feature: Responsive mobile layout for home page

Migrate hero, section-header, and section-split to MudGrid with xs/sm/md breakpoints (Spacing=0 to keep color panels flush); add @media collapse rules for genre/features card grids and the CTA banner. Visual styling unchanged at desktop width.

DeepDrftPublic.Client/Pages/Home.razor.css

@@ -6,8 +6,6 @@
 /* ── HERO ── */
 .hero {
     min-height: 100vh;
-    display: grid;
-    grid-template-columns: 1fr 1fr;
     overflow: hidden;
 }
 
@@ -18,6 +16,7 @@
     padding: 6rem 3rem;
     position: relative;
     background: var(--deepdrft-white);
+    height: 100%;
 }
 
 .hero-right {
@@ -27,6 +26,13 @@
     flex-direction: column;
     justify-content: flex-end;
     overflow: hidden;
+    height: 100%;
+}
+
+@media (max-width: 960px) {
+    .hero { min-height: auto; }
+    .hero-left { padding: 4rem 1.5rem 3rem; }
+    .hero-right { min-height: 50vh; }
 }
 
 /* ── DIVIDER ── */
@@ -59,12 +65,10 @@
     background: var(--deepdrft-white);
 }
 
-.section-header {
-    display: grid;
-    grid-template-columns: 1fr 2fr;
-    gap: 4rem;
-    margin-bottom: 5rem;
-    align-items: end;
+@media (min-width: 960px) {
+    .section-header-grid {
+        align-items: end;
+    }
 }
 
 .section-label {
@@ -109,6 +113,14 @@
     margin-bottom: 4rem;
 }
 
+@media (max-width: 960px) {
+    .genre-grid { grid-template-columns: repeat(3, 1fr); }
+}
+
+@media (max-width: 600px) {
+    .genre-grid { grid-template-columns: repeat(2, 1fr); }
+}
+
 .genre-card {
     background: var(--deepdrft-white);
     padding: 2rem 1.5rem;
@@ -191,6 +203,20 @@
 
 .feature-card:hover { background: rgba(250, 250, 248, 0.04); }
 
+/* Below md: per-card border-right leaves dangling hairlines when columns
+   collapse, so switch to border-bottom dividers instead. */
+@media (max-width: 960px) {
+    .features-grid { grid-template-columns: repeat(2, 1fr); }
+    .feature-card { border-right: none; border-bottom: 1px solid rgba(250, 250, 248, 0.08); }
+    .feature-card:last-child { border-bottom: none; }
+}
+
+@media (max-width: 600px) {
+    .features-grid { grid-template-columns: 1fr; }
+    .feature-card { border-right: none; border-bottom: 1px solid rgba(250, 250, 248, 0.08); }
+    .feature-card:last-child { border-bottom: none; }
+}
+
 .feature-icon {
     width: 2.5rem;
     height: 2.5rem;
@@ -227,11 +253,13 @@
 
 /* ── SPLIT: ORIGIN + CONNECT ── */
 .section-split {
-    display: grid;
-    grid-template-columns: 1fr 1fr;
     min-height: 60vh;
 }
 
+@media (max-width: 960px) {
+    .section-split { min-height: auto; }
+}
+
 .split-left {
     background: var(--deepdrft-green);
     padding: 6rem 4rem;
@@ -240,6 +268,7 @@
     justify-content: center;
     position: relative;
     overflow: hidden;
+    height: 100%;
 }
 
 .split-left::before {
@@ -259,6 +288,7 @@
     flex-direction: column;
     justify-content: center;
     background: var(--deepdrft-white);
+    height: 100%;
 }
 
 .split-eyebrow {
@@ -442,6 +472,7 @@
     position: relative;
     z-index: 1;
     flex-shrink: 0;
+    flex-wrap: wrap;
 }
 
 .btn-white {
@@ -480,3 +511,29 @@
 }
 
 .btn-outline-white:hover { border-color: var(--deepdrft-white); }
+
+@media (max-width: 600px) {
+    .cta-banner {
+        flex-direction: column;
+        align-items: flex-start;
+        gap: 2rem;
+        padding: 4rem 1.5rem;
+    }
+
+    .cta-actions {
+        width: 100%;
+    }
+
+    .btn-white,
+    .btn-outline-white {
+        flex: 1;
+        text-align: center;
+        min-width: 140px;
+    }
+
+    /* At 22rem the "DRFT" watermark forces horizontal scroll on mobile. */
+    .cta-banner::before {
+        font-size: 8rem;
+        right: -0.5rem;
+    }
+}