/* ══════════════════════════════════════════════════
   Qbea — Shared stylesheet (all pages)
   Single source of truth for variables, header,
   nav, mobile menu, theme toggle, footer.
   ══════════════════════════════════════════════════ */

/* ── Light theme (default) ── */
:root, [data-theme="light"] {
  --bg: #ffffff;
  --surface: #f6f7f9;
  --surface-raised: #f0f1f3;
  --border: #e2e4e8;
  --border-light: #d0d3d8;
  --text: #1f2328;
  --text-strong: #111418;
  --text-muted: #656d76;
  --accent: #2563eb;
  --accent-dim: rgba(37,99,235,0.08);
  --green: #1a7f37;
  --header-bg: rgba(255,255,255,0.92);
  --table-zebra: rgba(246,247,249,0.6);
  --radius: 6px;
  --font: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "Fira Code", ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ── Dark theme ── */
[data-theme="dark"] {
  --bg: #1b1f27;
  --surface: #242830;
  --surface-raised: #2a2f38;
  --border: #333942;
  --border-light: #3d4450;
  --text: #e0e4e8;
  --text-strong: #f0f2f5;
  --text-muted: #b0b8c4;
  --accent: #5b9bd5;
  --accent-dim: rgba(91,155,213,0.12);
  --green: #4aba7a;
  --header-bg: rgba(27,31,39,0.92);
  --table-zebra: rgba(36,40,48,0.4);
}

/* ── Reset ── */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-y: scroll; }

/* ── Body ── */
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Utility ── */
.hidden { display: none !important; }

/* ══════════ Header ══════════ */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.header-left { position: absolute; left: 24px; display: flex; align-items: center; gap: 12px; }
.header-right { position: absolute; right: 24px; display: flex; align-items: center; gap: 12px; }
.header-nav { display: flex; align-items: center; gap: 8px; }

/* ── Logo ── */
.logo {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-strong);
  text-decoration: none;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
}
.logo-icon { width: 20px; height: 20px; margin-right: 8px; }
[data-theme="dark"] .logo-icon { filter: invert(0.85); }
.logo-sep { color: var(--border-light); margin: 0 4px; }
.logo-sub { color: var(--text-muted); font-weight: 400; font-size: 13px; }
.logo-badge {
  font-size: 10px;
  background: var(--accent-dim);
  color: var(--accent);
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* ── Nav links ── */
.nav-link {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--text-strong);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  transition: border-color 0.15s, background 0.15s;
}
.nav-link:hover { border-color: var(--border); }
.nav-active { border-color: var(--border) !important; }
.header-nav .nav-active { pointer-events: none; cursor: default; }
.nav-link .external { font-size: 10px; font-weight: 700; opacity: 0.8; margin-left: 2px; }

/* ── Theme toggle (SVG sun/moon) ── */
.theme-toggle {
  background: none;
  border: none;
  padding: 4px;
  cursor: pointer;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  transition: color 0.15s;
}
.theme-toggle:hover { color: var(--text); }
.theme-toggle svg { width: 20px; height: 20px; }
.theme-toggle .sun-icon { display: block; }
.theme-toggle .moon-icon { display: none; }
[data-theme="dark"] .theme-toggle .sun-icon { display: none; }
[data-theme="dark"] .theme-toggle .moon-icon { display: block; }

/* ── Burger menu ── */
.burger {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px;
  cursor: pointer;
  color: var(--text-muted);
}
.burger svg { display: block; width: 20px; height: 20px; }
.burger:hover { border-color: var(--accent); background: var(--accent-dim); }

/* ── Fullscreen mobile menu ── */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  background: var(--bg);
  z-index: 200;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 48px 24px 24px;
  overflow-y: auto;
}
.mobile-menu.open { display: flex; }
.mobile-menu-close {
  position: absolute;
  top: 16px; right: 16px;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px;
  cursor: pointer;
  color: var(--text-muted);
}
.mobile-menu-close:hover { border-color: var(--accent); background: var(--accent-dim); }
.mobile-menu-close svg { display: block; width: 20px; height: 20px; }
.mobile-menu a {
  font-family: var(--mono);
  font-size: 16px;
  color: var(--text-strong);
  text-decoration: none;
  padding: 8px 32px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  min-width: 200px;
  text-align: center;
  transition: border-color 0.15s, background 0.15s;
}
.mobile-menu a:hover { border-color: var(--accent); background: var(--accent-dim); }
.mobile-menu .theme-toggle {
  padding: 8px 32px;
  min-width: 200px;
  gap: 8px;
  font-size: 14px;
}

/* ══════════ Footer ══════════ */
footer {
  text-align: center;
  padding: 24px;
  font-size: 13px;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}
footer a { color: var(--accent); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ══════════ Responsive ══════════ */
@media (max-width: 860px) {
  .header-nav { display: none; }
  .header-right .theme-toggle { display: none; }
  .burger { display: block; }
}