/* ==========================================================================
   RenderFrost SMP — 05 Global navbar
   ========================================================================== */

.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 120;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background-color var(--t-base) var(--ease),
    border-color var(--t-base) var(--ease), backdrop-filter var(--t-base) var(--ease);
}

.nav.is-scrolled {
  background: rgba(8, 7, 16, 0.78);
  backdrop-filter: blur(18px) saturate(140%);
  border-bottom-color: var(--hairline);
}

.nav__inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
}

.nav__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  margin-right: auto;
  color: var(--frost-100);
  text-decoration: none;
}

.nav__mark { width: 30px; height: 30px; flex: none; color: var(--violet-300); }

.nav__wordmark { display: flex; flex-direction: column; line-height: 1; }

.nav__wordmark b {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--frost-100);
}

.nav__wordmark span {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.34em;
  color: var(--text-faint);
  margin-top: 3px;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.8rem;
  border-radius: var(--r-sm);
  color: var(--text-secondary);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: color var(--t-fast) var(--ease),
    background-color var(--t-fast) var(--ease);
}

.nav__link:hover { color: var(--frost-100); background: var(--surface-3); }

/* Active state uses an underline marker plus weight, so it is not colour-only. */
.nav__link[aria-current="page"] { color: var(--frost-100); font-weight: 600; }

.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0.8rem;
  right: 0.8rem;
  bottom: 0.15rem;
  height: 1px;
  background: var(--violet-400);
}

.nav__link::before {
  content: "";
  position: absolute;
  left: 0.8rem;
  right: 0.8rem;
  bottom: 0.15rem;
  height: 1px;
  background: var(--violet-400);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--t-base) var(--ease);
}

.nav__link:hover::before { transform: scaleX(1); }
.nav__link[aria-current="page"]::before { display: none; }

.nav__actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: 0.5rem;
}

.nav__toggle {
  display: none;
  min-height: 40px;
  width: 40px;
  padding: 0;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: var(--surface-1);
  cursor: pointer;
}

.nav__toggle-box {
  display: grid;
  place-items: center;
  width: 18px;
  height: 12px;
  margin-inline: auto;
  position: relative;
}

.nav__toggle-box span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.5px;
  background: var(--frost-200);
  border-radius: 2px;
  transition: transform var(--t-base) var(--ease-out),
    opacity var(--t-fast) var(--ease);
}

.nav__toggle-box span:nth-child(1) { transform: translateY(-4px); }
.nav__toggle-box span:nth-child(2) { transform: translateY(4px); }

.nav__toggle[aria-expanded="true"] .nav__toggle-box span:nth-child(1) {
  transform: rotate(45deg);
}

.nav__toggle[aria-expanded="true"] .nav__toggle-box span:nth-child(2) {
  transform: rotate(-45deg);
}

/* ----------------------------------------------------------- Mobile drawer */

.drawer {
  position: fixed;
  inset: var(--nav-h) 0 0;
  z-index: 110;
  display: grid;
  align-content: start;
  gap: 0.25rem;
  padding: 1.25rem var(--gutter) 2rem;
  background: rgba(7, 6, 14, 0.97);
  backdrop-filter: blur(20px);
  overflow-y: auto;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity var(--t-base) var(--ease-out),
    transform var(--t-base) var(--ease-out), visibility var(--t-base) linear;
}

.drawer.is-open { opacity: 1; visibility: visible; transform: none; }

.drawer__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0.25rem;
  border-bottom: 1px solid var(--hairline);
  color: var(--text-secondary);
  font-size: 1.0625rem;
  font-weight: 500;
  text-decoration: none;
}

.drawer__link[aria-current="page"] { color: var(--frost-100); }

.drawer__link span {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  color: var(--text-faint);
}

.drawer__cta { margin-top: 1.5rem; }
.drawer__cta .btn { width: 100%; }