:root {
            --primary: #00c7be;
            --primary-dark: #00a89c;
            --secondary: #5e5ce6;
            --accent: #30d158;
            --text-dark: #000000;
            --text-gray: #636366;
            --text-light: rgba(255,255,255,0.7);
            --text-muted: rgba(255,255,255,0.5);
            --bg-primary: #000000;
            --bg-secondary: #1c1c1e;
            --bg-tertiary: #2c2c2e;
            --glass: rgba(255,255,255,0.08);
            --glass-border: rgba(255,255,255,0.12);
            --radius: 16px;
            --radius-lg: 24px;
        }

        [data-theme="light"] {
            --text-dark: #1a1a1a;
            --text-light: rgba(0,0,0,0.7);
            --text-muted: rgba(0,0,0,0.5);
            --bg-primary: #f5f7fa;
            --bg-secondary: #ffffff;
            --bg-tertiary: #e8eaed;
            --glass: rgba(255,255,255,0.85);
            --glass-border: rgba(0,0,0,0.1);
        }

        body {
            font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
            background: var(--bg-primary);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            overflow-x: hidden;
            transition: background 0.4s, color 0.4s;
        }

        /* iOS Liquid Background */
        .bg-gradient {
            position: fixed;
            inset: 0;
            z-index: 0;
            overflow: hidden;
            pointer-events: none;
        }

        .liquid-layer {
            position: absolute;
            width: 100%;
            height: 100%;
            filter: blur(80px);
            opacity: 0.9;
        }

        .liquid-1 {
            background: radial-gradient(ellipse 100% 80% at 10% 5%, rgba(0,199,190,0.35) 0%, transparent 70%);
            animation: liquidFloat1 20s ease-in-out infinite;
        }

        .liquid-2 {
            background: radial-gradient(ellipse 90% 70% at 90% 10%, rgba(94,92,230,0.3) 0%, transparent 65%);
            animation: liquidFloat2 25s ease-in-out infinite;
        }

        .liquid-3 {
            background: radial-gradient(ellipse 80% 90% at 50% 95%, rgba(191,90,242,0.25) 0%, transparent 60%);
            animation: liquidFloat3 22s ease-in-out infinite;
        }

        .liquid-4 {
            background: radial-gradient(ellipse 100% 50% at 85% 85%, rgba(255,55,95,0.18) 0%, transparent 55%);
            animation: liquidFloat4 18s ease-in-out infinite;
        }

        .liquid-5 {
            background: radial-gradient(ellipse 70% 60% at 20% 60%, rgba(48,209,88,0.15) 0%, transparent 50%);
            animation: liquidFloat5 24s ease-in-out infinite;
        }

        @keyframes liquidFloat1 {
            0%, 100% { transform: translate(0, 0) scale(1); }
            33% { transform: translate(30px, -40px) scale(1.1); }
            66% { transform: translate(-20px, 20px) scale(0.95); }
        }

        @keyframes liquidFloat2 {
            0%, 100% { transform: translate(0, 0) scale(1); }
            33% { transform: translate(-40px, 30px) scale(1.05); }
            66% { transform: translate(20px, -30px) scale(1.1); }
        }

        @keyframes liquidFloat3 {
            0%, 100% { transform: translate(0, 0) scale(1); }
            33% { transform: translate(20px, 40px) scale(0.9); }
            66% { transform: translate(-30px, -20px) scale(1.05); }
        }

        @keyframes liquidFloat4 {
            0%, 100% { transform: translate(0, 0); }
            50% { transform: translate(40px, -20px); }
        }

        @keyframes liquidFloat5 {
            0%, 100% { transform: translate(0, 0) scale(1); }
            50% { transform: translate(-25px, 25px) scale(1.08); }
        }

        /* Floating Orbs */
        .floating-orbs {
            position: fixed;
            inset: 0;
            z-index: 0;
            pointer-events: none;
            overflow: hidden;
        }

        .orb {
            position: absolute;
            border-radius: 50%;
            filter: blur(60px);
            opacity: 0.4;
            animation: orbFloat 15s ease-in-out infinite;
        }

        .orb-1 {
            width: 300px;
            height: 300px;
            background: radial-gradient(circle, rgba(0,199,190,0.4) 0%, transparent 70%);
            top: 10%;
            left: -5%;
            animation-delay: 0s;
        }

        .orb-2 {
            width: 250px;
            height: 250px;
            background: radial-gradient(circle, rgba(94,92,230,0.35) 0%, transparent 70%);
            top: 50%;
            right: -3%;
            animation-delay: -5s;
        }

        .orb-3 {
            width: 200px;
            height: 200px;
            background: radial-gradient(circle, rgba(191,90,242,0.3) 0%, transparent 70%);
            bottom: 15%;
            left: 30%;
            animation-delay: -10s;
        }

