* { margin: 0; padding: 0; box-sizing: border-box; }
        
        :root {
            --primary: #667eea;
            --primary-dark: #5a6fd6;
            --secondary: #764ba2;
            --success: #10b981;
            --danger: #ef4444;
            --warning: #f59e0b;
            --bg-gradient-start: #1a1a2e;
            --bg-gradient-mid: #16213e;
            --bg-gradient-end: #0f3460;
            --card-bg: rgba(255, 255, 255, 0.97);
            --text-primary: #1a1a2e;
            --text-secondary: #666;
            --text-muted: #999;
            --border-color: #e8ecf1;
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
            --shadow-md: 0 8px 24px rgba(0,0,0,0.12);
            --shadow-lg: 0 20px 60px rgba(0,0,0,0.3);
            --shadow-primary: 0 8px 28px rgba(102, 126, 234, 0.4);
            --radius-sm: 12px;
            --radius-md: 16px;
            --radius-lg: 24px;
            --radius-xl: 32px;
        }
        
        html, body {
            height: 100%;
            min-height: 100vh;
        }
        
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-mid) 50%, var(--bg-gradient-end) 100%);
            background-attachment: fixed;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 16px;
            padding-bottom: calc(16px + env(safe-area-inset-bottom));
            -webkit-font-smoothing: antialiased;
        }

        .login-container {
            background: var(--card-bg);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            padding: 40px 24px;
            border-radius: var(--radius-xl);
            box-shadow: var(--shadow-lg);
            width: 100%;
            max-width: 400px;
            animation: fadeInUp 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
            position: relative;
            overflow: hidden;
        }
        
        .login-container::before {
            content: '';
            position: absolute;
            top: -50%;
            right: -20%;
            width: 200px;
            height: 200px;
            background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.1) 100%);
            border-radius: 50%;
            pointer-events: none;
        }
        
        .login-container::after {
            content: '';
            position: absolute;
            bottom: -40%;
            left: -15%;
            width: 160px;
            height: 160px;
            background: linear-gradient(135deg, rgba(245, 158, 11, 0.12) 0%, rgba(239, 68, 68, 0.08) 100%);
            border-radius: 50%;
            pointer-events: none;
        }
        
        @keyframes fadeInUp {
            from { 
                opacity: 0; 
                transform: translateY(30px) scale(0.95); 
            }
            to { 
                opacity: 1; 
                transform: translateY(0) scale(1); 
            }
        }

        .login-header {
            text-align: center;
            margin-bottom: 32px;
            position: relative;
            z-index: 1;
        }

        .login-header .logo-wrapper {
            position: relative;
            display: inline-block;
            margin-bottom: 20px;
        }
        
        .login-header .logo {
            width: 72px;
            height: 72px;
            background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: var(--shadow-primary);
            transition: all 0.3s ease;
        }
        
        .login-header .logo:hover {
            transform: scale(1.05);
            box-shadow: 0 12px 36px rgba(102, 126, 234, 0.5);
        }
        
        .login-header .logo svg { 
            width: 36px; 
            height: 36px; 
            color: white; 
        }
        
        .login-header .admin-badge {
            position: absolute;
            bottom: -4px;
            right: -4px;
            background: linear-gradient(135deg, var(--warning) 0%, #f97316 100%);
            color: white;
            font-size: 10px;
            font-weight: 700;
            padding: 4px 10px;
            border-radius: 20px;
            box-shadow: 0 2px 8px rgba(245, 158, 11, 0.4);
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }
        
        .login-header h1 { 
            color: var(--text-primary); 
            font-size: 28px; 
            font-weight: 800; 
            margin-bottom: 8px;
            letter-spacing: -0.5px;
        }
        
        .login-header p { 
            color: var(--text-muted); 
            font-size: 14px; 
            line-height: 1.6;
        }

        .form-group { 
            margin-bottom: 20px;
            position: relative;
            z-index: 1;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 10px;
            color: var(--text-secondary);
            font-weight: 600;
            font-size: 14px;
            letter-spacing: 0.3px;
        }
        
        .form-group input {
            width: 100%;
            padding: 18px 20px;
            border: 2px solid var(--border-color);
            border-radius: var(--radius-md);
            font-size: 16px;
            font-weight: 500;
            transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
            background: #fafafa;
            min-height: 56px;
        }
        
        .form-group input:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.15);
            background: white;
            transform: translateY(-1px);
        }
        
        .form-group input::placeholder {
            color: var(--text-muted);
            font-weight: 400;
        }
        
        .form-group input.error {
            border-color: var(--danger);
            background: #fef2f2;
        }

