/**
 * O.N.Precision - Performance Styles
 * Lazy loading, skeleton screens, and smooth transitions
 */

/* =============================================
   Lazy Loading Images
   ============================================= */

/* Image loading state */
img[data-src] {
    opacity: 0;
    transition: opacity 0.3s ease;
}

img.loading {
    opacity: 0.3;
    filter: blur(5px);
}

img.loaded {
    opacity: 1;
    filter: blur(0);
}

img.error {
    opacity: 0.5;
    filter: grayscale(100%);
}

/* Native lazy loading support */
img[loading="lazy"] {
    opacity: 1;
}

/* =============================================
   Skeleton Loading Screens
   ============================================= */

.skeleton {
    background: linear-gradient(
        90deg,
        var(--color-gray-200) 25%,
        var(--color-gray-100) 50%,
        var(--color-gray-200) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: var(--radius-sm);
}

.skeleton-text {
    height: 1em;
    margin-bottom: 0.5em;
}

.skeleton-text:last-child {
    width: 70%;
}

.skeleton-image {
    aspect-ratio: 16/9;
    width: 100%;
}

.skeleton-circle {
    width: 48px;
    height: 48px;
    border-radius: 50%;
}

@keyframes skeleton-loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* =============================================
   Content Visibility Optimization
   ============================================= */

/* Lazy render off-screen content */
.lazy-render {
    content-visibility: auto;
    contain-intrinsic-size: 0 500px;
}

/* Footer - lazy render */
.footer {
    content-visibility: auto;
    contain-intrinsic-size: auto 400px;
}

/* =============================================
   Smooth Page Transitions
   ============================================= */

.page-transition {
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =============================================
   Update Notification Toast
   ============================================= */

.update-toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--color-gray-800);
    color: white;
    padding: 16px 24px;
    border-radius: var(--radius-md);
    display: flex;
    gap: 16px;
    align-items: center;
    z-index: 9999;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    animation: slideUp 0.3s ease;
}

.update-toast button {
    background: var(--color-primary);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    transition: background 0.2s;
}

.update-toast button:hover {
    background: var(--color-primary-light);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =============================================
   Reduced Motion Preferences
   ============================================= */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .skeleton {
        animation: none;
        background: var(--color-gray-200);
    }
}

/* =============================================
   Print Styles
   ============================================= */

@media print {
    .header,
    .footer,
    .mobile-menu-toggle,
    .lang-switcher,
    .header-contact-btn,
    .update-toast {
        display: none !important;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
        color: black;
        background: white;
    }
    
    a {
        text-decoration: underline;
        color: black;
    }
    
    img {
        max-width: 100%;
        page-break-inside: avoid;
    }
    
    h1, h2, h3 {
        page-break-after: avoid;
    }
}

/* =============================================
   Focus Visible for Accessibility
   ============================================= */

:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Remove outline for mouse users */
:focus:not(:focus-visible) {
    outline: none;
}

/* =============================================
   Skip Link for Accessibility
   ============================================= */

.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-primary);
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    z-index: 9999;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 10px;
}