:root {
    --bg-color: #050510;
    --text-color: #00ffff;
    --text-glow: 0 0 10px rgba(0, 255, 255, 0.7);
    --warning-color: #ff3333;
    --warning-glow: 0 0 15px rgba(255, 51, 51, 0.8);
    --canvas-border: rgba(0, 255, 255, 0.3);
    --font-heading: 'Orbitron', sans-serif;
    --font-hud: 'Share Tech Mono', monospace;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
}

body {
    background: radial-gradient(circle at center, #0b0b24 0%, #03030b 100%);
    color: var(--text-color);
    font-family: var(--font-hud);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
    padding: 10px;
}

#game-container {
    position: relative;
    width: 95vw;
    max-width: 800px;
    max-height: 85vh;
    aspect-ratio: 16 / 9;
    box-shadow: 0 0 35px rgba(0, 255, 255, 0.15), 0 0 100px rgba(0, 255, 255, 0.05);
    border: 2px solid var(--canvas-border);
    border-radius: 12px;
    overflow: hidden;
    background-color: #000;
    touch-action: none;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    background-color: #000;
    touch-action: none;
}

#hud {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: clamp(8px, 2vw, 15px) clamp(10px, 2.5vw, 20px);
    pointer-events: none;
    z-index: 10;
}

.hud-item {
    font-size: clamp(12px, 2vw, 18px);
    font-weight: bold;
    text-shadow: var(--text-glow);
    letter-spacing: 1px;
}

#multiplierValue {
    color: #ffaa00;
    text-shadow: 0 0 10px rgba(255, 170, 0, 0.8);
    transition: opacity 0.3s;
}

.hidden {
    display: none !important;
}

/* Game Over Modal */
#gameOverModal {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(5, 5, 16, 0.9);
    backdrop-filter: blur(6px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 20;
    padding: 20px;
}

#gameOverModal h1 {
    font-family: var(--font-heading);
    font-size: clamp(24px, 5.5vw, 42px);
    color: var(--warning-color);
    text-shadow: var(--warning-glow);
    margin-bottom: clamp(10px, 2.5vw, 20px);
    letter-spacing: clamp(2px, 0.5vw, 4px);
    text-align: center;
    font-weight: 900;
}

#gameOverModal p {
    font-size: clamp(14px, 3vw, 24px);
    margin-bottom: clamp(20px, 5vw, 40px);
    text-shadow: var(--text-glow);
    text-align: center;
}

#restartButton {
    background: transparent;
    color: var(--text-color);
    border: 2px solid var(--text-color);
    padding: clamp(10px, 2vw, 15px) clamp(20px, 4vw, 35px);
    font-size: clamp(14px, 2.5vw, 20px);
    font-family: var(--font-heading);
    font-weight: bold;
    cursor: pointer;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 2px;
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3), inset 0 0 10px rgba(0, 255, 255, 0.1);
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

#restartButton:hover {
    background: var(--text-color);
    color: var(--bg-color);
    box-shadow: 0 0 25px rgba(0, 255, 255, 0.7);
    transform: translateY(-2px);
}

#restartButton:active {
    transform: scale(0.95);
}

/* Instructions footer */
#instructions {
    margin-top: clamp(10px, 2vh, 20px);
    font-family: var(--font-hud);
    font-size: clamp(10px, 1.8vw, 14px);
    color: rgba(0, 255, 255, 0.5);
    text-shadow: 0 0 5px rgba(0, 255, 255, 0.2);
    display: flex;
    gap: 10px;
    align-items: center;
    letter-spacing: 1.5px;
    pointer-events: none;
    animation: instructionsPulse 2s infinite alternate ease-in-out;
}

#instructions .separator {
    color: rgba(0, 255, 255, 0.3);
}

@keyframes instructionsPulse {
    0% {
        opacity: 0.4;
    }
    100% {
        opacity: 0.85;
    }
}