/* ==========================================================================
   Hao theme — design tokens + base + shell (header/footer).
   Page-level styles live in the sections marked OWNED BY below, or in
   separate files imported at the bottom.
   ========================================================================== */

:root {
  /* Colour (slate, shadcn-like) */
  --hx-bg: #ffffff;
  --hx-bg-muted: #f8fafc;
  --hx-bg-subtle: #f1f5f9;
  --hx-fg: #020817;
  --hx-fg-strong: #0f172a;
  --hx-fg-muted: #64748b;
  --hx-fg-faint: #94a3b8;
  --hx-border: #e2e8f0;
  --hx-border-strong: #cbd5e1;
  --hx-ring: #94a3b8;
  --hx-accent: #0f172a;
  --hx-accent-fg: #f8fafc;
  --hx-highlight: #2563eb;
  --hx-code-bg: #f8fafc;

  /* Shape & depth */
  --hx-radius-sm: 4px;
  --hx-radius: 6px;
  --hx-radius-lg: 10px;
  --hx-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --hx-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.06);

  /* Type */
  --hx-font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --hx-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  /* Layout */
  --hx-w-content: 720px;
  --hx-w-wide: 960px;
  --hx-gutter: 20px;
  --hx-header-h: 56px;

  /* Motion */
  --hx-ease: cubic-bezier(0.2, 0, 0, 1);
  --hx-dur: 180ms;

  /* NexT-compat aliases so legacy inline page styles (notes, playground) follow the scheme */
  --text-color: var(--hx-fg);
  --text-color-light: var(--hx-fg-muted);
  --link-color: var(--hx-fg-strong);
  --content-bg-color: var(--hx-bg);

  color-scheme: light;
}

:root[data-scheme="dark"] {
  --hx-bg: #020817;
  --hx-bg-muted: #0b1324;
  --hx-bg-subtle: #111a2e;
  --hx-fg: #f8fafc;
  --hx-fg-strong: #ffffff;
  --hx-fg-muted: #94a3b8;
  --hx-fg-faint: #64748b;
  --hx-border: #1e293b;
  --hx-border-strong: #334155;
  --hx-ring: #475569;
  --hx-accent: #f8fafc;
  --hx-accent-fg: #0f172a;
  --hx-highlight: #60a5fa;
  --hx-code-bg: #0b1324;
  --hx-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --hx-shadow: 0 4px 10px rgba(0, 0, 0, 0.4);
  color-scheme: dark;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--hx-header-h) + 16px); }
@view-transition { navigation: auto; }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--hx-bg);
  color: var(--hx-fg);
  font: 16px/1.7 var(--hx-font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg, video { max-width: 100%; }
img { height: auto; }
a { color: inherit; }
::selection { background: color-mix(in srgb, var(--hx-highlight) 22%, transparent); }
:focus-visible { outline: 2px solid var(--hx-ring); outline-offset: 2px; border-radius: var(--hx-radius-sm); }
hr { border: 0; border-top: 1px solid var(--hx-border); margin: 32px 0; }
kbd, code, pre, samp { font-family: var(--hx-mono); }

.hx-skip { position: absolute; left: -9999px; }
.hx-skip:focus { left: 16px; top: 8px; z-index: 100; padding: 6px 10px; background: var(--hx-bg); border: 1px solid var(--hx-border); border-radius: var(--hx-radius); }

.hx-main { flex: 1; width: 100%; padding: 40px 0 64px; animation: hx-fade-in 360ms var(--hx-ease) both; }
.hx-container { max-width: calc(var(--hx-w-content) + var(--hx-gutter) * 2); margin: 0 auto; padding: 0 var(--hx-gutter); }
.hx-container-wide { max-width: calc(var(--hx-w-wide) + var(--hx-gutter) * 2); margin: 0 auto; padding: 0 var(--hx-gutter); }

@keyframes hx-fade-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  @view-transition { navigation: none; }
}

