*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--chrome-height) + 16px); }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "cv11", "ss01";
}
img, svg { max-width: 100%; }
a { color: var(--color-link); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.icon { flex-shrink: 0; }

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  grid-template-rows: auto 1fr;
  grid-template-areas: "chrome chrome" "sidebar main";
  min-height: 100vh;
}

/* ---- Top chrome: header + surface tabs ---- */
.app-chrome {
  grid-area: chrome;
  min-width: 0;
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--color-bg) 86%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.app-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: var(--header-height);
  padding: 0 var(--space-5);
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
  text-decoration: none;
  white-space: nowrap;
}
.brand-logo { height: 26px; width: auto; display: block; }
.brand-logo-dark { display: none; }
:root[data-theme="dark"] .brand-logo-light { display: none; }
:root[data-theme="dark"] .brand-logo-dark { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .brand-logo-light { display: none; }
  :root:not([data-theme="light"]) .brand-logo-dark { display: block; }
}
.brand-name { font-weight: 700; font-size: 15px; letter-spacing: -0.01em; }
.brand-divider { width: 1px; height: 18px; background: var(--color-border-strong); }
.brand-sub { font-size: 12px; font-weight: 600; color: var(--color-text-muted); padding: 2px 8px; border-radius: 999px; background: var(--color-bg-inset); border: 1px solid var(--color-border); }
.app-header .spacer { flex: 1; }
.menu-toggle { display: none; }

.app-subnav {
  display: flex;
  align-items: stretch;
  gap: var(--space-1);
  height: var(--subnav-height);
  padding: 0 var(--space-5);
  overflow-x: auto;
  scrollbar-width: none;
}
.app-subnav::-webkit-scrollbar { display: none; }

.app-sidebar {
  grid-area: sidebar;
  position: sticky;
  top: var(--chrome-height);
  height: calc(100vh - var(--chrome-height));
  border-right: 1px solid var(--color-border);
  background: var(--color-bg);
  overflow-y: auto;
  padding: var(--space-4) var(--space-3) var(--space-7);
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-strong) transparent;
}

.app-main {
  grid-area: main;
  min-width: 0;
  overflow-x: clip;
}
.page {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-6) var(--space-6) var(--space-8);
}
.page-narrow { max-width: 860px; }

/* ---- Endpoint reference: prose left, sticky code right ---- */
.ref-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 480px);
  gap: var(--space-7);
  align-items: start;
}
.ref-aside {
  position: sticky;
  top: calc(var(--chrome-height) + var(--space-5));
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  max-height: calc(100vh - var(--chrome-height) - var(--space-6));
  overflow-y: auto;
  scrollbar-width: none;
}
.ref-aside::-webkit-scrollbar { display: none; }

@media (max-width: 1240px) {
  .ref-grid { grid-template-columns: minmax(0, 1fr); gap: var(--space-5); }
  .ref-aside { position: static; max-height: none; overflow: visible; }
}

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas: "chrome" "main";
  }
  .menu-toggle { display: inline-flex; }
  .brand-sub { display: none; }
  .app-header, .app-subnav { padding: 0 var(--space-4); }
  .app-sidebar {
    position: fixed;
    inset: var(--chrome-height) auto 0 0;
    height: auto;
    width: min(320px, 88vw);
    transform: translateX(-100%);
    transition: transform var(--transition-base);
    z-index: 40;
    box-shadow: var(--shadow-lg);
  }
  .app-sidebar.is-open { transform: translateX(0); }
  .sidebar-scrim {
    display: none;
    position: fixed;
    inset: var(--chrome-height) 0 0 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 35;
  }
  .sidebar-scrim.is-open { display: block; }
  .page { padding: var(--space-5) var(--space-4) var(--space-7); }
  .app-header { gap: var(--space-2); }
  .hero-actions .btn { flex: 1 1 auto; }
}

@media (max-width: 560px) {
  .hide-sm { display: none !important; }
}

.two-col {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: var(--space-5);
  align-items: start;
}
@media (max-width: 760px) {
  .two-col { grid-template-columns: minmax(0, 1fr); }
}