Header/Navigation-Styling ueberarbeitet

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

public/css/styles.css

@@ -10,12 +10,37 @@
 /* ============================================
    Top navigation (views/partials/header.ejs)
    ============================================
-   The bar keeps its deep navy in both themes: it frames the light content area
-   like the chrome of a tool, and it is the one surface that never changes as you
-   move through the app. Everything in it is quiet — slate on navy — except the
-   active item, which is the single accent: a thin, glowing sky rail. That rail is
-   the whole point, since the previous header had no active state at all.
-   The dropdown panels follow the theme (white / slate) so they read as content. */
+   The bar carries no surface of its own — it takes the page background and is
+   held apart from the content only by a hairline (and, once scrolled, the
+   faintest shadow). Everything in it is quiet; the single accent is the active
+   item, marked by a thin rail on the bottom edge. That rail is the whole point,
+   since the header used to have no active state at all.
+
+   --nav-bg mirrors the page background per theme. It is what the focus rings and
+   the badge ring cut themselves out against — without it they would need a
+   hard-coded colour and would break in one of the two themes. */
+:root { --nav-bg: #f9fafb; }            /* gray-50, matches body */
+.dark { --nav-bg: #111827; }            /* gray-900, matches body */
+
+.nav-brand:focus-visible,
+.nav-item:focus-visible,
+.icon-btn:focus-visible {
+    outline: none;
+    box-shadow: 0 0 0 2px var(--nav-bg), 0 0 0 4px rgba(37, 99, 235, 0.6);
+}
+.dark .nav-brand:focus-visible,
+.dark .nav-item:focus-visible,
+.dark .icon-btn:focus-visible {
+    box-shadow: 0 0 0 2px var(--nav-bg), 0 0 0 4px rgba(56, 189, 248, 0.7);
+}
+
+/* Hairline separation only once content actually slides underneath. */
+#siteHeader.is-scrolled {
+    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
+}
+.dark #siteHeader.is-scrolled {
+    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
+}
 
 .nav-item {
     position: relative;
@@ -27,22 +52,23 @@
     font-size: 0.875rem;
     font-weight: 500;
     letter-spacing: -0.01em;
-    color: rgb(148 163 184);            /* slate-400 */
+    color: rgb(71 85 105);              /* slate-600 */
     white-space: nowrap;
     transition: color 150ms ease, background-color 150ms ease;
 }
 button.nav-item, .icon-btn { cursor: pointer; }
 .nav-item:hover {
+    color: rgb(15 23 42);               /* slate-900 */
+    background-color: rgba(15, 23, 42, 0.05);
+}
+.nav-item.is-active { color: rgb(15 23 42); }
+
+.dark .nav-item { color: rgb(148 163 184); }        /* slate-400 */
+.dark .nav-item:hover {
     color: #fff;
     background-color: rgba(255, 255, 255, 0.06);
 }
-.nav-item.is-active {
-    color: #fff;
-}
-.nav-item:focus-visible {
-    outline: none;
-    box-shadow: 0 0 0 2px #0b1220, 0 0 0 4px rgba(56, 189, 248, 0.7);
-}
+.dark .nav-item.is-active { color: #fff; }
 
 /* The rail: sits on the header's bottom edge, lights up for the active section
    and previews faintly on hover. */
@@ -58,14 +84,18 @@ button.nav-item, .icon-btn { cursor: pointer; }
     transition: transform 200ms ease, background-color 200ms ease;
 }
 .nav-item:hover .nav-rail {
-    background-color: rgba(148, 163, 184, 0.45);
+    background-color: rgba(100, 116, 139, 0.35);
     transform: scaleX(1);
 }
 .nav-item.is-active .nav-rail {
-    background-color: rgb(56 189 248);  /* sky-400 */
-    box-shadow: 0 0 12px rgba(56, 189, 248, 0.8);
+    background-color: rgb(37 99 235);   /* blue-600, the app's action colour */
     transform: scaleX(1);
 }
+.dark .nav-item:hover .nav-rail { background-color: rgba(148, 163, 184, 0.4); }
+.dark .nav-item.is-active .nav-rail {
+    background-color: rgb(56 189 248);  /* sky-400 reads better on the dark page */
+    box-shadow: 0 0 10px rgba(56, 189, 248, 0.6);
+}
 
 /* Counters shown inline next to a nav label.
    `:not(.hidden)` is deliberate: a bare `display: inline-flex` would fight
@@ -97,17 +127,18 @@ button.nav-item, .icon-btn { cursor: pointer; }
     width: 2.25rem;
     height: 2.25rem;
     border-radius: 0.5rem;
-    color: rgb(148 163 184);
+    color: rgb(71 85 105);              /* slate-600 */
     transition: color 150ms ease, background-color 150ms ease;
 }
 .icon-btn:hover {
+    color: rgb(15 23 42);
+    background-color: rgba(15, 23, 42, 0.05);
+}
+.dark .icon-btn { color: rgb(148 163 184); }
+.dark .icon-btn:hover {
     color: #fff;
     background-color: rgba(255, 255, 255, 0.08);
 }
-.icon-btn:focus-visible {
-    outline: none;
-    box-shadow: 0 0 0 2px #0b1220, 0 0 0 4px rgba(56, 189, 248, 0.7);
-}
 
 /* Count badge floating on an icon button. Same `:not(.hidden)` reason as above. */
 .dot-badge:not(.hidden) {
@@ -127,7 +158,7 @@ button.nav-item, .icon-btn { cursor: pointer; }
     font-weight: 700;
     line-height: 1;
     color: #fff;
-    box-shadow: 0 0 0 2px #0b1220;
+    box-shadow: 0 0 0 2px var(--nav-bg);   /* cut out against the bar in both themes */
 }
 .dot-badge--red { background-color: rgb(244 63 94); }
 
@@ -216,11 +247,18 @@ nav .dd-panel { right: auto; left: 0; }
     border-radius: 0.5rem;
     font-size: 0.9375rem;
     font-weight: 500;
-    color: rgb(148 163 184);
+    color: rgb(71 85 105);              /* slate-600 */
     transition: background-color 150ms ease, color 150ms ease;
 }
-.m-item:hover { background-color: rgba(255, 255, 255, 0.06); color: #fff; }
+.m-item:hover { background-color: rgba(15, 23, 42, 0.05); color: rgb(15 23 42); }
 .m-item.is-active {
+    color: rgb(29 78 216);              /* blue-700 */
+    background-color: rgb(239 246 255);  /* blue-50 */
+    box-shadow: inset 2px 0 0 rgb(37 99 235);
+}
+.dark .m-item { color: rgb(148 163 184); }
+.dark .m-item:hover { background-color: rgba(255, 255, 255, 0.06); color: #fff; }
+.dark .m-item.is-active {
     color: #fff;
     background-color: rgba(56, 189, 248, 0.12);
     box-shadow: inset 2px 0 0 rgb(56 189 248);