/* 主体样式 */
* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
        }
        /* 基础淡入效果 - 应用于body元素 */
body {
  opacity: 0;
  animation: pageFadeIn 1.2s cubic-bezier(0.39, 0.575, 0.565, 1);
  animation-fill-mode: forwards;
}

@keyframes pageFadeIn {
  0% {
    opacity: 0;
    transform: scale(0.98);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

/* 元素级动画 - 按需添加 */
.fade-element {
  opacity: 0;
  animation: elementFadeIn 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes elementFadeIn {
  0% {
    opacity: 0;
    transform: translateY(20px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 动画延迟控制 */
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

/* 防止闪烁前加载 */
html.prestop * {
  visibility: hidden;
}

html.loaded * {
  visibility: visible;
}
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #0f1a42, #1c3a6b, #2c5282);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }
        
        .container {
            width: 100%;
            max-width: 520px;
            background: rgba(255, 255, 255, 0.08);
            backdrop-filter: blur(12px);
            border-radius: 16px;
            box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
            padding: 40px;
            text-align: center;
            position: relative;
            overflow: hidden;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        .container::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: conic-gradient(
                transparent,
                rgba(255, 255, 255, 0.1),
                transparent 70%
            );
            animation: rotate 10s linear infinite;
            z-index: -1;
        }
        
        @keyframes rotate {
            to {
                transform: rotate(360deg);
            }
        }
        
        .header {
            margin-bottom: 30px;
        }
        
        .lock-icon {
            font-size: 50px;
            color: #4fc3f7;
            margin-bottom: 15px;
            display: inline-block;
            padding: 15px;
            border-radius: 50%;
            background: rgba(0, 0, 0, 0.2);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }
        
        h1 {
            color: white;
            margin-bottom: 10px;
            font-size: 28px;
            font-weight: 600;
            letter-spacing: 0.5px;
        }
        
        .subtitle {
            color: rgba(255, 255, 255, 0.75);
            margin-bottom: 30px;
            font-size: 15px;
            line-height: 1.6;
        }
        
        .form-group {
            margin-bottom: 25px;
            position: relative;
            text-align: left;
        }
        
        .form-group label {
            display: block;
            color: rgba(255, 255, 255, 0.85);
            margin-bottom: 8px;
            font-size: 14px;
            font-weight: 500;
        }
        
        .input-wrapper {
            position: relative;
        }
        
        input {
            width: 100%;
            padding: 14px 20px;
            padding-right: 100px;
            border: none;
            background: rgba(255, 255, 255, 0.09);
            color: white;
            border-radius: 10px;
            font-size: 15px;
            transition: all 0.3s ease;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        input:focus {
            background: rgba(255, 255, 255, 0.12);
            outline: none;
            box-shadow: 0 0 0 2px rgba(79, 195, 247, 0.4);
            border-color: rgba(79, 195, 247, 0.4);
        }
        
        input::placeholder {
            color: rgba(255, 255, 255, 0.4);
        }
        
        .toggle-password {
            position: absolute;
            right: 15px;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: rgba(255, 255, 255, 0.6);
            cursor: pointer;
            font-size: 16px;
            transition: color 0.3s;
        }
        
        .toggle-password:hover {
            color: rgba(255, 255, 255, 0.9);
        }
        
        .password-requirements {
            margin-top: 10px;
            font-size: 12px;
            color: rgba(255, 255, 255, 0.5);
            line-height: 1.5;
        }
        
        .btn-submit {
            width: 100%;
            padding: 14px;
            border: none;
            background: linear-gradient(135deg, #1976d2, #1565c0);
            color: white;
            font-size: 16px;
            font-weight: 600;
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            letter-spacing: 0.5px;
            margin-top: 10px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
        }
        
        .btn-submit:hover {
            background: linear-gradient(135deg, #1e88e5, #1976d2);
            transform: translateY(-2px);
            box-shadow: 0 6px 8px rgba(0, 0, 0, 0.25);
        }
        
        .btn-submit:active {
            transform: translateY(1px);
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
        }
        
        .attempts {
            color: rgba(255, 255, 255, 0.8);
            font-size: 14px;
            margin: 20px 0;
            padding: 12px;
            background: rgba(0, 0, 0, 0.2);
            border-radius: 8px;
        }
        
        .alert {
            padding: 16px;
            border-radius: 10px;
            margin: 20px 0;
            font-size: 14px;
            transition: all 0.3s ease;
            animation: slideDown 0.5s ease;
            text-align: left;
            display: flex;
            align-items: flex-start;
        }
        
        .alert i {
            margin-right: 10px;
            font-size: 18px;
        }
        
        @keyframes slideDown {
            from {
                opacity: 0;
                transform: translateY(-20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .alert-error {
            background-color: rgba(229, 57, 53, 0.2);
            color: #ff8a80;
            border-left: 4px solid #f44336;
        }
        
        .alert-success {
            background-color: rgba(67, 160, 71, 0.2);
            color: #a5d6a7;
            border-left: 4px solid #4caf50;
        }
        
        .fade-out {
            animation: fadeOut 0.5s ease forwards;
        }
        
        @keyframes fadeOut {
            to {
                opacity: 0;
                height: 0;
                padding: 0;
                margin: 0;
            }
        }
        
        .info-box {
            background: rgba(0, 0, 0, 0.15);
            padding: 15px;
            border-radius: 10px;
            margin-top: 25px;
            text-align: left;
        }
        
        .info-box h3 {
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: 10px;
            font-size: 16px;
            display: flex;
            align-items: center;
        }
        
        .info-box h3 i {
            margin-right: 8px;
            color: #4fc3f7;
        }
        
        .info-box p {
            color: rgba(255, 255, 255, 0.6);
            font-size: 13px;
            line-height: 1.5;
            margin-bottom: 15px;
        }
        
        .admin-contact {
            display: inline-flex;
            align-items: center;
            color: #4fc3f7;
            text-decoration: none;
            font-size: 13px;
            margin-top: 5px;
            transition: color 0.3s;
        }
        
        .admin-contact:hover {
            color: #29b6f6;
            text-decoration: underline;
        }
        
        .admin-contact i {
            margin-right: 5px;
        }
        
        .footer {
            margin-top: 25px;
            color: rgba(255, 255, 255, 0.4);
            font-size: 12px;
        }
        
        /* 响应式设计 */
        @media (max-width: 600px) {
            .container {
                padding: 30px 20px;
            }
            
            h1 {
                font-size: 24px;
            }
            
            input, .btn-submit {
                padding: 12px 15px;
            }
            
            .lock-icon {
                font-size: 40px;
                padding: 12px;
            }
        }