:root {
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
}

header {
    background: var(--card-bg);
    padding: 2rem;
    border-bottom: 1px solid var(--border);
    text-align: center;
}

header h1 {
    margin: 0 0 0.5rem 0;
    font-size: 2rem;
    font-weight: 700;
}

header p {
    margin: 0.25rem 0;
    color: var(--text-muted);
}

.subtitle {
    font-family: monospace;
    font-size: 0.9rem;
    background: #f1f5f9;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    display: inline-block;
    margin-top: 0.75rem !important;
}

main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.controls {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    margin-bottom: 2rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.controls label {
    font-weight: 600;
    display: block;
    margin-bottom: 0.75rem;
}

.legend-toggles {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    border: 1px solid var(--border);
    cursor: pointer;
    user-select: none;
    transition: background 0.15s;
}

.toggle-label:hover {
    background: #f1f5f9;
}

.charts-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 900px) {
    .charts-container {
        grid-template-columns: 1fr 1fr;
    }
}

.chart-box {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.chart-box h2 {
    margin: 0 0 0.5rem 0;
    font-size: 1.25rem;
}

.chart-box p {
    color: var(--text-muted);
    margin: 0 0 1.5rem 0;
    font-size: 0.9rem;
}

.canvas-wrapper {
    position: relative;
    height: 400px;
    width: 100%;
}

.error {
    background: #fef2f2;
    color: #991b1b;
    padding: 1rem;
    border: 1px solid #f87171;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.data-table th, .data-table td {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    text-align: right;
}

.data-table th:first-child, .data-table td:first-child {
    text-align: left;
    font-weight: 600;
    background: #f8fafc;
}

.data-table thead th {
    background: #f1f5f9;
    font-weight: 600;
}

.data-table tbody tr:nth-child(even) {
    background: #f8fafc;
}

.best-val {
    background-color: #dcfce7 !important;
    color: #166534;
    font-weight: 600;
}

.pos-delta {
    color: #16a34a;
    font-weight: 600;
}

.neg-delta {
    color: #dc2626;
    font-weight: 600;
}