:root {
    --bg: #0b1220;
    --ink: #eaf2ff;
    --muted: rgba(234, 242, 255, .72);
    --blue: #3b82f6;
    --green: #22c55e;
    --line: rgba(255, 255, 255, .14);
    --radius: 16px;
}

* {
    box-sizing: border-box
}

body {
    margin: 0;
    font-family: Arial, system-ui, sans-serif;
    background: var(--bg);
    color: var(--ink);
}

.top {
    text-align: center;
    padding: 22px 14px 10px;
}

.top h1 {
    margin: 0
}

.top p {
    margin: 6px 0 0;
    color: var(--muted)
}

.wrap {
    width: min(980px, 92vw);
    margin: 0 auto;
    padding: 18px 0 60px;
}

/* hide radio buttons */
input[type="radio"] {
    position: absolute;
    left: -9999px;
}

/* BOOK */
.book {
    position: relative;
    width: min(760px, 92vw);
    height: min(620px, 78vh);
    margin: 0 auto;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, .03);
    overflow: hidden;
    box-shadow: 0 14px 40px rgba(0, 0, 0, .45);
    perspective: 1500px;
}

/* PAGES */
.page {
    position: absolute;
    inset: 0;
    padding: 18px;
    background: linear-gradient(120deg, rgba(255, 255, 255, .04), rgba(255, 255, 255, .02));
    border-left: 1px solid rgba(255, 255, 255, .10);

    transform-origin: left center;
    transform-style: preserve-3d;
    backface-visibility: hidden;
    transition: transform 700ms ease;

    /* default: closed */
    transform: rotateY(-180deg);

    /* no clicking on hidden pages */
    pointer-events: none;
}

.cover {
    transform: rotateY(0deg)
}

/* cover starts open */

/* content layout */
.content {
    height: 100%;
    background: rgba(255, 255, 255, .04);
    border: 1px solid rgba(255, 255, 255, .10);
    border-radius: var(--radius);
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.content h2,
.content h3 {
    margin: 0
}

.content p {
    margin: 0;
    line-height: 1.5
}

.content li {
    line-height: 1.45
}

.scrollArea {
    overflow: auto;
    padding-right: 6px;
}

/* media (BIG + FULL IMAGE) */
.media {
    width: 100%;
    border-radius: 14px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, .12);
    background: rgba(0, 0, 0, .22);
    display: flex;
    align-items: center;
    justify-content: center;
}

.media img {
    width: 100%;
    height: auto;
    max-height: 340px;
    /* big */
    object-fit: contain;
    /* show FULL image */
    display: block;
}

/* cover overlay */
.coverMedia {
    position: relative
}

.coverOverlay {
    position: absolute;
    inset: 0;
    display: flex;
    justify-content: flex-end;
    flex-direction: column;
    padding: 14px;
    background: linear-gradient(to top, rgba(0, 0, 0, .55), rgba(0, 0, 0, 0));
}

.coverTitle {
    margin: 0;
    font-size: 1.6rem;
    line-height: 1.1;
}

.coverTitle span {
    font-weight: 400;
    color: rgba(255, 255, 255, .9);
}

/* text styles */
.quote {
    color: var(--muted);
    font-style: italic;
}

.thanks {
    font-weight: 800;
    letter-spacing: .5px;
}

/* buttons */
.navRow {
    display: flex;
    gap: 10px;
    margin-top: auto;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 12px;
    border-radius: 12px;
    cursor: pointer;
    user-select: none;
    font-weight: 700;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, .04);
    color: var(--ink);
    text-decoration: none;
}

.btn:hover {
    background: rgba(255, 255, 255, .07)
}

.btn.next {
    border: none;
    background: linear-gradient(135deg, var(--blue), var(--green));
    color: #071423;
}

.btn.ghost {
    background: transparent
}

/* STAR (hover secret) */
.starBox {
    margin-top: 10px;
    padding: 14px;
    border-radius: 14px;
    border: 1px dashed rgba(255, 255, 255, .25);
    background: rgba(0, 0, 0, .22);
}

.star {
    font-size: 42px;
    width: fit-content;
    animation: starFloat 2.6s ease-in-out infinite;
}

.hint {
    margin: 6px 0 0;
    color: var(--muted)
}

.secret {
    margin-top: 10px;
    padding: 10px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, .12);
    background: rgba(255, 255, 255, .04);
    opacity: 0;
    transform: translateY(8px);
    transition: 350ms ease;
}

.starBox:hover .secret {
    opacity: 1;
    transform: translateY(0);
}

.secret ol {
    margin: 10px 0 0
}

/* Credits */
.credits {
    color: var(--muted)
}

/* ✅ FLIP LOGIC (THIS FIXES EVERYTHING) */
/* p1 = cover open */
#p1:checked~.wrap .cover {
    transform: rotateY(0deg)
}

/* p2 = cover flips, page1 opens */
#p2:checked~.wrap .cover {
    transform: rotateY(-180deg)
}

#p2:checked~.wrap .page1 {
    transform: rotateY(0deg)
}

/* p3 = cover stays flipped + page1 flips, page2 opens */
#p3:checked~.wrap .cover {
    transform: rotateY(-180deg)
}

#p3:checked~.wrap .page1 {
    transform: rotateY(-180deg)
}

#p3:checked~.wrap .page2 {
    transform: rotateY(0deg)
}

/* p4 = cover + page1 + page2 flipped, page3 opens */
#p4:checked~.wrap .cover {
    transform: rotateY(-180deg)
}

#p4:checked~.wrap .page1 {
    transform: rotateY(-180deg)
}

#p4:checked~.wrap .page2 {
    transform: rotateY(-180deg)
}

#p4:checked~.wrap .page3 {
    transform: rotateY(0deg)
}

/* p5 = all flipped, back opens */
#p5:checked~.wrap .cover {
    transform: rotateY(-180deg)
}

#p5:checked~.wrap .page1 {
    transform: rotateY(-180deg)
}

#p5:checked~.wrap .page2 {
    transform: rotateY(-180deg)
}

#p5:checked~.wrap .page3 {
    transform: rotateY(-180deg)
}

#p5:checked~.wrap .back {
    transform: rotateY(0deg)
}

/* only active page is clickable */
#p1:checked~.wrap .cover,
#p2:checked~.wrap .page1,
#p3:checked~.wrap .page2,
#p4:checked~.wrap .page3,
#p5:checked~.wrap .back {
    pointer-events: auto;
}

/* Animations */
@keyframes starFloat {

    0%,
    100% {
        transform: translateY(0)
    }

    50% {
        transform: translateY(-8px)
    }
}

/* Responsive */
@media (max-width:520px) {
    .book {
        height: 80vh
    }

    .content {
        padding: 14px
    }

    .media img {
        max-height: 230px
    }

    .star {
        font-size: 38px
    }
}