body {
    margin: 0;
    padding: 0;
    background-color: #111;
    font-family: Helvetica, Arial, sans-serif;
}
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: #333;
    color: #fff;
    padding: 4px;
    text-align: center;
    z-index: 10;
    font-family: inherit;
}
header h1 {
    margin: 0;
    font-size: 24px;
    font-weight: bold;
    height: 100%;
}
.sidebar {
    position: fixed;
    top: 32px; /* 32px header */
    left: 0;
    width: 220px;
    height: calc(100vh - 112px);
    background: #222;
    color: #fff;
    padding: 16px;
    box-sizing: border-box;
    z-index: 9;
    display: flex;
    flex-direction: column;
    gap: 24px;
    font-family: inherit;
}
.sidebar label {
    margin-bottom: 8px;
    font-size: 1rem;
    display: block;
    font-family: inherit;
}
.sidebar select {
    width: 100%;
    padding: 6px;
    font-size: 1rem;
    border-radius: 4px;
    border: none;
    margin-bottom: 8px;
    font-family: inherit;
}
.sidebar input[type="text"] {
    width: 94%;
    padding: 6px;
    font-size: 1rem;
    border-radius: 4px;
    border: none;
    margin-bottom: 8px;
    font-family: inherit;
}
.sidebar input[type="number"] {
    width: 100%;
    padding: 6px;
    font-size: 1rem;
    border-radius: 4px;
    border: none;
    margin-bottom: 8px;
    font-family: inherit;
}
.sidebar input[type="color"] {
    width: 40%;
    padding: 0px;
    font-size: 1rem;
    border-radius: 1px;
    border: none;
    margin-bottom: 8px;
    font-family: inherit;
}
.sidebar button {
    padding: 10px 16px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    font-family: inherit;
}
canvas {
    display: block;
    border: 0px solid black;
    margin: 0;
    position: absolute;
    top: 200px; /* 64px header + 48px sidebar + 48px tab bar */
    left: 220px; /* Width of sidebar */
}
.tab-bar {
    position: fixed;
    top: 32px; /* Below header*/
    left: 220px; /* Next to sidebar */
    width: calc(100% - 220px);
    height: 32px;
    background: #222;
    display: flex;
    align-items: center;
    z-index: 11;
    border-bottom: 1px solid #444;
}
.tab-bar .tab {
    background: none;
    border: none;
    color: #fff;
    padding: 0 32px;
    height: 100%;
    font-size: 1rem;
    cursor: pointer;
    font-family: inherit;
    outline: none;
    transition: background 0.2s;
}
.tab-bar .tab:hover,
.tab-bar .tab.active {
    background: #444;
}