/* =========================================================
   KalkulatorHub — header.css
   ========================================================= */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 14, 20, 0.82);
  backdrop-filter: blur(10px) saturate(140%);
  border-bottom: 1px solid var(--border-soft);
}
:root[data-theme="light"] .site-header {
  background: rgba(246, 245, 241, 0.85);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding-block: 1.1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}
.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: var(--accent-gold);
  color: #14100a;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
}
.brand__accent {
  color: var(--accent-teal);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.main-nav a {
  font-size: 0.95rem;
  color: var(--text-secondary);
  position: relative;
  padding-block: 0.25rem;
  transition: color var(--dur) var(--ease);
}
.main-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 1px;
  background: var(--accent-teal);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}
.main-nav a:hover {
  color: var(--text-primary);
}
.main-nav a:hover::after {
  transform: scaleX(1);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.theme-toggle,
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  transition:
    border-color var(--dur) var(--ease),
    color var(--dur) var(--ease);
}
.theme-toggle:hover,
.nav-toggle:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
}
.theme-toggle svg,
.nav-toggle svg {
  width: 17px;
  height: 17px;
}

.nav-toggle {
  display: none;
}
.icon-moon {
  display: none;
}
:root[data-theme="light"] .icon-sun {
  display: none;
}
:root[data-theme="light"] .icon-moon {
  display: block;
}

/* Mobile nav drawer */
.mobile-nav {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 60;
  background: var(--bg);
}
.mobile-nav.is-open {
  display: block;
}
.mobile-nav__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 1.5rem;
  border-bottom: 1px solid var(--border-soft);
}
.mobile-nav__list {
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.mobile-nav__list a {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--text-primary);
}