@font-face {
    font-family: 'Brittany Script';
    src: url('assets/fonts/TheBrittanyScript.otf') format('opentype');
    font-weight: normal;
    font-style: normal;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    background-image: url('background.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    font-family: 'Brittany Script', cursive;
    overflow-x: auto;
    padding-top: 40px;
    display: flex;
    align-items: center;
}

.forest-container {
    display: flex;
    gap: 10px;
    align-items: flex-end;
    height: 90vh;
}

/* Card dimensions: maintain 100:70 aspect ratio (1.4286:1) based on actual image dimensions */
/* Total height = 90vh, 14 rows (skipping first 2 rows of images) */
/* Each card height = 90vh / 14 */
/* Each card width = height * (100/70) */

.tree {
    display: grid;
    grid-template-columns: repeat(20, calc(90vh / 14 * 100 / 70));
    grid-template-rows: repeat(14, calc(90vh / 14));
    gap: 3px 3px;
    height: 90vh;
}

.flip-card {
    width: 100%;
    height: 100%;
    perspective: 1000px;
    cursor: pointer;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.flip-card.flipped .flip-card-inner {
    transform: rotateY(180deg);
}

/* Overlay for expanded card */
.card-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    transition: background 0.4s ease;
}

.card-overlay.active {
    background: rgba(0, 0, 0, 0.8);
    pointer-events: all;
}

/* Expanded card */
.expanded-card {
    width: 700px;
    height: 400px;
    perspective: 1000px;
    opacity: 0;
    transform: scale(0.5);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.card-overlay.active .expanded-card {
    opacity: 1;
    transform: scale(1);
}

.expanded-card .flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.expanded-card.flipped .flip-card-inner {
    transform: rotateY(180deg);
}

.expanded-card .flip-card-front,
.expanded-card .flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

.expanded-card .flip-card-front {
    background: transparent;
}

.expanded-card .flip-card-front img {
    width: 100%;
    height: 100%;
    object-fit: fill;
    display: block;
}

.expanded-card .flip-card-back {
    background: #f5f5f0;
    border-radius: 8px;
    transform: rotateY(180deg);
    display: flex;
    flex-direction: column;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

.expanded-card .message-content {
    font-size: 40px;
    line-height: 64px;
}

.expanded-card .message-meta {
    font-size: 14px;
}

.flip-card-front,
.flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

.flip-card-front {
    background: transparent;
    filter: drop-shadow(0 0 0 rgba(255, 255, 255, 0));
    transition: filter 0.3s ease 0s; /* no delay for glow */
}

.flip-card:hover {
    outline: 2px solid #fff;
    outline-offset: 2px;
    z-index: 2;
}
.flip-card:hover .flip-card-front {
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.8));
}

.flip-card-front img {
    width: 100%;
    height: 100%;
    object-fit: fill;
    display: block;
    filter: grayscale(100%) brightness(1.5) contrast(0.7);
    transition: filter 3s ease 2s; /* 2s delay, 3s smooth fade to grayscale */
}


.flip-card.colored .flip-card-front img {
    filter: grayscale(0%) brightness(1.0) contrast(1.3) saturate(1.5);
    transition: filter 0.3s ease 0s;
}

.flip-card:hover .flip-card-front img {
    filter: grayscale(0%);
    transition: filter 0.3s ease 0s; /* no delay when hovering */
}

.flip-card-back {
    background: #f5f5f0;
    border-radius: 8px;
    transform: rotateY(180deg);
    display: flex;
    flex-direction: column;
    padding: 5%;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

.message-content {
    position: relative;
    z-index: 1;
    flex: 1;
    font-size: 8px;
    line-height: 1.4;
    color: #333;
    overflow-y: auto;
    word-wrap: break-word;
}

.message-content .strikethrough {
    text-decoration: line-through;
    text-decoration-style: wavy;
    text-decoration-color: #333;
}

.message-meta {
    position: relative;
    z-index: 1;
    margin-top: auto;
    padding-top: 10px;
    font-size: 8px;
    color: #666;
    text-align: right;
}

/* Empty card (no message) */
.flip-card.empty .flip-card-back {
    background: #e8e8e3;
    display: flex;
    align-items: center;
    justify-content: center;
}

.flip-card.empty .message-content {
    color: #999;
    font-style: italic;
    text-align: center;
}