body {
    font-family: 'Arial', sans-serif;
    background-color: #f8e6e6;
    margin: 0;
    padding: 20px;
    text-align: center;
    position: relative;
    overflow-x: hidden;
}

body::before, body::after {
    content: '';
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: -1;
}

body::after {
    background: 
        radial-gradient(circle at 20% 80%, rgba(255, 182, 193, 0.4) 1%, transparent 3%),
        radial-gradient(circle at 80% 20%, rgba(255, 105, 180, 0.4) 1%, transparent 3%);
    background-size: 100px 100px;
    animation: sparkle 8s ease-in-out infinite;
}

@keyframes sparkle {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 0.8; }
}

h1 {
    color: #d14d72;
    margin-bottom: 30px;
    text-shadow: 2px 2px 4px rgba(209, 77, 114, 0.2);
}

@keyframes float-heart {
    0% { transform: translateY(0) rotate(0deg); opacity: 0; }
    20% { opacity: 0.8; }
    100% { transform: translateY(-100px) rotate(20deg); opacity: 0; }
}

.heart {
    position: fixed;
    color: #d14d72;
    font-size: 20px;
    animation: float-heart 10s ease-in infinite;
    z-index: -1;
    opacity: 0;
}

.container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    max-width: 1200px;
    margin: 0 auto;
}

.card {
    width: 200px;
    height: 200px;
    perspective: 1000px;
    margin: 10px;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.8s;
    transform-style: preserve-3d;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    border-radius: 10px;
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 15px;
    box-sizing: border-box;
}

.card-front {
    background-color: #ffc0cb;
    color: #333;
}

.card-back {
    background-color: #ffccd5;
    color: #333;
    transform: rotateY(180deg);
    overflow-y: auto;
}

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

.locked {
    background-color: #e6e6e6;
    color: #666;
}

.countdown {
    font-size: 14px;
    margin-top: 10px;
    color: #666;
}

.card-number {
    position: absolute;
    top: 10px;
    left: 10px;
    background-color: #d14d72;
    color: white;
    width: 25px;
    height: 25px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}

footer {
    margin-top: 30px;
    color: #666;
    font-size: 14px;
}