* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: aliceblue;
}

main { padding: 8px 12px; }

.chart-box {
    height: 330px;
    background-color: white;
    border: 1px solid silver;
    border-radius: 6px;
    padding: 6px;
}

.controls {
    margin-top: 8px;
    display: flex;
    align-items: center;
    gap: 14px;
    background-color: white;
    border: 1px solid silver;
    border-radius: 6px;
    padding: 9px 12px;
    font-size: 15px;
}

.controls label { white-space: nowrap; }
.controls .check { cursor: pointer; }
.controls strong { color: #e65100; }
#markerN { flex: 1; min-width: 90px; }

.readout {
    margin-top: 8px;
    background-color: white;
    border: 1px solid silver;
    border-radius: 6px;
    padding: 9px 12px;
    font-size: 14px;
    line-height: 1.5;
}

.readout .dft { color: #e65100; font-weight: bold; }
.readout .lin { color: #1565c0; font-weight: bold; }
.readout .ratio { color: #2e7d32; font-weight: bold; }

@media (max-width: 620px) {
    .controls { flex-wrap: wrap; }
    .controls label { white-space: normal; }
}