* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

body.dark-mode {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

.container {
    max-width: 1600px;
    margin: 0 auto;
}

.top-bar {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 20px;
}

body.dark-mode .top-bar {
    background: #2a2a3e;
    color: #fff;
}

.top-bar h1 {
    color: #667eea;
    font-size: 28px;
    flex: 1;
}

.controls {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 25px;
    display: flex;
    gap: 15px;
    align-items: center;
    flex-wrap: wrap;
}

body.dark-mode .controls {
    background: #2a2a3e;
    color: #fff;
}

select {
    padding: 10px 15px;
    border: 2px solid #667eea;
    border-radius: 8px;
    min-width: 200px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    background: #667eea;
    color: white;
    cursor: pointer;
    font-weight: 600;
}

#graphs {
    display: none;
    grid-template-columns: repeat(auto-fit, minmax(600px, 1fr));
    gap: 25px;
}

.card {
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.buttons button.active {
    background: #667eea;
    color: white;
}

.buttons button.inactive {
    opacity: 0.5;
}

.hint {
    color: #666;
    font-style: italic;
}