body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 16px 20px;
    background-color: #f4f6f8;
    color: #333;
}

/* Main layout container - wider + charts get priority (modern pattern) */
section.tool-page {
    max-width: 1480px;
    margin: 16px auto;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    display: flex;
    gap: 20px;
}

/* Left controls column - narrower for wider chart area */
.calculator {
    background-color: #f9f9f9;
    padding: 18px 20px;
    border-radius: 8px;
    border: 1px solid #e5e7eb;
    width: 36%;
    flex-shrink: 0;
}

/* Right visualization column - more breathing room */
.charts {
    width: 64%;
    padding-left: 12px;
    min-width: 0; /* allow canvas to shrink properly */
}

.calculator label {
    display: block;
    margin: 8px 0 3px;
    font-weight: 600;
    font-size: 0.9rem;
    color: #374151;
}

.calculator .param-group {
    margin-bottom: 12px;
}

/* Checkbox row at top */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 4px 0 12px;
    font-weight: 500;
    cursor: pointer;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 15px;
    height: 15px;
    accent-color: #1a73e8;
    cursor: pointer;
}

.calculator input[type="number"] {
    width: 100%;
    max-width: 180px;
    padding: 6px 8px;
    border: 1px solid #d1d5db;
    border-radius: 4px;
    font-size: 0.95rem;
}

.calculator input[type="number"]:focus {
    border-color: #1a73e8;
    outline: none;
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
}

.calculator input[type="range"] {
    width: 100%;
    max-width: 180px;
    margin: 2px 0 8px;
    -webkit-appearance: none;
    height: 6px;
    background: #e5e7eb;
    border-radius: 999px;
    outline: none;
}

.calculator input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 15px;
    height: 15px;
    background: #1a73e8;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.calculator input[type="range"]::-webkit-slider-thumb:hover {
    background: #1557b0;
}

.calculator button {
    background-color: #1a73e8;
    color: white;
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    margin-top: 6px;
}

.calculator button:hover {
    background-color: #1557b0;
}

/* Output / results area */
.calculator .output,
.charts .transfer,
.charts .phase-boost {
    margin-top: 14px;
    font-size: 0.95rem;
    color: #1f2937;
}

.transfer {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.transfer .mathjax-eq {
    display: inline-block;
    padding: 6px 10px;
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    font-size: 0.95rem;
}

.phase-boost {
    font-weight: 500;
    color: #1a73e8;
}

/* Chart coordinate readouts (live crosshair values) */
.chart-coordinates {
    font-size: 0.85rem;
    color: #4b5563;
    margin-top: 2px;
    margin-bottom: 10px;
    padding-left: 4px;
}

canvas {
    max-width: 100%;
    display: block;
}

/* Make the section header inside calculator a bit nicer */
.calculator h3 {
    margin: 0 0 10px 0;
    font-size: 1.0rem;
    color: #1f2937;
    border-bottom: 1px solid #e5e7eb;
    padding-bottom: 6px;
}