/**
 * Nature Index - Animation Utilities
 * CSS animations and transitions
 * =================================
 */

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

@keyframes ni-fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes ni-fade-out {
    from { opacity: 1; }
    to { opacity: 0; }
}

@keyframes ni-fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes ni-fade-in-down {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes ni-fade-in-left {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes ni-fade-in-right {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

@keyframes ni-slide-in-up {
    from { transform: translateY(100%); }
    to { transform: translateY(0); }
}

@keyframes ni-slide-in-down {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

@keyframes ni-slide-in-left {
    from { transform: translateX(-100%); }
    to { transform: translateX(0); }
}

@keyframes ni-slide-in-right {
    from { transform: translateX(100%); }
    to { transform: translateX(0); }
}

@keyframes ni-bounce {
    0%, 20%, 53%, 100% {
        animation-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
        transform: translateY(0);
    }
    40%, 43% {
        animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
        transform: translateY(-20px);
    }
    70% {
        animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
        transform: translateY(-10px);
    }
    80% {
        transform: translateY(0);
    }
    90% {
        transform: translateY(-4px);
    }
}

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

@keyframes ni-shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

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

@keyframes ni-ping {
    75%, 100% {
        transform: scale(2);
        opacity: 0;
    }
}

@keyframes ni-shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

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

.ni-animate-fade-in { animation: ni-fade-in var(--ni-transition-normal) forwards; }
.ni-animate-fade-out { animation: ni-fade-out var(--ni-transition-normal) forwards; }
.ni-animate-fade-in-up { animation: ni-fade-in-up var(--ni-transition-normal) forwards; }
.ni-animate-fade-in-down { animation: ni-fade-in-down var(--ni-transition-normal) forwards; }
.ni-animate-fade-in-left { animation: ni-fade-in-left var(--ni-transition-normal) forwards; }
.ni-animate-fade-in-right { animation: ni-fade-in-right var(--ni-transition-normal) forwards; }
.ni-animate-scale-in { animation: ni-scale-in var(--ni-transition-normal) forwards; }
.ni-animate-scale-out { animation: ni-scale-out var(--ni-transition-normal) forwards; }
.ni-animate-slide-in-up { animation: ni-slide-in-up var(--ni-transition-normal) forwards; }
.ni-animate-slide-in-down { animation: ni-slide-in-down var(--ni-transition-normal) forwards; }
.ni-animate-slide-in-left { animation: ni-slide-in-left var(--ni-transition-normal) forwards; }
.ni-animate-slide-in-right { animation: ni-slide-in-right var(--ni-transition-normal) forwards; }
.ni-animate-bounce { animation: ni-bounce 1s; }
.ni-animate-pulse { animation: ni-pulse 2s infinite; }
.ni-animate-shake { animation: ni-shake 0.5s; }
.ni-animate-spin { animation: ni-spin 1s linear infinite; }
.ni-animate-ping { animation: ni-ping 1s cubic-bezier(0, 0, 0.2, 1) infinite; }

/* Animation delays */
.ni-delay-100 { animation-delay: 100ms; }
.ni-delay-200 { animation-delay: 200ms; }
.ni-delay-300 { animation-delay: 300ms; }
.ni-delay-500 { animation-delay: 500ms; }
.ni-delay-700 { animation-delay: 700ms; }
.ni-delay-1000 { animation-delay: 1000ms; }

/* Animation durations */
.ni-duration-fast { animation-duration: 150ms; }
.ni-duration-normal { animation-duration: 250ms; }
.ni-duration-slow { animation-duration: 500ms; }
.ni-duration-slower { animation-duration: 750ms; }

/* ========================================
   Transition Utilities
   ======================================== */

.ni-transition-none { transition: none !important; }
.ni-transition-all { transition: all var(--ni-transition-normal); }
.ni-transition-colors { transition: var(--ni-transition-colors); }
.ni-transition-opacity { transition: opacity var(--ni-transition-normal); }
.ni-transition-transform { transition: var(--ni-transition-transform); }
.ni-transition-shadow { transition: var(--ni-transition-shadow); }