        @keyframes orbFloat {
            0%, 100% { transform: translate(0, 0) rotate(0deg); }
            25% { transform: translate(20px, -30px) rotate(5deg); }
            50% { transform: translate(-15px, 20px) rotate(-3deg); }
            75% { transform: translate(10px, 15px) rotate(2deg); }
        }

        /* iOS Glass Card */
        .glass {
            position: relative;
            z-index: 1;
            background: var(--glass);
            backdrop-filter: blur(40px) saturate(180%);
            -webkit-backdrop-filter: blur(40px) saturate(180%);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            padding: 48px;
            width: 100%;
            max-width: 440px;
            margin: 20px;
            box-shadow: 
                0 0 0 0.5px rgba(255, 255, 255, 0.05) inset,
                0 8px 40px rgba(0, 0, 0, 0.25),
                0 0 80px rgba(0,199,190,0.05) inset;
            animation: glassIn 0.6s ease-out;
        }

        .glass::before {
            content: '';
            position: absolute;
            inset: 0;
            border-radius: inherit;
            background: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, transparent 50%);
            pointer-events: none;
        }

        @keyframes glassIn {
            from {
                opacity: 0;
                transform: translateY(30px) scale(0.95);
            }
            to {
                opacity: 1;
                transform: translateY(0) scale(1);
            }
        }

        [data-theme="light"] .glass {
            box-shadow: 
                0 0 0 0.5px rgba(0, 0, 0, 0.05) inset,
                0 8px 40px rgba(0, 0, 0, 0.1),
                0 0 80px rgba(0,199,190,0.03) inset;
        }

        /* Logo */
        .logo {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 12px;
            margin-bottom: 20px;
        }

        .logo-icon {
            width: 48px;
            height: 48px;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            border-radius: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            box-shadow: 0 4px 20px rgba(0, 199, 190, 0.4);
            transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }

        .logo:hover .logo-icon {
            transform: scale(1.05) rotate(-3deg);
            box-shadow: 0 8px 30px rgba(0, 199, 190, 0.5);
        }

        .logo-text {
            font-size: 26px;
            font-weight: 700;
            letter-spacing: -0.5px;
            color: white;
        }

        [data-theme="light"] .logo-text {
            color: #1a1a1a;
        }

        .logo-text span {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        /* Title */
        .title {
            text-align: center;
            margin-bottom: 32px;
        }

        .title h1 {
            font-size: 24px;
            font-weight: 600;
            margin-bottom: 8px;
            background: linear-gradient(135deg, #fff 0%, rgba(255,255,255,0.8) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        [data-theme="light"] .title h1 {
            background: linear-gradient(135deg, #000 0%, #333 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .title p {
            font-size: 14px;
            color: var(--text-muted);
        }

        .title p a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s;
        }

        .title p a:hover {
            color: var(--accent);
        }

        /* Tabs */
        .tabs {
            display: flex;
            gap: 10px;
            margin-bottom: 28px;
            background: rgba(255,255,255,0.04);
            padding: 6px;
            border-radius: 16px;
        }

        .tab {
            flex: 1;
            padding: 14px;
            background: transparent;
            border: none;
            border-radius: 12px;
            color: var(--text-muted);
            cursor: pointer;
            text-align: center;
            font-weight: 500;
            font-size: 14px;
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            font-family: inherit;
        }

        .tab.active {
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: black;
            box-shadow: 0 4px 15px rgba(0,199,190,0.3);
        }

        .tab:not(.active):hover {
            color: var(--text-light);
            background: rgba(255,255,255,0.05);
        }

        /* Form */
        .form-group {
            margin-bottom: 18px;
        }

        .form-label {
            display: block;
            font-size: 13px;
            color: var(--text-light);
            margin-bottom: 8px;
            font-weight: 500;
        }

        .form-input {
            width: 100%;
            padding: 14px 18px;
            background: rgba(255,255,255,0.06);
            border: 1px solid var(--glass-border);
            border-radius: 14px;
            color: white;
            font-size: 15px;
            font-family: inherit;
            outline: none;
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }

        [data-theme="light"] .form-input {
            background: rgba(0,0,0,0.04);
            color: #1a1a1a;
        }

        .form-input::placeholder {
            color: var(--text-muted);
        }

        .form-input:focus {
            border-color: var(--primary);
            background: rgba(255,255,255,0.1);
            box-shadow: 0 0 0 3px rgba(0,199,190,0.15);
        }

        .form-input:disabled {
            opacity: 0.6;
            cursor: not-allowed;
        }

        /* Input Group */
        .input-group {
            display: flex;
            gap: 10px;
        }

