:root {
    --bg-color: #0d1117;
    --panel-bg: rgba(22, 27, 34, 0.8);
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent: #10b981;
    --accent-hover: #059669;
    --error: #f85149;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
}

.container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

.sidebar {
    width: 350px;
    background: var(--panel-bg);
    backdrop-filter: blur(10px);
    border-right: 1px solid var(--border-color);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    overflow-y: auto;
    box-shadow: 4px 0 15px rgba(0,0,0,0.5);
    z-index: 10;
}

.header h1 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.header p {
    font-size: 13px;
    color: var(--text-secondary);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

input[type="text"] {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 10px 12px;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.2s;
    outline: none;
}

input[type="text"]:focus {
    border-color: var(--accent);
}

input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 100%;
    height: 40px;
    border-radius: 6px;
    cursor: pointer;
    background: var(--bg-color);
    padding: 4px;
}

input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 4px;
}

input[type="range"] {
    accent-color: var(--accent);
    width: 100%;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 400;
    font-size: 13px;
    cursor: pointer;
    margin-top: 4px;
}

.btn {
    padding: 12px 16px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.primary-btn {
    background-color: var(--accent);
    color: #fff;
    margin-top: 10px;
}

.primary-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.primary-btn:active {
    transform: translateY(1px);
}

.error-box {
    background-color: rgba(248, 81, 73, 0.1);
    border: 1px solid rgba(248, 81, 73, 0.4);
    color: var(--error);
    padding: 10px;
    border-radius: 6px;
    font-size: 13px;
    margin-top: 5px;
}

.hidden {
    display: none;
}

.canvas-container {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    background: radial-gradient(circle at center, #1b2028 0%, #0d1117 100%);
    position: relative;
}

canvas {
    background: transparent;
    border-radius: 8px;
    /* Box shadow used just to show bounds visually in editor, output PNG is strictly the drawing */
    box-shadow: 0 0 50px rgba(0,0,0,0.5);
    transition: transform 0.2s ease-out;
}