:root {
    --bg-color: #050505;
    --grid-color: #1a1a1a;
    --snake-color: #00ff9d;
    --snake-glow: 0 0 10px #00ff9d, 0 0 20px #00ff9d;
    --food-color: #ff0055;
    --food-glow: 0 0 10px #ff0055, 0 0 20px #ff0055;
    --wall-color: #00d9ff;
    --wall-glow: 0 0 5px #00d9ff;
    --text-color: #ffffff;
    --ui-bg: rgba(0, 0, 0, 0.8);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Rajdhani', sans-serif;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

#game-container {
    position: relative;
    box-shadow: 0 0 50px rgba(0, 255, 157, 0.1);
    border: 2px solid #333;
}

canvas {
    display: block;
    background-color: var(--bg-color);
    /* Grid pattern effect */
    background-image:
        linear-gradient(var(--grid-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
    background-size: 20px 20px;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#score-board {
    position: absolute;
    top: 20px;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 0 40px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.5rem;
    text-shadow: 0 0 10px var(--snake-color);
    z-index: 10;
    transition: opacity 0.3s ease;
}

/* Hide score board when start screen OR game over screen is active */
#ui-layer:has(#start-screen.active) #score-board,
#ui-layer:has(#game-over-screen.active) #score-board {
    display: none;
}

#start-screen,
#game-over-screen {
    background: var(--ui-bg);
    padding: 40px 60px;
    border: 1px solid var(--snake-color);
    box-shadow: 0 0 20px rgba(0, 255, 157, 0.2);
    text-align: center;
    pointer-events: auto;
    backdrop-filter: blur(5px);
    transform: scale(1);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.9) !important;
}

.active {
    opacity: 1;
    pointer-events: auto;
}

h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 4rem;
    margin-bottom: 10px;
    background: linear-gradient(to bottom, #fff, #aaa);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 20px rgba(255, 255, 255, 0.5);
}

.subtitle {
    font-size: 1.5rem;
    letter-spacing: 5px;
    color: var(--snake-color);
    margin-bottom: 40px;
    text-shadow: 0 0 10px var(--snake-color);
}

button {
    background: transparent;
    border: 2px solid var(--snake-color);
    color: var(--snake-color);
    padding: 15px 40px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 2px;
}

button:hover {
    background: var(--snake-color);
    color: #000;
    box-shadow: 0 0 20px var(--snake-color);
}

.controls {
    margin-top: 20px;
    font-size: 0.9rem;
    color: #888;
}

.footer {
    margin-top: 15px;
    font-size: 0.75rem;
    color: #666;
    line-height: 1.4;
}

.footer a {
    color: #888;
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer a:hover {
    color: var(--snake-color);
}

.splash-logo {
    display: block;
    width: 512px;
    /* 1/2 of 1024px */
    height: auto;
    margin: 0 auto 20px auto;
    border: 2px solid var(--snake-color);
    box-shadow: 0 0 15px var(--snake-color);
    border-radius: 8px;
}