.nl-prompt {
    font-size: 1.1rem;
    font-weight: 600;
    color: #444;
    text-align: center;
    margin: 0.5rem 0 1rem;
}

.nl-scroll {
    overflow-x: auto;
    padding: 0.4rem 0 0.2rem;
    margin-bottom: 1rem;
}

.nl-scroll-vertical {
    display: flex;
    justify-content: center;
    overflow: visible;
}

.nl-svg {
    display: block;
}

.nl-svg-horizontal {
    width: 100%;
    min-width: 520px;
    height: auto;
}

.nl-svg-vertical {
    height: min(62vh, 360px);
    width: auto;
}

.nl-axis {
    stroke: #1f3a5f;
    stroke-width: 0.7;
    stroke-linecap: round;
}

.nl-arrow {
    fill: #1f3a5f;
}

.nl-tick {
    stroke: #8fa2bd;
    stroke-width: 0.6;
    stroke-linecap: round;
}

.nl-tick-zero {
    stroke: #1f3a5f;
    stroke-width: 1;
}

.nl-tick-major {
    stroke: #6d819c;
    stroke-width: 0.8;
}

.nl-label {
    fill: #5a6b83;
    font-size: 4px;
    font-weight: 600;
}

.nl-label-zero {
    fill: #1f3a5f;
    font-weight: 800;
}

.nl-marker-stem {
    stroke: #e08a00;
    stroke-width: 0.7;
    stroke-dasharray: 1.4 1.2;
}

.nl-marker {
    fill: #f0a020;
}

.nl-marker-dot {
    fill: #e08a00;
}

.nl-svg-horizontal.nl-clickable {
    cursor: pointer;
}

.nl-tube {
    fill: #ffffff;
    stroke: #b9c6dc;
    stroke-width: 1.2;
}

.nl-bulb {
    fill: #ffffff;
    stroke: #b9c6dc;
    stroke-width: 1.2;
}

.nl-mercury {
    fill: #ef5b5b;
}

.nl-mercury-bulb {
    fill: #ef5b5b;
}

.nl-level-line {
    stroke: #ef5b5b;
    stroke-width: 0.9;
    stroke-dasharray: 1.6 1.4;
}

.nl-svg-vertical.nl-clickable {
    cursor: pointer;
}

.nl-options {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.nl-option {
    min-width: 4.5rem;
    padding: 0.85rem 1.2rem;
    font-size: 1.4rem;
    font-weight: 700;
    color: #1f3a5f;
    background: #ffffff;
    border: 2px solid #bcd4f6;
    border-radius: 14px;
    cursor: pointer;
    transition: transform 0.1s ease, box-shadow 0.1s ease;
}

.nl-option:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(31, 58, 95, 0.15);
}

.nl-input {
    display: block;
    width: min(12rem, 80%);
    margin: 0 auto 1rem;
    padding: 0.75rem;
    font-size: 1.6rem;
    font-weight: 700;
    text-align: center;
    color: #1f3a5f;
    border: 2px solid #bcd4f6;
    border-radius: 14px;
}

.nl-hint {
    text-align: left;
}

.nl-hint p {
    margin: 0.35rem 0;
}