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

:root {
    --color-bg: #ffffff;
    --color-surface: #f7f7f5;
    --color-border: #e5e5e2;
    --color-text: #1a1a1a;
    --color-text-muted: #6b6b6b;
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --sidebar-width: 240px;
    --header-height: 56px;
    --font-sans: system-ui, -apple-system, sans-serif;
    --font-mono: ui-monospace, monospace;
}

body {
    font-family: var(--font-sans);
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
}

/* Header */

.app-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    padding: 0 24px;
    z-index: 100;
    gap: 16px;
}

.app-sidebar-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-height: 32px;
    padding: 5px 9px;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    background: var(--color-bg);
    color: var(--color-text);
    font: inherit;
    font-size: 13px;
    cursor: pointer;
}

.app-sidebar-toggle:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.app-sidebar-toggle-icon,
.app-sidebar-toggle-icon::before,
.app-sidebar-toggle-icon::after {
    display: block;
    width: 14px;
    height: 1px;
    background: currentColor;
}

.app-sidebar-toggle-icon {
    position: relative;
}

.app-sidebar-toggle-icon::before,
.app-sidebar-toggle-icon::after {
    content: "";
    position: absolute;
    left: 0;
}

.app-sidebar-toggle-icon::before {
    top: -5px;
}

.app-sidebar-toggle-icon::after {
    top: 5px;
}

.app-header-brand {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.app-header-tagline {
    font-size: 13px;
    color: var(--color-text-muted);
    border-left: 1px solid var(--color-border);
    padding-left: 16px;
}

/* Layout */

.app-layout {
    display: flex;
    padding-top: var(--header-height);
    min-height: 100vh;
}

/* Sidebar */

.app-sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    position: fixed;
    top: var(--header-height);
    bottom: 0;
    left: 0;
    overflow-y: auto;
    background: var(--color-surface);
    border-right: 1px solid var(--color-border);
    padding: 24px 0;
    transition: transform 160ms ease;
    z-index: 80;
}

.app-sidebar-collapsed .app-sidebar {
    transform: translateX(calc(-1 * var(--sidebar-width)));
}

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

.app-nav-heading {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    padding: 0 20px 8px;
}

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

.app-nav-link {
    display: block;
    padding: 6px 20px;
    font-size: 14px;
    color: var(--color-text);
    text-decoration: none;
    border-left: 2px solid transparent;
}

.app-nav-link:hover {
    background: var(--color-border);
    color: var(--color-accent);
}

.app-nav-link.app-nav-link--active {
    color: var(--color-accent);
    border-left-color: var(--color-accent);
    background: rgba(37, 99, 235, 0.06);
}

/* Main */

.app-main {
    flex: none;
    margin-left: var(--sidebar-width);
    width: calc(100% - var(--sidebar-width));
    padding: 48px 56px;
    min-width: 0;
    max-width: none;
    overflow-x: hidden;
}

.app-sidebar-collapsed .app-main {
    margin-left: 0;
    width: 100%;
}

.app-page-title {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.app-page-lead {
    font-size: 16px;
    color: var(--color-text-muted);
    margin-bottom: 40px;
    max-width: 560px;
}

.app-section {
    margin-bottom: 40px;
}

.app-section-title {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    margin-bottom: 12px;
}

.app-card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}

.app-card {
    display: block;
    padding: 16px 18px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    text-decoration: none;
    color: var(--color-text);
}

.app-card:hover {
    border-color: var(--color-accent);
}

.app-card-title {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 4px;
}

.app-card-desc {
    font-size: 13px;
    color: var(--color-text-muted);
}

/* Term grid */

.app-term-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 8px;
}

.app-term-card {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 12px 14px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    text-decoration: none;
}

.app-term-card:hover {
    border-color: var(--color-accent);
}

.app-term-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text);
}

.app-term-authority {
    font-size: 12px;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

/* Term detail */

.app-term-header {
    margin-bottom: 32px;
}

.app-term-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.app-badge {
    font-size: 12px;
    font-weight: 500;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--color-border);
    color: var(--color-text-muted);
}

.app-badge--canonical {
    background: #dcfce7;
    color: #166534;
}

.app-badge--reserved {
    background: #fef3c7;
    color: #92400e;
}

.app-back-link {
    display: inline-block;
    margin-top: 40px;
    font-size: 14px;
    color: var(--color-accent);
    text-decoration: none;
}

.app-back-link:hover {
    text-decoration: underline;
}

.app-placeholder-notice {
    font-style: italic;
}

/* Prose (rendered markdown) */

.app-prose {
    max-width: none;
    overflow-wrap: anywhere;
}

.app-prose h1 {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin: 32px 0 12px;
}

.app-prose h2 {
    font-size: 16px;
    font-weight: 600;
    margin: 28px 0 8px;
    padding-top: 12px;
    border-top: 1px solid var(--color-border);
}

.app-prose h3 {
    font-size: 14px;
    font-weight: 600;
    margin: 20px 0 6px;
}

.app-prose p {
    margin: 0 0 14px;
    max-width: 76ch;
}

.app-prose ul,
.app-prose ol {
    padding-left: 20px;
    margin: 0 0 14px;
    max-width: 76ch;
}

.app-prose li {
    margin-bottom: 4px;
}

.app-prose code {
    font-family: var(--font-mono);
    font-size: 13px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 3px;
    padding: 1px 5px;
    overflow-wrap: anywhere;
}

.app-prose pre {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 16px;
    max-width: 100%;
    overflow-x: auto;
    margin: 0 0 16px;
}

.app-prose pre code {
    background: none;
    border: none;
    padding: 0;
    font-size: 13px;
}

.app-prose strong {
    font-weight: 600;
}

.app-prose a {
    color: var(--color-accent);
    text-decoration: none;
}

.app-prose a:hover {
    text-decoration: underline;
}

.app-prose table {
    display: block;
    width: 100%;
    max-width: 100%;
    overflow-x: auto;
    border-collapse: collapse;
    font-size: 14px;
    margin: 0 0 20px;
}

.app-prose img,
.app-prose video,
.app-prose svg {
    max-width: 100%;
    height: auto;
}

.app-prose th {
    text-align: left;
    font-weight: 600;
    padding: 8px 12px;
    border-bottom: 2px solid var(--color-border);
}

.app-prose td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
}

.app-prose tr:last-child td {
    border-bottom: none;
}

/* Footer */

.app-footer {
    margin-left: var(--sidebar-width);
    padding: 20px 56px;
    border-top: 1px solid var(--color-border);
    font-size: 13px;
    color: var(--color-text-muted);
}

.app-sidebar-collapsed .app-footer {
    margin-left: 0;
}

@media (max-width: 860px) {
    :root {
        --sidebar-width: min(82vw, 300px);
    }

    .app-header {
        padding: 0 14px;
        gap: 10px;
    }

    .app-header-tagline {
        display: none;
    }

    .app-sidebar {
        transform: translateX(calc(-1 * var(--sidebar-width)));
        box-shadow: 16px 0 32px rgba(0, 0, 0, 0.08);
    }

    body:not(.app-sidebar-collapsed) .app-sidebar {
        transform: translateX(0);
    }

    .app-main,
    .app-sidebar-collapsed .app-main {
        width: 100%;
        margin-left: 0;
        padding: 28px 18px;
    }

    .app-footer,
    .app-sidebar-collapsed .app-footer {
        margin-left: 0;
        padding: 18px;
    }
}