/* header.css — fonte de verdade compartilhada (linkado nas 4 páginas + 404) */

.header{
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-4) var(--gutter);
  color: var(--paper);
  pointer-events: none;
  background: linear-gradient(180deg,
    oklch(0.05 0.005 65 / 0.65) 0%,
    oklch(0.05 0.005 65 / 0.25) 65%,
    oklch(0.05 0.005 65 / 0) 100%);
  transition:
    background 500ms var(--ease-quart),
    backdrop-filter 500ms var(--ease-quart),
    padding 500ms var(--ease-quart);
}
.header > *{ pointer-events: auto; }

.header__brand{
  display: inline-block;
  line-height: 0;
}
.header__brand-mark{
  height: clamp(2.8rem, 5vw, 3.8rem);
  width: auto;
  display: block;
  transition: transform var(--t-base) var(--ease-quart), height 400ms var(--ease-quart);
}
.header__brand:hover .header__brand-mark{
  transform: rotate(-6deg);
}

.header__nav{
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, 2vw, 2rem);
  font-family: var(--font-body);
  font-weight: 700;
  font-size: clamp(0.98rem, 1.2vw, 1.15rem);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.header__nav a{
  position: relative;
  transition: opacity var(--t-base) var(--ease-quart);
}
.header__nav a:hover{ opacity: 0.55; }
.header__nav a[data-active]::after{
  content: "";
  position: absolute;
  left: 0; right: 0;
  bottom: -0.5em;
  height: 1.5px;
  background: var(--accent, currentColor);
}

/* shrinks ao rolar 80px+ */
.header.is-scrolled{
  padding: var(--space-2) var(--gutter);
  background: oklch(0.05 0.005 65 / 0.88);
  backdrop-filter: blur(16px) saturate(1.2);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
}
.header.is-scrolled .header__brand-mark{
  height: clamp(2rem, 3.5vw, 2.6rem);
}

@media (max-width: 768px){
  .header{ padding: var(--space-3) var(--gutter); }
  .header__nav{ gap: 1rem; letter-spacing: 0.1em; font-size: 0.8rem; }
}
@media (max-width: 460px){
  .header__brand-mark{ height: 2.6rem; }
  .header__nav{ gap: 0.7rem; font-size: 0.72rem; letter-spacing: 0.08em; }
}