/* ===========================
   AI-Native Motion System
   Based on Disney Animation Principles
   =========================== */

/* Spring Physics Keyframes */
@keyframes spring-in {
    0% {
        transform: scale(0.8) translateY(20px);
        opacity: 0;
    }
    60% {
        transform: scale(1.05) translateY(-5px);
        opacity: 0.9;
    }
    100% {
        transform: scale(1) translateY(0);
        opacity: 1;
    }
}

@keyframes spring-out {
    0% {
        transform: scale(1) translateY(0);
        opacity: 1;
    }
    100% {
        transform: scale(0.9) translateY(10px);
        opacity: 0;
    }
}

@keyframes spring-bounce {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* Follow-Through: Staggered Entrance Animations */
@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Staggered delays for card grids (Follow-Through principle) */
.stagger-item {
    animation: fade-in-up 0.6s ease-out backwards;
}

.stagger-item:nth-child(1) { animation-delay: 0ms; }
.stagger-item:nth-child(2) { animation-delay: 50ms; }
.stagger-item:nth-child(3) { animation-delay: 100ms; }
.stagger-item:nth-child(4) { animation-delay: 150ms; }
.stagger-item:nth-child(5) { animation-delay: 200ms; }
.stagger-item:nth-child(6) { animation-delay: 250ms; }

/* Micro-interactions */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.6;
    }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-4px); }
    20%, 40%, 60%, 80% { transform: translateX(4px); }
}

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

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

/* Loading States */
@keyframes skeleton-loading {
    0% {
        background-position: -200px 0;
    }
    100% {
        background-position: calc(200px + 100%) 0;
    }
}

.skeleton {
    background: linear-gradient(
        90deg,
        #f0f0f0 0px,
        #e0e0e0 40px,
        #f0f0f0 80px
    );
    background-size: 200px 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
}

/* Spring Physics Utilities */
.spring-in {
    animation: spring-in 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.spring-out {
    animation: spring-out 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.spring-bounce {
    animation: spring-bounce 0.5s ease-in-out;
}

/* Button Press Feedback */
.button-press {
    transition: transform 0.1s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.button-press:active {
    transform: scale(0.95);
}

/* Card Hover with Spring */
.card-spring-hover {
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
                box-shadow 0.3s ease;
}

.card-spring-hover:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

/* Reduced Motion Support */
@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-item {
        animation: none !important;
    }
}

/* GPU-Optimized Animations */
.gpu-accelerated {
    will-change: transform, opacity;
    transform: translateZ(0);
    backface-visibility: hidden;
    perspective: 1000px;
}

/* Pause animations when not visible */
.pause-animation {
    animation-play-state: paused;
}

/* ===========================
   Hero Section Animations
   =========================== */
@keyframes hero-text-fade-up {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes hero-cta-spring {
    0% {
        opacity: 0;
        transform: scale(0.9) translateY(20px);
    }
    60% {
        transform: scale(1.05) translateY(-5px);
    }
    100% {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.hero-text-animate {
    animation: hero-text-fade-up 0.8s cubic-bezier(0.34, 1.56, 0.64, 1) backwards;
}

.hero-text-animate-delay-1 {
    animation-delay: 0.1s;
}

.hero-text-animate-delay-2 {
    animation-delay: 0.2s;
}

.hero-subtitle-animate {
    animation: hero-subtitle-fade 0.6s ease-out 0.3s backwards;
}

.hero-cta-animate {
    animation: hero-cta-spring 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) 0.5s backwards;
}

.hero-cta-animate-delay {
    animation-delay: 0.7s;
}

/* ===========================
   Scroll Reveal Animations
   =========================== */
/* fade-in-up keyframe already defined above */

@keyframes slide-in-left {
    from {
        opacity: 0;
        transform: translateX(-40px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slide-in-right {
    from {
        opacity: 0;
        transform: translateX(40px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

.animate-fade-in-up {
    animation: fade-in-up 0.6s ease-out forwards;
}

.animate-slide-in-left {
    animation: slide-in-left 0.6s ease-out forwards;
}

.animate-slide-in-right {
    animation: slide-in-right 0.6s ease-out forwards;
}

.animate-scale-in {
    animation: scale-in 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.animate-fade-in {
    animation: fade-in 0.6s ease-out forwards;
}

/* ===========================
   Image Hover Effects
   =========================== */
.image-hover-spring {
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
                opacity 0.3s ease;
    will-change: transform;
}

.image-hover-spring:hover {
    transform: scale(1.08) translateY(-4px);
}

.image-lazy-fade {
    opacity: 0;
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    transform: scale(0.98);
}

