/* Header Styles */
.site-header {
  background: transparent;
  backdrop-filter: none;
  border-bottom: 1px solid transparent;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  transition: all 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  box-shadow: none;
  transform: translateZ(0);
  will-change: background-color, backdrop-filter, box-shadow;
}

.site-header.scrolled {
  background: rgba(0, 0, 0, 0.98);
  backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 
    0 8px 32px rgba(0, 212, 255, 0.12),
    0 4px 16px rgba(0, 0, 0, 0.25),
    0 2px 8px rgba(0, 0, 0, 0.15);
  border-bottom: 1px solid rgba(0, 212, 255, 0.25);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: 70px;
  max-width: 1200px;
  margin: 0 auto;
}

.header-content .logo-area {
  flex-shrink: 0;
}

.header-content .main-nav {
  margin-left: 40px;
  flex-grow: 0;
}

.header-content .user-actions {
  flex-shrink: 0;
  margin-left: auto;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  text-decoration: none;
}

.logo img {
  height: 36px;
  margin-right: 12px;
}

.logo:hover {
  color: #00d4ff;
}

/* Navigation */
.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  position: relative;
  margin: 0 5px;
}

.nav-link {
  display: block;
  padding: 20px 16px;
  color: #ffffff;
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.3s ease;
  position: relative;
}

.nav-link:hover {
  color: #00d4ff;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #00d4ff, #0099cc);
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.nav-link:hover::after {
  width: 80%;
}

/* Dropdown Menu */
.nav-item.dropdown {
  position: relative;
}

.nav-item.dropdown .nav-link::before {
  content: '\25BC';
  font-size: 10px;
  margin-left: 8px;
  transition: transform 0.3s ease;
}

.nav-item.dropdown:hover .nav-link::before {
  transform: rotate(180deg);
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  background: rgba(0, 0, 0, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.3s ease;
  z-index: 1001;
}

.nav-item.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: 12px 20px;
  color: #cccccc;
  font-size: 13px;
  text-decoration: none;
  transition: all 0.3s ease;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.dropdown-item:last-child {
  border-bottom: none;
}

.dropdown-item:hover {
  background: rgba(0, 212, 255, 0.1);
  color: #00d4ff;
  padding-left: 25px;
}

/* User Actions */
.user-actions {
  display: flex;
  align-items: center;
  gap: 15px;
}

.user-actions .btn {
  padding: 10px 18px;
  font-size: 14px;
  border-radius: 20px;
  transition: all 0.3s ease;
  text-decoration: none;
  font-weight: 500;
  white-space: nowrap;
}

.user-actions .btn-outline {
  color: #00d4ff;
  border: 1px solid #00d4ff;
  background: transparent;
}

.user-actions .btn-outline:hover {
  background: #00d4ff;
  color: #000000;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 212, 255, 0.3);
}

.user-actions .btn-primary {
  background: linear-gradient(135deg, #00d4ff 0%, #0099cc 100%);
  color: #ffffff;
  border: 1px solid #00d4ff;
}

.user-actions .btn-primary:hover {
  background: linear-gradient(135deg, #0099cc 0%, #007399 100%);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 212, 255, 0.4);
}

/* User Menu */
.user-menu {
  position: relative;
}

/* User Info */
.user-info {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00d4ff 0%, #0099cc 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.user-avatar:hover {
  transform: scale(1.1);
  box-shadow: 0 5px 15px rgba(0, 212, 255, 0.3);
}

.username {
  color: #ffffff;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  transition: color 0.3s ease;
}

.user-info:hover .username {
  color: #00d4ff;
}

.user-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  min-width: 180px;
  background: rgba(0, 0, 0, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.3s ease;
  z-index: 1001;
  margin-top: 10px;
}

.user-menu:hover .user-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  width: 24px;
  height: 18px;
  cursor: pointer;
  justify-content: space-between;
}

.mobile-menu-toggle span {
  width: 100%;
  height: 2px;
  background: #ffffff;
  transition: all 0.3s ease;
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Navigation */
.mobile-nav {
  position: fixed;
  top: 50px;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.98);
  backdrop-filter: blur(10px);
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
}

.mobile-nav.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.mobile-nav-content {
  padding: 15px 0;
}

.mobile-nav-menu {
  list-style: none;
  margin: 0;
  padding: 0;
}

.mobile-nav-link {
  display: block;
  padding: 12px 20px;
  color: #ffffff;
  font-size: 14px;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.3s ease;
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  background: rgba(0, 212, 255, 0.1);
  color: #00d4ff;
}

.mobile-user-actions {
  padding: 15px 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.mobile-user-actions .btn {
  display: block;
  width: 100%;
  margin-bottom: 10px;
  text-align: center;
}

.mobile-nav-dropdown {
  position: relative;
}

.mobile-dropdown-menu {
  list-style: none;
  margin: 0;
  padding: 0;
  background: rgba(255, 255, 255, 0.05);
  display: none;
}

.mobile-nav-dropdown.active .mobile-dropdown-menu {
  display: block;
}

.mobile-dropdown-link {
  display: block;
  padding: 10px 40px;
  color: #cccccc;
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  transition: all 0.3s ease;
}

.mobile-dropdown-link:hover {
  background: rgba(0, 212, 255, 0.1);
  color: #00d4ff;
  padding-left: 45px;
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }
  
  .main-nav {
    display: none;
  }
  
  .user-actions {
    display: none;
  }

  .mobile-nav {
    top: 70px;
  }

  .mobile-nav-content {
    padding: 20px 0;
  }

  .mobile-nav-link {
    padding: 15px 20px;
    font-size: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .mobile-user-actions {
    padding: 20px;
  }

  .mobile-user-actions .btn {
    padding: 12px 20px;
    font-size: 16px;
    margin-bottom: 12px;
    border-radius: 25px;
  }
}

@media (max-width: 576px) {
  .header-content {
    padding: 0 15px;
    height: 60px;
  }
  
  .logo {
    font-size: 18px;
  }
  
  .logo img {
    height: 30px;
    margin-right: 8px;
  }
  
  .mobile-menu-toggle {
    width: 26px;
    height: 20px;
  }

  .mobile-menu-toggle span {
    height: 3px;
    border-radius: 2px;
  }

  .mobile-nav {
    top: 60px;
  }

  .mobile-nav-link {
    padding: 16px 20px;
    font-size: 17px;
  }

  .mobile-user-actions .btn {
    padding: 14px 20px;
    font-size: 17px;
    margin-bottom: 15px;
  }
}

/* 触摸优化 */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    padding: 10px;
    margin: -10px;
    touch-action: manipulation;
  }

  .mobile-nav-link,
  .mobile-user-actions .btn {
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(0, 212, 255, 0.2);
  }

  .mobile-nav-link:active {
    background: rgba(0, 212, 255, 0.2);
  }

  .mobile-user-actions .btn:active {
    transform: scale(0.98);
  }
}