/* ---------- Primitives ---------- */
.hx-card {
  border: 1px solid var(--hx-border);
  border-radius: var(--hx-radius-lg);
  background: var(--hx-bg);
  box-shadow: var(--hx-shadow-sm);
}
.hx-muted { color: var(--hx-fg-muted); }
.hx-eyebrow { margin: 0 0 12px; color: var(--hx-fg-muted); font-size: 13px; font-weight: 500; letter-spacing: 0.02em; }
.hx-badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 1px 8px; min-height: 22px;
  border: 1px solid var(--hx-border); border-radius: 999px;
  background: var(--hx-bg-muted); color: var(--hx-fg-muted);
  font-size: 12px; line-height: 1.5; text-decoration: none; white-space: nowrap;
  transition: color var(--hx-dur), border-color var(--hx-dur), background var(--hx-dur);
}
a.hx-badge:hover { color: var(--hx-fg); border-color: var(--hx-border-strong); }
.hx-btn {
  display: inline-flex; align-items: center; gap: 6px;
  height: 36px; padding: 0 14px;
  border: 1px solid var(--hx-border); border-radius: var(--hx-radius);
  background: var(--hx-bg); color: var(--hx-fg);
  font: 500 14px/1 var(--hx-font); text-decoration: none; cursor: pointer;
  box-shadow: var(--hx-shadow-sm);
  transition: background var(--hx-dur), border-color var(--hx-dur);
}
.hx-btn:hover { background: var(--hx-bg-muted); border-color: var(--hx-border-strong); }
.hx-btn-primary { background: var(--hx-accent); border-color: var(--hx-accent); color: var(--hx-accent-fg); }
.hx-btn-primary:hover { background: var(--hx-accent); opacity: 0.9; }
.hx-icon-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  min-width: 34px; height: 34px; padding: 0 8px;
  border: 1px solid transparent; border-radius: var(--hx-radius);
  background: transparent; color: var(--hx-fg-muted); cursor: pointer;
  transition: color var(--hx-dur), background var(--hx-dur), border-color var(--hx-dur);
}
.hx-icon-btn:hover { color: var(--hx-fg); background: var(--hx-bg-subtle); }
.hx-kbd {
  padding: 1px 5px; border: 1px solid var(--hx-border); border-radius: var(--hx-radius-sm);
  background: var(--hx-bg-muted); color: var(--hx-fg-muted); font-size: 11px; line-height: 1.4;
}

/* ---------- Header ---------- */
.hx-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--hx-bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--hx-border);
  box-shadow: var(--hx-shadow-sm);
}
.hx-header-inner {
  display: flex; align-items: center; gap: 24px;
  max-width: calc(var(--hx-w-wide) + var(--hx-gutter) * 2);
  height: var(--hx-header-h); margin: 0 auto; padding: 0 var(--hx-gutter);
}
.hx-brand { display: inline-flex; align-items: center; gap: 10px; color: var(--hx-fg-strong); font-weight: 700; text-decoration: none; white-space: nowrap; }
.hx-brand-avatar { width: 28px; height: 28px; border-radius: 999px; border: 1px solid var(--hx-border); object-fit: cover; }
.hx-nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.hx-nav-link {
  padding: 6px 10px; border-radius: var(--hx-radius);
  color: var(--hx-fg-muted); font-size: 14px; font-weight: 500; text-decoration: none;
  transition: color var(--hx-dur), background var(--hx-dur);
}
.hx-nav-link:hover { color: var(--hx-fg); background: var(--hx-bg-subtle); }
.hx-nav-link.is-active { color: var(--hx-fg-strong); }
.hx-header-actions { display: flex; align-items: center; gap: 2px; }
.hx-menu-toggle { display: none; }
:root[data-scheme="dark"] .hx-i-sun, :root:not([data-scheme="dark"]) .hx-i-moon { display: none; }

.hx-progress {
  position: absolute; left: 0; bottom: -1px; height: 2px; width: 100%;
  background: var(--hx-fg-strong);
  transform-origin: 0 50%; transform: scaleX(var(--hx-progress, 0));
  opacity: 0; transition: opacity var(--hx-dur);
}
.hx-progress.is-visible { opacity: 1; }

@media (max-width: 760px) {
  .hx-header-inner { gap: 8px; }
  .hx-menu-toggle { display: inline-flex; }
  .hx-search-trigger .hx-kbd { display: none; }
  .hx-header-actions { margin-left: auto; }
  .hx-nav {
    position: absolute; top: var(--hx-header-h); left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    margin: 0; padding: 8px var(--hx-gutter) 12px;
    background: var(--hx-bg); border-bottom: 1px solid var(--hx-border);
    box-shadow: var(--hx-shadow);
    display: none;
  }
  .hx-header.is-menu-open .hx-nav { display: flex; }
  .hx-nav-link { padding: 10px 8px; font-size: 15px; }
}

/* ---------- Footer ---------- */
.hx-footer { border-top: 1px solid var(--hx-border); color: var(--hx-fg-muted); font-size: 13px; }
.hx-footer-inner {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px;
  max-width: calc(var(--hx-w-wide) + var(--hx-gutter) * 2);
  margin: 0 auto; padding: 24px var(--hx-gutter);
}
.hx-footer-links { display: flex; flex-wrap: wrap; gap: 16px; }
.hx-footer-links a { text-decoration: none; }
.hx-footer-links a:hover { color: var(--hx-fg); }
.hx-back-top {
  position: fixed; right: 20px; bottom: 20px; z-index: 40;
  border-color: var(--hx-border); background: var(--hx-bg); box-shadow: var(--hx-shadow);
  opacity: 0; pointer-events: none; transform: translateY(8px);
  transition: opacity var(--hx-dur), transform var(--hx-dur);
}
.hx-back-top.is-visible { opacity: 1; pointer-events: auto; transform: none; }

/* ---------- Localisation (zh / en) ---------- */
/* Pairs: <span data-l="zh">…</span><span data-l="en">…</span>; html[data-locale] picks one. */
:root[data-locale="zh"] [data-l="en"],
:root[data-locale="en"] [data-l="zh"] { display: none !important; }
.hx-locale-toggle { font: 600 12px/1 var(--hx-font); letter-spacing: 0.02em; }