        .input-group .form-input {
            flex: 1;
        }

        /* Button */
        .btn {
            width: 100%;
            padding: 16px;
            border-radius: 24px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            border: none;
            font-size: 15px;
            font-family: inherit;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: black;
            box-shadow: 0 4px 20px rgba(0,199,190,0.3);
        }

        .btn-primary:hover {
            transform: translateY(-2px) scale(1.01);
            box-shadow: 0 8px 30px rgba(0,199,190,0.4);
        }

        .btn-primary:active {
            transform: translateY(0) scale(0.98);
        }

        .btn-outline {
            background: transparent;
            border: 1px solid var(--glass-border);
            color: var(--text-light);
        }

        .btn-outline:hover {
            background: rgba(255,255,255,0.1);
            border-color: var(--primary);
        }

        .btn:disabled {
            opacity: 0.6;
            cursor: not-allowed;
            transform: none !important;
        }

        .input-group .btn {
            width: auto;
            white-space: nowrap;
            padding: 14px 20px;
        }

        /* Error */
        .error {
            background: rgba(255,55,95,0.1);
            border: 1px solid rgba(255,55,95,0.3);
            color: #ff6b8a;
            padding: 14px 18px;
            border-radius: 12px;
            margin-bottom: 20px;
            font-size: 13px;
            display: none;
            animation: shake 0.5s ease;
        }

        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            25% { transform: translateX(-5px); }
            75% { transform: translateX(5px); }
        }

        /* Divider */
        .divider {
            display: flex;
            align-items: center;
            gap: 16px;
            margin: 24px 0;
        }

        .divider-line {
            flex: 1;
            height: 1px;
            background: linear-gradient(90deg, transparent, var(--glass-border), transparent);
        }

        .divider span {
            font-size: 12px;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        /* OAuth */
        .oauth-section {
            margin: 24px 0;
        }

        .oauth-divider {
            display: flex;
            align-items: center;
            margin: 20px 0;
        }

        .oauth-divider::before,
        .oauth-divider::after {
            content: '';
            flex: 1;
            height: 1px;
            background: var(--glass-border);
        }

        .oauth-divider span {
            padding: 0 16px;
            color: var(--text-muted);
            font-size: 13px;
        }

        .oauth-buttons {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 12px;
        }

        .oauth-btn {
            padding: 16px 20px;
            background: var(--glass);
            border: 1px solid var(--glass-border);
            border-radius: 14px;
            color: var(--text-light);
            font-size: 14px;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            font-family: inherit;
        }

        .oauth-btn:hover {
            background: rgba(255,255,255,0.12);
            border-color: var(--primary);
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(0,199,190,0.25);
        }

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

        .oauth-btn img {
            width: 22px;
            height: 22px;
            object-fit: contain;
        }

        .oauth-btn.wechat {
            border-color: rgba(7, 193, 96, 0.3);
        }

        .oauth-btn.wechat:hover {
            border-color: #07c160;
            box-shadow: 0 8px 25px rgba(7, 193, 96, 0.3);
        }

        .oauth-btn.qq {
            border-color: rgba(12, 150, 240, 0.3);
        }

        .oauth-btn.qq:hover {
            border-color: #0c96f0;
            box-shadow: 0 8px 25px rgba(12, 150, 240, 0.3);
        }

        .oauth-btn.github:hover {
            border-color: #fff;
            box-shadow: 0 8px 25px rgba(255,255,255,0.2);
        }

        .oauth-btn.google:hover {
            border-color: #4285f4;
            box-shadow: 0 8px 25px rgba(66, 133, 244, 0.3);
        }

        @media (max-width: 480px) {
            .oauth-buttons {
                grid-template-columns: 1fr;
            }
        }

        /* Footer */
        .footer {
            text-align: center;
            margin-top: 24px;
            font-size: 12px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        .footer a {
            color: var(--primary);
            text-decoration: none;
            transition: all 0.3s;
        }

        .footer a:hover {
            color: var(--accent);
        }

        .footer-links {
            margin-top: 8px;
        }

        .footer-links a {
            margin: 0 8px;
        }

        /* Theme Toggle */
        .theme-toggle {
            position: fixed;
            top: 20px;
            right: 20px;
            z-index: 100;
            width: 44px;
            height: 44px;
            border-radius: 50%;
            border: 1px solid var(--glass-border);
            background: var(--glass);
            backdrop-filter: blur(20px);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 18px;
            color: var(--text-light);
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            box-shadow: 0 4px 20px rgba(0,0,0,0.2);
        }

        .theme-toggle:hover {
            background: var(--primary);
            border-color: var(--primary);
            color: black;
            transform: scale(1.1) rotate(15deg);
        }

        /* Modal Styles */
        .modal-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(0,0,0,0.8);
            backdrop-filter: blur(10px);
            z-index: 9999;
            align-items: center;
            justify-content: center;
            animation: fadeIn 0.3s ease;
        }

