index.css

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

html,
body {
    height: 100%;
}

body {
    padding: 16px 32px;
}

body,
#container,
#upload-button {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

h1 {
    text-align: center;
}

#container {
    position: relative;
    width: 640px;
    height: 420px;
    max-width: 100%;
    max-height: 100%;
    border: 2px dashed #D1D5DB;
    border-radius: 0.75rem;
    overflow: hidden;
    cursor: pointer;
    margin-top: 1rem;
    background-size: 100% 100%;
    background-position: center;
    background-repeat: no-repeat;
}

#mask-output {
    position: absolute;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

#upload-button {
    gap: 0.4rem;
    font-size: 18px;
    cursor: pointer;
}

#upload {
    display: none;
}

svg {
    pointer-events: none;
}

#example {
    font-size: 14px;
    text-decoration: underline;
    cursor: pointer;
}

#example:hover {
    color: #2563EB;
}

canvas {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0.6;
}

#status {
    min-height: 16px;
    margin: 8px 0;
}

.icon {
    height: 16px;
    width: 16px;
    position: absolute;
    transform: translate(-50%, -50%);
}

#controls>button {
    padding: 6px 12px;
    background-color: #3498db;
    color: white;
    border: 1px solid #2980b9;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}

#controls>button:disabled {
    background-color: #d1d5db;
    color: #6b7280;
    border: 1px solid #9ca3af;
    cursor: not-allowed;
}

#information {
    margin-top: 0.25rem;
    font-size: 15px;
}