/* ─── Theme tokens ───────────────────────────────────────────── */
:root {
    --bg:           #ffffff;
    --bg-soft:      #f8fafc;
    --bg-code:      #f1f5f9;
    --text:         #0f172a;
    --text-muted:   #64748b;
    --text-faint:   #94a3b8;
    --border:       #e2e8f0;
    --border-soft:  #f1f5f9;
    --accent:       #2563eb;
    --accent-soft:  #dbeafe;
    --accent-text:  #1d4ed8;
    --shadow:       0 1px 3px rgba(15, 23, 42, 0.06);
    --shadow-lg:    0 10px 25px rgba(15, 23, 42, 0.08);

    --topbar-h:     60px;
    --sidebar-w:    260px;
    --toc-w:        220px;
    --content-max:  760px;

    --font-sans:    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono:    ui-monospace, "SF Mono", Menlo, Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;

    color-scheme:   light;
}

[data-theme="dark"] {
    --bg:           #0b1220;
    --bg-soft:      #0f172a;
    --bg-code:      #1e293b;
    --text:         #e2e8f0;
    --text-muted:   #94a3b8;
    --text-faint:   #64748b;
    --border:       #1e293b;
    --border-soft:  #1e293b;
    --accent:       #60a5fa;
    --accent-soft:  #1e3a8a;
    --accent-text:  #93c5fd;
    --shadow:       0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-lg:    0 10px 25px rgba(0, 0, 0, 0.4);

    color-scheme:   dark;
}

/* ─── Base ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.15s ease;
}
a:hover { text-decoration: underline; }

code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--bg-code);
    padding: 0.15em 0.4em;
    border-radius: 4px;
    color: var(--text);
}

/* ─── Top bar ────────────────────────────────────────────────── */
.topbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--topbar-h);
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.menu-toggle {
    display: none;
    background: transparent;
    border: 0;
    color: var(--text);
    cursor: pointer;
    padding: 6px;
    border-radius: 6px;
}
.menu-toggle:hover { background: var(--bg-soft); }

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
    font-weight: 600;
    font-size: 17px;
    text-decoration: none;
}
.logo:hover { text-decoration: none; }

.logo-mark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--accent), #7c3aed);
    color: white;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 700;
    box-shadow: var(--shadow);
}

.logo-text { font-size: 17px; }

.logo-version {
    font-size: 11px;
    font-weight: 500;
    color: var(--text-muted);
    background: var(--bg-soft);
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid var(--border);
}

.topbar-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link, .theme-toggle, .lang-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 36px;
    border-radius: 8px;
    color: var(--text-muted);
    background: transparent;
    border: 0;
    cursor: pointer;
    transition: background 0.15s ease, color 0.15s ease;
}
.nav-link, .theme-toggle { width: 36px; }
.lang-toggle {
    padding: 0 12px;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.05em;
    border: 1px solid var(--border);
}
.nav-link:hover, .theme-toggle:hover, .lang-toggle:hover {
    background: var(--bg-soft);
    color: var(--text);
    text-decoration: none;
}

/* ─── Sidebar ────────────────────────────────────────────────── */
.sidebar {
    position: fixed;
    top: var(--topbar-h);
    left: 0;
    bottom: 0;
    width: var(--sidebar-w);
    overflow-y: auto;
    background: var(--bg);
    border-right: 1px solid var(--border);
    padding: 24px 16px;
}

.nav-section { margin-bottom: 24px; }

.nav-section-title {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-faint);
    padding: 0 12px 8px;
}

.nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-list a {
    display: block;
    padding: 7px 12px;
    margin: 1px 0;
    border-radius: 6px;
    color: var(--text-muted);
    font-size: 14px;
    transition: all 0.15s ease;
    text-decoration: none;
}
.nav-list a:hover {
    background: var(--bg-soft);
    color: var(--text);
}
.nav-list a.active {
    background: var(--accent-soft);
    color: var(--accent-text);
    font-weight: 500;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 50;
}

