/* Reset and layout */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body, html {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: #ffffff;
    font-family: sans-serif;
}
/* Canvas takes up the full screen */
canvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    cursor: crosshair;
}
/* Fixed toolbar UI */
.toolbar {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(240, 240, 240, 0.9);
    padding: 10px 20px;
    border-radius: 50px;
    display: flex;
    align-items: center;
    gap: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
    z-index: 10;
}
/* Color selection circles */
.color-palette {
    display: flex;
    gap: 10px;
}
.color-btn {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.1s ease;
}
.color-btn.active {
    border-color: #000;
    transform: scale(1.1);
}
/* Action buttons */
.clear-btn {
    background: #ff4757;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: bold;
    cursor: pointer;
}
.clear-btn:active {
    background: #ff6b81;
}