body {
    margin: 0;
    font-family: Arial, sans-serif;
    transition: filter 0.3s;
}

.loader-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(4px);
    visibility: hidden;
    opacity: 0;
    transition: visibility 0s, opacity 0.3s;
    z-index: 9999;
}

.loader {
    display: flex;
    gap: 8px;
}

.loader div {
    width: 12px;
    height: 12px;
    background-color: blue;
    border-radius: 50%;
    animation: wave 1.5s infinite ease-in-out;
}

.loader div:nth-child(1) { animation-delay: 0s; }
.loader div:nth-child(2) { animation-delay: 0.2s; }
.loader div:nth-child(3) { animation-delay: 0.4s; }
.loader div:nth-child(4) { animation-delay: 0.6s; }

@keyframes wave {
    0%, 100% { transform: translateY(0); opacity: 0.5; }
    50% { transform: translateY(-10px); opacity: 1; }
}

.active .loader-overlay {
    visibility: visible;
    opacity: 1;
}