/* ==========================================================================
   COMPONENT: header
   --------------------------------------------------------------------------
   Site-wide top navigation. Logo + nav links + primary CTA. Mobile collapses
   nav into a hamburger overlay.

   Markup contract:
     <header class="e-header">
         <div class="e-container e-header__inner">
             <a class="e-header__logo">...</a>
             <nav class="e-header__nav">
                 <a class="e-header__nav-link">Link</a>
             </nav>
             <a class="e-btn e-btn--primary e-header__cta">CTA</a>
             <button class="e-header__menu-btn">...</button>
         </div>
         <nav class="e-header__mobile-nav">
             <a class="e-header__mobile-link">Link</a>
         </nav>
     </header>
   ========================================================================== */

.e-header {
    position: relative;
    z-index: var(--e-z-fixed);
    background: transparent;
}

.e-header__inner {
    display: flex;
    align-items: center;
    height: 64px;
}


/* LOGO */

.e-header__logo {
    display: flex;
    align-items: center;
    gap: var(--e-space-xs);
    padding: var(--e-space-xs) 0;
    text-decoration: none;
}

.e-header__logo img {
    height: 25px;
    width: auto;
}


/* NAV (DESKTOP) — hidden on mobile, visible 1024px+. */

.e-header__nav {
    display: none;
    align-items: center;
    gap: var(--e-space-sm);
    margin-left: var(--e-space-md);
}

.e-header__nav-link {
    color: var(--e-color-muted);
    text-decoration: none;
    font-size: var(--e-font-size-sm);
    opacity: 0.5;
    transition: color var(--e-transition-fast), opacity var(--e-transition-fast);
}

.e-header__nav-link:hover,
.e-header__nav-link--active {
    color: var(--e-color-primary);
    opacity: 1;
}


/* CTA — pushed to the right via auto margin. */

.e-header__cta {
    margin-left: auto;
    height: 40px;
    padding-left: var(--e-space-sm);
    padding-right: var(--e-space-sm);
    font-size: var(--e-font-size-sm);
}


/* MOBILE MENU BUTTON */

.e-header__menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    margin-left: auto;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--e-color-muted);
    opacity: 0.5;
    transition: opacity var(--e-transition-fast);
}

.e-header__menu-btn:hover { opacity: 1; }

.e-header__menu-line {
    transition: transform var(--e-transition-base), opacity var(--e-transition-fast);
    transform-box: view-box;
    transform-origin: center;
}

.e-header__menu-btn--open .e-header__menu-line-1 { transform: rotate( 45deg) translateY( 5.5px); }
.e-header__menu-btn--open .e-header__menu-line-2 { opacity: 0; }
.e-header__menu-btn--open .e-header__menu-line-3 { transform: rotate(-45deg) translateY(-5.5px); }


/* MOBILE NAV OVERLAY */

.e-header__mobile-nav {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background: var(--e-color-surface);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    padding: calc(64px + var(--e-space-xs)) var(--e-space-sm) var(--e-space-sm);
    z-index: -1;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--e-transition-fast), visibility var(--e-transition-fast);
}

.e-header__mobile-nav--open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.e-header__mobile-link {
    color: var(--e-color-muted);
    text-decoration: none;
    font-size: var(--e-font-size-sm);
    padding: var(--e-space-xs) 0;
    opacity: 0.7;
    border-bottom: var(--e-border-light);
    transition: color var(--e-transition-fast), opacity var(--e-transition-fast);
}

.e-header__mobile-link:last-child {
    border-bottom: none;
}

.e-header__mobile-link:hover,
.e-header__mobile-link--active {
    color: var(--e-color-primary);
    opacity: 1;
}


/* RESPONSIVE — desktop nav appears at 1024px+. */

@media (min-width: 1024px) {

    .e-header__menu-btn       { display: none; }
    .e-header__mobile-nav     { display: none; }
    .e-header__nav            { display: flex; }
    .e-header__cta            { margin-left: var(--e-space-sm); }

}