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

:root {
    --max-width: 860px;
    --color-bg: #fff;
    --color-text: #222;
    --color-muted: #666;
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --color-border: #e5e7eb;
    --color-surface: #f9fafb;
    --color-code-bg: #f3f4f6;
    --font-sans: system-ui, -apple-system, 'Segoe UI', sans-serif;
    --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
}

/* -- Header -------------------------------- */

header {
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 2rem;
}

header nav {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.site-name {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--color-text);
    text-decoration: none;
}

.nav-links {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

header a {
    color: var(--color-muted);
    text-decoration: none;
    font-size: 0.95rem;
}

header a:hover,
header a.active {
    color: var(--color-accent);
}

/* -- Hamburger ----------------------------- */

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    margin-left: auto;
    flex-direction: column;
    gap: 4px;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 1px;
}

/* -- Dropdown ------------------------------ */

.dropdown {
    position: relative;
}

.dropdown-toggle {
    cursor: pointer;
}

.caret {
    font-size: 0.7em;
    vertical-align: 1px;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    list-style: none;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 0.5rem 0;
    min-width: 180px;
    box-shadow: 0 4px 12px rgba(0,0,0,.08);
    z-index: 100;
}

.dropdown-menu li a {
    display: block;
    padding: 0.4rem 1rem;
    white-space: nowrap;
}

.dropdown-menu li a:hover {
    background: var(--color-surface);
}

.dropdown:hover > .dropdown-menu {
    display: block;
}

.dropdown-toggle:focus + .dropdown-menu,
.dropdown-menu:focus-within {
    display: block;
}

/* -- Main ---------------------------------- */

main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 3rem 2rem;
}

/* -- Typography ---------------------------- */

article h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

article h2 { font-size: 1.35rem; margin: 2.5rem 0 0.75rem; }
article h3 { font-size: 1.1rem; margin: 1.5rem 0 0.5rem; }
article p { margin-bottom: 1rem; }
article ul, article ol { margin: 0 0 1rem 1.5rem; }
article li { margin-bottom: 0.3rem; }
article a { color: var(--color-accent); }
article a:hover { color: var(--color-accent-hover); }

article img {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    margin: 1rem 0;
}

article blockquote {
    border-left: 3px solid var(--color-border);
    padding-left: 1rem;
    color: var(--color-muted);
    margin: 1rem 0;
}

.lead {
    font-size: 1.15rem;
    color: var(--color-muted);
    line-height: 1.7;
}

/* -- Code ---------------------------------- */

code {
    font-family: var(--font-mono);
    font-size: 0.88em;
    background: var(--color-code-bg);
    padding: 0.15em 0.4em;
    border-radius: 4px;
}

pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1.25rem 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0 1.5rem;
    line-height: 1.5;
}

pre code {
    background: none;
    padding: 0;
    font-size: 0.875rem;
    color: inherit;
}

/* -- Parameter tables ---------------------- */

.param-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0 1.5rem;
    font-size: 0.95rem;
}

.param-table td {
    padding: 0.5rem 0.75rem;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
}

.param-table td:first-child {
    white-space: nowrap;
    width: 1%;
}

/* -- Hero ---------------------------------- */

.hero {
    margin-bottom: 3rem;
    padding-bottom: 2.5rem;
    border-bottom: 1px solid var(--color-border);
}

.hero h1 {
    font-size: 2.4rem;
    line-height: 1.15;
    margin-bottom: 1.25rem;
}

/* -- Features (home) ----------------------- */

.features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.feature h3 {
    margin: 0 0 0.5rem;
    font-size: 1.1rem;
}

.feature p {
    color: var(--color-muted);
    font-size: 0.95rem;
}

/* -- Doc sections (home) ------------------- */

.doc-section {
    margin-top: 3rem;
    padding-top: 2.5rem;
    border-top: 1px solid var(--color-border);
}

.doc-section h2 {
    font-size: 1.35rem;
    margin: 0 0 0.75rem;
}

.doc-section p { margin-bottom: 1rem; }
.doc-section ol { margin: 0 0 1rem 1.5rem; }
.doc-section li { margin-bottom: 0.3rem; }
.doc-section a { color: var(--color-accent); }
.doc-section a:hover { color: var(--color-accent-hover); }

/* -- Footer -------------------------------- */

footer {
    border-top: 1px solid var(--color-border);
    padding: 2rem;
    text-align: center;
    color: var(--color-muted);
    font-size: 0.9rem;
}

/* -- Responsive ---------------------------- */

@media (max-width: 700px) {
    .features {
        grid-template-columns: 1fr;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        align-items: flex-start;
        width: 100%;
        gap: 0;
        padding-top: 0.75rem;
    }

    header nav.open .nav-links {
        display: flex;
    }

    .nav-links > li {
        width: 100%;
    }

    .nav-links > li > a,
    .dropdown-toggle {
        display: block;
        padding: 0.5rem 0;
    }

    .dropdown-menu {
        position: static;
        box-shadow: none;
        border: none;
        padding: 0 0 0 1rem;
    }

    .dropdown-menu li a {
        padding: 0.4rem 0;
    }

    .dropdown.open > .dropdown-menu {
        display: block;
    }

    .hero h1 { font-size: 1.8rem; }
}