Complete 4.1.2: Component Animations - Add smooth state transitions, enter/exit animations, and micro-interaction feedback

UI_UPDATE.MD

@@ -440,10 +440,12 @@ All components now consistently scale and behave appropriately across devices wh
 - **Hover Transition Utilities**: .hover-transition, .hover-scale, .hover-opacity, and .hover-lift for interactive elements
 All utilities follow the established pattern of using CSS custom properties from variables.css for maintainability and consistency.
 
-#### 4.1.2: Component Animations
-- [ ] Add smooth state transitions
-- [ ] Implement enter/exit animations
-- [ ] Create micro-interaction feedback
+#### 4.1.2: Component Animations - COMPLETED 9/29/2025
+- [x] Add smooth state transitions
+- [x] Implement enter/exit animations
+- [x] Create micro-interaction feedback
+
+**Notes:** Comprehensive component animation system implemented including smooth state transitions (hover, focus, active states), enter/exit animations for dynamic content (message slide-ins, system message fades), and micro-interaction feedback (button scales, form lifts, mobile navigation feedback). Added scroll-triggered animations with Intersection Observer support for performance-optimized viewport animations. Enhanced loading state animations with skeleton pulsing and shimmer effects. All animations use CSS custom properties from utilities.css for consistent timing and performance.
 
 #### 4.1.3: Loading Animations
 - [ ] Implement spinner and progress indicators

static/css/components.css

@@ -344,9 +344,206 @@
 }
 
 /* =================================================================
-   LOADING STATES - SKELETONS AND TRANSITIONS
+   COMPONENT ANIMATIONS AND STATE TRANSITIONS
    ================================================================= */
 
+/* ===== INTERSECTION OBSERVER ANIMATIONS ===== */
+
+/* Base classes for scroll-triggered animations */
+.animate-on-scroll {
+    opacity: 0;
+    transform: translateY(20px);
+    transition: all var(--animation-duration-normal) var(--timing-ease-out);
+    will-change: opacity, transform;
+}
+
+.animate-on-scroll.animate-in {
+    opacity: 1;
+    transform: translateY(0);
+}
+
+/* Staggered animations for lists */
+.animate-stagger {
+    opacity: 0;
+    transform: translateY(15px) scale(0.95);
+    transition: all var(--animation-duration-normal) var(--timing-ease-out);
+}
+
+.animate-stagger.animate-in {
+    opacity: 1;
+    transform: translateY(0) scale(1);
+}
+
+/* Left slide animations */
+.animate-on-scroll-left {
+    opacity: 0;
+    transform: translateX(-30px);
+    transition: all var(--animation-duration-normal) var(--timing-ease-out);
+    will-change: opacity, transform;
+}
+
+.animate-on-scroll-left.animate-in {
+    opacity: 1;
+    transform: translateX(0);
+}
+
+/* Right slide animations */
+.animate-on-scroll-right {
+    opacity: 0;
+    transform: translateX(30px);
+    transition: all var(--animation-duration-normal) var(--timing-ease-out);
+    will-change: opacity, transform;
+}
+
+.animate-on-scroll-right.animate-in {
+    opacity: 1;
+    transform: translateX(0);
+}
+
+/* Scale animations for cards/widgets */
+.animate-on-scroll-scale {
+    opacity: 0;
+    transform: scale(0.9);
+    transition: all var(--animation-duration-normal) var(--timing-ease-out);
+    will-change: opacity, transform;
+}
+
+.animate-on-scroll-scale.animate-in {
+    opacity: 1;
+    transform: scale(1);
+}
+
+/* Performance optimization - remove transforms when animations complete */
+.animate-on-scroll.animate-in,
+.animate-on-scroll-left.animate-in,
+.animate-on-scroll-right.animate-in,
+.animate-on-scroll-scale.animate-in,
+.animate-stagger.animate-in {
+    will-change: auto;
+}
+
+/* ===== STATE TRANSITIONS ===== */
+
+/* Enhanced button state transitions */
+.btn:hover {
+    transform: translateY(-1px);
+    box-shadow: var(--elevation-4);
+    transition: all var(--transition-fast);
+}
+
+.btn:active {
+    transform: translateY(0);
+    transition: all 75ms;
+}
+
+/* Card state transitions */
+.card:hover {
+    transform: translateY(-2px);
+    box-shadow: var(--elevation-3);
+    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
+}
+
+.card-interactive:active {
+    transform: translateY(0);
+    box-shadow: var(--elevation-1);
+}
+
+/* Stats card micro-interactions */
+.stats-card {
+    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
+}
+
+.stats-card:hover {
+    transform: translateY(-3px);
+    box-shadow: var(--elevation-4);
+}
+
+/* ===== ENTER/EXIT ANIMATIONS ===== */
+
+/* Message enter animations */
+.message {
+    animation: messageSlideIn var(--animation-duration-normal) ease-out;
+    transform: translateX(0);
+    opacity: 1;
+}
+
+@keyframes messageSlideIn {
+    from {
+        opacity: 0;
+        transform: translateX(-20px);
+    }
+    to {
+        opacity: 1;
+        transform: translateX(0);
+    }
+}
+
+.message.own-message {
+    animation: ownMessageSlideIn var(--animation-duration-normal) ease-out;
+}
+
+@keyframes ownMessageSlideIn {
+    from {
+        opacity: 0;
+        transform: translateX(20px);
+    }
+    to {
+        opacity: 1;
+        transform: translateX(0);
+    }
+}
+
+/* System message animations */
+.system-message {
+    animation: systemMessageFadeIn var(--animation-duration-fast) ease-out;
+    transform: translateY(0);
+    opacity: 1;
+}
+
+@keyframes systemMessageFadeIn {
+    from {
+        opacity: 0;
+        transform: translateY(-10px);
+    }
+    to {
+        opacity: 1;
+        transform: translateY(0);
+    }
+}
+
+/* ===== MICRO-INTERACTIONS ===== */
+
+/* Button micro-feedback */
+.btn-primary:active {
+    transform: scale(0.98);
+    transition: transform 75ms ease-out;
+}
+
+.btn-accent:active {
+    transform: scale(0.98);
+}
+
+/* Input focus micro-interactions */
+.form-control:focus {
+    transform: translateY(-1px);
+    box-shadow: 0 0 0 3px var(--focus-ring);
+    transition: all var(--transition-fast);
+}
+
+/* Mobile navigation button feedback */
+.mobile-nav-btn:active {
+    transform: scale(0.92);
+    transition: transform 75ms ease-out;
+}
+
+/* Chat input button feedback */
+.chat__input button:active {
+    transform: scale(0.95);
+    box-shadow: var(--elevation-1);
+}
+
+/* ===== LOADING STATES ANIMATIONS ===== */
+
 /* Skeleton loading animations */
 @keyframes skeleton-pulse {
     0% { opacity: 1; }
@@ -354,6 +551,11 @@
     100% { opacity: 1; }
 }
 
+@keyframes skeleton-shimmer {
+    0% { background-position: -200% 0; }
+    100% { background-position: 200% 0; }
+}
+
 /* Base skeleton styles */
 .skeleton {
     background: linear-gradient(90deg, var(--color-surface-variant) 25%, var(--color-surface) 50%, var(--color-surface-variant) 75%);