* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f5f7fb;
    color: #1f2937;
    line-height: 1.6;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

h1 {
    font-size: 2.25rem;
    margin-bottom: 0.5rem;
}

h2 {
    margin-top: 0;
    font-size: 1.25rem;
}

.card {
    background: #fff;
    border-radius: 12px;
    padding: 1.5rem;
    margin-top: 1.5rem;
    box-shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
}

ul {
    padding-left: 1.25rem;
}

a {
    color: #2563eb;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

form {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.75rem;
}

input[type="text"] {
    flex: 1;
    padding: 0.6rem 0.9rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
}

button {
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: 8px;
    background: #2563eb;
    color: white;
    font-size: 1rem;
    cursor: pointer;
}

button:hover {
    background: #1d4ed8;
}

pre {
    background: #0f172a;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
    min-height: 2rem;
    overflow-x: auto;
}