:root {
    --primary-color: #00d4ff;
    --primary-hover-color: #00b8e6;
    --secondary-color: #6c5ce7;
    --accent-color: #ff6b6b;
    --success-color: #00b894;
    --warning-color: #fdcb6e;
    
    --bg-color: #0d1117;
    --bg-secondary: #161b22;
    --panel-bg-color: #21262d;
    --panel-bg-hover: #30363d;
    
    --text-color: #f0f6fc;
    --text-secondary: #8b949e;
    --label-color: #c9d1d9;
    --border-color: #30363d;
    --border-hover: #40464d;
    
    --focus-shadow: 0 0 0 2px rgba(0, 212, 255, 0.4);
    --active-tool-bg: linear-gradient(135deg, rgba(0, 212, 255, 0.15), rgba(108, 92, 231, 0.15));
    --button-gradient: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(108, 92, 231, 0.1));
    --panel-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --glow-effect: 0 0 20px rgba(0, 212, 255, 0.3);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, var(--bg-color) 0%, var(--bg-secondary) 100%);
    background-attachment: fixed;
    display: flex;
    flex-direction: column;
    padding: 20px;
    margin: 0;
    color: var(--text-color);
    height: 100vh;
    box-sizing: border-box;
    overflow: hidden;
    letter-spacing: 0.01em;
}

h1 { 
    text-align: center; 
    flex-shrink: 0; 
    margin-bottom: 20px; 
    color: var(--text-color);
    font-weight: 700;
    font-size: 2.2em;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
}

#main-layout { 
    display: flex; 
    flex-direction: row; 
    gap: 25px; 
    width: 100%; 
    height: 100%; 
    overflow: hidden; 
}

#canvas-wrapper { 
    flex-grow: 1; 
    display: flex; 
    flex-direction: column; 
    position: relative;
}

#canvas-container { 
    position: relative;
    width: 100%; 
    height: 100%; 
    border: 2px solid var(--border-color); 
    background: #1a1a1a;
    box-shadow: var(--panel-shadow), inset 0 0 50px rgba(0, 0, 0, 0.3); 
    border-radius: 12px; 
    overflow: hidden;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
#canvas-container:hover {
    border-color: var(--primary-color);
    box-shadow: var(--panel-shadow), var(--glow-effect);
}

canvas { 
    display: block; 
    width: 100%; 
    height: 100%; 
    position: absolute;
    top: 0;
    left: 0;
}

::selection {
    background: rgba(0, 212, 255, 0.3);
    color: var(--text-color);
}

*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    border-radius: 4px;
}