/* SaaS专业背景 */
 body {
     background: linear-gradient(135deg, #D7DDF7 0%, #E8ECFA 50%, #F5F7FF 100%);
     min-height: 100vh;
     position: relative;
     font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
 }

 /* 桌面端背景动画优化 */
 @media (min-width: 768px) {
     body {
         overflow: hidden;
     }
 }

 body::before {
     content: '';
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     background:
         radial-gradient(circle at 20% 50%, rgba(65, 114, 248, 0.1) 0%, transparent 50%),
         radial-gradient(circle at 80% 20%, rgba(90, 132, 247, 0.1) 0%, transparent 50%),
         radial-gradient(circle at 40% 80%, rgba(215, 221, 247, 0.3) 0%, transparent 50%);
     animation: backgroundMove 25s ease infinite;
 }

 @keyframes backgroundMove {

     0%,
     100% {
         transform: scale(1) rotate(0deg);
     }

     33% {
         transform: scale(1.05) rotate(120deg);
     }

     66% {
         transform: scale(0.95) rotate(240deg);
     }
 }

 /* 动态点阵背景 */
 .grid-bg {
     position: fixed;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     background-image:
         radial-gradient(circle, rgba(65, 114, 248, 0.15) 2px, transparent 2px),
         radial-gradient(circle, rgba(90, 132, 247, 0.1) 2px, transparent 2px);
     background-size: 50px 50px;
     background-position: 0 0, 25px 25px;
     animation: dotMove 20s linear infinite;
     z-index: -1;
 }

 @keyframes dotMove {
     0% {
         transform: translate(0, 0);
         background-size: 50px 50px, 50px 50px;
     }

     50% {
         transform: translate(25px, 25px);
         background-size: 55px 55px, 45px 45px;
     }

     100% {
         transform: translate(0, 0);
         background-size: 50px 50px, 50px 50px;
     }
 }

 /* 登录面板 */
 .signinpanel {
     position: relative;
     z-index: 10;
     max-width: 1100px;
     margin: 20vh auto;
     background: rgba(255, 255, 255, 0.95);
     backdrop-filter: blur(10px);
     border-radius: 24px;
     box-shadow:
         0 20px 60px rgba(65, 114, 248, 0.2),
         0 0 0 1px rgba(65, 114, 248, 0.1);
     overflow: hidden;
     transition: all 0.3s ease;
 }

 /* 确保行和列填满高度 */
 .signinpanel .row {
     display: flex;
     margin: 0;
 }

 .signinpanel .col-sm-7,
 .signinpanel .col-sm-5 {
     display: flex;
     flex-direction: column;
     padding: 0;
 }

 .signinpanel:hover {
     box-shadow:
         0 25px 70px rgba(65, 114, 248, 0.25),
         0 0 0 1px rgba(65, 114, 248, 0.15);
 }

 /* 左侧信息区 */
 .signin-info {
     position: relative;
     z-index: 10;
     padding: 80px 50px;
     background: linear-gradient(135deg, #4172F8 0%, #5A84F7 100%);
     text-align: center;
     color: white;
     height: 100%;
     display: flex;
     flex-direction: column;
     justify-content: center;
 }

 .signin-info::before {
     content: '';
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     background: radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.15) 0%, transparent 50%), radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%), radial-gradient(circle at 40% 80%, rgba(255, 255, 255, 0.08) 0%, transparent 50%);
     opacity: 0.3;
 }

 .signin-info h2 {
     font-size: 2.6rem;
     font-weight: 700;
     color: white;
     margin-bottom: 20px;
     animation: fadeInUp 1s ease-out;
     letter-spacing: -0.5px;
 }

 /* 右侧登录区 */
 .signinpanel .col-sm-5 {
     position: relative;
     z-index: 10;
     padding: 60px 50px;
     background: white;
 }

 /* 表单样式 */
 .form-control {
     background: #F8FAFF;
     border: 2px solid #E1E8F7;
     border-radius: 12px;
     color: #2D3748;
     padding: 16px 20px;
     font-size: 1rem;
     font-weight: 500;
     transition: all 0.3s ease;
     box-shadow: inset 0 2px 4px rgba(65, 114, 248, 0.05);
 }

 .form-control:focus {
     background: white;
     border-color: #5A84F7;
     box-shadow: 0 0 0 4px rgba(65, 114, 248, 0.1), 0 2px 8px rgba(65, 114, 248, 0.15);
     color: #2D3748;
     outline: none;
 }

