/* ===================================================
   BASIC.CSS — DOUBLE SPREAD + SMOOTH ZOOM VERSION
   =================================================== */

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #fcfcfc;
}

/* Viewport */
.flipbook-viewport {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

/* Center container */
.flipbook-viewport .container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(1);
    transform-origin: center center;
    transition: transform 0.25s ease;
}

/* Flipbook */
.flipbook {
    margin: 0 auto;
}

/* Pages */
.flipbook-viewport .page,
.flipbook .turn-page {
    background-color: #fff;
    background-repeat: no-repeat;
    background-position: center center;
    background-size: contain;
    box-shadow: 0 0 25px rgba(0,0,0,0.2);
}

/* Prevent image dragging */
.flipbook-viewport img {
    user-select: none;
    -webkit-user-drag: none;
    pointer-events: none;
}

/* Smooth shadow */
.flipbook-viewport .shadow {
    transition: box-shadow 0.4s ease;
}

/* Touch improvement */
button {
    touch-action: manipulation;
}