:root {
            /* Material Design 3 颜色系统 */
            --md-primary: #6750a4;
            --md-on-primary: #ffffff;
            --md-primary-container: #eaddff;
            --md-on-primary-container: #21005d;
            --md-secondary: #625b71;
            --md-on-secondary: #ffffff;
            --md-secondary-container: #e8def8;
            --md-on-secondary-container: #1d192b;
            --md-tertiary: #7d5260;
            --md-on-tertiary: #ffffff;
            --md-tertiary-container: #ffd8e4;
            --md-on-tertiary-container: #31111d;
            --md-error: #ba1a1a;
            --md-on-error: #ffffff;
            --md-error-container: #ffdad6;
            --md-on-error-container: #410002;
            --md-background: #fffbfe;
            --md-on-background: #1c1b1f;
            --md-surface: #fffbfe;
            --md-on-surface: #1c1b1f;
            --md-surface-variant: #e7e0ec;
            --md-on-surface-variant: #49454f;
            --md-outline: #79747e;
            --md-shadow: #000000;

            /* 间距和尺寸 */
            --md-radius-small: 4px;
            --md-radius-medium: 8px;
            --md-radius-large: 16px;
            --md-elevation-1: 0 1px 2px rgba(0,0,0,0.3), 0 1px 3px 1px rgba(0,0,0,0.15);
            --md-elevation-2: 0 1px 2px rgba(0,0,0,0.3), 0 2px 6px 2px rgba(0,0,0,0.15);
            --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,0.15), 0 1px 3px rgba(0,0,0,0.3);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Roboto', 'Noto Sans SC', sans-serif;
        }

        body {
            background-color: var(--md-background);
            color: var(--md-on-background);
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            padding: 20px;
            background-image: 
                radial-gradient(circle at 15% 50%, rgba(103, 80, 164, 0.05) 0%, transparent 25%),
                radial-gradient(circle at 85% 30%, rgba(232, 222, 248, 0.1) 0%, transparent 25%);
        }

        .login-container {
            width: 100%;
            max-width: 450px;
        }

        .login-card {
            background-color: var(--md-surface);
            border-radius: var(--md-radius-large);
            box-shadow: var(--md-elevation-3);
            padding: 40px 32px;
            position: relative;
            overflow: hidden;
        }

        .card-header {
            text-align: center;
            margin-bottom: 32px;
        }

        .hero-brand {
            margin-bottom: 16px;
        }

        .hero-brand-img {
            width: 80px;
            height: 80px;
            border-radius: 16px;
            object-fit: cover;
        }

        .card-header h1 {
            font-size: 28px;
            font-weight: 400;
            margin-bottom: 8px;
        }

        .hero-sub {
            color: var(--md-on-surface-variant);
            font-size: 14px;
            line-height: 1.5;
            text-align: center;
        }

        .form-group {
            position: relative;
            margin-bottom: 24px;
        }

        .input-container {
            position: relative;
        }

        .input-field {
            width: 100%;
            padding: 16px;
            border: 1px solid var(--md-outline);
            border-radius: var(--md-radius-medium);
            background-color: transparent;
            font-size: 16px;
            outline: none;
            transition: all 0.2s;
        }

        .input-field:focus {
            border-color: var(--md-primary);
            border-width: 2px;
            padding: 15px; /* 补偿边框宽度增加 */
        }

        .input-field.error {
            border-color: var(--md-error);
        }

        .input-label {
            position: absolute;
            left: 16px;
            top: 16px;
            background-color: var(--md-surface);
            padding: 0 4px;
            color: var(--md-on-surface-variant);
            font-size: 16px;
            pointer-events: none;
            transition: all 0.2s;
        }

        .input-field:focus + .input-label,
        .input-field:not(:placeholder-shown) + .input-label {
            top: -8px;
            font-size: 12px;
            color: var(--md-primary);
        }

        .input-field:focus.error + .input-label,
        .input-field:not(:placeholder-shown).error + .input-label {
            color: var(--md-error);
        }

        .input-icon {
            position: absolute;
            right: 16px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--md-on-surface-variant);
        }

        .password-toggle {
            position: absolute;
            right: 16px;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: var(--md-on-surface-variant);
            cursor: pointer;
            padding: 4px;
            border-radius: 50%;
            transition: background-color 0.2s;
        }

