body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f0f0f0;
}

#app {
    width: 80%;
    max-width: 800px;
    background: white;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    overflow: hidden;
}

header {
    background: #007aff;
    color: white;
    padding: 1rem;
    text-align: center;
}

.list-item {
    padding: 1rem;
    border-bottom: 1px solid #e0e0e0;
    cursor: pointer;
}

.list-item:hover {
    background-color: #f9f9f9;
}

.detail-view {
    padding: 1rem;
    display: none;
}

.detail-view.active {
    display: block;
}

button {
    background-color: #007aff;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    margin-top: 1rem;
}

button:hover {
    background-color: #005bb5;
}