* {
    box-sizing: border-box;
    font-family: system-ui, sans-serif;
}

body {
    margin: 0;
    background: #0f172a;
    color: #e5e7eb;
}

#app {
    display: flex;
    height: 100vh;
}

#panel {
    width: 260px;
    background: #020617;
    padding: 16px;
    border-right: 1px solid #1e293b;
}

h2 {
    margin-top: 0;
}

label {
    display: block;
    margin-bottom: 12px;
    font-size: 14px;
}

select, button {
    width: 100%;
    margin-top: 4px;
    padding: 6px;
    background: #020617;
    color: white;
    border: 1px solid #334155;
}

button:hover {
    background: #1e293b;
}

.legend {
    margin-top: 20px;
    font-size: 13px;
}

.legend span {
    display: inline-block;
    width: 12px;
    height: 12px;
    margin-right: 6px;
}

.g { background: green; }
.y { background: yellow; }
.o { background: orange; }
.r { background: red; }

canvas {
    flex: 1;
    background: #020617;
    cursor: crosshair;
}