* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #fff;
    overflow: hidden;
}

.loading-container {
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 24px;
}

body.show-loading .loading-container {
    opacity: 1;
    visibility: visible;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(255, 255, 255, 0.2);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-text {
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 0.5px;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 0.6;
    }
    50% {
        opacity: 1;
    }
}

.fallback-message {
    position: absolute;
    bottom: 32px;
    text-align: center;
    font-size: 14px;
    opacity: 0.8;
    padding: 0 20px;
}

.fallback-message a {
    color: #fff;
    text-decoration: underline;
    transition: opacity 0.2s ease;
}

.fallback-message a:hover {
    opacity: 0.7;
}

/* モバイル対応 */
@media (max-width: 768px) {
    .loading-text {
        font-size: 14px;
    }
    
    .spinner {
        width: 40px;
        height: 40px;
        border-width: 3px;
    }
    
    .fallback-message {
        font-size: 12px;
        bottom: 24px;
    }
}