body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 30px;
    background: #f8f9fa;
    color: #2c3e50;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

h1 {
    color: #2c3e50;
    border-bottom: 3px solid #3498db;
    padding-bottom: 15px;
    margin-bottom: 25px;
    font-size: 28px;
}

.description {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    margin-bottom: 30px;
    border-left: 4px solid #3498db;
}

.description h3 {
    color: #3498db;
    margin-top: 0;
    font-size: 20px;
}

.data-source {
    color: #7f8c8d;
    font-size: 14px;
    margin-top: 15px;
}

.filters {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.filter-row {
    display: flex;
    gap: 25px;
    align-items: center;
}

label {
    font-weight: 600;
    color: #2c3e50;
    font-size: 14px;
}

select, input[type="number"] {
    padding: 8px 12px;
    border: 1px solid #bdc3c7;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.3s;
}

select:focus, input[type="number"]:focus {
    border-color: #3498db;
    outline: none;
}

select {
    background: white;
    min-width: 200px;
}

#viz {
    margin-top: 20px;
}

.bubble {
    fill-opacity: 0.8;
    stroke: #fff;
    stroke-width: 1px;
    cursor: pointer;
    transition: r 0.3s, opacity 0.3s;
}

.bubble:hover {
    stroke-width: 2px;
    fill-opacity: 1;
}

.tooltip {
    position: absolute;
    padding: 12px;
    background: rgba(0,0,0,0.85);
    color: white;
    border-radius: 6px;
    pointer-events: none;
    font-size: 14px;
    line-height: 1.4;
}

.axis text {
    font-size: 12px;
    fill: #7f8c8d;
}

.axis path, .axis line {
    stroke: #bdc3c7;
}