新增注册（页面跳转）及登录（弹窗）功能

css/style.css

@@ -322,6 +322,107 @@ main.flex-fill {
   transform: translateY(-2px);
 }
 
+.modal {
+  position: fixed;
+  z-index: 999;
+  left: 0;
+  top: 0;
+  width: 100%;
+  height: 100%;
+  overflow: auto;
+  background-color: rgba(0, 0, 0, 0.4);
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  }
+  
+  .modal-content {
+  background-color: #fff;
+  padding: 2rem;
+  width: 90%;
+  max-width: 400px;
+  border-radius: 12px;
+  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
+  position: relative;
+  animation: fadeIn 0.3s ease-in-out;
+  }
+  
+  @keyframes fadeIn {
+  from { opacity: 0; transform: translateY(-20px); }
+  to { opacity: 1; transform: translateY(0); }
+  }
+  
+  .modal-content h2 {
+  margin-top: 0;
+  font-size: 1.5rem;
+  text-align: center;
+  color: #333;
+  }
+  
+  .modal-content label {
+  display: block;
+  margin: 1rem 0 0.3rem;
+  font-weight: 600;
+  color: #444;
+  }
+  
+  .modal-content input {
+  width: 100%;
+  padding: 0.6rem;
+  border: 1px solid #ccc;
+  border-radius: 6px;
+  box-sizing: border-box;
+  font-size: 1rem;
+  }
+  
+  .modal-actions {
+  margin-top: 1.5rem;
+  display: flex;
+  justify-content: space-between;
+  }
+  
+  .modal-actions button {
+  flex: 1;
+  margin: 0 0.3rem;
+  padding: 0.6rem;
+  border: none;
+  border-radius: 6px;
+  background-color: #5aa9fe;
+  color: white;
+  font-weight: bold;
+  cursor: pointer;
+  transition: background-color 0.2s ease;
+  }
+  
+  .modal-actions button:hover {
+  background-color: #0056b3;
+  }
+  
+  .modal-actions button#cancelLogin,
+  .modal-actions button#cancelRegister {
+  background-color: #ccc;
+  color: #333;
+  }
+  
+  .modal-actions button#cancelLogin:hover,
+  .modal-actions button#cancelRegister:hover {
+  background-color: #999;
+  }
+  
+  .close {
+  position: absolute;
+  top: 12px;
+  right: 16px;
+  font-size: 24px;
+  font-weight: bold;
+  color: #666;
+  cursor: pointer;
+  }
+  
+  .close:hover {
+  color: #000;
+  }
+
 @media (max-width: 768px) {
   .slider-wrapper {
     flex-direction: column;