        .password-toggle:hover {
            background-color: rgba(0, 0, 0, 0.04);
        }

        .password-toggle:active {
            background-color: rgba(0, 0, 0, 0.12);
        }

        .checkbox-group {
            display: flex;
            align-items: center;
            margin-bottom: 24px;
        }

        .checkbox-container {
            position: relative;
            display: inline-block;
            width: 18px;
            height: 18px;
            margin-right: 12px;
        }

        .checkbox-input {
            opacity: 0;
            width: 0;
            height: 0;
            position: absolute;
        }

        .checkbox-box {
            position: absolute;
            top: 0;
            left: 0;
            width: 18px;
            height: 18px;
            border: 2px solid var(--md-outline);
            border-radius: 2px;
            transition: all 0.2s;
        }

        .checkbox-input:checked + .checkbox-box {
            background-color: var(--md-primary);
            border-color: var(--md-primary);
        }

        .checkbox-input:checked + .checkbox-box::after {
            content: "";
            position: absolute;
            left: 5px;
            top: 2px;
            width: 4px;
            height: 8px;
            border: solid white;
            border-width: 0 2px 2px 0;
            transform: rotate(45deg);
        }

        .checkbox-label {
            font-size: 14px;
            color: var(--md-on-surface);
        }

        .error-message {
            color: var(--md-error);
            font-size: 12px;
            margin-top: 4px;
            display: flex;
            align-items: center;
        }

        .error-message .material-icons {
            font-size: 16px;
            margin-right: 4px;
        }

        .submit-button {
            position: relative;
            width: 100%;
            padding: 16px;
            background-color: var(--md-primary);
            color: var(--md-on-primary);
            border: none;
            border-radius: var(--md-radius-medium);
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            overflow: hidden;
            transition: background-color 0.2s, box-shadow 0.2s;
            box-shadow: var(--md-elevation-1);
        }

        .submit-button:hover {
            box-shadow: var(--md-elevation-2);
        }

        .submit-button:active {
            box-shadow: var(--md-elevation-1);
        }

        .submit-button:disabled {
            background-color: var(--md-on-surface-variant);
            color: var(--md-surface-variant);
            cursor: not-allowed;
            box-shadow: none;
        }

        .ripple {
            position: absolute;
            border-radius: 50%;
            background-color: rgba(255, 255, 255, 0.7);
            transform: scale(0);
            animation: ripple-animation 0.6s linear;
            pointer-events: none;
        }

        @keyframes ripple-animation {
            to {
                transform: scale(4);
                opacity: 0;
            }
        }

        .loading-spinner {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 2px solid transparent;
            border-radius: 50%;
            border-top: 2px solid var(--md-on-primary);
            animation: spin 1s linear infinite;
            margin-right: 8px;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        .server-error {
            background-color: var(--md-error-container);
            color: var(--md-on-error-container);
            padding: 16px;
            border-radius: var(--md-radius-medium);
            margin-bottom: 24px;
            display: flex;
            align-items: center;
        }

        .server-error .material-icons {
            margin-right: 8px;
            color: var(--md-error);
        }

        .additional-options {
            display: flex;
            justify-content: space-between;
            margin-top: 24px;
            font-size: 14px;
        }

        .additional-options a {
            color: var(--md-primary);
            text-decoration: none;
        }

        .additional-options a:hover {
            text-decoration: underline;
        }

        .toast-container {
            position: fixed;
            top: 20px;
            right: 20px;
            z-index: 1000;
        }

        .toast {
            background-color: #323232;
            color: white;
            padding: 16px 24px;
            border-radius: var(--md-radius-medium);
            margin-bottom: 10px;
            box-shadow: var(--md-elevation-3);
            display: flex;
            align-items: center;
            min-width: 288px;
            max-width: 568px;
        }

        .toast .material-icons {
            margin-right: 12px;
            color: white;
        }

        @media (max-width: 480px) {
            .login-card {
                padding: 24px 16px;
            }
            
            .card-header h1 {
                font-size: 24px;
            }
            
            .toast-container {
                top: 10px;
                right: 10px;
                left: 10px;
            }
            
            .toast {
                min-width: auto;
                width: 100%;
            }
        }