/* Body */
body {
    margin: 0;
    font-family: 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: #f8f9fa;
    color: #333;
}

/* Main container */
#heatmap {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
}

/* Title */
#heatmap h1 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #222;
}

/* SVG  */
svg {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-radius: 12px;
    background: white;
    transition: transform 0.3s ease;
}

svg:hover {
    transform: scale(1.01);
}

/* Axes */
#x-axis path,
#y-axis path,
#x-axis line,
#y-axis line {
    stroke: #bbb;
    stroke-width: 1;
}

#x-axis text,
#y-axis text {
    font-size: 12px;
    fill: #555;
    font-weight: 500;
}

/* Cells */
.cell {
    stroke: #fff;
    stroke-width: 0.2;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.cell:hover {
    opacity: 0.85;
    cursor: pointer;
}

/* Tooltip */
#tooltip {
    pointer-events: none;
    font-size: 14px;
    font-weight: 500;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    background: white;
    border: none;
    padding: 10px 14px;
    line-height: 1.4;
    color: #222;
    transition: opacity 0.2s ease;
}

/* Legend */
#legend rect {
    stroke: #ddd;
    stroke-width: 0.5;
}

#legend text {
    font-size: 12px;
    fill: #444;
}

/* Responsive */
@media (max-width: 768px) {
    svg {
        width: 95% !important;
        height: auto !important;
    }
}