/* ─── Content ────────────────────────────────────────────────── */
.content-wrap {
    margin-left: var(--sidebar-w);
    margin-top: var(--topbar-h);
    display: grid;
    grid-template-columns: minmax(0, 1fr) var(--toc-w);
    gap: 48px;
    padding: 48px 48px 24px;
    max-width: calc(var(--content-max) + var(--toc-w) + 96px);
}

.content {
    max-width: var(--content-max);
    min-width: 0;
}

.content .loading {
    color: var(--text-muted);
    padding: 100px 0;
    text-align: center;
}

/* Markdown elements */
.content h1 {
    font-size: 2.25rem;
    font-weight: 700;
    margin: 0 0 0.5em;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.content h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 2em 0 0.75em;
    letter-spacing: -0.01em;
    padding-top: 0.5em;
    border-top: 1px solid var(--border-soft);
}
.content > h2:first-of-type { border-top: 0; padding-top: 0; }

.content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin: 1.5em 0 0.5em;
}

.content h4 {
    font-size: 1rem;
    font-weight: 600;
    margin: 1.25em 0 0.5em;
    color: var(--text-muted);
}

.content h2 .anchor,
.content h3 .anchor,
.content h4 .anchor {
    opacity: 0;
    margin-left: 8px;
    color: var(--text-faint);
    font-weight: 400;
    transition: opacity 0.15s ease;
}
.content h2:hover .anchor,
.content h3:hover .anchor,
.content h4:hover .anchor { opacity: 1; }

.content p {
    margin: 0 0 1em;
}

.content ul, .content ol {
    margin: 0 0 1em;
    padding-left: 1.5em;
}
.content li { margin-bottom: 0.4em; }

.content blockquote {
    border-left: 3px solid var(--accent);
    background: var(--bg-soft);
    margin: 1em 0;
    padding: 0.75em 1em;
    border-radius: 0 6px 6px 0;
    color: var(--text-muted);
}
.content blockquote p:last-child { margin-bottom: 0; }
.content blockquote strong { color: var(--text); }

.content pre {
    background: #1e293b !important;
    color: #e2e8f0;
    padding: 16px 18px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1em 0;
    font-size: 13.5px;
    line-height: 1.55;
    border: 1px solid var(--border);
}
.content pre code {
    background: transparent;
    color: inherit;
    padding: 0;
    font-size: inherit;
}

.content table {
    width: 100%;
    border-collapse: collapse;
    margin: 1em 0;
    font-size: 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
}
.content th, .content td {
    padding: 10px 14px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}
.content th {
    background: var(--bg-soft);
    font-weight: 600;
    font-size: 13px;
    color: var(--text);
}
.content tr:last-child td { border-bottom: 0; }
.content tr:nth-child(even) td { background: var(--bg-soft); }

.content hr {
    border: 0;
    border-top: 1px solid var(--border);
    margin: 2.5em 0;
}

.content img { max-width: 100%; }

.content a code { color: var(--accent); }

/* ─── Right TOC (in-page) ────────────────────────────────────── */
.page-toc {
    position: sticky;
    top: calc(var(--topbar-h) + 32px);
    align-self: start;
    max-height: calc(100vh - var(--topbar-h) - 64px);
    overflow-y: auto;
    font-size: 13px;
    border-left: 1px solid var(--border);
    padding-left: 24px;
}

.page-toc-title {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-faint);
    margin-bottom: 12px;
}

.page-toc ul {
    list-style: none;
    margin: 0;
    padding: 0;
}
.page-toc li { margin: 4px 0; }
.page-toc a {
    display: block;
    color: var(--text-muted);
    padding: 4px 0;
    line-height: 1.4;
    border-left: 2px solid transparent;
    padding-left: 10px;
    margin-left: -12px;
    transition: all 0.15s ease;
    text-decoration: none;
}
.page-toc a:hover {
    color: var(--text);
    border-color: var(--border);
}
.page-toc a.active {
    color: var(--accent);
    border-color: var(--accent);
    font-weight: 500;
}
.page-toc .toc-h3 { padding-left: 22px; font-size: 12.5px; }

