:root {
    --bg-color: #0f172a;
    --container-bg: rgba(30, 41, 59, 0.6);
    --border-color: rgba(255, 255, 255, 0.1);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #10b981;
    --accent-glow: rgba(16, 185, 129, 0.4);
    --danger-color: #ef4444;
    --snake-head: #34d399;
    --snake-body: #10b981;
    --food-color: #f43f5e;
}

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

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #020617 0%, #0f172a 100%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.game-container {
    background: var(--container-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 95vw;
}

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

h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.2rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.highlight {
    color: var(--accent-color);
    text-shadow: 0 0 15px var(--accent-glow);
}

.score-board {
    display: flex;
    gap: 1rem;
}

.score-box {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 0.6rem 1.2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 100px;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
}

.score-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 600;
    letter-spacing: 1.5px;
    margin-bottom: 2px;
}

#score, #high-score {
    font-family: 'Outfit', sans-serif;
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
}

.canvas-wrapper {
    position: relative;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8), 0 0 0 1px var(--border-color);
    background-color: #020617;
    width: 500px;
    height: 500px;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(2, 6, 23, 0.85);
    backdrop-filter: blur(8px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.overlay.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(1.05);
}

#overlay-title {
    font-family: 'Outfit', sans-serif;
    font-size: 3.5rem;
    margin-bottom: 0.5rem;
    color: var(--danger-color);
    text-shadow: 0 0 20px rgba(239, 68, 68, 0.5);
    font-weight: 800;
}

.overlay p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-weight: 500;
}

#final-score {
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.5rem;
}

.btn {
    background: linear-gradient(135deg, var(--accent-color) 0%, #059669 100%);
    color: white;
    border: none;
    border-radius: 50px;
    padding: 1rem 3rem;
    font-family: 'Inter', sans-serif;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px var(--accent-glow);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px var(--accent-glow);
    filter: brightness(1.15);
}

.btn:active {
    transform: translateY(1px);
}

.controls-hint {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: 0.5rem;
}

.controls-hint strong {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    font-weight: 500;
}