:root {
            --bg-color: #0f0f0f;
            --btn-bg: rgba(255, 255, 255, 0.15);
            --accent: #ffffff;
        }

        body, html {
            margin: 0; padding: 0; width: 100%; height: 100%;
            background-color: var(--bg-color);
            overflow: hidden;
            font-family: sans-serif;
            touch-action: none; /* Prevents default browser pull-to-refresh */
        }
        /* BACK BUTTON */
.backbtn {
    position: fixed;
    top: 16px;
    left: 16px;

    width: 44px;
    height: 44px;

    display: flex;
    align-items: center;
    justify-content: center;

    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);

    border-radius: 50%;
    z-index: 9999;

    text-decoration: none;
    pointer-events: auto;
    -webkit-tap-highlight-color: transparent;
}

/* Back icon image */
.img-back {
    width: 22px;
    height: 22px;
    object-fit: contain;
    filter: invert(1); /* makes SVG white */
    pointer-events: none;
}

/* Optional hover (desktop only) */
@media (hover: hover) {
    .backbtn:hover {
        background: rgba(255, 255, 255, 0.2);
    }
}


        #book-wrapper {
            width: 100vw;
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            position: relative;
        }

        #my-book {
            /* Basic container styling */
            box-shadow: 0 0 50px rgba(0,0,0,0.5);
        }

        .page {
            background-color: #222; /* Page back color */
            width: 100%;
            height: 100%;
        }

        .page-content {
            width: 100%;
            height: 100%;
            display: flex;
            background: white;
            box-sizing: border-box;
        }

        .page img {
            width: 100%;
            height: 100%;
            object-fit: contain;
            user-select: none;
            -webkit-user-drag: none;
        }

        /* UI CONTROLS */
        .ui-layer {
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            pointer-events: none;
            z-index: 100;
        }

        /* Large Tap Zones for Mobile */
        .tap-zone {
            position: absolute;
            top: 0;
            width: 15%;
            height: 100%;
            pointer-events: auto;
            cursor: pointer;
            z-index: 101;
        }
        .tap-left { left: 0; }
        .tap-right { right: 0; }

        .bottom-controls {
            position: absolute;
            bottom: 40px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            align-items: center;
            gap: 25px;
            pointer-events: auto;
            z-index: 102;
        }

        .nav-btn {
            width: 50px;
            height: 50px;
            background: var(--btn-bg);
            border: 1px solid rgba(255,255,255,0.3);
            border-radius: 50%;
            color: white;
            display: flex;
            justify-content: center;
            align-items: center;
            backdrop-filter: blur(10px);
            font-size: 20px;
            -webkit-tap-highlight-color: transparent;
        }

        .page-counter {
            color: white;
            background: rgba(0,0,0,0.5);
            padding: 8px 18px;
            border-radius: 20px;
            font-size: 14px;
            border: 1px solid rgba(255,255,255,0.1);
        }

        /* Zoom styling */
        .zoomed-mode .ui-layer { display: none; }
        .img-zoomed {
            transform: scale(2.5);
            z-index: 9999;
        }