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

:root {
    --sidebar-width: 240px;
    --header-height: 48px;
    --ink: #1c1c1e;
    --ink-2: #3a3a3c;
    --ink-3: #636366;
    --ink-4: #aeaeb2;
    --bg: #ffffff;
    --bg-sidebar: #f8f9fa;
    --bg-code: #f4f5f6;
    --border: #d1d5db;
    --border-light: #e5e7eb;
    --green: #1a7f37;
    --green-bg: #f0fdf4;
    --green-border: #bbf7d0;
    --amber: #b45309;
    --amber-bg: #fffbeb;
    --amber-border: #fde68a;
    --red: #b91c1c;
    --red-bg: #fef2f2;
    --red-border: #fecaca;
    --sidebar-active-border: #1a7f37;
    --link: #0969da;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    color: var(--ink);
    background: var(--bg);
    font-size: 15px;
    line-height: 1.7;
}

/* ── TOP HEADER ── */
#top-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 1.25rem;
    gap: 0.75rem;
    z-index: 200;
}

#top-header .hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    padding: 6px;
    border: none;
    background: none;
    border-radius: 4px;
}

#top-header .hamburger span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--ink-2);
    border-radius: 1px;
}

#top-header .hamburger:hover { background: var(--bg-sidebar); }

.header-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--ink);
}

.header-logo img {
    height: 22px;
    width: auto;
}

.header-logo-text {
    font-size: 0.9375rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.header-divider {
    width: 1px;
    height: 20px;
    background: var(--border);
    margin: 0 0.25rem;
}

.header-subtitle {
    font-size: 0.8125rem;
    color: var(--ink-3);
}

.header-spacer { flex: 1; }

.header-github {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.8125rem;
    color: var(--ink-3);
    text-decoration: none;
    padding: 0.3125rem 0.625rem;
    border: 1px solid var(--border);
    border-radius: 6px;
}

.header-github:hover {
    background: var(--bg-sidebar);
    color: var(--ink);
}

.header-github svg {
    width: 14px;
    height: 14px;
    fill: currentColor;
}

/* ── LAYOUT SHELL ── */
#layout {
    display: flex;
    padding-top: var(--header-height);
    min-height: 100vh;
}

/* ── SIDEBAR ── */
#sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--header-height));
    overflow-y: auto;
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    padding: 1.25rem 0 2rem;
    z-index: 100;
}

#sidebar::-webkit-scrollbar { width: 4px; }
#sidebar::-webkit-scrollbar-track { background: transparent; }
#sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-section {
    margin-bottom: 0.25rem;
}

.sidebar-label {
    display: block;
    font-size: 0.6875rem;
    font-weight: 600;
    letter-spacing: 0.07em;
    text-transform: uppercase;
    color: var(--ink-4);
    padding: 0.75rem 1.125rem 0.375rem;
}

.sidebar-nav {
    list-style: none;
}

.sidebar-nav li a {
    display: block;
    padding: 0.3125rem 1.125rem 0.3125rem 1rem;
    font-size: 0.8125rem;
    color: var(--ink-2);
    text-decoration: none;
    border-left: 3px solid transparent;
    transition: color 0.1s, background 0.1s;
}

.sidebar-nav li a:hover {
    background: #eef0f2;
    color: var(--ink);
}

.sidebar-nav li a.active {
    color: var(--green);
    border-left-color: var(--sidebar-active-border);
    background: #f0fdf4;
    font-weight: 500;
}

.sidebar-nav li.sub a {
    padding-left: 1.75rem;
    font-size: 0.8rem;
    color: var(--ink-3);
}

.sidebar-nav li.sub a:hover { color: var(--ink); }
.sidebar-nav li.sub a.active {
    color: var(--green);
    border-left-color: var(--sidebar-active-border);
    background: #f0fdf4;
}

/* ── MAIN CONTENT ── */
#content {
    margin-left: var(--sidebar-width);
    flex: 1;
    min-width: 0;
}

.content-inner {
    max-width: 820px;
    padding: 2.5rem 3rem 4rem;
}

/* ── SECTION HEADINGS ── */
.doc-section {
    margin-bottom: 0;
    padding-bottom: 3rem;
}

.doc-section + .doc-section {
    padding-top: 2rem;
    border-top: 1px solid var(--border-light);
}

h1 {
    font-size: 1.875rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    margin-bottom: 0.625rem;
    padding-bottom: 0.625rem;
    border-bottom: 1px solid var(--border);
    color: var(--ink);
}

h2 {
    font-size: 1.375rem;
    font-weight: 600;
    letter-spacing: -0.015em;
    margin: 2rem 0 0.875rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--ink);
}

h2:first-child { margin-top: 0; }

h3 {
    font-size: 1.0625rem;
    font-weight: 600;
    margin: 1.75rem 0 0.625rem;
    color: var(--ink);
}

h4 {
    font-size: 0.9375rem;
    font-weight: 600;
    margin: 1.25rem 0 0.375rem;
    color: var(--ink);
}

p {
    margin-bottom: 0.875rem;
    color: var(--ink-2);
}

p:last-child { margin-bottom: 0; }

ul, ol {
    margin: 0.75rem 0 0.875rem 1.5rem;
    color: var(--ink-2);
}

li { margin-bottom: 0.25rem; }

a {
    color: var(--link);
    text-decoration: none;
}

a:hover { text-decoration: underline; }

strong { color: var(--ink); font-weight: 600; }
em { font-style: italic; }

/* ── CODE ── */
code {
    font-family: 'SF Mono', ui-monospace, 'Cascadia Code', Consolas, 'Liberation Mono', monospace;
    background: var(--bg-code);
    padding: 0.125rem 0.375rem;
    border-radius: 4px;
    font-size: 0.875em;
    color: var(--ink);
    border: 1px solid var(--border-light);
}

pre {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 1.125rem 1.25rem;
    overflow-x: auto;
    margin: 1rem 0 1.25rem;
    line-height: 1.55;
}

pre code {
    font-family: 'SF Mono', ui-monospace, 'Cascadia Code', Consolas, 'Liberation Mono', monospace;
    font-size: 0.8125rem;
    background: none;
    padding: 0;
    border: none;
    color: var(--ink);
}

