:root {
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --accent-color: #4fc3f7;
    --border-color: #333;
}

body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; 
    background: var(--bg-color); 
    color: var(--text-color); 
    margin: 0;
    padding: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    box-sizing: border-box;
}

h1 {
    margin-top: 0;
    font-size: 2rem;
    text-align: center;
}

/* Responsive layout container for the canvas and labels */
.viewer-container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    grid-template-rows: auto 1fr auto;
    gap: 8px;
    align-items: center;
    justify-items: center;
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
    background: var(--card-bg);
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.5);
}

/* Canvas Wrapper maintains aspect ratio and scales */
.canvas-wrapper {
    grid-column: 2;
    grid-row: 2;
    width: 100%;
    position: relative;
    aspect-ratio: 400 / 300;
}

canvas { 
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 1px solid var(--border-color); 
    background: #000; 
    cursor: grab; 
    border-radius: 4px;
    touch-action: none;
    overscroll-behavior: none;
    -webkit-user-select: none;
    user-select: none;
    pointer-events: auto;
}

canvas:active { cursor: grabbing; }

/* Boundary Label Styles */
.label {
    font-family: monospace;
    font-size: 0.8rem;
    color: #aaa;
    white-space: nowrap;
    pointer-events: none;
}
.label.top    { grid-column: 2; grid-row: 1; }
.label.bottom { grid-column: 2; grid-row: 3; }
.label.left   { grid-column: 1; grid-row: 2; transform: rotate(-90deg); }
.label.right  { grid-column: 3; grid-row: 2; transform: rotate(90deg); }

.controls { 
    margin: 15px 0; 
    color: #aaa; 
    font-size: 0.9rem;
    text-align: center;
}

/* Content and About Section Styles */
.content-area {
    width: 100%;
    max-width: 500px;
    text-align: left;
    line-height: 1.6;
    margin-top: 20px;
}

#about-area {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

#about-area h2 {
    margin-top: 0;
    font-size: 1.3rem;
    color: var(--accent-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 5px;
}

#about-area h3 {
    font-size: 1rem;
    margin-bottom: 5px;
    color: #fff;
}

#about-area a {
    color: var(--accent-color);
    text-decoration: none;
}

#about-area a:hover {
    text-decoration: underline;
}

.iteration-control {
    margin-top: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
}

.iteration-control label {
    font-family: monospace;
    font-size: 0.9rem;
    color: #fff;
}

#iter-val {
    color: var(--accent-color);
    font-weight: bold;
}

.iteration-control input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 80%;
    max-width: 300px;
    height: 8px;
    background: #2a2a2a;
    border-radius: 4px;
    outline: none;
    border: 1px solid var(--border-color);
}

.iteration-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--accent-color);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

.iteration-control input[type="range"]::-moz-range-thumb {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--accent-color);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

.scale-container {
    width: 100%;
    max-width: 400px; /* Matches canvas width */
    margin: 10px auto 0 auto;
    background: #1e1e1e;
    padding: 10px;
    border-radius: 6px;
    border: 1px solid #333;
    box-sizing: border-box;
}

.zoom-stats {
    display: flex;
    justify-content: space-between;
    font-family: monospace;
    font-size: 0.85rem;
    color: #4fc3f7;
    margin-bottom: 8px;
}

.scale-ruler-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

/* Creates a classic mapping scale bar with ticked ends */
.scale-ruler {
    width: 50%; /* Represents exactly half the canvas width */
    height: 6px;
    border: 2px solid #aaa;
    border-top: none; /* Leaves ticks on the left and right */
    box-sizing: border-box;
}

.scale-label {
    font-family: monospace;
    font-size: 0.8rem;
    color: #aaa;
    margin-top: 4px;
}

@media (max-width: 600px) {
    body {
        padding: 8px;
    }

    /* Change the container layout into a tight vertical stack */
    .viewer-container {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr auto auto;
        gap: 4px;
        padding: 8px; /* Extra thin padding gives maximum width to canvas */
    }

    /* Force the canvas wrapper to grab full container width */
    .canvas-wrapper {
        grid-column: 1;
        grid-row: 3;
        width: 100%;
    }

    /* Re-stack the labels sequentially from top to bottom so they don't crowd the sides */
    .label.top    { grid-column: 1; grid-row: 1; }
    .label.left   { grid-column: 1; grid-row: 2; transform: none; }
    .label.right  { grid-column: 1; grid-row: 4; transform: none; }
    .label.bottom { grid-column: 1; grid-row: 5; }

    .label {
        font-size: 0.75rem;
        margin: 2px 0;
    }
}