Refactor CSS styles across multiple components for improved consistency and maintainability

- Removed redundant styles and consolidated common styles in styles.scss
- Updated layout and spacing variables for better responsiveness
- Simplified component-specific styles in apartment, lease, tenant, and dashboard components
- Enhanced readability and organization of CSS by utilizing CSS layers
- Ensured consistent use of design tokens for colors, spacing, and borders

frontend/src/app/components/settings-page/settings-page.css

@@ -1,40 +1,8 @@
 :host {
   display: block;
 }
-.page-section {
-  animation: page-in 180ms ease-out;
-}
-@keyframes page-in {
-  from {
-    opacity: 0;
-    transform: translateY(4px);
-  }
-  to {
-    opacity: 1;
-    transform: translateY(0);
-  }
-}
-.page-heading {
-  margin-bottom: 30px;
-}
-.page-heading h1 {
-  margin-bottom: 8px;
-  font-size: clamp(2rem, 7vw, 3.2rem);
-  font-weight: 750;
-  letter-spacing: -0.055em;
-  line-height: 1.02;
-}
-.page-heading > div > p:last-child {
-  margin-bottom: 0;
-  color: var(--text-muted);
-  line-height: 1.6;
-}
 .settings-card {
   overflow: hidden;
-  border: 1px solid var(--border);
-  border-radius: 22px;
-  background: var(--surface);
-  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.04);
 }
 .settings-card h2 {
   margin-bottom: 9px;
@@ -131,14 +99,6 @@
   --mdc-outlined-button-outline-color: var(--border-strong);
   border-radius: 12px;
 }
-@media (min-width: 700px) {
-  .page-heading {
-    display: flex;
-    align-items: flex-end;
-    justify-content: space-between;
-    gap: 28px;
-  }
-}
 @media (min-width: 960px) {
   .settings-card {
     display: grid;