header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 72px;
  z-index: 999;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
  border-bottom: 1px solid rgba(102, 126, 234, 0.1);
}

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

.logo-container {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo {
  height: 44px;
  width: auto;
  max-width: 160px;
  display: block;
}

.logo-text {
  font-size: 18px;
  font-weight: 700;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-item-core {
  color: var(--text-primary);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  padding: 8px 14px;
  border-radius: 10px;
}

.nav-item-core:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.user-welcome {
  color: var(--text-secondary);
  font-weight: 500;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 16px;
}

.page {
  display: none;
  padding: 92px 0 40px;
  min-height: calc(100vh - 72px);
}

.page.active {
  display: block;
}

footer {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 48px 0 32px;
  margin-top: 60px;
  width: 100%;
  position: relative;
  overflow: hidden;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 20%, rgba(255,255,255,0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 80%, rgba(255,255,255,0.1) 0%, transparent 50%);
  pointer-events: none;
}

.footer-links {
  text-align: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
  display: flex;
  justify-content: center;
  position: relative;
  z-index: 1;
}

.footer-link {
  color: rgba(255, 255, 255, 0.95);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  margin: 0 16px 12px;
  transition: all 0.3s ease;
  white-space: nowrap;
  padding: 6px 12px;
  border-radius: 8px;
}

.footer-link:hover {
  color: white;
  background: rgba(255, 255, 255, 0.15);
}

.copyright {
  text-align: center;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.85);
  position: relative;
  z-index: 1;
  font-weight: 500;
}