/* ============================================
   SMOOTH TRANSITIONS - Global Styles
   Enhances user experience with fluid animations
   ============================================ */

/* CSS Custom Properties for Transitions */
:root {
    /* Duration variables */
    --transition-fast: 150ms;
    --transition-normal: 250ms;
    --transition-slow: 350ms;
    --transition-slower: 500ms;
    
    /* Easing functions */
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-out: cubic-bezier(0.0, 0, 0.2, 1);
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
    --ease-smooth: cubic-bezier(0.25, 0.46, 0.45, 0.94);
    
    /* Animation timing */
    --fade-duration: var(--transition-normal);
    --slide-duration: var(--transition-slow);
    --scale-duration: var(--transition-fast);
}

/* ============================================
   FADE ANIMATIONS
   ============================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   SLIDE ANIMATIONS
   ============================================ */

@keyframes slideInFromLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInFromRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideDown {
    from {
        max-height: 0;
        opacity: 0;
    }
    to {
        max-height: 1000px;
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        max-height: 1000px;
        opacity: 1;
    }
    to {
        max-height: 0;
        opacity: 0;
    }
}

/* ============================================
   SCALE & ZOOM ANIMATIONS
   ============================================ */

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes scaleOut {
    from {
        opacity: 1;
        transform: scale(1);
    }
    to {
        opacity: 0;
        transform: scale(0.9);
    }
}

@keyframes zoomIn {
    from {
        opacity: 0;
        transform: scale(0.5);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* ============================================
   PULSE & BOUNCE ANIMATIONS
   ============================================ */

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes gentleBounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-5px);
    }
}

/* ============================================
   LOADING & PROCESSING ANIMATIONS
   ============================================ */

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

@keyframes wave {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-5px);
    }
}

/* ============================================
   UTILITY CLASSES FOR TRANSITIONS
   ============================================ */

.transition-all {
    transition: all var(--transition-normal) var(--ease-in-out);
}

.transition-fast {
    transition: all var(--transition-fast) var(--ease-in-out);
}

.transition-slow {
    transition: all var(--transition-slow) var(--ease-in-out);
}

/* Fade utilities */
.fade-in {
    animation: fadeIn var(--fade-duration) var(--ease-out) forwards;
}

.fade-out {
    animation: fadeOut var(--fade-duration) var(--ease-in) forwards;
}

.fade-in-up {
    animation: fadeInUp var(--transition-slow) var(--ease-out) forwards;
}

.fade-in-down {
    animation: fadeInDown var(--transition-slow) var(--ease-out) forwards;
}

/* Slide utilities */
.slide-in-left {
    animation: slideInFromLeft var(--slide-duration) var(--ease-out) forwards;
}

.slide-in-right {
    animation: slideInFromRight var(--slide-duration) var(--ease-out) forwards;
}

/* Scale utilities */
.scale-in {
    animation: scaleIn var(--transition-normal) var(--ease-bounce) forwards;
}

.scale-out {
    animation: scaleOut var(--transition-normal) var(--ease-in) forwards;
}

.zoom-in {
    animation: zoomIn var(--transition-slow) var(--ease-out) forwards;
}

/* Interactive state utilities */
.hover-lift {
    transition: transform var(--transition-fast) var(--ease-out),
                box-shadow var(--transition-fast) var(--ease-out);
}

.hover-lift:hover {
    transform: translateY(-2px);
}

.hover-scale {
    transition: transform var(--transition-fast) var(--ease-out);
}

.hover-scale:hover {
    transform: scale(1.02);
}

.hover-glow {
    transition: box-shadow var(--transition-normal) var(--ease-out);
}

.hover-glow:hover {
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
}

/* ============================================
   STAGGER ANIMATIONS (for lists/grids)
   ============================================ */

.stagger-fade-in > * {
    opacity: 0;
    animation: fadeInUp var(--transition-slow) var(--ease-out) forwards;
}

.stagger-fade-in > *:nth-child(1) { animation-delay: 0ms; }
.stagger-fade-in > *:nth-child(2) { animation-delay: 100ms; }
.stagger-fade-in > *:nth-child(3) { animation-delay: 200ms; }
.stagger-fade-in > *:nth-child(4) { animation-delay: 300ms; }
.stagger-fade-in > *:nth-child(5) { animation-delay: 400ms; }
.stagger-fade-in > *:nth-child(6) { animation-delay: 500ms; }

/* ============================================
   MODAL & OVERLAY TRANSITIONS
   ============================================ */

