.site-header {
  position: sticky;
  top: 0;
  z-index: 999;
  height: var(--header-h);
  display: flex;
  align-items: center;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(250, 251, 255, 0.82);
  border-bottom: 1px solid rgba(255, 255, 255, 0.62);
}

.header-inner {
  width: min(100% - 40px, 1500px);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--text);
  font-size: 24px;
  font-weight: 900;
  letter-spacing: -0.055em;
  white-space: nowrap;
  text-decoration: none;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: #fff;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  box-shadow: 0 10px 24px rgba(109, 76, 255, 0.28);
  flex: 0 0 auto;
}

.brand-mark svg {
  width: 20px;
  height: 20px;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(20px, 2.5vw, 44px);
  color: #11182f;
  font-weight: 600;
  font-size: 15px;
}

.main-nav a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease;
}

.main-nav a:hover {
  color: var(--primary);
}

.header-actions {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.login-btn,
.mobile-auth-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 19px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.88);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.85);
  box-shadow: 0 10px 28px rgba(43, 50, 90, 0.08);
  font-weight: 800;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.login-btn:hover,
.mobile-auth-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 34px rgba(43, 50, 90, 0.12);
}

.mobile-auth-btn {
  display: none;
}

.mobile-menu-btn {
  display: none;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 10px 28px rgba(43, 50, 90, 0.08);
  color: var(--text);
  position: relative;
}

.mobile-menu-btn span,
.mobile-menu-btn::before,
.mobile-menu-btn::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  border-radius: 999px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.mobile-menu-btn.is-open span {
  opacity: 0;
}

.mobile-menu-btn.is-open::before {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-btn.is-open::after {
  transform: translateY(-7px) rotate(-45deg);
}