/* Base styles */
body {
    font-family: 'Inter', sans-serif;
    font-size: 16px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Flashcard container */
.flashcard {
    perspective: 1000px;
    margin: 10px;
    display: inline-block;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.flashcard:hover {
    transform: translateY(-2px);
}

/* Card inner container */
.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
    will-change: transform;
}

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

/* Card faces */
.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    flex-direction: column;
    overflow: hidden;
    transition: opacity 0.3s ease;
}

.card-front {
    background-color: #f9fafb;
    color: #1f2937;
}

.card-back {
    background-color: #3b82f6;
    color: white;
    transform: rotateY(180deg);
}

/* Card images */
.card-front img,
.card-back img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 0.5rem;
    opacity: 0.5;
    z-index: 0;
    transition: opacity 0.3s ease;
}

/* Card text */
.card-front h2,
.card-back h2 {
    word-wrap: break-word;
    overflow: hidden;
    max-height: 3rem;
    line-height: 1.2;
    position: relative;
    z-index: 1;
    text-align: center;
    margin: 0.5rem 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.card-front p,
.card-back p {
    position: relative;
    z-index: 1;
    text-align: center;
    margin: 0.5rem 0;
    padding: 0 1rem;
}

/* Flip states */
.flashcard.flipped .card-inner .card-front {
    opacity: 0;
}

.flashcard.flipped .card-inner .card-back {
    opacity: 1;
}

/* Focus states for accessibility */
.flashcard:focus {
    outline: 2px solid #3b82f6;
    outline-offset: 2px;
}

/* Loading animation */
@keyframes cardLoad {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.flashcard {
    animation: cardLoad 0.3s ease-out forwards;
}

/* Responsive adjustments */
@media (max-width: 640px) {
    .flashcard {
        width: 100% !important;
        height: 180px !important;
    }
    
    .card-front h2,
    .card-back h2 {
        font-size: 1.1rem;
    }
    
    .card-front p,
    .card-back p {
        font-size: 0.9rem;
    }
}

/* Card number */
.card-number {
    position: absolute;
    bottom: 8px;
    left: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    color: rgba(0, 0, 0, 0.6);
    z-index: 2;
    background-color: rgba(255, 255, 255, 0.8);
    padding: 2px 6px;
    border-radius: 4px;
}

.card-back .card-number {
    color: rgba(255, 255, 255, 0.8);
    background-color: rgba(0, 0, 0, 0.4);
}