body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f0f2f5;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

.balance-box {
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.stock-item {
    background: white;
    padding: 15px;
    margin: 10px 0;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

button {
    background: #007bff;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
    transition: opacity 0.2s;
}

button:hover {
    opacity: 0.8;
}

#holdings {
    background: white;
    padding: 15px;
    border-radius: 8px;
    margin-top: 10px;
}

#history {
    background: white;
    padding: 15px;
    margin-top: 20px;
    border-radius: 8px;
}