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

html {
    height: 100%;
}

body {
    height: 100%;
    background-color: var(--bs-body-bg);
    color: var(--bs-body-color);
    font-family: "Comic Relief", system-ui;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 500px;
    width: 100%;
}

h1 {
    color: var(--bs-body-color);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    font-weight: 700;
}

.lead {
    color: var(--bs-body-color);
    opacity: 0.8;
    margin-bottom: 20px;
}

.score-box {
    background-color: var(--bs-tertiary-bg);
    border: 2px solid var(--bs-border-color);
    border-radius: 10px;
    padding: 15px 25px;
    min-width: 120px;
}

.score-label {
    font-size: 0.9rem;
    color: var(--bs-body-color);
    opacity: 0.7;
    text-transform: uppercase;
    font-weight: 600;
    margin-bottom: 5px;
}

.score-value {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--bs-body-color);
}

#game-container {
    position: relative;
    background-color: var(--bs-tertiary-bg);
    border: 2px solid var(--bs-border-color);
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

#wrapper {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 10px;
    background-color: var(--bs-secondary-bg);
    border-radius: 10px;
    padding: 10px;
    aspect-ratio: 1;
}

.cella {
    aspect-ratio: 1;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: bold;
    background-color: var(--bs-secondary-bg);
    color: var(--bs-body-color);
    transition: all 0.15s ease-in-out;
    font-family: 'Courier New', monospace;
}

.cella:not(.empty) {
    background-color: var(--bs-card-bg);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    animation: appear 0.2s;
    border: 1px solid var(--bs-border-color);
}

@keyframes appear {
    0% {
        transform: scale(0);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

.cella.empty {
    background-color: var(--bs-secondary-bg);
}

/* Colori per i diversi valori - adattati al tema */
[data-bs-theme="dark"] .cella[data-value="2"] { background: #3d3d3d; color: #ffffff; font-size: 1.8rem; }
[data-bs-theme="dark"] .cella[data-value="4"] { background: #4d4d4d; color: #ffffff; font-size: 1.8rem; }
[data-bs-theme="dark"] .cella[data-value="8"] { background: #6d4d2d; color: #ffffff; font-size: 1.8rem; }
[data-bs-theme="dark"] .cella[data-value="16"] { background: #8d5d3d; color: #ffffff; font-size: 1.6rem; }
[data-bs-theme="dark"] .cella[data-value="32"] { background: #ad6d4d; color: #ffffff; font-size: 1.6rem; }
[data-bs-theme="dark"] .cella[data-value="64"] { background: #cd7d5d; color: #ffffff; font-size: 1.6rem; }
[data-bs-theme="dark"] .cella[data-value="128"] { background: #8d7d4d; color: #ffffff; font-size: 1.4rem; box-shadow: 0 0 10px rgba(141, 125, 77, 0.5); }
[data-bs-theme="dark"] .cella[data-value="256"] { background: #9d8d5d; color: #ffffff; font-size: 1.4rem; box-shadow: 0 0 10px rgba(157, 141, 93, 0.5); }
[data-bs-theme="dark"] .cella[data-value="512"] { background: #ad9d6d; color: #ffffff; font-size: 1.4rem; box-shadow: 0 0 10px rgba(173, 157, 109, 0.5); }
[data-bs-theme="dark"] .cella[data-value="1024"] { background: #bdad7d; color: #ffffff; font-size: 1.2rem; box-shadow: 0 0 15px rgba(189, 173, 125, 0.6); }
[data-bs-theme="dark"] .cella[data-value="2048"] { background: #cdbd8d; color: #ffffff; font-size: 1.2rem; box-shadow: 0 0 20px rgba(205, 189, 141, 0.7); animation: win 0.6s; }

[data-bs-theme="light"] .cella[data-value="2"] { background: #eee4da; color: #776e65; font-size: 1.8rem; }
[data-bs-theme="light"] .cella[data-value="4"] { background: #ede0c8; color: #776e65; font-size: 1.8rem; }
[data-bs-theme="light"] .cella[data-value="8"] { background: #f2b179; color: #f9f6f2; font-size: 1.8rem; }
[data-bs-theme="light"] .cella[data-value="16"] { background: #f59563; color: #f9f6f2; font-size: 1.6rem; }
[data-bs-theme="light"] .cella[data-value="32"] { background: #f67c5f; color: #f9f6f2; font-size: 1.6rem; }
[data-bs-theme="light"] .cella[data-value="64"] { background: #f65e3b; color: #f9f6f2; font-size: 1.6rem; }
[data-bs-theme="light"] .cella[data-value="128"] { background: #edcf72; color: #f9f6f2; font-size: 1.4rem; box-shadow: 0 0 10px rgba(237, 207, 114, 0.5); }
[data-bs-theme="light"] .cella[data-value="256"] { background: #edcc61; color: #f9f6f2; font-size: 1.4rem; box-shadow: 0 0 10px rgba(237, 204, 97, 0.5); }
[data-bs-theme="light"] .cella[data-value="512"] { background: #edc850; color: #f9f6f2; font-size: 1.4rem; box-shadow: 0 0 10px rgba(237, 200, 80, 0.5); }
[data-bs-theme="light"] .cella[data-value="1024"] { background: #edc53f; color: #f9f6f2; font-size: 1.2rem; box-shadow: 0 0 15px rgba(237, 197, 63, 0.6); }
[data-bs-theme="light"] .cella[data-value="2048"] { background: #edc22e; color: #f9f6f2; font-size: 1.2rem; box-shadow: 0 0 20px rgba(237, 194, 46, 0.7); animation: win 0.6s; }

@keyframes win {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.cella[data-value="4096"],
.cella[data-value="8192"] { 
    background-color: var(--bs-body-color);
    color: var(--bs-body-bg);
    font-size: 1rem; 
}

#game-over {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(5px);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

#game-over.hidden {
    display: none;
}

.game-over-content {
    text-align: center;
    color: white;
    padding: 30px;
}

.game-over-content h2 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #fff;
}

.game-over-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: rgba(255, 255, 255, 0.9);
}

.btn {
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.btn-info.text-white {
    color: #fff !important; /* Ensure white text for the info button */
}

.text-muted {
    opacity: 0.7;
}

.modal-body kbd {
    display: inline-block;
    padding: 0.2em 0.4em;
    font-size: 0.875em;
    font-weight: 700;
    line-height: 1;
    color: #212529;
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 0.25rem;
    box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.25);
}

/* On-screen controls enhancements */
.text-center.mt-4 .btn-outline-secondary {
    width: 60px; /* Make buttons larger */
    height: 60px;
    font-size: 1.5rem; /* Increase icon size */
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Responsive */
@media (max-width: 576px) {
    .cella {
        font-size: 1.2rem;
    }
    
    .cella[data-value="2"],
    .cella[data-value="4"] { font-size: 1.1rem; }
    
    .cella[data-value="8"],
    .cella[data-value="16"],
    .cella[data-value="32"],
    .cella[data-value="64"] { font-size: 1rem; }
    
    .cella[data-value="128"],
    .cella[data-value="256"],
    .cella[data-value="512"] { font-size: 0.9rem; }
    
    .cella[data-value="1024"],
    .cella[data-value="2048"] { font-size: 0.8rem; }
    
    h1 {
        font-size: 2rem;
    }
}