:root {
    --bg-dark: #0a0a16;
    --panel-bg: rgba(20, 20, 45, 0.7);
    --border-neon: #390099;
    --neon-blue: #00f0ff;
    --neon-pink: #ff007f;
    --neon-green: #39ff14;
    --neon-yellow: #ffea00;
    --text-color: #f0f0ff;
    --shadow-glow: 0 0 15px rgba(0, 240, 255, 0.4);
    --font-arcade: 'Press Start 2P', monospace;
    --font-sans: 'Outfit', sans-serif;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-color);
    font-family: var(--font-sans);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(57, 0, 153, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(0, 240, 255, 0.1) 0%, transparent 50%);
}

#game-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    max-width: 900px;
    padding: 20px;
}

header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding: 15px 25px;
    background: var(--panel-bg);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.game-title {
    font-family: var(--font-arcade);
    font-size: 1.5rem;
    color: var(--neon-yellow);
    text-shadow: 0 0 10px rgba(255, 234, 0, 0.6);
    letter-spacing: 2px;
}

.game-title span {
    color: var(--neon-blue);
    text-shadow: 0 0 10px rgba(0, 240, 255, 0.6);
}

.stats-container {
    display: flex;
    gap: 15px;
    align-items: center;
}

.stat-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    padding: 5px 12px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.15);
    min-width: 80px;
}

.stat-label {
    font-size: 0.6rem;
    font-family: var(--font-arcade);
    color: rgba(240, 240, 255, 0.6);
    margin-bottom: 4px;
}

.stat-value {
    font-family: var(--font-arcade);
    font-size: 1.2rem;
    color: var(--neon-green);
    text-shadow: 0 0 8px rgba(57, 255, 20, 0.5);
}

.speed-dropdown {
    background: #14142d;
    color: var(--text-color);
    border: 1px solid var(--neon-blue);
    border-radius: 4px;
    padding: 2px 8px;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    outline: none;
    transition: all 0.2s ease;
}

.speed-dropdown:focus {
    box-shadow: 0 0 8px var(--neon-blue);
}

.speed-dropdown.large {
    padding: 8px 16px;
    font-size: 1rem;
    border-radius: 8px;
    margin-top: 5px;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--text-color);
    transition: transform 0.2s ease;
    outline: none;
}

.icon-btn:hover {
    transform: scale(1.2);
}

/* Static Equation Panel */
#equation-panel {
    width: 100%;
    background: rgba(0, 240, 255, 0.08);
    border: 2px solid var(--neon-blue);
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.2);
    border-radius: 12px;
    padding: 12px;
    text-align: center;
    margin-bottom: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
}

#equation-panel .panel-label {
    font-family: var(--font-arcade);
    font-size: 0.9rem;
    color: rgba(240, 240, 255, 0.7);
}

#equation-panel .panel-value {
    font-family: var(--font-arcade);
    font-size: 1.8rem;
    color: var(--neon-blue);
    text-shadow: 0 0 10px rgba(0, 240, 255, 0.8);
    letter-spacing: 2px;
}

main {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
    margin-bottom: 15px;
}

.canvas-wrapper {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    border: 4px solid var(--border-neon);
    box-shadow: 0 0 25px rgba(57, 0, 153, 0.5), inset 0 0 20px rgba(0, 0, 0, 0.8);
    background: #020208;
    max-width: 100%;
}

canvas {
    display: block;
    max-width: 100%;
    height: auto;
}

/* Overlays (Start & Game Over) */
.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(5, 5, 15, 0.85);
    backdrop-filter: blur(8px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10;
    transition: opacity 0.3s ease;
}

.overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.overlay-content {
    text-align: center;
    padding: 30px;
    max-width: 500px;
}

.overlay h2 {
    font-family: var(--font-arcade);
    font-size: 1.6rem;
    color: var(--neon-pink);
    text-shadow: 0 0 10px rgba(255, 0, 127, 0.6);
    margin-bottom: 20px;
}

.overlay p {
    font-size: 1.1rem;
    line-height: 1.6;
    margin-bottom: 20px;
    color: rgba(240, 240, 255, 0.8);
}

.settings-group {
    margin-bottom: 25px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.settings-group label {
    font-weight: 600;
    color: var(--neon-yellow);
}

.controls-guide {
    margin-bottom: 25px;
    font-size: 0.9rem;
    color: var(--neon-blue);
}

.controls-guide strong {
    border: 1px solid var(--neon-blue);
    padding: 3px 8px;
    border-radius: 4px;
    box-shadow: 0 0 5px rgba(0, 240, 255, 0.3);
}

button#start-btn, button#restart-btn {
    font-family: var(--font-arcade);
    background: transparent;
    color: var(--neon-green);
    border: 2px solid var(--neon-green);
    padding: 15px 30px;
    font-size: 1rem;
    border-radius: 30px;
    cursor: pointer;
    box-shadow: 0 0 15px rgba(57, 255, 20, 0.2);
    transition: all 0.3s ease;
}

button#start-btn:hover, button#restart-btn:hover {
    background: var(--neon-green);
    color: var(--bg-dark);
    box-shadow: 0 0 25px rgba(57, 255, 20, 0.6);
    transform: translateY(-3px);
}

.final-score {
    font-family: var(--font-arcade);
    font-size: 3rem;
    color: var(--neon-yellow);
    text-shadow: 0 0 15px rgba(255, 234, 0, 0.6);
    margin-bottom: 30px;
}

/* Mobile Controls */
.mobile-controls {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    margin-top: 15px;
    width: 100%;
}

.horizontal-ctrls {
    display: flex;
    gap: 20px;
}

.ctrl-btn {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    color: var(--text-color);
    font-size: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    touch-action: manipulation;
    transition: all 0.1s ease;
}

.ctrl-btn:active {
    background: var(--neon-blue);
    border-color: var(--neon-blue);
    box-shadow: 0 0 15px var(--neon-blue);
    transform: scale(0.9);
}

footer {
    text-align: center;
    font-size: 0.85rem;
    color: rgba(240, 240, 255, 0.5);
    margin-top: 15px;
}

/* Show mobile controls on touch devices */
@media (max-width: 768px) {
    .mobile-controls {
        display: flex;
    }
    
    .overlay h2 {
        font-size: 1.2rem;
    }
    
    .overlay p {
        font-size: 0.9rem;
    }
}