/**
 * PhotoFlow Image Viewer (Lightbox) Styles
 *
 * Full-screen image viewer with navigation controls, keyboard/touch support,
 * accessibility features, and responsive layout.
 *
 * @package     com_photoflow
 * @version     1.0.0
 * @since       2026-05-12
 */

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */

:root {
    --pf-viewer-z-index: 9999;
    --pf-viewer-backdrop: rgba(0, 0, 0, 0.92);
    --pf-viewer-control-bg: rgba(255, 255, 255, 0.08);
    --pf-viewer-control-bg-hover: rgba(255, 255, 255, 0.18);
    --pf-viewer-control-color: #fff;
    --pf-viewer-control-size: 48px;
    --pf-viewer-control-size-mobile: 56px;
    --pf-viewer-transition: 220ms ease-out;
    --pf-viewer-touch-min: 44px;
    --pf-viewer-accent: var(--pf-primary-color, #0066cc);
}

/* ==========================================================================
   Overlay Container
   ========================================================================== */

.photoflow-viewer {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--pf-viewer-z-index);
    opacity: 0;
    visibility: hidden;
    transition:
        opacity var(--pf-viewer-transition),
        visibility var(--pf-viewer-transition);
    overflow: hidden;
    -webkit-tap-highlight-color: transparent;
}

.photoflow-viewer--open {
    opacity: 1;
    visibility: visible;
}

/* ==========================================================================
   Backdrop
   ========================================================================== */

.photoflow-viewer__backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--pf-viewer-backdrop);
    cursor: pointer;
    z-index: 1;
}

/* ==========================================================================
   Stage / Image Container
   ========================================================================== */

.photoflow-viewer__stage {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--pf-viewer-control-size) + 32px);
    z-index: 2;
    pointer-events: none;
}

.photoflow-viewer__image {
    max-width: 85vw;
    max-height: 85vh;
    width: auto;
    height: auto;
    object-fit: contain;
    display: block;
    transform: scale(0.96);
    opacity: 0;
    transition:
        transform var(--pf-viewer-transition),
        opacity var(--pf-viewer-transition);
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.5);
    pointer-events: auto;
    user-select: none;
    -webkit-user-drag: none;
}

.photoflow-viewer--open .photoflow-viewer__image {
    transform: scale(1);
    opacity: 1;
}

.photoflow-viewer__image--loading {
    opacity: 0;
}

/* ==========================================================================
   Title & Counter
   ========================================================================== */

.photoflow-viewer__title {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    margin: 0;
    padding: 0 80px;
    color: var(--pf-viewer-control-color);
    font-size: 1.125rem;
    font-weight: 500;
    line-height: 1.4;
    max-width: calc(100% - 160px);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    text-align: center;
    z-index: 3;
    pointer-events: none;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);
}

.photoflow-viewer__counter {
    position: absolute;
    top: 52px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.875rem;
    font-variant-numeric: tabular-nums;
    z-index: 3;
    pointer-events: none;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
}

/* ==========================================================================
   Controls
   ========================================================================== */

.photoflow-viewer__controls {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 10000;
    pointer-events: none;
}

.photoflow-viewer__btn {
    position: absolute;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--pf-viewer-control-size);
    height: var(--pf-viewer-control-size);
    min-width: var(--pf-viewer-touch-min);
    min-height: var(--pf-viewer-touch-min);
    padding: 0;
    margin: 0;
    background-color: var(--pf-viewer-control-bg);
    color: var(--pf-viewer-control-color);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    pointer-events: auto;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition:
        background-color var(--pf-viewer-transition),
        transform var(--pf-viewer-transition),
        opacity var(--pf-viewer-transition);
    -webkit-tap-highlight-color: transparent;
    appearance: none;
    -webkit-appearance: none;
}

.photoflow-viewer__btn:hover {
    background-color: var(--pf-viewer-control-bg-hover);
}

.photoflow-viewer__btn:active {
    transform: scale(0.94);
}

.photoflow-viewer__btn svg {
    width: 50%;
    height: 50%;
    fill: currentColor;
    pointer-events: none;
}

.photoflow-viewer__btn--close {
    top: 16px;
    right: 16px;
}

.photoflow-viewer__btn--prev {
    top: 50%;
    left: 16px;
    transform: translateY(-50%);
}

.photoflow-viewer__btn--prev:active {
    transform: translateY(-50%) scale(0.94);
}

.photoflow-viewer__btn--next {
    top: 50%;
    right: 16px;
    transform: translateY(-50%);
}

.photoflow-viewer__btn--next:active {
    transform: translateY(-50%) scale(0.94);
}

.photoflow-viewer__btn--disabled,
.photoflow-viewer__btn:disabled,
.photoflow-viewer__btn[aria-disabled="true"] {
    opacity: 0.3;
    cursor: not-allowed;
    pointer-events: none;
}

/* ==========================================================================
   Accessibility — Focus States
   ========================================================================== */

.photoflow-viewer__btn:focus {
    outline: none;
}

.photoflow-viewer__btn:focus-visible {
    outline: 2px solid var(--pf-viewer-accent);
    outline-offset: 2px;
}

/* ==========================================================================
   Responsive — Mobile (<= 768px)
   ========================================================================== */

@media (max-width: 768px) {
    .photoflow-viewer__stage {
        padding: calc(var(--pf-viewer-control-size-mobile) + 16px) 8px;
    }

    .photoflow-viewer__image {
        max-width: 95vw;
        max-height: 80vh;
    }

    .photoflow-viewer__btn {
        width: var(--pf-viewer-control-size-mobile);
        height: var(--pf-viewer-control-size-mobile);
    }

    .photoflow-viewer__btn--close {
        top: 12px;
        right: 12px;
    }

    .photoflow-viewer__btn--prev {
        left: 8px;
    }

    .photoflow-viewer__btn--next {
        right: 8px;
    }

    .photoflow-viewer__title {
        top: 16px;
        font-size: 0.95rem;
        padding: 0 72px;
        max-width: calc(100% - 144px);
    }

    .photoflow-viewer__counter {
        top: auto;
        bottom: 20px;
        left: 50%;
        transform: translateX(-50%);
        font-size: 0.8125rem;
        padding: 4px 12px;
        background-color: rgba(0, 0, 0, 0.4);
        border-radius: 999px;
    }
}

/* ==========================================================================
   Accessibility — Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    .photoflow-viewer,
    .photoflow-viewer__image,
    .photoflow-viewer__btn {
        transition: none !important;
    }

    .photoflow-viewer__image {
        transform: none !important;
    }

    .photoflow-viewer__btn--prev,
    .photoflow-viewer__btn--next {
        transform: translateY(-50%) !important;
    }

    .photoflow-viewer__btn:active {
        transform: none !important;
    }
}