/* --- 起動ローディング画面のスタイル --- */
.initial-loader {
    position: fixed;
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%;
    background-color: var(--bg-color, #f8fafc); 
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 99999;
    transition: opacity 0.5s ease, visibility 0.5s;
}

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

.spinner {
    width: 60px; 
    height: 60px;
    border: 6px solid var(--border-color, #cbd5e1);
    border-top-color: var(--primary-color, #3b82f6);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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