.modal-backdrop {
    transition: opacity var(--transition-normal) var(--ease-in-out),
                backdrop-filter var(--transition-normal) var(--ease-in-out);
}

.modal-backdrop.entering,
.modal-backdrop.entered {
    opacity: 1;
}

.modal-backdrop.exiting,
.modal-backdrop.exited {
    opacity: 0;
}

.modal-content {
    transition: transform var(--transition-slow) var(--ease-bounce),
                opacity var(--transition-normal) var(--ease-out);
}

.modal-content.entering,
.modal-content.entered {
    opacity: 1;
    transform: scale(1) translateY(0);
}

.modal-content.exiting,
.modal-content.exited {
    opacity: 0;
    transform: scale(0.9) translateY(20px);
}

/* ============================================
   SMOOTH SCROLLING
   ============================================ */

@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
    
    * {
        scroll-behavior: smooth;
    }
}

/* ============================================
   ACCESSIBILITY - RESPECT REDUCED MOTION
   ============================================ */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .stagger-fade-in > * {
        animation: none;
        opacity: 1;
    }
}

/* ============================================
   PERFORMANCE OPTIMIZATION
   ============================================ */

/* Will-change hints for frequently animated elements */
.will-animate {
    will-change: transform, opacity;
}

/* Hardware acceleration for smooth animations */
.gpu-accelerated {
    transform: translateZ(0);
    backface-visibility: hidden;
    perspective: 1000px;
}

/* ============================================
   PAGE TRANSITIONS
   ============================================ */

.page-transition-enter {
    opacity: 0;
    transform: translateY(30px);
}

.page-transition-enter-active {
    opacity: 1;
    transform: translateY(0);
    transition: opacity var(--transition-slow) var(--ease-out),
                transform var(--transition-slow) var(--ease-out);
}

.page-transition-exit {
    opacity: 1;
    transform: translateY(0);
}

.page-transition-exit-active {
    opacity: 0;
    transform: translateY(-30px);
    transition: opacity var(--transition-normal) var(--ease-in),
                transform var(--transition-normal) var(--ease-in);
}

/* ============================================
   FOCUS TRANSITIONS
   ============================================ */

*:focus-visible {
    transition: outline-offset var(--transition-fast) var(--ease-out);
}

/* ============================================
   LOADING STATES
   ============================================ */

.skeleton {
    background: linear-gradient(
        90deg,
        rgba(255, 255, 255, 0.1) 25%,
        rgba(255, 255, 255, 0.2) 50%,
        rgba(255, 255, 255, 0.1) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
}

.spinner {
    animation: spin 1s linear infinite;
}

/* ============================================
   CARD TRANSITIONS
   ============================================ */

.card-appear {
    animation: scaleIn var(--transition-slow) var(--ease-bounce) forwards;
}

.card-hover {
    transition: transform var(--transition-normal) var(--ease-out),
                box-shadow var(--transition-normal) var(--ease-out);
}

.card-hover:hover {
    transform: translateY(-4px) scale(1.02);
}

/* ============================================
   BUTTON TRANSITIONS
   ============================================ */

button, .btn, a.button {
    transition: background-color var(--transition-fast) var(--ease-out),
                color var(--transition-fast) var(--ease-out),
                border-color var(--transition-fast) var(--ease-out),
                transform var(--transition-fast) var(--ease-out),
                box-shadow var(--transition-fast) var(--ease-out);
}

button:active, .btn:active, a.button:active {
    transform: scale(0.97);
    transition-duration: var(--transition-fast);
}

/* ============================================
   INPUT TRANSITIONS
   ============================================ */

input, textarea, select {
    transition: border-color var(--transition-normal) var(--ease-out),
                box-shadow var(--transition-normal) var(--ease-out),
                background-color var(--transition-normal) var(--ease-out);
}

/* ============================================
   COLLAPSIBLE SECTIONS
   ============================================ */

.collapsible-enter {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
}

.collapsible-enter-active {
    max-height: 2000px;
    opacity: 1;
    transition: max-height var(--transition-slower) var(--ease-smooth),
                opacity var(--transition-slow) var(--ease-out);
}

.collapsible-exit {
    max-height: 2000px;
    opacity: 1;
    overflow: hidden;
}

.collapsible-exit-active {
    max-height: 0;
    opacity: 0;
    transition: max-height var(--transition-slow) var(--ease-in),
                opacity var(--transition-normal) var(--ease-in);
}