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/components.css

@@ -104,13 +104,14 @@
 .card {
   background-color: var(--color-box-body);
   border: 1px solid var(--color-border);
-  border-radius: 6px;
+  border-radius: 8px;
   overflow: hidden;
-  transition: box-shadow 0.2s ease;
+  box-shadow: 0 1px 3px var(--color-shadow);
+  transition: all 0.2s ease;
 }
 
 .card:hover {
-  box-shadow: 0 2px 8px var(--color-shadow);
+  box-shadow: 0 4px 12px var(--color-shadow);
 }
 
 .card-header {
@@ -121,7 +122,7 @@
 }
 
 .card-body {
-  padding: 1.25rem;
+  padding: 1.5rem 2rem;
 }
 
 .card-footer {
@@ -254,13 +255,14 @@
 .badge {
   display: inline-flex;
   align-items: center;
-  padding: 0.125rem 0.5rem;
+  padding: 0.25rem 0.75rem;
   font-size: 0.75rem;
-  font-weight: 500;
+  font-weight: 600;
   line-height: 1.5;
   border-radius: 9999px;
   background-color: var(--color-label-bg);
   color: var(--color-label-text);
+  white-space: nowrap;
 }
 
 .badge-primary {
@@ -288,16 +290,31 @@
   display: inline-flex;
   align-items: center;
   gap: 0.25rem;
-  padding: 0.125rem 0.5rem;
-  font-size: 0.75rem;
+  padding: 0.25rem 0.75rem;
+  font-size: 0.8125rem;
+  font-weight: 500;
   background-color: var(--color-secondary-light-3);
   border: 1px solid var(--color-border);
-  border-radius: 4px;
+  border-radius: 6px;
   color: var(--color-text-light);
+  cursor: pointer;
+  transition: all 0.2s ease;
 }
 
 .tag:hover {
-  background-color: var(--color-hover);
+  background-color: var(--color-primary-alpha-10);
+  border-color: var(--color-primary);
+  color: var(--color-primary);
+}
+
+/* Checkbox styling */
+input[type="checkbox"] {
+  width: 1.25rem;
+  height: 1.25rem;
+  margin-right: 0.5rem;
+  accent-color: var(--color-primary);
+  cursor: pointer;
+  vertical-align: middle;
 }
 
 /* Avatar */