:root {
    --toolbar-width: 250px;
    --primary-color: #4CAF50;
    --secondary-color: #333;
}

* {
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
    background-color: #f0f0f0;
}

#toolbar {
    background-color: var(--secondary-color);
    color: white;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
}

#canvas-container {
    position: relative;
    flex: 1;
    overflow: auto;
    background-color: #fff;
}

canvas {
    max-height: 100%;
    max-width: 100%;
}

#maskCanvas {
    position: absolute;
    top: 0;
    left: 0;
    mix-blend-mode: screen;
    opacity: 0.5;
}

h1 {
    font-size: 1.2em;
    margin-bottom: 20px;
}

button, .file-input-label, .radio-button-group label {
    background-color: var(--primary-color);
    border: none;
    color: white;
    padding: 10px 15px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 14px;
    margin: 4px 2px;
    cursor: pointer;
    border-radius: 4px;
    transition: background-color 0.3s;
}

button:hover, .file-input-label:hover, .radio-button-group label:hover {
    background-color: #45a049;
}

input[type="file"] {
    display: none;
}

input[type="range"] {
    width: 100%;
    margin: 10px 0;
}

.radio-button-group {
    display: flex;
    justify-content: space-between;
}

.radio-button-group input[type="radio"] {
    display: none;
}

.radio-button-group label {
    flex: 1;
    background-color: #555;
}

.radio-button-group input[type="radio"]:checked + label {
    background-color: var(--primary-color);
}

body {
    flex-direction: row;
}

#toolbar {
    width: var(--toolbar-width);
}


@media (max-width: 767px) {
    body {
        flex-direction: column;
    }

    h1 {
        display: none;
    }

    #toolbar {
        width: 100%;
        padding: 0.5em;
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: space-between;
        align-items: center;
        gap: 0.5em;
    }

    #toolbar > * {
        flex-grow: 1;
    }

    input[type="range"] {
        width: 100%;
    }

    .radio-button-group {
        gap: 0.5rem;
    }
}