.site-header{position:sticky;top:0;z-index:100;background:rgba(248,247,244,.92);backdrop-filter:blur(8px);border-bottom:1px solid transparent;transition:border-color .2s,box-shadow .2s}
.site-header.is-scrolled{border-color:var(--mist);box-shadow:0 1px 0 rgba(0,0,0,.02)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:72px}

.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:1.15rem;letter-spacing:-.01em;color:var(--void)}
.brand-mark{width:28px;height:28px;flex:0 0 auto}
.custom-logo{max-height:40px;width:auto;display:block}

.primary-nav ul{display:flex;gap:36px}
.primary-nav a{font-size:.94rem;font-weight:500;color:var(--ink);position:relative;padding:4px 0;display:inline-block}
.primary-nav a::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;background:var(--signal);transform:scaleX(0);transition:transform .18s}
.primary-nav a:hover::after,.primary-nav a.is-active::after{transform:scaleX(1)}
.primary-nav a.is-active{color:var(--void);font-weight:600}

.header-actions{display:flex;align-items:center;gap:18px}
.icon-btn{width:36px;height:36px;display:grid;place-items:center;border-radius:50%;border:1px solid transparent;background:none;cursor:pointer;color:var(--ink)}
.icon-btn:hover{background:var(--paper-2)}

.nav-toggle{display:none;width:36px;height:36px;border:none;background:none;cursor:pointer;flex-direction:column;justify-content:center;gap:5px}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--ink);transition:transform .2s,opacity .2s}
.nav-toggle.is-open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle.is-open span:nth-child(2){opacity:0}
.nav-toggle.is-open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.search-overlay{position:fixed;inset:0;background:rgba(16,19,26,.6);z-index:200;display:flex;align-items:flex-start;justify-content:center;padding:120px 20px 0}
.search-overlay[hidden]{display:none}
.search-overlay-inner{position:relative;width:100%;max-width:640px;background:var(--white);border-radius:var(--radius);padding:32px;box-shadow:0 24px 60px -20px rgba(16,19,26,.4)}
.search-overlay-inner form{display:flex;gap:10px}
.search-overlay-inner input[type=search],.search-overlay-inner input[type=text]{flex:1;padding:14px 18px;border:1px solid var(--mist);border-radius:var(--radius-sm);font-size:1rem}
.search-overlay-inner input:focus{border-color:var(--void)}
.search-overlay-inner .search-submit{padding:14px 22px;border-radius:var(--radius-sm);background:var(--void);color:var(--paper);font-weight:600}
.search-close{position:absolute;top:14px;right:14px;width:32px;height:32px;border-radius:50%;font-size:1.4rem;line-height:1;color:var(--slate);display:grid;place-items:center}
.search-close:hover{background:var(--paper-2)}

@media(max-width:880px){
  .primary-nav ul{display:none;flex-direction:column;position:absolute;top:72px;left:0;right:0;background:var(--paper);padding:20px 32px;border-bottom:1px solid var(--mist);gap:18px;z-index:99}
  .primary-nav ul.is-open{display:flex}
  .nav-toggle{display:flex}
}
@media(max-width:640px){
  .header-actions .btn-outline{display:none}
}