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

:root {
    --bg-primary: #0d1117;
    --bg-card: #161b22;
    --bg-sidebar: #161b22;
    --border: #30363d;
    --accent: #58a6ff;
    --accent-hover: #79c0ff;
    --text: #e6edf3;
    --text-muted: #8b949e;
    --text-dim: #484f58;

    /* Layout tokens — reference these in all layout rules */
    --content-max-width: 1200px;
    --sidebar-width: 240px;
    --sidebar-width-md: 200px;
    --doc-line-width: 72ch;
}

body {
    background: var(--bg-primary);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* Links */
.links { margin-top: 10px; }

.links a {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.85em;
    margin-right: 16px;
    transition: color 0.15s;
}

.links a:hover { color: var(--accent-hover); }

.nav-link { font-weight: 600; }

/* ============================================
   Grid page (index.html)
   ============================================ */
.page-grid { min-height: 100vh; }

.page-grid header {
    text-align: center;
    padding: 40px 20px 28px;
}

.page-grid .header-inner {
    max-width: 860px;
    margin: 0 auto;
}

.page-grid header h1 {
    font-size: 1.6em;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
}

.page-grid header p {
    color: var(--text-muted);
    font-size: 0.9em;
    margin-top: 6px;
}

/* Demo grid */
.demo-section {
    display: flex;
    gap: 20px;
    max-width: var(--content-max-width);
    margin: 0 auto 28px;
    padding: 0 24px;
}

.demo-section-left {
    flex-shrink: 0;
    width: 320px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
}

.demo-section-right {
    flex: 1;
    min-width: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    max-height: 340px;
    overflow-y: auto;
}

.demo-section.single-column {
    display: block;
}

.demo-section.single-column .demo-section-left {
    width: 100%;
}

.demo-title {
    padding: 10px 14px;
    font-size: 0.85em;
    font-weight: 600;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
    text-transform: capitalize;
}

.demo-iframe {
    width: 100%;
    min-height: 280px;
    border: none;
    background: #000;
}

/* ============================================
   Sidebar page (basic.html)
   ============================================ */
.page-sidebar {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

.page-sidebar aside {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    padding: 20px 16px 14px;
    border-bottom: 1px solid var(--border);
}

.sidebar-header h1 {
    font-size: 1.1em;
    font-weight: 700;
    color: var(--text);
}

.sidebar-header p {
    font-size: 0.78em;
    color: var(--text-muted);
    margin-top: 2px;
}

#demo-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px 0;
}

.demo-item {
    display: block;
    padding: 8px 16px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.85em;
    border-left: 3px solid transparent;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
    text-transform: capitalize;
}

.demo-item:hover {
    background: rgba(88, 166, 255, 0.06);
    color: var(--text);
}

.demo-item.active {
    background: rgba(88, 166, 255, 0.1);
    color: var(--accent);
    border-left-color: var(--accent);
}

.demo-item strong {
    font-weight: 500;
}

.page-sidebar main {
    flex: 1;
    min-width: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    position: relative;
    overflow: auto;
}

#placeholder {
    color: var(--text-dim);
    font-size: 0.9em;
}

/* Demo wrapper (sidebar page: iframe + doc) */
#demo-wrapper {
    flex-direction: column;
    width: 100%;
    max-width: var(--content-max-width);
    height: 100%;
    margin: 0 auto;
    overflow: hidden;
}

#demo-wrapper #demo-frame {
    width: 100%;
    height: 320px;
    min-height: 200px;
    border: none;
    background: #000;
    flex-shrink: 0;
}

#demo-wrapper #demo-doc {
    flex: 1;
    overflow-y: auto;
    /* Center-constrain long-form text for readability */
    padding-left: max(20px, calc(50% - var(--doc-line-width) / 2));
    padding-right: max(20px, calc(50% - var(--doc-line-width) / 2));
}

/* ============================================
   Documentation panel
   ============================================ */
.doc-panel {
    padding: 16px 20px;
    font-size: 0.85em;
    line-height: 1.6;
    color: var(--text-muted);
    border-top: 1px solid var(--border);
}

.doc-panel h1, .doc-panel h2, .doc-panel h3 {
    color: var(--text);
    margin: 12px 0 6px;
    font-size: 1em;
}

.doc-panel h1 { font-size: 1.15em; }

.doc-panel p { margin: 6px 0; }

.doc-panel ul, .doc-panel ol {
    padding-left: 20px;
    margin: 6px 0;
}

.doc-panel table {
    width: 100%;
    border-collapse: collapse;
    margin: 8px 0;
    font-size: 0.9em;
}

.doc-panel th, .doc-panel td {
    border: 1px solid var(--border);
    padding: 6px 10px;
    text-align: left;
}

.doc-panel th {
    background: rgba(88, 166, 255, 0.08);
    color: var(--text);
}

.doc-panel code {
    background: rgba(110, 118, 129, 0.15);
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 0.9em;
}

.doc-loading {
    color: var(--text-dim);
    font-style: italic;
}

/* Grid page: doc panel in section */
.demo-section-right.doc-panel {
    border-top: none;
}

/* Scrollbar */
#demo-list::-webkit-scrollbar { width: 4px; }
#demo-list::-webkit-scrollbar-track { background: transparent; }
#demo-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* ============================================
   Responsive — 3-tier breakpoints
   ============================================ */

/* Tier 2: tablet / mid-size (769px – 1199px) */
@media (min-width: 769px) and (max-width: 1199px) {
    .page-sidebar aside {
        width: var(--sidebar-width-md);
        min-width: var(--sidebar-width-md);
    }
    .demo-item { font-size: 0.8em; padding: 7px 12px; }
}

/* Tier 1: mobile (≤ 768px) */
@media (max-width: 768px) {
    .demo-section { flex-direction: column; padding: 0 12px; }
    .demo-section-left { width: 100%; }
    .page-sidebar { flex-direction: column; }
    .page-sidebar aside { width: 100%; min-width: 0; max-height: 40vh; border-right: none; border-bottom: 1px solid var(--border); }
    #demo-wrapper #demo-doc {
        padding-left: 12px;
        padding-right: 12px;
    }
}