:root {
    --paper: #fffefa;
    --ink: #37342f;
    --muted: #706c66;
    --background: #efebe4;
    --background-deep: #ded7cd;
    --envelope: #f4efe6;
    --envelope-light: #fffaf1;
    --envelope-shadow: #d9d0c3;
    --accent: #756d62;
    --panel-width: 420px;
    --panel-height: 594px;
    --card-ratio: .7048;
    --soft-shadow: 0 24px 70px rgb(62 54 44 / 20%);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    min-height: 100%;
    margin: 0;
}

body {
    overflow: hidden;
    color: var(--ink);
    background:
        radial-gradient(circle at 50% 18%, rgb(255 255 255 / 72%), transparent 42%),
        linear-gradient(145deg, var(--background) 0%, #f7f4ef 48%, var(--background-deep) 100%);
    font-family: Georgia, "Times New Roman", serif;
    -webkit-font-smoothing: antialiased;
}

button {
    font: inherit;
}

.card-experience {
    position: relative;
    isolation: isolate;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    min-height: 420px;
    overflow: hidden;
}

.card-experience::before {
    position: absolute;
    inset: 0;
    z-index: -1;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120' viewBox='0 0 120 120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.78' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.035'/%3E%3C/svg%3E");
    content: "";
    pointer-events: none;
}

/* Envelop */
.envelope-stage {
    position: absolute;
    inset: 0;
    z-index: 20;
    display: grid;
    place-items: center;
    padding: max(24px, env(safe-area-inset-top)) 20px max(24px, env(safe-area-inset-bottom));
    transition: opacity 700ms ease, visibility 700ms ease, transform 700ms ease;
}

.envelope-stage.is-finished {
    visibility: hidden;
    opacity: 0;
    transform: scale(1.025);
    pointer-events: none;
}

.envelope-trigger {
    display: flex;
    width: min(88vw, 560px);
    margin: 0;
    padding: 0;
    flex-direction: column;
    align-items: center;
    border: 0;
    color: inherit;
    background: transparent;
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
}

.envelope-trigger:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 12px;
    border-radius: 6px;
}

.envelope {
    position: relative;
    display: block;
    width: min(86vw, 540px);
    aspect-ratio: 1.52 / 1;
    perspective: 1500px;
    filter: drop-shadow(0 24px 24px rgb(65 56 45 / 18%));
    transform: translateZ(0);
}

.envelope__shadow {
    position: absolute;
    right: 8%;
    bottom: -8%;
    left: 8%;
    height: 13%;
    border-radius: 50%;
    background: rgb(63 54 44 / 18%);
    filter: blur(18px);
    transition: opacity 700ms ease, transform 1200ms ease;
}

.envelope__back {
    position: absolute;
    inset: 15% 0 0;
    z-index: 1;
    border: 1px solid rgb(97 85 71 / 11%);
    border-radius: 3px;
    background: var(--envelope-shadow);
}

.envelope__card {
    position: absolute;
    top: 20%;
    left: 50%;
    z-index: 3;
    display: block;
    width: auto;
    height: 75%;
    max-width: 78%;
    aspect-ratio: var(--card-ratio);
    overflow: hidden;
    border-radius: 2px;
    background: var(--paper);
    box-shadow: 0 5px 18px rgb(53 46 38 / 12%);
    /* Houd de kaart in rust volledig achter de onderrand van de envelop. */
    transform: translate(-50%, 5%);
    transition: transform 1250ms cubic-bezier(.2, .75, .2, 1), box-shadow 900ms ease;
}

.envelope__card img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: top center;
}

.envelope__front-left,
.envelope__front-right,
.envelope__front-bottom {
    position: absolute;
    inset: 15% 0 0;
    z-index: 5;
    display: block;
    pointer-events: none;
}

.envelope__front-left {
    background: linear-gradient(128deg, var(--envelope-light), var(--envelope));
    clip-path: polygon(0 0, 52% 50%, 0 100%);
}

.envelope__front-right {
    background: linear-gradient(230deg, #eee7dc, var(--envelope));
    clip-path: polygon(100% 0, 48% 50%, 100% 100%);
}

.envelope__front-bottom {
    background: linear-gradient(0deg, #eee8de, var(--envelope-light));
    clip-path: polygon(0 100%, 50% 46%, 100% 100%);
}

.envelope__flap {
    position: absolute;
    top: 15%;
    left: 0;
    z-index: 6;
    display: block;
    width: 100%;
    height: 54%;
    background: linear-gradient(155deg, var(--envelope-light), #e7dfd3);
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    transform: rotateX(0deg);
    transform-origin: 50% 0;
    transition: transform 850ms cubic-bezier(.45, 0, .22, 1), z-index 0ms linear 420ms;
    backface-visibility: hidden;
}

