:root {
    --primary-bg: #fdfbf7;
    --header-bg: #2c3e50;
    --panel-bg: #ffffff;
    --accent-color: #e67e22;
    --text-dark: #333333;
    --text-light: #ecf0f1;
    --border-color: #e0e0e0;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--primary-bg);
    color: var(--text-dark);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: var(--header-bg);
    color: var(--text-light);
    padding: 1.5rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

header p {
    margin: 0;
    font-size: 1.1rem;
    color: #bdc3c7;
}

nav {
    background-color: #34495e;
    padding: 0.5rem 2rem;
    display: flex;
    gap: 2rem;
}

nav a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: bold;
    padding: 0.5rem 0;
}

nav a:hover {
    color: var(--accent-color);
}

.app-container {
    display: flex;
    flex: 1;
    overflow: hidden;
    height: calc(100vh - 140px);
}

.sidebar {
    width: 350px;
    background-color: var(--panel-bg);
    border-right: 1px solid var(--border-color);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
    overflow-y: auto;
}

.control-group, .info-panel {
    background: var(--primary-bg);
    padding: 1.2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.control-group h3, .info-panel h3 {
    margin-top: 0;
    color: var(--header-bg);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

select, button, input {
    width: 100%;
    padding: 0.8rem;
    margin-top: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
}

button.primary-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    cursor: pointer;
    font-weight: bold;
    margin-top: 1rem;
}

button.primary-btn:hover {
    background-color: #d35400;
}

.viz-area {
    flex: 1;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    overflow-y: auto;
}

.viz-card {
    background: var(--panel-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    padding: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    min-height: 400px;
    display: flex;
    flex-direction: column;
}

.viz-card h2 {
    margin-top: 0;
    color: var(--header-bg);
}

.d3-container {
    flex: 1;
    background-color: #fafafa;
    border: 1px dashed #ccc;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #7f8c8d;
    border-radius: 4px;
}

.eda-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.eda-chart {
    background: #fafafa;
    border: 1px dashed #ccc;
    height: 250px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #7f8c8d;
    border-radius: 4px;
}