.page-toc:empty { display: none; }

/* ─── Footer ─────────────────────────────────────────────────── */
.footer {
    margin-left: var(--sidebar-w);
    border-top: 1px solid var(--border);
    padding: 24px 48px;
    color: var(--text-muted);
    font-size: 13px;
    background: var(--bg-soft);
}
.footer p { margin: 0; }

/* ─── Responsive ─────────────────────────────────────────────── */
@media (max-width: 1100px) {
    .content-wrap {
        grid-template-columns: 1fr;
        padding: 32px 32px 24px;
    }
    .page-toc { display: none; }
}

@media (max-width: 768px) {
    :root { --topbar-h: 56px; }

    .menu-toggle { display: inline-flex; }

    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        z-index: 60;
        box-shadow: var(--shadow-lg);
    }
    .sidebar.open { transform: translateX(0); }
    .sidebar-overlay.show { display: block; }

    .content-wrap {
        margin-left: 0;
        padding: 24px 20px;
    }
    .content h1 { font-size: 1.75rem; }
    .content h2 { font-size: 1.3rem; }
    .content pre { font-size: 12.5px; padding: 12px 14px; }
    .content table { font-size: 13px; }
    .content th, .content td { padding: 8px 10px; }

    .footer { margin-left: 0; padding: 20px; }

    .logo-version { display: none; }
}

/* ─── RTL (Arabic) ───────────────────────────────────────────── */
[dir="rtl"] {
    /* Sidebar moves to the right edge */
    .sidebar {
        left: auto;
        right: 0;
        border-right: 0;
        border-left: 1px solid var(--border);
    }
    .nav-section-title { text-align: right; }
    .nav-list a { text-align: right; }

    /* Content slides to make room on the right */
    .content-wrap, .footer { margin-left: 0; margin-right: var(--sidebar-w); }

    /* Right TOC becomes left TOC */
    .page-toc {
        border-left: 0;
        padding-left: 0;
        border-right: 1px solid var(--border);
        padding-right: 24px;
    }

    /* Lists / blockquotes flip their indentation */
    .content ul, .content ol { padding-left: 0; padding-right: 1.5em; }
    .content blockquote {
        border-left: 0;
        border-right: 3px solid var(--accent);
        border-radius: 6px 0 0 6px;
    }

    /* Heading anchor sits on the left of the heading text in RTL */
    .content h2 .anchor,
    .content h3 .anchor,
    .content h4 .anchor { margin-left: 0; margin-right: 8px; }

    /* Code blocks stay LTR — code is always read left-to-right. */
    .content pre, .content code, .content table { direction: ltr; text-align: left; }
    /* But re-align tables' captions / overall block to RTL flow */
    .content table { margin-left: auto; margin-right: 0; }

    /* Mobile sidebar slides in from the right */
    @media (max-width: 768px) {
        .sidebar { transform: translateX(100%); }
        .sidebar.open { transform: translateX(0); }
        .content-wrap, .footer { margin-right: 0; }
    }
}

/* Banner shown when AR translation is missing — falls back to EN. */
.lang-fallback {
    background: var(--accent-soft);
    color: var(--accent-text);
    border: 1px solid var(--accent);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 0 0 1.5em;
    font-size: 13.5px;
}
[dir="rtl"] .lang-fallback { text-align: right; }

/* ─── Scrollbar polish ───────────────────────────────────────── */
.sidebar::-webkit-scrollbar,
.page-toc::-webkit-scrollbar,
.content pre::-webkit-scrollbar {
    width: 8px; height: 8px;
}
.sidebar::-webkit-scrollbar-thumb,
.page-toc::-webkit-scrollbar-thumb,
.content pre::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}
.sidebar::-webkit-scrollbar-thumb:hover,
.page-toc::-webkit-scrollbar-thumb:hover,
.content pre::-webkit-scrollbar-thumb:hover {
    background: var(--text-faint);
}