.envelope__seal {
    position: absolute;
    top: 59%;
    left: 50%;
    z-index: 7;
    display: grid;
    width: 42px;
    height: 42px;
    place-items: center;
    border: 1px solid rgb(255 255 255 / 36%);
    border-radius: 50%;
    color: #f6f0e7;
    background: #8a8175;
    box-shadow: 0 3px 9px rgb(68 57 46 / 25%);
    font-family: Arial, sans-serif;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .08em;
    transform: translate(-50%, -50%);
    transition: opacity 280ms ease, transform 280ms ease;
}

.envelope-message {
    display: block;
    max-width: 520px;
    margin-top: clamp(24px, 5vh, 44px);
    font-size: clamp(18px, 2.7vw, 25px);
    line-height: 1.5;
    text-align: center;
    text-wrap: balance;
    transition: opacity 400ms ease, transform 400ms ease;
}

.envelope-message::after {
    display: block;
    width: 36px;
    height: 1px;
    margin: 18px auto 0;
    background: currentColor;
    content: "";
    opacity: .38;
}

.envelope-stage.is-opening .envelope__flap {
    z-index: 2;
    transform: rotateX(180deg);
}

.envelope-stage.is-opening .envelope__seal {
    opacity: 0;
    transform: translate(-50%, -75%) scale(.78);
}

.envelope-stage.is-opening .envelope-message {
    opacity: 0;
    transform: translateY(8px);
}

.envelope-stage.is-rising .envelope__card {
    z-index: 4;
    box-shadow: 0 22px 44px rgb(53 46 38 / 20%);
    transform: translate(-50%, -70%);
}

.envelope-stage.is-rising .envelope__shadow {
    opacity: .55;
    transform: scale(.88);
}

/* Kaartweergave */
.card-viewer {
    position: absolute;
    inset: 0;
    z-index: 10;
    display: flex;
    padding: max(14px, env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) max(14px, env(safe-area-inset-bottom)) max(12px, env(safe-area-inset-left));
    flex-direction: column;
    align-items: center;
    justify-content: center;
    visibility: hidden;
    opacity: 0;
    transform: scale(.985);
    pointer-events: none;
    transition: opacity 700ms ease, visibility 700ms ease, transform 900ms ease;
}

.card-viewer.is-visible {
    visibility: visible;
    opacity: 1;
    transform: scale(1);
    pointer-events: auto;
}

.book-stage {
    position: relative;
    width: 100%;
    height: calc(100% - 42px);
    perspective: 2600px;
    perspective-origin: 50% 48%;
}

.book-positioner {
    position: absolute;
    top: 50%;
    left: 50%;
    width: calc(var(--panel-width) * 2);
    height: var(--panel-height);
    transform: translate(-75%, -50%);
    transform-style: preserve-3d;
    transition:
        width 750ms cubic-bezier(.22, .75, .2, 1),
        height 750ms cubic-bezier(.22, .75, .2, 1),
        transform 900ms cubic-bezier(.22, .75, .2, 1);
    will-change: width, height, transform;
}

.book-flipper {
    position: absolute;
    inset: 0;
    transform: rotateY(0deg);
    transform-origin: 75% 50%;
    transform-style: preserve-3d;
    transition: transform 900ms cubic-bezier(.42, 0, .2, 1);
    will-change: transform;
}

.card-panel {
    overflow: hidden;
    border-radius: 2px;
    background: var(--paper);
    box-shadow: var(--soft-shadow);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

.card-panel img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
    background: var(--paper);
    pointer-events: none;
    user-select: none;
    -webkit-user-drag: none;
}

.right-page,
.front-cover,
.back-panel {
    position: absolute;
    top: 0;
    left: 50%;
    width: 50%;
    height: 100%;
}

.right-page {
    z-index: 1;
    box-shadow: inset 10px 0 22px rgb(44 38 31 / 6%), var(--soft-shadow);
    transform: translateZ(0);
}

.front-cover {
    z-index: 4;
    transform: rotateY(0deg) translateZ(2px);
    transform-origin: 0 50%;
    transform-style: preserve-3d;
    transition: transform 1100ms cubic-bezier(.44, .02, .17, 1);
    will-change: transform;
}

.cover-face {
    position: absolute;
    inset: 0;
}

.cover-face--front {
    transform: rotateY(0deg);
}

.cover-face--inside {
    box-shadow: inset -10px 0 22px rgb(44 38 31 / 6%), var(--soft-shadow);
    transform: rotateY(180deg);
}

.back-panel {
    z-index: 2;
    transform: rotateY(180deg) translateZ(3px);
}

.card-experience[data-view="open"] .book-positioner {
    transform: translate(-50%, -50%);
}

