/* Shared shell: the header and the always-open sidebar that index.html got with v3.
   Prefixed sh- so it cannot collide with the older ../assets/style.css each inner
   page still uses for its own content. */
:root { --sh-bg: #ffffff; --sh-bg2: #f6f7f9; --sh-line: #e5e7eb; --sh-fg: #0f172a; --sh-body: #334155;
  --sh-dim: #64748b; --sh-accent: #2563eb; }
@media (prefers-color-scheme: dark) {
  :root { --sh-bg: #0b0f17; --sh-bg2: #111722; --sh-line: #232b3a; --sh-fg: #f1f5f9; --sh-body: #cbd5e1;
    --sh-dim: #8b95a7; --sh-accent: #4a9eff; }
}
.sh-top { border-bottom: 1px solid var(--sh-line); background: var(--sh-bg); }
.sh-top .sh-inner { max-width: 1040px; margin: 0 auto; padding: 0 22px; display: flex; align-items: center;
  justify-content: space-between; height: 58px; gap: 16px; }
.sh-brand { display: flex; align-items: center; gap: 10px; color: var(--sh-fg); font-weight: 600;
  font-size: 15px; text-decoration: none; }
.sh-brand img { width: 28px; height: 28px; border-radius: 7px; }
.sh-cta { border: 1px solid var(--sh-accent); background: var(--sh-accent); color: #fff; border-radius: 9px;
  padding: 7px 13px; font-size: 14px; font-weight: 600; text-decoration: none; white-space: nowrap; }

/* launch banner (2026-09-23, App Store launch + intro sale) */
.launch-banner { background: var(--sh-bg2); border-bottom: 1px solid var(--sh-line); padding: 10px 22px; text-align: center; }
.launch-banner p { margin: 0; }
.launch-banner-main { font-size: 14.5px; font-weight: 600; color: var(--sh-accent); }
.launch-banner-sub { margin-top: 2px !important; font-size: 12px; color: var(--sh-dim); font-weight: 400; }
@media (max-width: 480px) { .launch-banner-main { font-size: 13.5px; } }

.sh-rail { position: fixed; top: 0; left: 0; bottom: 0; width: 216px; overflow-y: auto; z-index: 20;
  background: var(--sh-bg2); border-right: 1px solid var(--sh-line); padding: 16px 18px 26px; }
.sh-rail h4 { margin: 18px 0 6px; font-size: 11px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--sh-dim); }
.sh-rail h4:first-of-type { margin-top: 0; }
.sh-rail a { display: block; padding: 7px 0; color: var(--sh-body); font-size: 14.5px;
  border-bottom: 1px solid var(--sh-line); text-decoration: none; }
.sh-rail a:hover { color: var(--sh-accent); }
.sh-rail .sh-cta { display: block; margin-top: 18px; text-align: center; border-bottom: 0; }
@media (min-width: 1000px) { body { padding-left: 216px; } }
@media (max-width: 999px) {
  .sh-rail { position: static; width: auto; height: auto; border-right: 0; border-bottom: 1px solid var(--sh-line); }
}

/* ── The rail collapses behind a Menu button on phones ────────────────────────
   Added 2026-09-06. Above 1000px nothing changes — the rail stays open, always,
   which is what he asked for on desktop. Markup comes from assets/rail-menu.js.
   2026-09-20 (Chris 03:20, "make the side menu on the mobile site stay on screen"):
   the Menu button sits in a slim bar that is position: sticky at the top of the
   viewport, and the open rail is a drawer over the page with a dimmed backdrop. */
.rail-bar, .rail-backdrop, .rail-close { display: none; }
@media (max-width: 999px) {
  .rail-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px;
    position: sticky; top: 0; z-index: 30; padding: 0 22px 0 0;
    background: var(--sh-bg2, #f6f7f9); border-bottom: 1px solid var(--sh-line, #e5e7eb); }
  .rail-toggle { display: flex; align-items: center; gap: 10px; flex: 1 1 auto; min-width: 0;
    padding: 12px 22px; font: inherit; font-size: 15px; font-weight: 600;
    color: var(--sh-fg, #0f172a); background: transparent; border: 0; cursor: pointer; text-align: left; }
  .rail-bars { display: inline-block; width: 18px; height: 2px; position: relative;
    background: currentColor; box-shadow: 0 -6px 0 currentColor, 0 6px 0 currentColor; }
  .rail-bar-cta { display: none; flex: none; white-space: nowrap; border: 1px solid var(--sh-accent, #2563eb);
    background: var(--sh-accent, #2563eb); color: #fff; border-radius: 8px; padding: 6px 11px;
    font-size: 13px; font-weight: 600; text-decoration: none; }
  .rail-bar-stuck .rail-bar-cta { display: inline-block; }
  .sh-rail, .rail { display: none; }
  /* Open: a drawer pinned to the left edge, above the bar and the backdrop. */
  .sh-rail.rail-open, .rail.rail-open { display: block; position: fixed; top: 0; left: 0; bottom: 0;
    width: min(300px, 86vw); height: auto; overflow-y: auto; -webkit-overflow-scrolling: touch;
    z-index: 40; padding: 16px 18px 26px; background: var(--sh-bg2, #f6f7f9);
    border-right: 1px solid var(--sh-line, #e5e7eb); border-bottom: 0;
    box-shadow: 0 8px 24px rgba(15,23,42,.18); }
  .rail-backdrop.rail-open { display: block; position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    z-index: 35; background: rgba(15,23,42,.45); }
  .rail-close { display: block; position: absolute; top: 8px; right: 10px; width: 36px; height: 36px;
    font: inherit; font-size: 26px; line-height: 36px; text-align: center; color: var(--sh-dim, #64748b);
    background: transparent; border: 0; cursor: pointer; }
  .sh-rail.rail-open h4:first-of-type, .rail.rail-open h4:first-of-type { margin-top: 0; padding-right: 36px; }
  html.rail-locked, html.rail-locked body { overflow: hidden; }
}