body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f6f8;
    color: #24292e;
    margin: 0;
    padding: 2rem;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

header p {
    font-size: 1.25rem;
    color: #586069;
}

.demo-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.demo-card {
    background-color: #ffffff;
    border: 1px solid #e1e4e8;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 12px rgba(149, 157, 165, 0.1);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.demo-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(149, 157, 165, 0.15);
}

.demo-card h2 {
    margin-top: 0;
    font-size: 1.5rem;
    color: #0366d6;
}

.demo-card p {
    color: #586069;
    line-height: 1.6;
}

.demo-card a.button {
    display: inline-block;
    margin-top: 1rem;
    background-color: #2ea44f;
    color: white;
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 6px;
    text-decoration: none;
    transition: background-color 0.2s cubic-bezier(0.3, 0, 0.5, 1);
}

.demo-card a.button:hover {
    background-color: #2c974b;
}