/* ============================================
   Animation Keyframes
   ============================================ */

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

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

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

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

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

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

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

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

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

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

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

/* ============================================
   Animation Classes
   ============================================ */

.animate-fade-in {
    animation: fadeIn 0.3s ease-out;
}

.animate-slide-up {
    animation: slideUp 0.3s ease-out;
}

.animate-slide-down {
    animation: slideDown 0.3s ease-out;
}

.animate-scale-in {
    animation: scaleIn 0.2s ease-out;
}

/* ============================================
   Entrance Animations (GSAP)
   ============================================ */

.fade-in-up {
    opacity: 0;
    transform: translateY(20px);
}

.fade-in-down {
    opacity: 0;
    transform: translateY(-20px);
}

.fade-in-left {
    opacity: 0;
    transform: translateX(-20px);
}

.fade-in-right {
    opacity: 0;
    transform: translateX(20px);
}

.scale-in {
    opacity: 0;
    transform: scale(0.9);
}

/* ============================================
   Folder Open/Close Animation
   ============================================ */

.folder-item {
    transition: transform var(--transition-base), 
                box-shadow var(--transition-base),
                border-color var(--transition-base);
}

.folder-item.opening {
    animation: folderOpen 0.3s ease-out;
}

@keyframes folderOpen {
    0% {
        transform: scale(1) rotateY(0deg);
    }
    50% {
        transform: scale(1.05) rotateY(5deg);
    }
    100% {
        transform: scale(1) rotateY(0deg);
    }
}

/* ============================================
   File Upload Animation
   ============================================ */

.file-item.uploading {
    position: relative;
    overflow: hidden;
}

.file-item.uploading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(99, 102, 241, 0.2),
        transparent
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
}

/* ============================================
   Drag and Drop Animations
   ============================================ */

.drag-over {
    border-color: var(--color-primary) !important;
    background: rgba(99, 102, 241, 0.1) !important;
    transform: scale(1.02);
}

.drop-zone {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    color: var(--color-text-muted);
    transition: all var(--transition-base);
}

.drop-zone.active {
    border-color: var(--color-primary);
    background: rgba(99, 102, 241, 0.05);
    color: var(--color-primary);
}

.drop-zone.drag-over {
    border-color: var(--color-primary);
    background: rgba(99, 102, 241, 0.1);
    transform: scale(1.02);
}

/* ============================================
   Music Player Animations
   ============================================ */

.track-artwork.playing {
    animation: rotate 20s linear infinite;
}

.track-artwork img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-md);
}

.progress-bar {
    transition: background-color var(--transition-fast);
}

.progress-bar.seeking .progress-handle {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1.2);
}

/* ============================================
   Focus Mode Animations
   ============================================ */

.focus-overlay.entering {
    animation: fadeIn 0.5s ease-out;
}

.focus-overlay.exiting {
    animation: fadeOut 0.3s ease-out;
}

.timer-display.pulsing {
    animation: pulse 1s ease-in-out infinite;
}

/* ============================================
   Widget Animations
   ============================================ */

.widget {
    transition: transform var(--transition-base),
                box-shadow var(--transition-base),
                opacity var(--transition-base);
}

.widget.resizing {
    opacity: 0.7;
}

.widget-placeholder {
    background: var(--color-bg-secondary);
    border: 2px dashed var(--color-primary);
    border-radius: var(--radius-lg);
    opacity: 0.5;
}

/* ============================================
   Button Animations
   ============================================ */

.btn {
    position: relative;
    overflow: hidden;
}

.btn-loading {
    pointer-events: none;
    opacity: 0.7;
}

.btn-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 16px;
    height: 16px;
    margin: -8px 0 0 -8px;
    border: 2px solid currentColor;
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

/* ============================================
   Loading States
   ============================================ */

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-skeleton {
    background: linear-gradient(
        90deg,
        var(--color-bg-secondary) 0%,
        var(--color-bg-tertiary) 50%,
        var(--color-bg-secondary) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-md);
}

/* ============================================
   Notification Animations
   ============================================ */

.notification {
    position: fixed;
    top: 100px;
    right: var(--spacing-xl);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 5000;
    animation: slideInRight 0.3s ease-out;
    max-width: 300px;
}

.notification.exiting {
    animation: slideInRight 0.3s ease-out reverse;
}

/* ============================================
   Smooth Transitions
   ============================================ */

.smooth-transition {
    transition: all var(--transition-base);
}

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

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

/* ============================================
   Hover Effects
   ============================================ */

.hover-lift {
    transition: transform var(--transition-fast);
}

.hover-lift:hover {
    transform: translateY(-4px);
}

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

.hover-scale:hover {
    transform: scale(1.05);
}

.hover-glow {
    transition: box-shadow var(--transition-fast);
}

.hover-glow:hover {
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

/* ============================================
   Audio Reactive Effects (will be enhanced with JS)
   ============================================ */

.audio-reactive {
    transition: transform 0.1s ease-out;
}

.audio-reactive.active {
    animation: pulse 0.5s ease-in-out;
}

/* ============================================
   Particle Animation (for background)
   ============================================ */

.particle {
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
    opacity: 0.6;
    animation: float 6s ease-in-out infinite;
}

/* ============================================
   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;
    }
    
    .animate-fade-in,
    .animate-slide-up,
    .animate-slide-down,
    .animate-scale-in {
        animation: none;
    }
}