 .form-control::placeholder {
     color: #A0AEC0;
     font-weight: 400;
 }

 /* 按钮样式 */
 .btn-primary {
     background: linear-gradient(135deg, #4172F8 0%, #5A84F7 100%);
     border: none;
     border-radius: 12px;
     padding: 16px;
     font-size: 1.1rem;
     font-weight: 600;
     color: white;
     transition: all 0.3s ease;
     position: relative;
     box-shadow: 0 8px 24px rgba(65, 114, 248, 0.3);
     letter-spacing: 0.3px;
 }

 .btn-primary::before {
     content: '';
     position: absolute;
     top: 0;
     left: -100%;
     width: 100%;
     height: 100%;
     background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
     transition: all 0.6s ease;
 }

 .btn-primary:hover::before {
     left: 100%;
 }

 .btn-primary:hover {
     background: linear-gradient(135deg, #3763E6 0%, #4E75F6 100%);
     box-shadow: 0 12px 32px rgba(65, 114, 248, 0.4);
     transform: translateY(-2px);
     color: white;
 }

 .btn-primary:active {
     transform: translateY(0);
     box-shadow: 0 6px 20px rgba(65, 114, 248, 0.35);
 }

 /* 验证码区域 */
 #code {
     background: #F8FAFF;
     border: 2px solid #E1E8F7;
     border-radius: 12px 0 0 12px;
     border-right: none;
 }

 #code:focus {
     border-radius: 12px 0 0 12px;
     border-right: none;
 }

 .signinpanel img {
     border-radius: 0 12px 12px 0;
     border: 2px solid #E1E8F7;
     border-left: none;
     transition: all 0.3s ease;
     height: 56px;
 }

 .signinpanel img:hover {
     border-color: #5A84F7;
     box-shadow: 0 0 20px rgba(65, 114, 248, 0.2);
 }

 /* 页脚 */
 .signup-footer {
     position: relative;
     z-index: 10;
     padding: 24px;
     background: #F8FAFF;
     border-top: 1px solid #E1E8F7;
 }

 /* 错误信息 */
 #err_msg {
     font-size: 1.2rem;
     font-weight: 600;
     color: #4172F8;
     margin-bottom: 30px;
     text-align: center;
     letter-spacing: -0.3px;
 }

 /* 登录标题 */
 .signinpanel .col-sm-5 h3 {
     font-size: 1.8rem;
     font-weight: 700;
     color: #2D3748;
     margin-bottom: 40px;
     text-align: center;
     letter-spacing: -0.5px;
 }

 /* 欢迎文本 */
 .welcome-text {
     font-size: 1.1rem;
     margin-bottom: 40px;
     opacity: 0.8;
     color: rgba(255, 255, 255, 0.9);
     line-height: 1.5;
 }

 /* 特性网格 */
 .features-grid {
     display: flex;
     justify-content: center;
     gap: 20px;
     flex-wrap: wrap;
 }

 /* 左侧特性卡片 */
 .feature-card {
     background: rgba(255, 255, 255, 0.15);
     border-radius: 16px;
     padding: 24px;
     margin: 10px;
     backdrop-filter: blur(10px);
     border: 1px solid rgba(255, 255, 255, 0.2);
     transition: all 0.3s ease;
     flex: 1;
     min-width: 120px;
     max-width: 180px;
 }

 .feature-card:hover {
     background: rgba(255, 255, 255, 0.2);
     transform: translateY(-4px);
     box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
 }

 .feature-card i {
     font-size: 2.2rem;
     color: white;
     margin-bottom: 12px;
     display: block;
 }

 .feature-card p {
     font-size: 1rem;
     font-weight: 600;
     color: white;
     margin: 0;
     opacity: 0.95;
 }

 /* 动画效果 */
 @keyframes fadeInUp {
     from {
         opacity: 0;
         transform: translateY(30px);
     }

     to {
         opacity: 1;
         transform: translateY(0);
     }
 }

 /* 响应式设计 */
 @media (max-width: 768px) {
     .signinpanel {
         margin: 5vh 20px;
         border-radius: 20px;
     }

     .signinpanel .col-sm-5 {
         border-left: none;
         border-top: 1px solid #E1E8F7;
     }

     .signin-info,
     .signinpanel .col-sm-5 {
         padding: 45px 30px;
     }

     .signin-info h2 {
         font-size: 2.1rem;
     }

     .signinpanel .col-sm-5 h3 {
         font-size: 1.5rem;
     }

     /* 移动端特性卡片优化 */
     .features-grid {
         gap: 15px;
     }

     .feature-card {
         padding: 20px;
         margin: 5px;
         flex: 1;
         min-width: 100px;
         max-width: none;
     }

     .welcome-text {
         font-size: 1rem;
         margin-bottom: 30px;
     }
 }