* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    background: #f4f4f4;
    padding: 30px;
}

.container {
    width: 620px;
    margin: auto;
}

h2 {
    margin-bottom: 10px;
    text-align: center;
}
.toolbar {
    text-align: center;
    margin-bottom: 10px;
}

button {
    padding: 8px 16px;
    margin: 0 5px;
    border: none;
    cursor: pointer;
    background: #2c3e50;
    color: white;
    border-radius: 4px;
}

button.active {
    background: #00aaff;
}
svg {
    border: 2px solid black;
    background: white;
    cursor: crosshair;
}