/* Global Styles */
body {
    background-color: #f4f6f9;
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
    overflow-x: hidden;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

/* Prevent blue highlight on mobile */
* {
    -webkit-tap-highlight-color: transparent;
}

/* Game Wrapper */
.game-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f8f9fa;
}

/* Game Container */
.game-container {
    background-color: #ffffff;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: all 0.3s ease;
}

.game-container:hover {
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    transform: translateY(-5px);
}

/* Game Board */
.game-board {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    justify-content: center;
    padding: 20px;
    perspective: 1000px;
}

/* Card Styles */
.card {
    perspective: 1000px;
    transition: all 0.3s ease;
}

.game-board .card {
    width: 100%;
    height: 90px;
    cursor: pointer;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.game-board .card .card-front,
.game-board .card .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    font-size: 4.5rem;
    transition: transform 0.6s;
}

.game-board .card .card-back {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
    transform: rotateY(0deg);
}

.game-board .card .card-front {
    background: linear-gradient(135deg, #2ecc71, #27ae60);
    color: white;
    transform: rotateY(180deg);
}

.game-board .card.flipped .card-back {
    transform: rotateY(180deg);
}

.game-board .card.flipped .card-front {
    transform: rotateY(0);
}

.game-board .card.matched {
    opacity: 0.7;
    cursor: default;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

/* Buttons */
.btn-danger, .btn-success, .btn-warning {
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.btn-danger i, .btn-success i, .btn-warning i {
    margin-right: 10px;
    position: relative;
    z-index: 2;
}

.btn-danger::before, 
.btn-success::before, 
.btn-warning::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.2);
    transition: all 0.3s ease;
    z-index: 1;
}

.btn-danger:hover::before, 
.btn-success:hover::before, 
.btn-warning:hover::before {
    left: 0;
}

.btn-danger:hover, 
.btn-success:hover, 
.btn-warning:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

/* Leaderboard */
.table thead {
    background: linear-gradient(to right, #3494e6, #ec6ead);
    color: white;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(0, 0, 0, 0.05);
}

.table-hover tbody tr:hover {
    background-color: rgba(52, 152, 219, 0.1);
    transition: background-color 0.3s ease;
}

/* Contact Info */
.contact-info {
    margin-top: 15px;
}

.contact-info a {
    color: #007bff;
    text-decoration: none;
    transition: all 0.3s ease;
    position: relative;
}

.contact-info a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -2px;
    left: 0;
    background-color: #007bff;
    transition: width 0.3s ease;
}

.contact-info a:hover::after {
    width: 100%;
}

/* Upcoming Features */
.bg-info ul li {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    transition: transform 0.3s ease;
}

.bg-info ul li:hover {
    transform: translateX(10px);
}

.bg-info ul li i {
    margin-right: 10px;
    color: rgba(255, 255, 255, 0.7);
    transition: color 0.3s ease;
}

.bg-info ul li:hover i {
    color: rgba(255, 255, 255, 1);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .game-board {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
        padding: 10px;
    }

    .game-board .card {
        height: 90px;
    }

    .game-board .card .card-front,
    .game-board .card .card-back {
        font-size: 2rem;
    }

    .btn-group {
        flex-direction: column;
    }

    .btn-group .btn {
        margin-bottom: 10px;
    }
}

@media (max-width: 576px) {
    .game-board {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .game-board .card {
        height: 70px;
    }

    .game-board .card .card-front,
    .game-board .card .card-back {
        font-size: 2.5rem;
    }

    .container-fluid {
        padding: 10px;
    }
}

/* Difficulty Badge */
#current-difficulty {
    font-size: 0.9rem;
    padding: 0.3rem 0.6rem;
    background: linear-gradient(to right, #ff6b6b, #feca57);
    color: white !important;
}

/* Hover Effects */
.card-header, .card-footer {
    transition: all 0.3s ease;
}

.card-header:hover, .card-footer:hover {
    background-color: rgba(0, 0, 0, 0.1);
}

/* Sound Control Buttons */
#mute-btn, #bg-music-btn {
    transition: all 0.3s ease;
}

#mute-btn:hover, #bg-music-btn:hover {
    transform: scale(1.1);
}

/* Accessibility and Touch Improvements */
@media (max-width: 480px) {
    .btn, .game-board .card {
        min-height: 50px;
        touch-action: manipulation;
    }
}