body {
    background-color: #f4f7f9;
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
}

.dark-mode {
    background-color: #1e272e;
    color: #f5f6fa;
}

.container {
    max-width: 90%;
    margin: 40px auto;
    background: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
}

.dark-mode .container {
    background-color: #2f3640;
}

h2, h3 {
    font-family: 'Poppins', sans-serif;
    color: #2c3e50;
}

a {
    color: #3498db;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

form {
    margin: 20px 0;
    position: sticky;
    top: 0;
    background: #fff;
    padding: 15px;
    z-index: 99;
    border-bottom: 1px solid #ccc;
}

select, input[type="date"], input[type="text"] {
    padding: 10px;
    font-size: 1em;
    margin-right: 10px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

select:hover,
input[type="date"]:hover,
button:hover {
    box-shadow: 0 0 5px rgba(52, 152, 219, 0.6);
    transition: all 0.2s ease;
}

#priceChart {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 10px;
}

.chart-container {
    width: 100%;
    height: 480px;
}

button {
    padding: 10px 16px;
    border: none;
    background-color: #3498db;
    color: #fff;
    border-radius: 6px;
    cursor: pointer;
}

.stat-card {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
}

.stat {
    flex: 1;
    background: #ecf0f1;
    padding: 5px;
    border-radius: 10px;
    text-align: center;
}

.stat h4 {
    margin-bottom: 10px;
}

.stat p {
    font-size: 1.5em;
    font-weight: bold;
}

.toggle-dark-mode {
    float: right;
    font-size: 0.9em;
}

.center-text {
    text-align: center;
}

.copyright {
    margin-top: 60px;
    padding: 15px 0;
    text-align: center;
    font-size: 0.85em;
    color: #888;
}