body, html {
    margin: 0;
    padding: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    background-color: #0b0f19; /* Deep dark aesthetic */
    font-family: 'Inter', Tahoma, Geneva, Verdana, sans-serif;
    color: white;
}

#viewer-container {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
}

.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, #1e293b 0%, #0b0f19 100%);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 100;
    transition: opacity 0.8s ease-in-out, visibility 0.8s;
}

.glass-box {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-top: 4px solid #38bdf8; /* vibrant blue */
    border-right: 4px solid #818cf8; /* indigo */
    border-radius: 50%;
    animation: spin 1s cubic-bezier(0.55, 0.085, 0.68, 0.53) infinite;
    margin-bottom: 24px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#loading-text {
    margin: 0;
    font-weight: 600;
    letter-spacing: 0.5px;
    color: #e2e8f0;
    font-size: 1.1rem;
}

.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}