/* Cabeçalho fixo e menu principal (recolhível no celular, ver responsivo.css) */
.site-header { position: fixed; inset: 0 0 auto; z-index: 100; color: var(--white); border-bottom: 1px solid transparent; transition: background .3s, box-shadow .3s, border-color .3s; }
.site-header.scrolled { background: rgba(6, 26, 51, .95); backdrop-filter: blur(14px); border-color: rgba(255,255,255,.08); box-shadow: 0 10px 30px rgba(0,0,0,.15); }
.header-inner { min-height: 80px; display: flex; align-items: center; gap: 28px; }
.brand { flex: 0 0 auto; }
.brand img { width: 210px; filter: brightness(0) invert(1); }
.main-nav { margin-left: auto; display: flex; align-items: center; gap: 24px; font-size: 14px; font-weight: 700; }
.main-nav a { position: relative; display: inline-flex; align-items: center; gap: 5px; opacity: .86; transition: opacity .2s, color .2s; }
.main-nav a::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -8px; height: 2px; background: var(--orange); transition: right .2s; }
.main-nav a:hover, .main-nav a.active { opacity: 1; }
.main-nav a:hover::after, .main-nav a.active::after { right: 0; }
.main-nav a.active { color: var(--orange); }
.main-nav .nav-external { padding: 8px 14px; border: 1px solid rgba(255,255,255,.3); border-radius: 8px; }
.main-nav .nav-external::after { display: none; }
.main-nav .nav-external svg { width: 14px; height: 14px; }
.menu-button { display: none; margin-left: auto; width: 46px; height: 46px; padding: 11px; border: 0; border-radius: 10px; background: rgba(255,255,255,.1); cursor: pointer; }
.menu-button span:not(.sr-only) { display: block; height: 2px; margin: 5px 0; background: var(--white); transition: transform .2s, opacity .2s; }