:root {
    --primary-color: #4CAF50;
    --secondary-color: #2E7D32;
    --background-color: #121212;
    --text-color: #FFFFFF;
    --grid-color: #1E1E1E;
    --grid-line-color: #2D2D2D;
    --snake-color: #4CAF50;
    --snake-head-color: #388E3C;
    --food-color: #FF5252;
    --button-color: #333;
    --button-hover-color: #444;
    --overlay-bg: rgba(0, 0, 0, 0.8);
    --score-color: #FFFFFF;
}

.light-theme {
    --primary-color: #4CAF50;
    --secondary-color: #2E7D32;
    --background-color: #F5F5F5;
    --text-color: #212121;
    --grid-color: #FFFFFF;
    --grid-line-color: #E0E0E0;
    --snake-color: #4CAF50;
    --snake-head-color: #388E3C;
    --food-color: #FF5252;
    --button-color: #E0E0E0;
    --button-hover-color: #BDBDBD;
    --overlay-bg: rgba(255, 255, 255, 0.9);
    --score-color: #212121;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.game-container {
    width: 100%;
    max-width: 500px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.header h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    text-align: center;
}

.score-display {
    display: flex;
    justify-content: space-between;
    width: 100%;
    background-color: var(--button-color);
    padding: 10px 20px;
    border-radius: 10px;
    font-size: 1.1rem;
}

.score, .high-score {
    color: var(--score-color);
}

.game-area {
    position: relative;
    width: 100%;
    aspect-ratio: 1/1;
    background-color: var(--grid-color);
    border: 2px solid var(--primary-color);
    border-radius: 10px;
    overflow: hidden;
}

.grid {
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    grid-template-rows: repeat(20, 1fr);
    width: 100%;
    height: 100%;
    gap: 1px;
    background-color: var(--grid-line-color);
}

.grid-cell {
    background-color: var(--grid-color);
}

.snake {
    background-color: var(--snake-color);
    border-radius: 2px;
}

.snake-head {
    background-color: var(--snake-head-color);
    border-radius: 4px;
}

.food {
    background-color: var(--food-color);
    border-radius: 50%;
    animation: pulse 0.5s infinite alternate;
}

@keyframes pulse {
    from {
        transform: scale(0.9);
    }
    to {
        transform: scale(1.1);
    }
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--overlay-bg);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10;
    flex-direction: column;
}

.overlay-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    padding: 30px;
    background-color: var(--background-color);
    border-radius: 10px;
    max-width: 80%;
    text-align: center;
}

.overlay-content h2 {
    color: var(--primary-color);
    font-size: 2rem;
}

.overlay-content p {
    font-size: 1.2rem;
}

button {
    background-color: var(--button-color);
    color: var(--text-color);
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    min-width: 150px;
    text-align: center;
}

button:hover {
    background-color: var(--button-hover-color);
    transform: scale(1.05);
}

button:active {
    transform: scale(0.95);
}

.controls {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.controls button {
    padding: 15px;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.mobile-controls {
    display: none;
}

.d-pad {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.d-pad-row {
    display: flex;
    justify-content: center;
    gap: 5px;
}

.d-pad-btn {
    width: 60px;
    height: 60px;
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
}

.settings-panel {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    background-color: var(--background-color);
    border: 2px solid var(--primary-color);
    border-radius: 15px;
    padding: 20px;
    width: 90%;
    max-width: 400px;
    z-index: 100;
    opacity: 0;
    transition: transform 0.3s, opacity 0.3s;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.settings-panel.active {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
}

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

.settings-header h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
}

.settings-header button {
    width: 40px;
    height: 40px;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.settings-content {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.setting {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.setting label {
    font-size: 1.1rem;
}

select {
    background-color: var(--button-color);
    color: var(--text-color);
    border: none;
    padding: 8px 12px;
    border-radius: 5px;
    font-size: 1rem;
}

.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

@media (max-width: 768px) {
    .mobile-controls {
        display: block;
    }

    .controls {
        justify-content: space-between;
    }

    .game-container {
        padding: 10px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .score-display {
        font-size: 0.9rem;
    }
}