/* 导航栏样式 */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "Noto Sans", sans-serif;
  background: linear-gradient(135deg, #fdfcfb 0%, #f7f7f8 50%, #fdfcfb 100%);
}

/* 顶部导航栏容器 */
.top-navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 20px;
  background: #ffffff;
  
  /* 非常明显的底部边框 - 加粗加深 */
  border-bottom: 4px solid #8b5cf6;
  
  /* 增强的阴影效果 - 多层阴影营造更强的分隔感 */
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.25), 
              0 3px 10px rgba(0, 0, 0, 0.12),
              0 1px 3px rgba(0, 0, 0, 0.08);
  
  /* 添加上边框增强边界感 */
  border-top: 1px solid rgba(229, 231, 235, 0.8);
  
  /* 禁用文字选中 */
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  
  /* 固定定位，确保边框始终可见 */
  position: relative;
  z-index: 100;
}

/* 导航栏左侧区域（Logo） */
.nav-left {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

/* Logo样式 */
.nav-logo {
  height: 40px;
  width: auto;
  object-fit: contain;
}

/* 标题样式 */
.nav-title {
  font-size: 18px;
  font-weight: 600;
  color: #1f2937;
  letter-spacing: 0.5px;
}

/* 导航栏中间区域（导航按钮） */
.nav-center {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  flex: 1;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

/* 导航栏右侧区域（登录注册按钮） */
.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

/* 导航按钮 */
.nav-btn {
  padding: 12px 32px;
  font-size: 15px;
  font-weight: 600;
  color: #6b7280;
  background: linear-gradient(135deg, #ffffff 0%, #f9fafb 100%);
  border: 2px solid #e5e7eb;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  outline: none;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  letter-spacing: 0.3px;
}

.nav-btn:hover {
  color: #8b5cf6;
  border-color: #8b5cf6;
  background: linear-gradient(135deg, #faf5ff 0%, #f3e8ff 100%);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(139, 92, 246, 0.2);
}

.nav-btn.active {
  color: #ffffff;
  background: linear-gradient(135deg, #8b5cf6 0%, #a78bfa 100%);
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(139, 92, 246, 0.4), 0 2px 8px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

.nav-btn.active:hover {
  background: linear-gradient(135deg, #7c3aed 0%, #9333ea 100%);
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.5), 0 3px 10px rgba(0, 0, 0, 0.15);
}

/* 登录注册按钮 */
.auth-btn {
  padding: 10px 24px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  outline: none;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  border: 2px solid transparent;
  letter-spacing: 0.3px;
}

.login-btn {
  color: #6b7280;
  background: linear-gradient(135deg, #ffffff 0%, #f9fafb 100%);
  border-color: #e5e7eb;
}

.login-btn:hover {
  color: #8b5cf6;
  border-color: #8b5cf6;
  background: linear-gradient(135deg, #faf5ff 0%, #f3e8ff 100%);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(139, 92, 246, 0.2);
}

.register-btn {
  color: #ffffff;
  background: linear-gradient(135deg, #8b5cf6 0%, #a78bfa 100%);
  border-color: transparent;
  box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
}

.register-btn:hover {
  background: linear-gradient(135deg, #7c3aed 0%, #9333ea 100%);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(139, 92, 246, 0.4), 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* 用户头像容器 */
.user-avatar-container {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid #8b5cf6;
  box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.user-avatar:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(139, 92, 246, 0.5);
  border-color: #7c3aed;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .top-navigation {
    padding: 16px 12px;
  }

  .nav-center {
    gap: 12px;
  }

  .nav-btn {
    padding: 10px 24px;
    font-size: 14px;
  }

  .nav-right {
    gap: 8px;
  }

  .auth-btn {
    padding: 8px 16px;
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  .top-navigation {
    padding: 12px 8px;
  }

  .nav-center {
    gap: 8px;
  }

  .nav-btn {
    padding: 8px 16px;
    font-size: 13px;
  }

  .nav-right {
    gap: 6px;
  }

  .auth-btn {
    padding: 6px 12px;
    font-size: 12px;
  }
}