/* Simple CSS for all pages */
body {
    font-family: Arial, sans-serif;
    margin: 20px;
    text-align: center;
}

h1 {
    color: #333;
}

h2 {
    color: #555;
}

p {
    color: #666;
    margin-bottom: 30px;
}

#chart {
    margin: 20px auto;
    display: flex;
    justify-content: center;
}

.navigation {
    margin-top: 40px;
}

.navigation button {
    padding: 10px 20px;
    margin: 0 10px;
    font-size: 16px;
    cursor: pointer;
}

.navigation button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.controls {
    margin: 20px 0;
}

.controls select {
    padding: 5px;
    font-size: 16px;
}

/* Chart styles */
.axis {
    font-size: 12px;
}

.axis path,
.axis line {
    fill: none;
    stroke: #000;
    shape-rendering: crispEdges;
}

.grid line {
    stroke: lightgray;
    stroke-opacity: 0.7;
}

.line {
    fill: none;
    stroke-width: 2;
}

.tooltip {
    position: absolute;
    text-align: left;
    padding: 10px;
    font-size: 12px;
    background: black;
    color: white;
    border-radius: 5px;
    pointer-events: none;
    opacity: 0;
}