/* ============================================================
   Prax — canonical exercise chrome
   Shared by all exercise pages. This file replaces the repeated
   per-page duplicate header/footer chrome so the exercise shell
   has a single source of truth.
   ============================================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(245, 240, 230, .9);
  -webkit-backdrop-filter: blur(10px) saturate(120%);
  backdrop-filter: blur(10px) saturate(120%);
  border-bottom: 1px solid var(--line);
}

.nav__in {
  max-width: var(--max);
  margin: 0 auto;
  padding: 11px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  color: var(--ink);
}

.brand__wm {
  font-family: var(--f-display);
  font-size: 19px;
  font-weight: 500;
  letter-spacing: -.01em;
  line-height: 1;
}

.brand__wm em {
  font-style: italic;
  font-weight: 400;
  color: var(--accent);
}

.brand__seg {
  font-family: var(--f-mono);
  font-size: 10.5px;
  font-weight: 400;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-mute);
  border-left: 1px solid var(--line-strong);
  padding-left: 10px;
  margin-left: 2px;
  display: inline-block;
}

@media (max-width:620px) {
  .brand__seg { display: none; }
}

.langSwitch {
  display: inline-flex;
  align-items: center;
  background: var(--paper-deep);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 3px;
  gap: 0;
  overflow: visible;
}

.langSwitch button {
  border: none;
  background: transparent;
  color: var(--ink-mute);
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .08em;
  text-transform: none;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: background .2s, color .2s;
}

.langSwitch button:hover { color: var(--ink); }
.langSwitch button.is-on,
.langSwitch button[aria-pressed="true"] {
  background: var(--ink);
  color: var(--paper);
}

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 100;
  opacity: .35;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='220' height='220'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='1.6' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.1 0 0 0 0 0.09 0 0 0 0 0.08 0 0 0 0.12 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

h1, .title, h1.title { font-weight: 350; }
.section__title, .brief__title { font-weight: 350; }

.foot {
  max-width: var(--max);
  margin: 0 auto;
  padding: var(--s-8, 64px) 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--s-5, 24px);
  font-size: 13px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
  margin-top: 70px;
}

.foot__brand {
  font-family: var(--f-display);
  font-size: 17px;
  color: var(--ink);
}

.foot__brand em {
  color: var(--accent);
  font-style: italic;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 999px;
  padding: 13px 24px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .01em;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: transform .15s, background .2s, color .2s, border-color .2s;
}

.btn:hover:not(:disabled) { transform: translateY(-1px); }
.btn--sm { padding: 9px 16px; font-size: 13.5px; }
.btn--accent {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--paper);
}
.btn--accent:hover:not(:disabled) {
  background: var(--accent-deep);
  border-color: var(--accent-deep);
}
.btn:disabled {
  opacity: .45;
  cursor: not-allowed;
  transform: none;
}

.actBar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  padding: 16px 18px;
  border-top: 1px solid var(--line);
  background: var(--paper-soft);
}