        .btn-login {
            width: 100%;
            padding: 20px;
            background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
            color: white;
            border: none;
            border-radius: var(--radius-md);
            font-size: 17px;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
            box-shadow: var(--shadow-primary);
            margin-top: 12px;
            min-height: 56px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            letter-spacing: 1px;
        }
        
        .btn-login:hover {
            transform: translateY(-3px);
            box-shadow: 0 14px 40px rgba(102, 126, 234, 0.5);
        }
        
        .btn-login:active {
            transform: translateY(-1px);
        }
        
        .btn-login:disabled {
            opacity: 0.7;
            cursor: not-allowed;
            transform: none;
            box-shadow: var(--shadow-sm);
        }
        
        .btn-login .spinner {
            width: 20px;
            height: 20px;
            border: 2px solid rgba(255, 255, 255, 0.4);
            border-top-color: white;
            border-radius: 50%;
            animation: spin 0.8s linear infinite;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        .message {
            padding: 16px 20px;
            border-radius: var(--radius-md);
            margin-bottom: 20px;
            display: none;
            text-align: center;
            font-size: 14px;
            font-weight: 500;
            animation: messageIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
            position: relative;
            z-index: 1;
        }
        
        @keyframes messageIn {
            from { 
                opacity: 0; 
                transform: translateY(-10px) scale(0.95); 
            }
            to { 
                opacity: 1; 
                transform: translateY(0) scale(1); 
            }
        }
        
        .message.error {
            background: linear-gradient(135deg, #fff5f5 0%, #ffe4e4 100%);
            color: var(--danger);
            border: 1px solid #fecaca;
            display: block;
        }
        
        .message.success {
            background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
            color: var(--success);
            border: 1px solid #bbf7d0;
            display: block;
        }
        
        .message.info {
            background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
            color: #2563eb;
            border: 1px solid #bfdbfe;
            display: block;
        }

        .form-footer {
            margin-top: 24px;
            text-align: center;
            position: relative;
            z-index: 1;
        }
        
        .form-footer .divider {
            display: flex;
            align-items: center;
            gap: 16px;
            margin-bottom: 16px;
        }
        
        .form-footer .divider::before,
        .form-footer .divider::after {
            content: '';
            flex: 1;
            height: 1px;
            background: var(--border-color);
        }
        
        .form-footer .divider span {
            color: var(--text-muted);
            font-size: 12px;
            font-weight: 500;
        }
        
        .form-footer .system-info {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 10px 16px;
            background: linear-gradient(135deg, rgba(102, 126, 234, 0.08) 0%, rgba(118, 75, 162, 0.08) 100%);
            border-radius: 20px;
            font-size: 12px;
            color: var(--text-secondary);
        }
        
        .form-footer .system-info svg {
            width: 14px;
            height: 14px;
            color: var(--primary);
        }

        .input-focus-ring {
            position: absolute;
            top: -4px;
            left: -4px;
            right: -4px;
            bottom: -4px;
            border: 2px solid var(--primary);
            border-radius: var(--radius-lg);
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s;
        }
        
        .form-group:focus-within .input-focus-ring {
            opacity: 0.5;
        }

        @media (max-width: 375px) {
            body {
                padding: 12px;
            }
            
            .login-container {
                padding: 32px 20px;
                border-radius: var(--radius-lg);
            }
            
            .login-header .logo {
                width: 64px;
                height: 64px;
            }
            
            .login-header .logo svg {
                width: 32px;
                height: 32px;
            }
            
            .login-header h1 {
                font-size: 24px;
            }
            
            .login-header p {
                font-size: 13px;
            }
            
            .form-group input {
                padding: 16px 18px;
                font-size: 15px;
                min-height: 52px;
            }
            
            .btn-login {
                padding: 18px;
                font-size: 16px;
                min-height: 52px;
            }
            
            .message {
                padding: 14px 16px;
                font-size: 13px;
            }
        }

        @media (max-width: 320px) {
            body {
                padding: 8px;
            }
            
            .login-container {
                padding: 28px 16px;
            }
            
            .login-header h1 {
                font-size: 22px;
            }
            
            .form-group input {
                padding: 14px 16px;
                font-size: 14px;
            }
            
            .btn-login {
                padding: 16px;
                font-size: 15px;
            }
        }

        @media (min-width: 768px) {
            .login-container {
                padding: 48px 40px;
                max-width: 420px;
            }
            
            .login-header h1 {
                font-size: 32px;
            }
            
            .login-header p {
                font-size: 15px;
            }
        }

        .wx-tip {
            display: none;
            background: #fff7ed;
            border: 1px solid #fdba74;
            color: #9a3412;
            border-radius: 12px;
            padding: 12px 14px;
            font-size: 13px;
            line-height: 1.6;
            margin-bottom: 16px;
        }
        .wx-tip.show { display: block; }
        .wx-tip a { color: #c2410c; font-weight: 600; }