/* ========================================
   SCROLL ANIMATIONS
   ======================================== */

/* Elements that will be animated on scroll */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.animate-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Delayed animations for staggered effect */
.animate-delay-1 {
    transition-delay: 0.1s;
}

.animate-delay-2 {
    transition-delay: 0.2s;
}

.animate-delay-3 {
    transition-delay: 0.3s;
}

.animate-delay-4 {
    transition-delay: 0.4s;
}

/* Slide from left */
.animate-slide-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-slide-left.animate-visible {
    opacity: 1;
    transform: translateX(0);
}

/* Slide from right */
.animate-slide-right {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-slide-right.animate-visible {
    opacity: 1;
    transform: translateX(0);
}

/* Scale in */
.animate-scale {
    opacity: 0;
    transform: scale(0.8);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* ========================================
   PARTICLE SYSTEM
   ======================================== */

#particles-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
    overflow: hidden;
}

.particle {
    position: absolute;
    pointer-events: none;
    user-select: none;
}

/* ========================================
   WINTER THEME - SNOWFLAKES
   ======================================== */

.particle-snowflake {
    color: rgba(255, 255, 255, 0.8);
    font-size: 20px;
    text-shadow: 0 0 5px rgba(255, 255, 255, 0.5);
    animation: snowfall linear infinite;
}

@keyframes snowfall {
    0% {
        transform: translateY(-10px) translateX(0) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) translateX(var(--drift)) rotate(360deg);
        opacity: 0;
    }
}

/* ========================================
   AUTUMN THEME - FALLING LEAVES
   ======================================== */

.particle-leaf {
    font-size: 24px;
    animation: leaffall linear infinite;
}

@keyframes leaffall {
    0% {
        transform: translateY(-10px) translateX(0) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    50% {
        transform: translateY(50vh) translateX(var(--drift)) rotate(180deg);
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) translateX(calc(var(--drift) * 2)) rotate(360deg);
        opacity: 0;
    }
}

/* ========================================
   SPRING THEME - FLOWER PETALS
   ======================================== */

.particle-petal {
    font-size: 18px;
    animation: petalfall linear infinite;
}

@keyframes petalfall {
    0% {
        transform: translateY(-10px) translateX(0) rotate(0deg) scale(1);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    50% {
        transform: translateY(50vh) translateX(var(--drift)) rotate(180deg) scale(1.2);
    }
    90% {
        opacity: 0.8;
    }
    100% {
        transform: translateY(100vh) translateX(calc(var(--drift) * 1.5)) rotate(360deg) scale(0.8);
        opacity: 0;
    }
}

/* ========================================
   SUMMER THEME - BUTTERFLIES & SPARKLES
   ======================================== */

.particle-butterfly {
    font-size: 20px;
    animation: butterfly-float linear infinite;
}

@keyframes butterfly-float {
    0% {
        transform: translateY(100vh) translateX(0) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    25% {
        transform: translateY(75vh) translateX(20px) rotate(10deg);
    }
    50% {
        transform: translateY(50vh) translateX(-10px) rotate(-10deg);
    }
    75% {
        transform: translateY(25vh) translateX(15px) rotate(5deg);
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-10px) translateX(0) rotate(0deg);
        opacity: 0;
    }
}

.particle-sparkle {
    font-size: 14px;
    animation: sparkle-twinkle 2s ease-in-out infinite;
}

@keyframes sparkle-twinkle {
    0%, 100% {
        opacity: 0;
        transform: scale(0.5);
    }
    50% {
        opacity: 1;
        transform: scale(1.2);
    }
}

/* ========================================
   HALLOWEEN THEME - GHOSTS & PUMPKINS
   ======================================== */

.particle-ghost {
    font-size: 22px;
    animation: ghost-float 8s ease-in-out infinite;
}

@keyframes ghost-float {
    0%, 100% {
        transform: translateY(0) translateX(0) rotate(0deg);
        opacity: 0.7;
    }
    25% {
        transform: translateY(-20px) translateX(30px) rotate(5deg);
        opacity: 1;
    }
    50% {
        transform: translateY(-10px) translateX(-20px) rotate(-5deg);
        opacity: 0.8;
    }
    75% {
        transform: translateY(-25px) translateX(10px) rotate(3deg);
        opacity: 0.9;
    }
}

.particle-bat {
    font-size: 18px;
    animation: bat-fly linear infinite;
}

@keyframes bat-fly {
    0% {
        transform: translateX(-50px) translateY(var(--start-y));
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateX(calc(100vw + 50px)) translateY(var(--end-y));
        opacity: 0;
    }
}

/* ========================================
   CHRISTMAS THEME - SNOWFLAKES & STARS
   ======================================== */

.particle-star {
    font-size: 16px;
    animation: star-twinkle 3s ease-in-out infinite;
}

@keyframes star-twinkle {
    0%, 100% {
        opacity: 0.3;
        transform: scale(0.8) rotate(0deg);
    }
    50% {
        opacity: 1;
        transform: scale(1.2) rotate(180deg);
    }
}

.particle-gift {
    font-size: 20px;
    animation: gift-bounce 2s ease-in-out infinite;
}

@keyframes gift-bounce {
    0%, 100% {
        transform: translateY(0) rotate(-5deg);
    }
    50% {
        transform: translateY(-10px) rotate(5deg);
    }
}

/* ========================================
   PERFORMANCE OPTIMIZATIONS
   ======================================== */

/* Use GPU acceleration */
.particle {
    will-change: transform, opacity;
    backface-visibility: hidden;
    perspective: 1000px;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    .animate-on-scroll,
    .animate-slide-left,
    .animate-slide-right,
    .animate-scale {
        transition: none;
        opacity: 1;
        transform: none;
    }
    
    .particle {
        display: none;
    }
}