/**
 * Site Header - canonical, single source for header + menu-toggle styles.
 * Depends on: core/marbl-v2.css (tokens, logo animation).
 *
 * IMPORTANT:
 * - static-positioned by default (use .site-header--fixed from marbl.css for sticky)
 * - NO border-bottom by default (use .site-header--bordered if you want one)
 */

.site-header {
  position: static;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--gap-sm, 20px) clamp(20px, 1.5625vw + 15px, 40px);
  background: var(--marbl-charcoal, #171415);
  border-bottom: none;
  box-sizing: border-box;
}

/* Optional border-bottom modifier */
.site-header--bordered {
  border-bottom: 1px solid var(--marbl-white-06, rgba(255, 255, 255, 0.06));
}

/* Optional sticky-fixed modifier — pins header above scrolling content.
 * Use sparingly. Documented in site-header.md but the implementation was
 * missing until 25 April 2026 (caught when subscribe.marbl.codes' 100vh
 * layout lost its footer after a hidden `.site-header { position: fixed }`
 * hack in local menu.css was removed). Now properly canonical.
 *
 * NOTE: consumer pages using --fixed must top-pad downstream content by
 * the header height (~90px) to avoid underlap. */
.site-header--fixed {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-fixed, 200);
}

/* Menu-open state: pin header above the menu overlay so logo + close (X)
   stay visible and reachable. menu.js toggles this class on open/close. */
.site-header.menu-is-open {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: calc(var(--z-modal, 300) + 10);
  background: transparent;
  border-bottom-color: transparent;
}

.site-header__left,
.site-header__right {
  display: flex;
  align-items: center;
}

.site-header__left .marbl-logo {
  display: inline-flex;
  align-items: center;
  min-width: 28px;
  min-height: 28px;
  color: var(--marbl-ember, #F35226);
}

/* ==========================================================================
   Menu Toggle (burger)
   Circular border with 3 decorative lines (18/13/18) that morph to X when open.
   Full menu behaviour lives in menu.css + menu.js.
   ========================================================================== */

.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  -webkit-appearance: none;
  appearance: none;
  border-radius: 50%;
}

.menu-toggle:focus-visible {
  outline: 2px solid var(--marbl-ember);
  outline-offset: 2px;
}

.menu-toggle:focus:not(:focus-visible) {
  outline: none;
}

.menu-toggle__circle {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--gap-half, 5px);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  border: 1px solid var(--marbl-white-30, rgba(255, 255, 255, 0.3));
  background: transparent;
  transition: border-color var(--transition-base, 0.2s ease);
}

.menu-toggle:hover .menu-toggle__circle {
  border-color: var(--marbl-white-70, rgba(255, 255, 255, 0.7));
}

.menu-toggle__line {
  display: block;
  height: 1.5px;
  background: var(--marbl-white, #ffffff);
  border-radius: 1px;
  transition: transform 0.4s cubic-bezier(0.77, 0, 0.175, 1),
              opacity 0.4s cubic-bezier(0.77, 0, 0.175, 1),
              width 0.4s cubic-bezier(0.77, 0, 0.175, 1);
  transform-origin: center;
}

/* Decorative 20/15/20 line widths (middle line shorter, hover levels them) */
.menu-toggle__line:nth-child(1) { width: 20px; }
.menu-toggle__line:nth-child(2) { width: 15px; }
.menu-toggle__line:nth-child(3) { width: 20px; }

.menu-toggle:hover .menu-toggle__line:nth-child(2) { width: 20px; }

/* X morph when menu is open (menu.js toggles .is-open on .menu-toggle) */
.menu-toggle.is-open .menu-toggle__line:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.menu-toggle.is-open .menu-toggle__line:nth-child(2) {
  opacity: 0;
  width: 0;
}

.menu-toggle.is-open .menu-toggle__line:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* Mobile */
@media (max-width: 768px) {
  .site-header {
    padding: var(--gap-xs, 10px) var(--gap-sm, 20px);
  }
}

/* Reduced motion: no burger line animation */
@media (prefers-reduced-motion: reduce) {
  .menu-toggle__line {
    transition: none;
  }
}