/* ================================
    LOADING OVERLAY — Book Loader
    (Based on Uiverse.io by anand_4957)
    Colors adapted to site theme (blue)
================================== */

.loader-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10000;
    background: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader-overlay.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

body.loader-active {
    overflow: hidden;
}

/* ================================
    BOOK LOADER (theme: blue)
================================== */
.book,
.book__pg-shadow,
.book__pg {
    animation: cover 5s ease-in-out infinite;
}

.book {
    background-color: var(--primary, #1560BD);
    border-radius: 0.25em;
    box-shadow:
        0 0.25em 0.5em hsla(0, 0%, 0%, 0.3),
        0 0 0 0.25em var(--primary-light, #3d7fcc) inset;
    padding: 0.25em;
    perspective: 37.5em;
    position: relative;
    width: 8em;
    height: 6em;
    transform: translate3d(0, 0, 0);
    transform-style: preserve-3d;
}

.book__pg-shadow,
.book__pg {
    position: absolute;
    left: 0.25em;
    width: calc(50% - 0.25em);
}

.book__pg-shadow {
    animation-name: shadow;
    background-image: linear-gradient(
        -45deg,
        hsla(0, 0%, 0%, 0) 50%,
        hsla(0, 0%, 0%, 0.3) 50%
    );
    filter: blur(0.25em);
    top: calc(100% - 0.25em);
    height: 3.75em;
    transform: scaleY(0);
    transform-origin: 100% 0%;
}

.book__pg {
    animation-name: pg1;
    background-color: hsl(223, 10%, 100%);
    background-image: linear-gradient(
        90deg,
        hsla(223, 10%, 90%, 0) 87.5%,
        hsl(223, 10%, 90%)
    );
    height: calc(100% - 0.5em);
    transform-origin: 100% 50%;
}

.book__pg--2,
.book__pg--3,
.book__pg--4 {
    background-image: repeating-linear-gradient(
            hsl(223, 10%, 10%) 0 0.125em,
            hsla(223, 10%, 10%, 0) 0.125em 0.5em
        ),
        linear-gradient(90deg, hsla(223, 10%, 90%, 0) 87.5%, hsl(223, 10%, 90%));
    background-repeat: no-repeat;
    background-position: center;
    background-size:
        2.5em 4.125em,
        100% 100%;
}

.book__pg--2 {
    animation-name: pg2;
}

.book__pg--3 {
    animation-name: pg3;
}

.book__pg--4 {
    animation-name: pg4;
}

.book__pg--5 {
    animation-name: pg5;
}

/* Animations — cover uses theme blue */
@keyframes cover {
    from,
    5%,
    45%,
    55%,
    95%,
    to {
        animation-timing-function: ease-out;
        background-color: var(--primary-light, #3d7fcc);
    }
    10%,
    40%,
    60%,
    90% {
        animation-timing-function: ease-in;
        background-color: var(--primary-dark, #0d4a94);
    }
}

@keyframes shadow {
    from,
    10.01%,
    20.01%,
    30.01%,
    40.01% {
        animation-timing-function: ease-in;
        transform: translate3d(0, 0, 1px) scaleY(0) rotateY(0);
    }
    5%,
    15%,
    25%,
    35%,
    45%,
    55%,
    65%,
    75%,
    85%,
    95% {
        animation-timing-function: ease-out;
        transform: translate3d(0, 0, 1px) scaleY(0.2) rotateY(90deg);
    }
    10%,
    20%,
    30%,
    40%,
    50%,
    to {
        animation-timing-function: ease-out;
        transform: translate3d(0, 0, 1px) scaleY(0) rotateY(180deg);
    }
    50.01%,
    60.01%,
    70.01%,
    80.01%,
    90.01% {
        animation-timing-function: ease-in;
        transform: translate3d(0, 0, 1px) scaleY(0) rotateY(180deg);
    }
    60%,
    70%,
    80%,
    90%,
    to {
        animation-timing-function: ease-out;
        transform: translate3d(0, 0, 1px) scaleY(0) rotateY(0);
    }
}

@keyframes pg1 {
    from,
    to {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.4deg);
    }
    10%,
    15% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(180deg);
    }
    20%,
    80% {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(180deg);
    }
    85%,
    90% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(180deg);
    }
}

@keyframes pg2 {
    from,
    to {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(0.3deg);
    }
    5%,
    10% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.3deg);
    }
    20%,
    25% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.9deg);
    }
    30%,
    70% {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(179.9deg);
    }
    75%,
    80% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.9deg);
    }
    90%,
    95% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.3deg);
    }
}

@keyframes pg3 {
    from,
    10%,
    90%,
    to {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(0.2deg);
    }
    15%,
    20% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.2deg);
    }
    30%,
    35% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.8deg);
    }
    40%,
    60% {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(179.8deg);
    }
    65%,
    70% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.8deg);
    }
    80%,
    85% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.2deg);
    }
}

@keyframes pg4 {
    from,
    20%,
    80%,
    to {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(0.1deg);
    }
    25%,
    30% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.1deg);
    }
    40%,
    45% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.7deg);
    }
    50% {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(179.7deg);
    }
    55%,
    60% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.7deg);
    }
    70%,
    75% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0.1deg);
    }
}

@keyframes pg5 {
    from,
    30%,
    70%,
    to {
        animation-timing-function: ease-in;
        background-color: hsl(223, 10%, 45%);
        transform: translate3d(0, 0, 1px) rotateY(0);
    }
    35%,
    40% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0deg);
    }
    50% {
        animation-timing-function: ease-in-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(179.6deg);
    }
    60%,
    65% {
        animation-timing-function: ease-out;
        background-color: hsl(223, 10%, 100%);
        transform: translate3d(0, 0, 1px) rotateY(0);
    }
}