:root {
    --bg-app: #0f1012;
    --bg-sidebar: #1b1d21;
    --border-color: #333;
    --accent: #4ade80; /* Green accent */
    --input-bg: #25282e;
}

body {
    background-color: var(--bg-app);
    color: #e0e0e0;
    font-family: 'Inter', sans-serif;
    height: 100vh;
    overflow: hidden;
}

.bg-sidebar { background-color: var(--bg-sidebar); }
.bg-dark-soft { background-color: #151515; }

/* Inputs */
.form-control-dark, .form-select-dark {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: #fff;
    font-size: 0.9rem;
}
.form-control-dark:focus, .form-select-dark:focus {
    background-color: #2a2e35;
    border-color: var(--accent);
    box-shadow: none;
    color: #fff;
}
input[type=range] { accent-color: var(--accent); }
.form-check-input:checked { background-color: var(--accent); border-color: var(--accent); }

/* Upload Boxes */
.upload-box {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: 0.3s;
    background: rgba(255,255,255,0.02);
}
.upload-box:hover { border-color: var(--accent); background: rgba(74, 222, 128, 0.05); }

.upload-box-sm {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    background: var(--input-bg);
    display: flex;
    align-items: center;
}
.upload-box-sm:hover { border-color: #666; }

/* Canvas Area */
.bg-app {
    background-color: #111;
    /* Chess pattern for transparency */
    background-image: 
        linear-gradient(45deg, #1a1a1a 25%, transparent 25%), 
        linear-gradient(-45deg, #1a1a1a 25%, transparent 25%), 
        linear-gradient(45deg, transparent 75%, #1a1a1a 75%), 
        linear-gradient(-45deg, transparent 75%, #1a1a1a 75%);
    background-size: 20px 20px;
    position: relative;
}

.canvas-toolbar {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 10;
    pointer-events: none; /* Let clicks pass through */
}
.canvas-toolbar .form-check {
    pointer-events: auto; /* Catch clicks on the switch */
}

#canvasContainer {
    /* Ensure canvas doesn't overlap header if huge */
    padding-top: 50px !important; 
}

canvas {
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    background: transparent;
    /* Important for dragging guides accurately */
    touch-action: none; 
}