/**
 * Animations and transitions for PMU Academy website
 * Provides elegant section transitions and smooth scrolling effects
 */

/* Section transitions */
section {
    transition: transform 0.6s ease-out, opacity 0.6s ease-out;
    will-change: opacity, transform;
    backface-visibility: hidden;
}

.section-active {
    animation: sectionFade 1.2s ease-out;
}

@keyframes sectionFade {
    0% {
        opacity: 0.5;
        transform: translateY(10px);
    }
    30% {
        opacity: 1;
        transform: translateY(0);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Fade-in animations for content */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s ease-out, transform 1s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-left {
    opacity: 0;
    transform: translateX(-40px);
    transition: opacity 1s ease-out, transform 1s ease-out;
}

.fade-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.fade-in-right {
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 1s ease-out, transform 1s ease-out;
}

.fade-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Staggered fade in for lists/grids */
.stagger-fade-in > * {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.stagger-fade-in > *.visible:nth-child(1) {
    transition-delay: 0.1s;
}

.stagger-fade-in > *.visible:nth-child(2) {
    transition-delay: 0.3s;
}

.stagger-fade-in > *.visible:nth-child(3) {
    transition-delay: 0.5s;
}

.stagger-fade-in > *.visible:nth-child(4) {
    transition-delay: 0.7s;
}

.stagger-fade-in > *.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Scale animations */
.scale-in {
    opacity: 0;
    transform: scale(0.92);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.scale-in.visible {
    opacity: 1;
    transform: scale(1);
}

/* Slide up animation */
.slide-up {
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.slide-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Active navigation highlight animation */
.navbar-nav .nav-link.active {
    position: relative;
    color: var(--primary-color) !important;
    transition: color 0.3s ease;
}

.navbar-nav .nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    animation: navHighlight 0.4s forwards;
}

@keyframes navHighlight {
    to {
        width: 70%;
    }
}

/* Smooth page transitions */
.page-transition {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--dark-color);
    z-index: 9999;
    transform: translateY(100%);
    transition: transform 0.6s cubic-bezier(0.65, 0, 0.35, 1);
}

.page-transition.active {
    transform: translateY(0);
}

.page-transition.leaving {
    transform: translateY(-100%);
}

.page-transition::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    background-image: url('../images/Short.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    opacity: 0.8;
}

/* Back to top button animation */
.back-to-top {
    position: fixed;
    bottom: -60px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: var(--dark-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transition: bottom 0.5s ease, opacity 0.5s ease;
    z-index: 99;
}

.back-to-top.visible {
    bottom: 20px;
    opacity: 0.8;
}

.back-to-top:hover {
    opacity: 1;
}

/* The actual arrow */
.back-to-top i {
    font-size: 20px;
    color: var(--dark-color);
    transition: transform 0.3s ease;
}

.back-to-top:hover i {
    transform: translateY(-3px);
}