refactor(ui): improve UI/UX design and spacing

- Increase card padding and gaps for better visual hierarchy
- Add hover lift effect to cards with smooth transitions
- Improve typography with larger headings and better line-height
- Darken meta text colors for better readability
- Add checkbox styling with accent color
- Make tags interactive with hover effects
- Add mobile responsive styles for forms and footer
- Replace Unicode arrows with SVG icons
- Improve focus styles for accessibility
- Increase badge padding and font-weight
- Add subtle shadow to cards by default

static/css/layout.css

@@ -228,14 +228,20 @@
 .post-list {
   display: flex;
   flex-direction: column;
-  gap: 1.5rem;
+  gap: 2rem;
 }
 
 /* Post card specific */
 .post-card {
   display: flex;
   flex-direction: column;
-  gap: 1rem;
+  gap: 1.25rem;
+  padding: 1.5rem;
+  transition: all 0.2s ease;
+}
+
+.post-card:hover {
+  transform: translateY(-2px);
 }
 
 .post-card-header {
@@ -247,7 +253,8 @@
 
 .post-card-title {
   margin-bottom: 0;
-  font-size: 1.25rem;
+  font-size: 1.5rem;
+  line-height: 1.3;
 }
 
 .post-card-title a {
@@ -263,7 +270,8 @@
   align-items: center;
   gap: 1rem;
   font-size: 0.875rem;
-  color: var(--color-text-light-2);
+  color: var(--color-text-light-1);
+  margin-bottom: 0.75rem;
 }
 
 .post-card-meta-item {
@@ -273,8 +281,9 @@
 }
 
 .post-card-content {
-  color: var(--color-text-light);
-  line-height: 1.6;
+  color: var(--color-text-light-1);
+  line-height: 1.7;
+  font-size: 1rem;
 }
 
 .post-card-footer {
@@ -423,15 +432,70 @@
 @media (max-width: 768px) {
   .site-header .container {
     height: 3.5rem;
+    padding: 0 1.25rem;
   }
-  
+
   .main-nav {
     display: none;
   }
-  
+
   .mobile-menu-btn {
     display: flex;
   }
+
+  /* Form actions mobile */
+  .form-actions {
+    flex-direction: column-reverse;
+    gap: 1rem;
+  }
+
+  .form-actions .btn {
+    width: 100%;
+  }
+
+  /* Footer mobile */
+  .site-footer .container {
+    flex-direction: column;
+    text-align: center;
+    gap: 1.5rem;
+    padding: 2rem 1rem;
+  }
+
+  .footer-links {
+    flex-wrap: wrap;
+    justify-content: center;
+  }
+
+  /* Post card mobile */
+  .post-card {
+    padding: 1.25rem;
+  }
+
+  .post-card-title {
+    font-size: 1.25rem;
+  }
+
+  .post-card-header {
+    flex-direction: column;
+    gap: 0.75rem;
+  }
+
+  .post-card-footer {
+    flex-direction: column;
+    align-items: flex-start;
+    gap: 1rem;
+  }
+
+  /* Page header mobile */
+  .page-header-flex {
+    flex-direction: column;
+    align-items: flex-start;
+    gap: 1rem;
+  }
+
+  .page-title {
+    font-size: 1.75rem;
+  }
 }
 
 @media (min-width: 769px) {