* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: #0d0d0d;
    color: #e0e0e0;
    line-height: 1.7;
    padding: 2rem 1rem;
    min-height: 100vh;
}

main {
    max-width: 720px;
    margin: 0 auto;
}

h1 {
    font-size: 2rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: #ffffff;
}

.subtitle {
    color: #888;
    font-size: 0.95rem;
    margin-top: 0.25rem;
    margin-bottom: 2rem;
}

nav {
    display: flex;
    gap: 0.25rem;
    margin-bottom: 2.5rem;
    border-bottom: 1px solid #222;
    padding-bottom: 0;
}

nav a {
    color: #888;
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: color 0.2s, border-color 0.2s;
}

nav a:hover,
nav a.active {
    color: #e0e0e0;
    border-bottom-color: #e0e0e0;
}

section {
    display: none;
}

section.active {
    display: block;
}

section h2 {
    font-size: 1.4rem;
    font-weight: 600;
    color: #ffffff;
    margin-bottom: 1rem;
}

section h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #ccc;
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
}

section p {
    margin-bottom: 1rem;
    color: #b0b0b0;
}

section p em {
    color: #888;
    font-size: 0.85rem;
}

section ol,
section ul {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    color: #b0b0b0;
}

section li {
    margin-bottom: 0.75rem;
}

section li strong {
    color: #ccc;
}

section a {
    color: #8ab4f8;
    text-decoration: none;
}

section a:hover {
    text-decoration: underline;
}