.image-lazy-fade.loaded {
    opacity: 1;
    transform: scale(1);
}

/* Coach Photo Hover */
.coach-photo-hover {
    position: relative;
    overflow: hidden;
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.coach-photo-hover::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.1);
    opacity: 0;
    transition: opacity 0.3s ease;
}

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

.coach-photo-hover:hover::after {
    opacity: 1;
}

/* ===========================
   Badge Animations
   =========================== */
@keyframes badge-pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

@keyframes badge-bounce {
    0%, 100% {
        transform: scale(1) translateY(0);
    }
    25% {
        transform: scale(1.2) translateY(-4px);
    }
    50% {
        transform: scale(1.1) translateY(-2px);
    }
    75% {
        transform: scale(1.15) translateY(-3px);
    }
}

.badge-pulse {
    animation: badge-pulse 2s ease-in-out infinite;
}

.badge-bounce {
    animation: badge-bounce 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Notification slide-in */
@keyframes notification-slide-in {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.notification-slide-in {
    animation: notification-slide-in 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ===========================
   Button Enhancements
   =========================== */
@keyframes btn-glow {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.4);
    }
    50% {
        box-shadow: 0 0 20px 4px rgba(37, 99, 235, 0.3);
    }
}

@keyframes btn-ripple {
    0% {
        transform: scale(0);
        opacity: 1;
    }
    100% {
        transform: scale(4);
        opacity: 0;
    }
}

@keyframes checkmark-draw {
    0% {
        stroke-dashoffset: 100;
    }
    100% {
        stroke-dashoffset: 0;
    }
}

.btn-glow {
    animation: btn-glow 2s ease-in-out infinite;
}

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

.btn-ripple::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-ripple:active::after {
    width: 300px;
    height: 300px;
    animation: btn-ripple 0.6s ease-out;
}

.checkmark-animate {
    stroke-dasharray: 100;
    stroke-dashoffset: 100;
    animation: checkmark-draw 0.6s ease-out forwards;
}

/* ===========================
   Navigation Enhancements
   =========================== */
@keyframes nav-underline {
    from {
        width: 0;
        left: 50%;
    }
    to {
        width: 100%;
        left: 0;
    }
}

@keyframes mobile-menu-slide {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.nav-link-underline {
    position: relative;
}

.nav-link-underline::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: currentColor;
    transition: width 0.3s ease, left 0.3s ease;
}

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

.mobile-menu-slide {
    animation: mobile-menu-slide 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Dropdown staggered children */
.login-dropdown > * {
    opacity: 0;
    transform: translateY(-10px);
    animation: fade-in-up 0.3s ease-out forwards;
}

.login-dropdown > *:nth-child(1) { animation-delay: 0.05s; }
.login-dropdown > *:nth-child(2) { animation-delay: 0.1s; }
.login-dropdown > *:nth-child(3) { animation-delay: 0.15s; }
.login-dropdown > *:nth-child(4) { animation-delay: 0.2s; }

.login-dropdown:hover > *,
.nav-login-wrapper:hover .login-dropdown > * {
    opacity: 1;
    transform: translateY(0);
}

/* ===========================
   Page Load Animation
   =========================== */
@keyframes page-fade-in {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.page-load {
    animation: page-fade-in 0.6s ease-out;
}

body {
    opacity: 0;
    animation: page-fade-in 0.6s ease-out forwards;
}

/* ===========================
   Coach Photo Animations
   =========================== */
.coach-photo-reveal-left {
    opacity: 0;
    transform: translateX(-40px);
    transition: opacity 0.6s ease-out, transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.coach-photo-reveal-right {
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.6s ease-out, transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.coach-photo-reveal-left.scroll-revealed,
.coach-photo-reveal-right.scroll-revealed {
    opacity: 1;
    transform: translateX(0);
}

/* ===========================
   Form Input Animations
   =========================== */
@keyframes label-float-up {
    from {
        transform: translateY(0) scale(1);
        opacity: 0.7;
    }
    to {
        transform: translateY(-20px) scale(0.85);
        opacity: 1;
    }
}

.floating-label {
    position: relative;
}

.floating-label input:focus + label,
.floating-label input:not(:placeholder-shown) + label {
    animation: label-float-up 0.3s ease-out forwards;
    color: var(--brand-blue);
}

.input-focus-ring {
    transition: box-shadow 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.input-focus-ring:focus {
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Enhanced error shake */
.input-error-shake {
    animation: shake 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}