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

        body {
            font-family: 'Inter', sans-serif;
            background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow-x: hidden;
            padding: 20px;
        }

        /* 动态网格背景装饰 (科技感) */
        body::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: 
                linear-gradient(rgba(56, 189, 248, 0.08) 1px, transparent 1px),
                linear-gradient(90deg, rgba(56, 189, 248, 0.08) 1px, transparent 1px);
            background-size: 40px 40px;
            pointer-events: none;
        }

        /* 光晕效果 */
        .glow-spot {
            position: absolute;
            width: 60vw;
            height: 60vw;
            background: radial-gradient(circle, rgba(56, 189, 248, 0.2) 0%, rgba(56, 189, 248, 0) 70%);
            border-radius: 50%;
            top: -30vw;
            right: -20vw;
            pointer-events: none;
            z-index: 0;
        }

        .glow-spot-bottom {
            position: absolute;
            width: 50vw;
            height: 50vw;
            background: radial-gradient(circle, rgba(168, 85, 247, 0.15) 0%, rgba(168, 85, 247, 0) 70%);
            border-radius: 50%;
            bottom: -25vw;
            left: -15vw;
            pointer-events: none;
            z-index: 0;
        }

        /* 卡片主容器 */
        .login-container {
            width: 100%;
            max-width: 460px;
            z-index: 10;
            position: relative;
            animation: fadeInUp 0.6s ease-out;
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* 玻璃态卡片 */
        .login-card {
            background: rgba(15, 23, 42, 0.75);
            backdrop-filter: blur(16px);
            border-radius: 2rem;
            padding: 2.5rem 2rem;
            box-shadow: 0 25px 45px -12px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(255, 255, 255, 0.05);
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: transform 0.2s ease;
        }

        .login-card:hover {
            transform: translateY(-2px);
        }

        /* 品牌区域 */
        .brand {
            text-align: center;
            margin-bottom: 2rem;
        }

        .logo-icon {
            background: linear-gradient(145deg, #38bdf8, #2dd4bf);
            width: 64px;
            height: 64px;
            border-radius: 24px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.25rem;
            box-shadow: 0 10px 20px -5px rgba(56, 189, 248, 0.3);
        }

        .logo-icon i {
            font-size: 2.2rem;
            color: white;
            filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
        }

        .brand h1 {
            font-size: 1.85rem;
            font-weight: 700;
            background: linear-gradient(135deg, #F0F9FF, #94a3b8);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            letter-spacing: -0.3px;
        }

        .brand p {
            color: #94a3b8;
            font-size: 0.9rem;
            margin-top: 0.5rem;
            font-weight: 400;
        }

        /* 表单组 */
        .input-group {
            margin-bottom: 1.5rem;
            position: relative;
        }

        .input-group i {
            position: absolute;
            left: 1rem;
            top: 50%;
            transform: translateY(-50%);
            color: #64748b;
            font-size: 1.2rem;
            transition: color 0.2s;
            pointer-events: none;
        }

        .input-field {
            width: 100%;
            background: rgba(30, 41, 59, 0.8);
            border: 1px solid rgba(255, 255, 255, 0.08);
            border-radius: 1.25rem;
            padding: 0.9rem 1rem 0.9rem 2.8rem;
            font-size: 0.95rem;
            font-weight: 500;
            color: #f1f5f9;
            font-family: 'Inter', sans-serif;
            transition: all 0.25s ease;
            outline: none;
        }

        .input-field:focus {
            border-color: #38bdf8;
            background: rgba(30, 41, 59, 0.95);
            box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.2);
        }

        .input-field:focus + i {
            color: #38bdf8;
        }

        /* 密码显示切换 */
        .password-toggle {
            position: absolute;
            right: 1rem;
            top: 50%;
            transform: translateY(-50%);
            cursor: pointer;
            color: #64748b;
            transition: color 0.2s;
            background: transparent;
            border: none;
            font-size: 1.1rem;
            z-index: 5;
        }

        .password-toggle:hover {
            color: #cbd5e1;
        }

        /* 选项区域 (记住我 & 忘记密码) */
        .options {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin: 1rem 0 1.8rem 0;
            font-size: 0.85rem;
        }

        .checkbox-label {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            color: #cbd5e6;
            cursor: pointer;
            user-select: none;
        }

        .checkbox-label input {
            width: 16px;
            height: 16px;
            accent-color: #38bdf8;
            cursor: pointer;
        }

        .forgot-link {
            color: #94a3b8;
            text-decoration: none;
            font-weight: 500;
            transition: color 0.2s;
        }

        .forgot-link:hover {
            color: #38bdf8;
            text-decoration: underline;
        }

        /* 登录按钮 */
        .login-btn {
            width: 100%;
            background: linear-gradient(95deg, #0f3b5e, #0284c7);
            border: none;
            border-radius: 1.5rem;
            padding: 0.9rem;
            font-size: 1rem;
            font-weight: 600;
            color: white;
            font-family: 'Inter', sans-serif;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            box-shadow: 0 8px 20px -8px rgba(2, 132, 199, 0.4);
            margin-top: 0.5rem;
        }

        .login-btn i {
            font-size: 1rem;
            transition: transform 0.2s;
        }

        .login-btn:hover {
            background: linear-gradient(95deg, #0e4b75, #0ea5e9);
            transform: translateY(-2px);
            box-shadow: 0 12px 24px -10px rgba(2, 132, 199, 0.6);
        }

        .login-btn:active {
            transform: translateY(1px);
        }

        /* 错误提示区域 */
        .error-message {
            background: rgba(239, 68, 68, 0.15);
            backdrop-filter: blur(4px);
            border-left: 3px solid #ef4444;
            border-radius: 1rem;
            padding: 0.7rem 1rem;
            margin-bottom: 1.2rem;
            font-size: 0.85rem;
            color: #fecaca;
            display: flex;
            align-items: center;
            gap: 0.6rem;
            transition: all 0.2s;
        }

        .error-message i {
            font-size: 1rem;
            color: #f87171;
        }

        .hidden {
            display: none;
        }

        /* 附加信息 或 演示提示 */
        .demo-hint {
            text-align: center;
            margin-top: 1.8rem;
            padding-top: 1rem;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
            font-size: 0.75rem;
            color: #62748c;
        }

        .demo-hint span {
            background: rgba(56, 189, 248, 0.1);
            padding: 0.2rem 0.5rem;
            border-radius: 0.5rem;
            font-family: monospace;
            font-size: 0.7rem;
        }

        /* 响应式调整 */
        @media (max-width: 480px) {
            .login-card {
                padding: 1.8rem 1.5rem;
            }
            .brand h1 {
                font-size: 1.6rem;
            }
            .input-field {
                padding: 0.8rem 1rem 0.8rem 2.8rem;
            }
        }