/* ============================================================
   header.css — vertical left sidebar + mobile hamburger
   ============================================================ */

/* ── SIDEBAR (desktop only) ──────────────────────────────── */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  z-index: 100;
  border-right: 1px solid var(--color-border);
}

/* ── LOGO ────────────────────────────────────────────────── */
.sidebar__logo {
  display: block;
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  font-size: 1.7rem;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin-bottom: 3.5rem;
  transition: opacity 0.2s ease;
  white-space: nowrap;
  text-decoration: none;
}
.sidebar__logo:hover { opacity: 0.6; }

/* ── NAV LINKS ───────────────────────────────────────────── */
.sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.nav-link {
  position: relative;
  display: inline-block;
  font-family: var(--font-nav);
  font-size: 0.85rem;
  font-weight: 500;
  font-style: normal;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-text-dim);
  padding-bottom: 5px;
  transition: color 0.2s ease;
  text-decoration: none;
}

/* Animated underline on hover */
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-text);
  transition: width 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}
.nav-link:hover { color: var(--color-text-mid); }
.nav-link:hover::after { width: 100%; }

/* Active page indicator */
.nav-link.is-active {
  color: var(--color-text) !important;
  font-weight: 600;
}
.nav-link.is-active::after { width: 100%; }

/* ── MOBILE HEADER BAR ───────────────────────────────────── */
.mobile-header {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 64px;
  padding: 0 1.5rem;
  align-items: center;
  justify-content: space-between;
  z-index: 300;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.mobile-logo {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  font-size: 1.5rem;
  color: var(--color-text);
  letter-spacing: -0.01em;
  text-decoration: none;
}

/* ── HAMBURGER BUTTON ────────────────────────────────────── */
.hamburger {
  position: relative;
  width: 44px;
  height: 44px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-end;
  gap: 6px;
  background: none;
  border: none;
  padding: 8px;
  z-index: 310;
}

.hamburger span {
  display: block;
  height: 1.5px;
  background: var(--color-text);
  border-radius: 2px;
  transition:
    transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    opacity   0.3s ease,
    width     0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.hamburger span:nth-child(1) { width: 26px; }
.hamburger span:nth-child(2) { width: 18px; }
.hamburger span:nth-child(3) { width: 22px; }

/* Open state — animates to X */
.hamburger.is-open span:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
  width: 26px;
}
.hamburger.is-open span:nth-child(2) {
  opacity: 0;
  transform: translateX(10px);
}
.hamburger.is-open span:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
  width: 26px;
}

/* ── MOBILE NAV DRAWER ───────────────────────────────────── */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--color-bg);
  z-index: 290;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.mobile-nav-drawer.is-open {
  opacity: 1;
  pointer-events: all;
}

/* Drawer links — larger than sidebar links */
.mobile-nav-drawer .nav-link {
  font-size: 1.2rem;
  letter-spacing: 0.28em;
  color: rgba(232, 224, 213, 0.55);
}
.mobile-nav-drawer .nav-link:hover {
  color: var(--color-text);
}
.mobile-nav-drawer .nav-link.is-active {
  color: var(--color-text) !important;
}

/* ── RESPONSIVE ──────────────────────────────────────────── */

/* Tablet — narrow sidebar */
@media (max-width: 1024px) {
  :root { --sidebar-width: 130px; }
}

/* Mobile — hide sidebar, show top bar + drawer */
@media (max-width: 768px) {
  .sidebar           { display: none !important; }
  .mobile-header     { display: flex !important; }
  .mobile-nav-drawer { display: flex !important; }

  .page-content {
    margin-left: 0 !important;
    padding-top: 64px;
  }
}

/* Small phones */
@media (max-width: 400px) {
  .mobile-header { padding: 0 1.25rem; }
  .mobile-logo   { font-size: 1.3rem; }
}