        .modal-overlay.show {
            display: flex;
        }

        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }

        .modal-content {
            position: relative;
            background: var(--glass);
            backdrop-filter: blur(40px) saturate(180%);
            -webkit-backdrop-filter: blur(40px) saturate(180%);
            border: 1px solid var(--glass-border);
            border-radius: 24px;
            padding: 40px;
            max-width: 400px;
            width: 90%;
            text-align: center;
            box-shadow: 
                0 0 0 0.5px rgba(255, 255, 255, 0.05) inset,
                0 20px 60px rgba(0, 0, 0, 0.4),
                0 0 80px rgba(0,199,190,0.1) inset;
            animation: modalSlideIn 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }

        @keyframes modalSlideIn {
            from { 
                opacity: 0; 
                transform: translateY(30px) scale(0.9); 
            }
            to { 
                opacity: 1; 
                transform: translateY(0) scale(1); 
            }
        }

        .modal-close {
            position: absolute;
            top: 16px;
            right: 16px;
            width: 32px;
            height: 32px;
            border-radius: 50%;
            border: none;
            background: var(--glass);
            color: var(--text-muted);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s;
            font-size: 14px;
        }

        .modal-close:hover {
            background: rgba(255,55,95,0.2);
            color: #ff6b8a;
            transform: rotate(90deg);
        }

        [data-theme="light"] .modal-close {
            background: rgba(0,0,0,0.05);
        }

        [data-theme="light"] .modal-content {
            box-shadow: 
                0 0 0 0.5px rgba(0, 0, 0, 0.05) inset,
                0 20px 60px rgba(0, 0, 0, 0.15),
                0 0 80px rgba(0,199,190,0.05) inset;
        }

        .modal-icon {
            font-size: 48px;
            margin-bottom: 16px;
            animation: bounce 0.6s ease;
        }

        @keyframes bounce {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-10px); }
        }

        .modal-title {
            margin: 0 0 8px;
            font-size: 24px;
            font-weight: 600;
            color: white;
        }

        [data-theme="light"] .modal-title {
            color: #1a1a1a;
        }

        .modal-desc {
            color: var(--text-muted);
            font-size: 14px;
            margin: 0 0 28px;
        }

        .modal-buttons {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .modal-btn {
            padding: 16px 24px;
            border-radius: 16px;
            font-size: 15px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            border: none;
            font-family: inherit;
        }

        .modal-btn i {
            font-size: 18px;
        }

        .modal-btn-admin {
            background: linear-gradient(135deg, var(--secondary), #8b5cf6);
            color: white;
            box-shadow: 0 4px 20px rgba(94, 92, 230, 0.3);
        }

        .modal-btn-admin:hover {
            transform: translateY(-2px) scale(1.01);
            box-shadow: 0 8px 30px rgba(94, 92, 230, 0.4);
        }

        .modal-btn-user {
            background: var(--glass);
            border: 1px solid var(--glass-border);
            color: var(--text-light);
        }

        .modal-btn-user:hover {
            background: rgba(255,255,255,0.15);
            border-color: var(--primary);
            transform: translateY(-2px);
        }

        [data-theme="light"] .modal-btn-user {
            background: rgba(0,0,0,0.04);
            border-color: rgba(0,0,0,0.1);
            color: #1a1a1a;
        }

        [data-theme="light"] .modal-btn-user:hover {
            background: rgba(0,0,0,0.08);
        }

        /* Responsive */
        @media (max-width: 480px) {
            .glass {
                padding: 32px 20px;
                border-radius: 20px;
                margin: 16px;
            }

            .logo {
                margin-bottom: 16px;
            }

            .logo-icon {
                width: 42px;
                height: 42px;
                font-size: 20px;
            }

            .logo-text {
                font-size: 22px;
            }

            .title {
                margin-bottom: 24px;
            }

            .title h1 {
                font-size: 20px;
            }

            .form-group {
                margin-bottom: 14px;
            }

            .form-input {
                padding: 12px 14px;
                font-size: 14px;
            }

            .btn {
                padding: 14px;
                font-size: 14px;
            }

            .tabs {
                margin-bottom: 20px;
            }

            .tab {
                padding: 12px;
                font-size: 13px;
            }

            .footer {
                margin-top: 18px;
                font-size: 11px;
            }

            .theme-toggle {
                top: 16px;
                right: 16px;
                width: 38px;
                height: 38px;
            }
        }

        /* Touch optimizations */
        @media (hover: none) and (pointer: coarse) {
            * { -webkit-tap-highlight-color: transparent; }
            .form-input { font-size: 16px !important; }
            .btn:active { transform: scale(0.98); }
            .tab:active { transform: scale(0.98); }
        }