:root {
    --bg-color: #faf8ef;
    --grid-color: #bbada0;
    --empty-cell-color: rgba(238, 228, 218, 0.35);
    --text-color: #776e65;
    --text-light: #f9f6f2;
    --font-family: 'Outfit', sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 500px;
    padding: 20px;
    box-sizing: border-box;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.title-container h1 {
    font-size: 80px;
    font-weight: 800;
    margin: 0;
    line-height: 1;
}

.title-container p {
    margin: 5px 0 0;
    font-size: 18px;
}

.score-container {
    display: flex;
    gap: 10px;
}

.score-box {
    background: #bbada0;
    padding: 10px 20px;
    border-radius: 6px;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 50px;
}

.score-box .label {
    color: #eee4da;
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
}

.score-box #score,
.score-box #best-score {
    color: white;
    font-size: 25px;
    font-weight: 700;
}

.game-controls {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
}

.home-btn,
#new-game-btn,
#try-again-btn {
    background: #8f7a66;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    font-weight: 700;
    font-size: 18px;
    cursor: pointer;
    text-decoration: none;
    font-family: var(--font-family);
    transition: background 0.2s;
}

.home-btn:hover,
#new-game-btn:hover,
#try-again-btn:hover {
    background: #7f6a56;
}

.game-container {
    position: relative;
    width: 100%;
    padding-bottom: 100%;
    /* Aspect ratio 1:1 */
    background: var(--grid-color);
    border-radius: 10px;
    touch-action: none;
}

.grid-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 15px;
    box-sizing: border-box;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 15px;
}

.grid-cell {
    background: var(--empty-cell-color);
    border-radius: 6px;
}

.tile-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 15px;
    box-sizing: border-box;
    pointer-events: none;
    /* Let clicks pass through */
}

.tile {
    position: absolute;
    width: calc(25% - 11.25px);
    /* (100% - 3 * 15px gap) / 4 */
    height: calc(25% - 11.25px);
    border-radius: 6px;
    background: #eee4da;
    color: #776e65;
    font-weight: 700;
    font-size: 35px;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: transform 0.1s ease-in-out, background 0.1s;
    z-index: 10;
}

/* Tile Colors */
.tile-2 {
    background: #eee4da;
}

.tile-4 {
    background: #ede0c8;
}

.tile-8 {
    background: #f2b179;
    color: #f9f6f2;
}

.tile-16 {
    background: #f59563;
    color: #f9f6f2;
}

.tile-32 {
    background: #f67c5f;
    color: #f9f6f2;
}

.tile-64 {
    background: #f65e3b;
    color: #f9f6f2;
}

.tile-128 {
    background: #edcf72;
    color: #f9f6f2;
    font-size: 30px;
}

.tile-256 {
    background: #edcc61;
    color: #f9f6f2;
    font-size: 30px;
}

.tile-512 {
    background: #edc850;
    color: #f9f6f2;
    font-size: 30px;
}

.tile-1024 {
    background: #edc53f;
    color: #f9f6f2;
    font-size: 25px;
}

.tile-2048 {
    background: #edc22e;
    color: #f9f6f2;
    font-size: 25px;
    box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.4);
}

.tile-new {
    animation: appear 0.2s;
}

.tile-merged {
    animation: pop 0.2s;
}

@keyframes appear {
    0% {
        opacity: 0;
        transform: scale(0);
    }

    100% {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pop {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.2);
    }

    100% {
        transform: scale(1);
    }
}

.game-over-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(238, 228, 218, 0.73);
    z-index: 100;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    animation: fade-in 0.8s;
}

.game-over-overlay p {
    font-size: 60px;
    font-weight: 700;
    color: #776e65;
    margin-bottom: 20px;
}

.hidden {
    display: none;
}

@keyframes fade-in {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

@media (max-width: 520px) {
    .container {
        padding: 10px;
    }

    .title-container h1 {
        font-size: 50px;
    }

    .title-container p {
        font-size: 14px;
    }

    .grid-container,
    .tile-container {
        padding: 10px;
        gap: 10px;
    }

    .tile {
        width: calc(25% - 7.5px);
        height: calc(25% - 7.5px);
        font-size: 25px;
    }
}