/* ============================================================
   HEADER.CSS
   ============================================================ */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--nav-bg);
  border-bottom: 1px solid var(--nav-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: box-shadow 0.3s;
}

.site-header.scrolled {
  box-shadow: 0 2px 20px var(--shadow-color);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
  text-decoration: none !important;
}

.logo-mark {
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform 0.2s;
  border-radius: 999px;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.18);
  border: 2px solid rgba(255, 255, 255, 0.8);
}

.logo-mark img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.logo:hover .logo-mark { transform: rotate(-5deg) scale(1.05); }

.logo-text {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.logo-name {
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--text-heading);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.logo-role {
  font-size: 0.76rem;
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1.2;
}

/* Navigation */
.main-nav { display: flex; align-items: center; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.18rem;
}

.nav-link {
  display: block;
  padding: 0.42rem 0.62rem;
  font-size: 0.93rem;
  font-weight: 500;
  color: var(--nav-text);
  border-radius: 6px;
  transition: background-color 0.15s, color 0.15s;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--nav-text-active);
  background: var(--nav-hover-bg);
  text-decoration: none;
}

.nav-link.active {
  color: var(--nav-text-active);
  background: var(--accent-blue-soft);
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

/* Theme Toggle */
.theme-toggle {
  width: 36px; height: 36px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 8px;
  color: var(--text-secondary);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

/* Ensure icon is always visible in dark mode */
[data-theme="dark"] .theme-toggle {
  background: #21262d;
  border-color: #30363d;
  color: #e6edf3;
}

.theme-toggle:hover {
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
  border-color: var(--accent-blue);
}

[data-theme="dark"] .theme-toggle:hover {
  background: rgba(88, 166, 255, 0.15);
  color: #58a6ff;
  border-color: #58a6ff;
}

.theme-toggle svg { width: 16px; height: 16px; }
.theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  width: 36px; height: 36px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: 8px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

.mobile-toggle span {
  display: block;
  width: 18px; height: 2px;
  background: var(--text-secondary);
  border-radius: 1px;
  transition: transform 0.25s, opacity 0.25s;
}

.mobile-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-toggle.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.mobile-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile Nav */
@media (max-width: 768px) {
  .mobile-toggle { display: flex; }
  .logo-text { display: none; }

  .main-nav {
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: var(--nav-bg);
    border-bottom: 1px solid var(--nav-border);
    padding: 1rem 1.5rem;
    flex-direction: column;
    align-items: flex-start;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s, opacity 0.3s;
    backdrop-filter: blur(12px);
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-list { flex-direction: column; align-items: flex-start; width: 100%; gap: 0.25rem; }
  .nav-link { width: 100%; padding: 0.7rem 0.75rem; }
}

/* Page offset for fixed header */
body { padding-top: 68px; }