:root {
    --primary-color: #ff8fa3;
    --secondary-color: #fff0f3;
    --accent-color: #c9184a;
    --text-color: #590d22;
    --bg-gradient: linear-gradient(135deg, #fff0f3 0%, #ffccd5 100%);
    --card-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

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

body {
    font-family: 'Montserrat', sans-serif;
    background: var(--bg-gradient);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    color: var(--text-color);
}

.main-container {
    text-align: center;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    max-width: 600px;
    width: 90%;
    position: relative;
}

header h1 {
    font-family: 'Dancing Script', cursive;
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--accent-color);
}

.game-area {
    position: relative;
    width: 450px;
    height: 450px;
    margin: 0 auto;
    background: #fff;
    border-radius: 10px;
    box-shadow: inset 0 0 20px rgba(0,0,0,0.05);
    overflow: hidden;
}

#puzzle-container {
    width: 100%;
    height: 100%;
    position: relative;
}

.tile {
    position: absolute;
    /* width/height set in JS or could be 33.33% here */
    background-image: url('photo.jpg');
    background-size: 300% 300%; /* Ensures image fits the 3x3 grid container relative to tile */
    border: 1px solid rgba(255, 255, 255, 0.5);
    transition: top 0.3s ease, left 0.3s ease;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.tile.empty {
    background: transparent;
    border: none;
    box-shadow: none;
    cursor: default;
}

.tile-number {
    position: absolute;
    top: 5px;
    left: 8px;
    font-family: 'Dancing Script', cursive;
    font-size: 1.5rem;
    font-weight: bold;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 2px 4px rgba(0,0,0,0.8);
    pointer-events: none;
    z-index: 2;
}

/* Overlays for transitions */
#victory-overlay, #valentine-reveal {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: white;
    opacity: 0;
    pointer-events: none;
    transition: opacity 1.5s ease;
    z-index: 10;
}

#valentine-reveal {
    z-index: 20;
    background: var(--bg-gradient);
}

#final-photo, #valentine-photo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 10px;
}

/* Visible states */
.visible {
    opacity: 1 !important;
    pointer-events: auto !important;
}

.intro-fade-out {
    opacity: 0;
    transition: opacity 1s ease;
}

.controls {
    margin-top: 1.5rem;
}

button {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 30px;
    font-size: 1.1rem;
    border-radius: 25px;
    cursor: pointer;
    font-family: 'Montserrat', sans-serif;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 15px rgba(255, 143, 163, 0.4);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 143, 163, 0.6);
    background: var(--accent-color);
}

/* Responsive adjustments */
@media (max-width: 500px) {
    .game-area {
        width: 300px;
        height: 300px;
    }
    /* Tile size handled by JS % now, background-size is % too */
}