/* ==========================================================================
   HEADER — geometric logo (circle / square / triangle) + 4px bottom rule.
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--white);
  border-bottom: var(--bw-strong) solid var(--border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s4);
  min-height: 72px;
}

/* --- Logo: the three Bauhaus forms in the three primaries ---------------- */

.logo {
  display: flex;
  align-items: center;
  gap: var(--s3);
  text-decoration: none;
  font-weight: 900;
  font-size: 1.125rem;
  text-transform: uppercase;
  letter-spacing: -0.02em;
  line-height: 1;
}

.logo:hover {
  color: inherit;
}

.logo__marks {
  display: flex;
  align-items: center;
  gap: var(--s1);
}

.logo__mark {
  width: 18px;
  height: 18px;
  border: 2px solid var(--border);
  transition: transform var(--dur) var(--ease);
}

.logo__mark--circle {
  background: var(--red);
  border-radius: 9999px;
}

.logo__mark--square {
  background: var(--blue);
}

/* Triangle can't carry a border via clip-path, so it is a solid form. */
.logo__mark--triangle {
  background: var(--yellow);
  border: 0;
  clip-path: polygon(50% 0%, 0% 100%, 100% 100%);
}

.logo:hover .logo__mark {
  transform: scale(1.15);
}

.logo__text span {
  display: block;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--blue);
}

/* --- Navigation ----------------------------------------------------------- */

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: var(--yellow);
  border: var(--bw) solid var(--border);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  color: var(--fg);
}

.nav-toggle:active {
  transform: translate(2px, 2px);
  box-shadow: none;
}

.site-nav {
  display: none;
}

/* List resets apply in both states — desktop never sets data-open. */
.site-nav ul {
  display: flex;
  flex-direction: column;
  gap: var(--s4);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav a {
  font-weight: 700;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  text-decoration: none;
}

/* Mobile: panel drops below the header bar. */
.site-nav[data-open="true"] {
  display: block;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  background: var(--white);
  border-bottom: var(--bw-strong) solid var(--border);
  padding: var(--s4) var(--pad-x) var(--s6);
}

.site-nav[data-open="true"] .site-nav__cta {
  margin-top: var(--s4);
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  /* Desktop: full horizontal nav, position/panel styles reset. */
  .site-nav,
  .site-nav[data-open="true"] {
    display: block;
    position: static;
    border: 0;
    padding: 0;
    background: none;
  }

  .site-nav ul,
  .site-nav[data-open="true"] ul {
    flex-direction: row;
    align-items: center;
    gap: var(--s6);
  }

  .site-nav[data-open="true"] .site-nav__cta {
    margin-top: 0;
  }

  .site-nav a:not(.btn):hover {
    color: var(--red);
  }
}