-shadow,border-color] duration-200"
                     >
                         {#if hit.image}
                             <div

src/lib/components/Card.svelte

@@ -7,7 +7,7 @@
    * tile + post: PostCard – Shell ohne Padding, Medien bündig, Text mit p-4 im Kind.
    * callout: CTA; layout wird ignoriert.
    */
-  const cardSurface = cva("relative min-w-0 overflow-hidden", {
+  const cardSurface = cva("relative min-w-0 overflow-hidden rounded-sm", {
     variants: {
       variant: {
         tile: "",
@@ -24,20 +24,17 @@
       {
         variant: "tile",
         layout: "stack",
-        class:
+        class: "card-surface flex flex-col gap-2 p-4 text-stein-900",
-          "flex flex-col gap-2 border border-stein-200 bg-white p-4 text-stein-900",
       },
       {
         variant: "tile",
         layout: "inline",
-        class:
+        class: "card-surface flex flex-row items-start gap-3 p-4 text-stein-900",
-          "flex flex-row items-start gap-3 border border-stein-200 bg-white p-4 text-stein-900",
       },
       {
         variant: "tile",
         layout: "post",
-        class:
+        class: "card-surface flex flex-col gap-0 p-0 text-stein-900",
-          "flex flex-col gap-0 border border-stein-200 bg-white p-0 text-stein-900",
       },
     ],
     defaultVariants: { variant: "tile", layout: "stack" },

src/lib/components/blocks/CalendarBlock.svelte

@@ -536,7 +536,7 @@
 </script>
 
 <div
-    class="{layoutClasses} w-full min-w-0 calendar-block border border-stein-200 overflow-hidden"
+    class="{layoutClasses} w-full min-w-0 calendar-block card-surface overflow-hidden"
     data-block="Calendar"
     data-block-type="calendar"
     data-block-slug={block._slug}
@@ -1044,7 +1044,7 @@
             <div class="grid grid-cols-7 gap-1.5 text-center text-sm">
                 {#each weekdays as w, i}
                     <div
-                        class="py-1.5 text-xs font-bold rounded-xs {i >= 5
+                        class="py-1.5 text-xs font-bold rounded-sm {i >= 5
                             ? 'bg-stein-100/80 text-stein-600'
                             : 'bg-himmel-200/50 text-himmel-800'}"
                     >
@@ -1068,6 +1068,7 @@
                             <button
                                 type="button"
                                 class="relative h-10 rounded-xs flex flex-col items-center justify-center min-w-0 transition-colors cursor-pointer font-semibold
+                                    {!isFuture ? 'opacity-20 day-past' : ''}
                                     {isCurrentMonth
                                     ? 'text-himmel-900'
                                     : 'text-himmel-700 opacity-60 hover:opacity-80'}
@@ -1106,6 +1107,7 @@
                         {:else}
                             <div
                                 class="relative h-10 rounded-xs flex flex-col items-center justify-center min-w-0 cursor-default
+                                    {!isFuture ? 'opacity-20 day-past' : ''}
                                     {isWeekend
                                     ? 'bg-stein-100/60'
                                     : 'bg-himmel-50/50'}

src/lib/components/blocks/DeadlineBannerBlock.svelte

@@ -116,10 +116,10 @@
         data-block-slug={block._slug}
     >
         <div
-            class="gradient-blob-bg flex items-center gap-x-6 bg-gray-50 px-6 py-2.5 sm:px-3.5"
+            class="gradient-blob-bg bg-gray-50 py-2.5"
         >
-            <span class="hidden flex-1 sm:block" aria-hidden="true"></span>
+            <div class="container-custom flex items-center gap-x-6">
-            <p class="my-0! text-sm/6 text-gray-900">
+            <p class="my-0! flex-1 text-sm/6 text-gray-900">
                 {sentence}{#if countdownStr}{sentence ? " · " : ""}<span
                         class="font-semibold">{countdownStr}</span
                     >{/if}{#if href}
@@ -137,7 +137,7 @@
                     </a>
                 {/if}
             </p>
-            <div class="flex flex-1 justify-end">
+            <div class="shrink-0">
                 <button
                     type="button"
                     onclick={() => (dismissed = true)}
@@ -151,6 +151,7 @@
                     />
                 </button>
             </div>
+            </div>
         </div>
     </div>
 {/if}

src/lib/components/blocks/OrganisationsBlock.svelte

@@ -64,12 +64,12 @@
 
 {#snippet defaultCard(o: OrganisationEntry, linkUrl: string | undefined, logoField: ReturnType<typeof organisationLogoField>, orgIndex: number)}
   <Card href={linkUrl} class="h-full">
-    <div class="flex h-11 w-11 shrink-0 items-center justify-center overflow-hidden bg-stein-100">
+    <div class="flex h-12 w-12 shrink-0 items-center justify-center overflow-hidden rounded-sm border border-stein-100 bg-stein-100">
       {#if logoField}
         <RustyImage
           src={logoField.url}
           focal={logoField.focal ?? null}
-          width={88}
+          width={96}
           aspect="1/1"
           fit="contain"
           quality={85}
@@ -98,9 +98,9 @@
         <Badge color={o.badge.color}>{o.badge.label}</Badge>
       </div>
     {/if}
-    <h5 class="mb-1 min-w-0 truncate text-sm font-medium leading-tight text-stein-900">{o.name ?? ""}</h5>
+    <h5 class="min-w-0 truncate text-sm font-medium leading-tight text-stein-900">{o.name ?? ""}</h5>
     {#if o.description}
-      <p class="line-clamp-2 text-xs font-light text-stein-600">{o.description}</p>
+      <p class="line-clamp-2 text-xs text-stein-500">{o.description}</p>
     {/if}
   </Card>
 {/snippet}
@@ -140,7 +140,7 @@
     <div class="relative">
       <div
         bind:this={scroller}
-        class="flex gap-4 overflow-x-auto scroll-smooth snap-x snap-mandatory pb-2 [scrollbar-width:thin]"
+        class="flex gap-4 overflow-x-auto scroll-smooth snap-x snap-mandatory pt-1 pb-2 [scrollbar-width:thin]"
       >
         {#each orgs as org, orgIndex}
           {#if typeof org === "object" && org !== null}

src/lib/components/blocks/SearchableTextBlock.svelte

@@ -193,7 +193,7 @@
 </script>
 
 <div
-  class="searchable-text flex flex-col gap-0 border border-stein-200 bg-white shadow-sm overflow-hidden {layoutClasses} {className}"
+  class="searchable-text card-surface flex flex-col gap-0 overflow-hidden {layoutClasses} {className}"
   data-block="SearchableText" data-block-type="searchable_text"
   data-block-slug={block._slug}
 >