/* ── TABLES ── */
.table-wrap {
    overflow-x: auto;
    margin: 1rem 0 1.25rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

thead { background: #f4f5f6; }

th {
    text-align: left;
    padding: 0.5625rem 0.875rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink-3);
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

td {
    padding: 0.5625rem 0.875rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--ink-2);
    vertical-align: top;
}

tbody tr:nth-child(even) td { background: #fbfcfd; }
tbody tr:last-child td { border-bottom: none; }

td code { font-size: 0.8125em; }

/* ── CALLOUTS ── */
.callout {
    padding: 0.875rem 1.125rem;
    border-left: 3px solid var(--green);
    background: var(--green-bg);
    border-radius: 0 6px 6px 0;
    margin: 1.25rem 0;
}

.callout p { color: var(--ink-2); margin: 0; font-size: 0.9rem; }
.callout strong { color: var(--ink); }

.callout.warning {
    border-left-color: var(--amber);
    background: var(--amber-bg);
}

.callout.danger {
    border-left-color: var(--red);
    background: var(--red-bg);
}

/* ── BADGES / PILLS ── */
.badge-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 1rem 0;
}

.badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.25rem 0.625rem;
    border-radius: 4px;
    border: 1px solid var(--border);
    color: var(--ink-3);
    background: var(--bg);
}

.badge.green {
    color: #166534;
    background: #f0fdf4;
    border-color: #bbf7d0;
}

/* ── FEATURE GRID ── */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1.25rem 0;
}

.feature-card {
    padding: 1rem 1.125rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg);
}

.feature-card h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin: 0 0 0.375rem;
    color: var(--ink);
}

.feature-card p {
    font-size: 0.8125rem;
    color: var(--ink-3);
    margin: 0;
    line-height: 1.5;
}

/* ── VIDEO ── */
.video-container {
    margin: 1.25rem 0;
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
    background: #000;
}

.video-container video {
    width: 100%;
    display: block;
    aspect-ratio: 16 / 9;
    object-fit: contain;
    background: #000;
}

.video-caption {
    font-size: 0.8rem;
    color: var(--ink-4);
    text-align: center;
    padding: 0.5rem 0 0;
}

/* ── INTRO BLOCK ── */
.page-intro {
    margin-bottom: 2rem;
    padding-bottom: 1.75rem;
    border-bottom: 1px solid var(--border-light);
}

.page-intro .lead {
    font-size: 1.0625rem;
    color: var(--ink-2);
    line-height: 1.65;
    margin-bottom: 1rem;
}

/* ── SECTION ANCHOR OFFSET ── */
.section-anchor {
    display: block;
    height: calc(var(--header-height) + 1.5rem);
    margin-top: calc(-1 * (var(--header-height) + 1.5rem));
    visibility: hidden;
    pointer-events: none;
}

/* ── FOOTER ── */
footer {
    border-top: 1px solid var(--border-light);
    padding: 1.5rem 3rem;
    font-size: 0.8125rem;
    color: var(--ink-4);
    margin-left: var(--sidebar-width);
}

footer a { color: var(--ink-3); }
footer a:hover { color: var(--ink); }

/* ── MOBILE OVERLAY ── */
#sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.35);
    z-index: 90;
}

/* ── CROSS-PAGE NAV (top header) ── */
.page-nav {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.125rem;
    margin-left: 0.5rem;
}

.page-nav a {
    display: inline-block;
    padding: 0.3125rem 0.625rem;
    font-size: 0.8125rem;
    color: var(--ink-3);
    text-decoration: none;
    border-radius: 5px;
    border: 1px solid transparent;
    line-height: 1.3;
}

.page-nav a:hover {
    background: var(--bg-sidebar);
    color: var(--ink);
    text-decoration: none;
}

.page-nav a.active {
    color: var(--green);
    background: var(--green-bg);
    border-color: var(--green-border);
    font-weight: 500;
}

/* ── RESPONSIVE ── */
@media (max-width: 768px) {
    #top-header .hamburger { display: flex; }

    #sidebar {
        transform: translateX(-100%);
        transition: transform 0.22s ease;
        z-index: 150;
        box-shadow: 2px 0 12px rgba(0,0,0,0.12);
    }

    #sidebar.open { transform: translateX(0); }
    #sidebar-overlay.visible { display: block; }

    #content { margin-left: 0; }
    footer { margin-left: 0; }

    .content-inner {
        padding: 1.75rem 1.25rem 3rem;
    }

    .feature-grid { grid-template-columns: 1fr; }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.1875rem; }

    .page-nav { display: none; }
    .header-github { margin-left: auto; }
}

@media (max-width: 480px) {
    .header-subtitle,
    .header-divider { display: none; }
}