.card-experience[data-view="open"] .front-cover {
    transform: rotateY(-180deg) translateZ(2px);
}

.card-experience[data-view="back"] .book-flipper {
    transform: rotateY(180deg);
}

.card-hitarea {
    position: absolute;
    top: 50%;
    left: 50%;
    z-index: 8;
    display: block;
    width: var(--panel-width);
    height: var(--panel-height);
    padding: 0;
    border: 0;
    border-radius: 2px;
    opacity: 0;
    background: transparent;
    cursor: pointer;
    transform: translate(-50%, -50%);
    transition: width 750ms ease, height 750ms ease;
}

.card-hitarea:focus-visible {
    opacity: 1;
    outline: 3px solid rgb(86 79 69 / 62%);
    outline-offset: 7px;
}

.card-experience:not([data-view="front"]) .card-hitarea {
    visibility: hidden;
    pointer-events: none;
}

.viewer-arrow {
    position: absolute;
    top: 50%;
    z-index: 12;
    display: grid;
    width: clamp(42px, 6vw, 54px);
    height: clamp(42px, 6vw, 54px);
    padding: 0;
    place-items: center;
    border: 1px solid rgb(74 67 58 / 18%);
    border-radius: 50%;
    color: #4d4841;
    background: rgb(255 253 249 / 82%);
    box-shadow: 0 8px 24px rgb(51 44 36 / 14%);
    opacity: 0;
    cursor: pointer;
    transform: translateY(-50%) scale(.88);
    pointer-events: none;
    backdrop-filter: blur(8px);
    transition: opacity 300ms ease, transform 300ms ease, background-color 200ms ease;
}

.viewer-arrow:hover {
    background: #fff;
}

.viewer-arrow:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
}

.viewer-arrow svg {
    width: 24px;
    height: 24px;
    fill: none;
    stroke: currentColor;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-width: 1.7;
}

.viewer-arrow--left {
    left: max(10px, env(safe-area-inset-left));
}

.viewer-arrow--right {
    right: max(10px, env(safe-area-inset-right));
}

.card-experience[data-view="open"] .viewer-arrow,
.card-experience[data-view="back"] .viewer-arrow--left {
    opacity: 1;
    transform: translateY(-50%) scale(1);
    pointer-events: auto;
}

.card-experience[data-view="front"] .viewer-arrow,
.card-experience[data-view="back"] .viewer-arrow--right {
    visibility: hidden;
}

.viewer-hint {
    min-height: 26px;
    margin: 10px 0 0;
    color: var(--muted);
    font-family: Arial, sans-serif;
    font-size: 14px;
    letter-spacing: .01em;
    text-align: center;
    transition: opacity 250ms ease;
}

.noscript-message {
    position: fixed;
    right: 16px;
    bottom: 16px;
    left: 16px;
    z-index: 100;
    margin: 0;
    padding: 14px 18px;
    border-radius: 6px;
    background: #fff;
    box-shadow: var(--soft-shadow);
    text-align: center;
}

.sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* Foutpagina */
.error-page {
    display: grid;
    min-height: 100vh;
    min-height: 100dvh;
    padding: 24px;
    place-items: center;
    overflow: auto;
}

.error-card {
    width: min(100%, 540px);
    padding: clamp(30px, 7vw, 58px);
    border: 1px solid rgb(74 67 58 / 11%);
    border-radius: 4px;
    background: rgb(255 254 250 / 88%);
    box-shadow: var(--soft-shadow);
    text-align: center;
}

.error-card__mark {
    display: grid;
    width: 54px;
    height: 54px;
    margin: 0 auto 24px;
    place-items: center;
    border: 1px solid #aaa197;
    border-radius: 50%;
    color: #6f685f;
    font-family: Arial, sans-serif;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .08em;
}

.error-card h1 {
    margin: 0 0 16px;
    font-size: clamp(26px, 5vw, 38px);
    font-weight: 400;
}

.error-card p {
    margin: 0;
    color: var(--muted);
    font-size: 18px;
    line-height: 1.6;
}

.error-card pre {
    margin-top: 24px;
    padding: 12px;
    overflow: auto;
    border-radius: 3px;
    background: #f1eee8;
    font-family: monospace;
    font-size: 12px;
    text-align: left;
    white-space: pre-wrap;
}

@media (min-width: 900px) {
    .viewer-arrow--left {
        left: 28px;
    }

    .viewer-arrow--right {
        right: 28px;
    }
}

@media (max-height: 560px) {
    .envelope {
        width: min(62vw, 390px);
    }

    .envelope-message {
        margin-top: 14px;
        font-size: 17px;
    }

    .viewer-hint {
        margin-top: 4px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 1ms !important;
        animation-duration: 1ms !important;
        animation-iteration-count: 1 !important;
    }
}