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

.ni-hover-lift {
    transition: transform var(--ni-transition-normal), box-shadow var(--ni-transition-normal);
}

.ni-hover-lift:hover {
    transform: translateY(-4px);
    box-shadow: var(--ni-shadow-lg);
}

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

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

.ni-hover-rotate {
    transition: transform var(--ni-transition-normal);
}

.ni-hover-rotate:hover {
    transform: rotate(5deg);
}

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

.ni-hover-glow:hover {
    box-shadow: var(--ni-shadow-primary);
}

.ni-hover-underline {
    position: relative;
}

.ni-hover-underline::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: currentColor;
    transition: width var(--ni-transition-normal);
}

.ni-hover-underline:hover::after {
    width: 100%;
}

/* ========================================
   Loading Skeleton
   ======================================== */

.ni-skeleton {
    background: linear-gradient(
        90deg,
        var(--ni-gray-200) 25%,
        var(--ni-gray-100) 50%,
        var(--ni-gray-200) 75%
    );
    background-size: 200% 100%;
    animation: ni-shimmer 1.5s infinite;
    border-radius: var(--ni-radius-md);
}

.ni-skeleton-text {
    height: 1em;
    margin-bottom: 0.5em;
}

.ni-skeleton-text:last-child {
    width: 70%;
}

.ni-skeleton-title {
    height: 1.5em;
    width: 50%;
    margin-bottom: 1em;
}

.ni-skeleton-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--ni-radius-full);
}

.ni-skeleton-image {
    width: 100%;
    height: 200px;
}

.ni-skeleton-button {
    height: 40px;
    width: 120px;
}

/* ========================================
   Page Transitions (for SPA-like feel)
   ======================================== */

.ni-page-enter {
    opacity: 0;
    transform: translateY(10px);
}

.ni-page-enter-active {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 300ms ease-out, transform 300ms ease-out;
}

.ni-page-exit {
    opacity: 1;
}

.ni-page-exit-active {
    opacity: 0;
    transition: opacity 200ms ease-in;
}

/* ========================================
   Staggered Animations (for lists/grids)
   ======================================== */

.ni-stagger-children > * {
    opacity: 0;
    animation: ni-fade-in-up 0.4s ease forwards;
}

.ni-stagger-children > *:nth-child(1) { animation-delay: 0ms; }
.ni-stagger-children > *:nth-child(2) { animation-delay: 50ms; }
.ni-stagger-children > *:nth-child(3) { animation-delay: 100ms; }
.ni-stagger-children > *:nth-child(4) { animation-delay: 150ms; }
.ni-stagger-children > *:nth-child(5) { animation-delay: 200ms; }
.ni-stagger-children > *:nth-child(6) { animation-delay: 250ms; }
.ni-stagger-children > *:nth-child(7) { animation-delay: 300ms; }
.ni-stagger-children > *:nth-child(8) { animation-delay: 350ms; }
.ni-stagger-children > *:nth-child(9) { animation-delay: 400ms; }
.ni-stagger-children > *:nth-child(10) { animation-delay: 450ms; }
.ni-stagger-children > *:nth-child(11) { animation-delay: 500ms; }
.ni-stagger-children > *:nth-child(12) { animation-delay: 550ms; }

/* ========================================
   Scroll-triggered Animations
   ======================================== */

.ni-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.ni-reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.ni-reveal-left {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.ni-reveal-left.is-visible {
    opacity: 1;
    transform: translateX(0);
}

.ni-reveal-right {
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.ni-reveal-right.is-visible {
    opacity: 1;
    transform: translateX(0);
}

.ni-reveal-scale {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.ni-reveal-scale.is-visible {
    opacity: 1;
    transform: scale(1);
}