body {
    background: #000000;
    min-height: 100vh;
    padding-top: 70px;
}

.game-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

.game-header {
    text-align: center;
    margin-bottom: 30px;
}

.game-title {
    color: #00d4ff;
    font-size: 4em;
    font-weight: bold;
    text-shadow: 0 0 20px rgba(0, 212, 255, 0.5);
    margin-bottom: 10px;
}

.game-subtitle {
    color: #ffffff;
    font-size: 1.2em;
    opacity: 0.8;
}

.game-panel {
    background: linear-gradient(135deg, #16213e 0%, #0f3460 100%);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 212, 255, 0.2);
}

.score-container {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 25px;
}

.score-box {
    background: rgba(0, 0, 0, 0.3);
    padding: 15px 30px;
    border-radius: 10px;
    text-align: center;
    min-width: 120px;
}

.score-label {
    color: #00d4ff;
    font-size: 0.9em;
    font-weight: bold;
    text-transform: uppercase;
    margin-bottom: 5px;
}

.score-value {
    color: #ffffff;
    font-size: 2em;
    font-weight: bold;
}

.game-board-container {
    position: relative;
    margin-bottom: 25px;
    display: flex;
    justify-content: center;
}

.game-board {
    background: #0f0f1e;
    border: 3px solid #00d4ff;
    border-radius: 15px;
    padding: 10px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
    width: 390px;
    height: 390px;
    position: relative;
}

.grid-cell {
    width: 85px;
    height: 85px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.tile {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2em;
    font-weight: bold;
    border-radius: 10px;
    transition: all 0.1s ease-in-out;
    animation: appear 0.2s ease;
    z-index: 10;
}

.tile-2 { background: linear-gradient(135deg, #00d4ff 0%, #0099ff 100%); color: #0f0f1e; }
.tile-4 { background: linear-gradient(135deg, #0099ff 0%, #0066cc 100%); color: #ffffff; }
.tile-8 { background: linear-gradient(135deg, #ff9900 0%, #ff6600 100%); color: #ffffff; }
.tile-16 { background: linear-gradient(135deg, #ff6600 0%, #ff3300 100%); color: #ffffff; }
.tile-32 { background: linear-gradient(135deg, #ff3366 0%, #ff0044 100%); color: #ffffff; }
.tile-64 { background: linear-gradient(135deg, #ff0044 0%, #cc0033 100%); color: #ffffff; }
.tile-128 { background: linear-gradient(135deg, #ffcc00 0%, #ff9900 100%); color: #ffffff; font-size: 1.8em; }
.tile-256 { background: linear-gradient(135deg, #ffcc00 0%, #ffaa00 100%); color: #ffffff; font-size: 1.8em; }
.tile-512 { background: linear-gradient(135deg, #ffaa00 0%, #ff8800 100%); color: #ffffff; font-size: 1.8em; }
.tile-1024 { background: linear-gradient(135deg, #00ff88 0%, #00cc66 100%); color: #ffffff; font-size: 1.5em; }
.tile-2048 { background: linear-gradient(135deg, #9966ff 0%, #6633ff 100%); color: #ffffff; font-size: 1.5em; animation: glow 1s infinite; }

.tile-super { background: linear-gradient(135deg, #ff00ff 0%, #cc00cc 100%); color: #ffffff; font-size: 1.3em; }

.game-message {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 15, 30, 0.95);
    border-radius: 15px;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.game-message.active {
    display: flex;
}

.message-content {
    text-align: center;
}

#message-text {
    color: #00d4ff;
    font-size: 3em;
    font-weight: bold;
    margin-bottom: 20px;
    text-shadow: 0 0 20px rgba(0, 212, 255, 0.8);
}

.game-controls {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 20px;
}

.game-controls .btn {
    padding: 12px 30px;
    font-size: 1.1em;
    font-weight: bold;
    border-radius: 25px;
    border: none;
    transition: all 0.3s ease;
}

.game-controls .btn-primary {
    background: linear-gradient(135deg, #00d4ff 0%, #0099ff 100%);
    color: #0f0f1e;
    box-shadow: 0 5px 15px rgba(0, 212, 255, 0.3);
}

.game-controls .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 7px 20px rgba(0, 212, 255, 0.5);
}

.game-controls .btn-info {
    background: linear-gradient(135deg, #9966ff 0%, #6633ff 100%);
    color: #ffffff;
    box-shadow: 0 5px 15px rgba(153, 102, 255, 0.3);
}

.game-controls .btn-info:hover {
    transform: translateY(-2px);
    box-shadow: 0 7px 20px rgba(153, 102, 255, 0.5);
}

#scroll-lock-btn.btn-warning {
    background: linear-gradient(135deg, #ffcc00 0%, #ff9900 100%);
    color: #0f0f1e;
}

#scroll-lock-btn.btn-danger {
    background: linear-gradient(135deg, #ff3366 0%, #cc0033 100%);
    color: #ffffff;
}

.instructions {
    background: rgba(0, 0, 0, 0.3);
    padding: 20px;
    border-radius: 10px;
}

.instructions h4 {
    color: #00d4ff;
    margin-bottom: 15px;
    text-align: center;
}

.control-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.control-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #ffffff;
}

.key {
    background: linear-gradient(135deg, #00d4ff 0%, #0099ff 100%);
    color: #0f0f1e;
    padding: 8px 15px;
    border-radius: 5px;
    font-weight: bold;
    min-width: 50px;
    text-align: center;
    display: inline-block;
}

@keyframes appear {
    from {
        transform: scale(0);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

@keyframes glow {
    0%, 100% {
        box-shadow: 0 0 20px rgba(153, 102, 255, 0.8);
    }
    50% {
        box-shadow: 0 0 40px rgba(153, 102, 255, 1);
    }
}

@media (max-width: 768px) {
    .game-title {
        font-size: 3em;
    }

    .tile {
        font-size: 1.5em;
    }

    .tile-128, .tile-256, .tile-512 {
        font-size: 1.3em;
    }

    .tile-1024, .tile-2048 {
        font-size: 1.1em;
    }

    .tile-super {
        font-size: 1em;
    }

    #message-text {
        font-size: 2em;
    }

    .control-grid {
        grid-template-columns: 1fr;
    }
}