:root {
    --code-panel-width: 45%;
    --animation-stage-width: 45%;
    --rhythm-color: #ff5722;
}

body {
    font-family: monospace, Courier New, monospace;
    background-color: #1a1a2e;
    color: #00ff00; /* Neon green terminal text */
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

#game-container {
    display: flex;
    justify-content: space-around;
    width: 900px;
    margin-bottom: 20px;
    background-color: #0d0d1b;
    border: 1px solid #333;
    padding: 10px;
}

/* --- Code Panel Styling --- */
#code-panel {
    width: var(--code-panel-width);
    position: relative;
    padding: 10px;
    border-right: 1px dashed #333;
}

#code-display {
    background-color: #000;
    padding: 10px;
    border-radius: 5px;
    line-height: 1.5;
    position: relative;
}

/* Execution Indicator */
#line-indicator {
    position: absolute;
    left: 0;
    width: 100%;
    height: 1.5em; /* Matches line height */
    background-color: rgba(255, 255, 0, 0.3); /* Highlight color */
    z-index: 10;
    transition: top 0.1s linear; /* Smooth line transitions */
    top: 5em; /* Initial position for 'Line 3' */
}

/* --- Animation Stage Styling --- */
#animation-stage {
    width: var(--animation-stage-width);
    height: 300px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

#animated-box {
    width: 50px;
    height: 50px;
    background-color: #00bcd4;
    position: absolute;
    border-radius: 50%;
    will-change: transform; /* Optimization hint */
}

#rhythm-cue {
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--rhythm-color);
    border-radius: 50%;
    opacity: 0;
    transition: opacity 0.1s;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* --- Visual Error Feedback --- */
.flow-error #animated-box {
    /* Example of a visual distortion on error */
    filter: hue-rotate(180deg) blur(2px); 
    transform: scale(1.5) !important; /* Force a jerky visual error */
    transition: all 0.1s;
}