/* base config */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Arial', sans-serif;
        }

        body {
            line-height: 1.6;
            color: #333;
            background-color: #f4f4f4;
        }

        .container {
            width: 90%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* nav bar */
        header {
            background-color: #fff;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            position: sticky;
            top: 0;
            z-index: 1000;
            padding: 0.5rem 0;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.5rem 0;
        }

        /* school logo image */
        .logo {
            display: flex;
            align-items: center;
            text-decoration: none;
            transition: opacity 0.3s ease;
        }

        .logo:hover {
            opacity: 0.8;
        }

        .logo-img {
            height: 60px;
            width: auto;
        }

        /* nav links */
        .nav-links {
            display: flex;
            list-style: none;
            gap: 2.5rem;
            align-items: center;
        }

        .nav-links a {
            text-decoration: none;
            color: #333;
            font-weight: 600;
            font-size: 1.1rem;
            padding: 0.5rem 0;
            position: relative;
            transition: color 0.3s ease;
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: #56b4a6;
        }

        /* nav bar active action*/
        .nav-links a.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 3px;
            background-color: #56b4a6;
            border-radius: 2px;
        }

        /* Language Switcher */
        .language-switcher {
            display: flex;
            align-items: center;
            margin-left: 1rem;
        }

        .lang-btn {
            background: none;
            border: 2px solid #56b4a6;
            color: #56b4a6;
            padding: 0.4rem 0.8rem;
            border-radius: 20px;
            cursor: pointer;
            font-weight: 600;
            transition: all 0.3s ease;
            margin-left: 0.5rem;
        }

        .lang-btn.active {
            background-color: #56b4a6;
            color: white;
        }

        .lang-btn:hover {
            background-color: #6de1d0;
            border-color: #6de1d0;
            color: white;
        }

        /* footer [contacts] */
        footer {
            text-align: center;
            padding: 1.5rem 0;
            background-color: #333;
            color: #fff;
            margin-top: 2rem;
        }

        /* About us Page*/
        h1 {
            font-size: 3rem;
            color: #6a4b90;
            margin-bottom: 10px;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
        }
        
        .subtitle {
            font-size: 1.3rem;
            color: #555;
            max-width: 600px;
            margin: 0 auto;
        }
        
        /* cards container */
        .cards-container {
            display: flex;
            flex-direction: column;
            gap: 80px;
        }
        
        /* card */
        .card {
            display: flex;
            background: white;
            border-radius: 5px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            position: relative;
            min-height: 400px;
        }
        
        .card-left {
            flex-direction: row;
        }
        
        .card-right {
            flex-direction: row-reverse;
        }
        
        .card-content {
            flex: 1;
            padding: 40px;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }
        
        .card-image {
            flex: 1;
            position: relative;
            overflow: hidden;
        }
        
        /* Image Grid */
        .image-grid {
            display: grid;
            height: 100%;
            gap: 5px;
        }
        
        .grid-2 {
            grid-template-columns: 1fr;
            grid-template-rows: 1fr 1fr;
        }
        
        .grid-3 {
            grid-template-columns: 1fr 1fr;
            grid-template-rows: 1fr 1fr;
        }
        
        .grid-4 {
            grid-template-columns: 1fr 1fr;
            grid-template-rows: 1fr 1fr;
        }
        
        .grid-item {
            overflow: hidden;
        }
        
        .grid-item img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        
        .grid-item:hover img {
            transform: scale(1.05);
        }
        
        .card-title {
            position: absolute;
            top: -20px;
            background: #6a4b90;
            color: white;
            padding: 15px 30px;
            border-radius: 10px;
            font-size: 1.5rem;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
            z-index: 10;
        }
        
        .card-left .card-title {
            left: 30px;
        }
        
        .card-right .card-title {
            right: 30px;
        }
        
        .text-content {
            margin-top: 20px;
        }
        
        .chinese-text, .english-text {
            margin-bottom: 20px;
            text-align: justify;
        }
        
        .chinese-text {
            font-size: 1rem;
            line-height: 1.7;
            color: #555;
            font-style: italic;
        }
        
        .english-text {
            font-size: 1.1rem;
            line-height: 1.8;
        }
        
        .card-number {
            position: absolute;
            font-size: 6rem;
            font-weight: 800;
            color: rgba(46, 125, 50, 0.1);
            z-index: 0;
        }
        
        .card-left .card-number {
            bottom: -20px;
            right: 30px;
        }
        
        .card-right .card-number {
            bottom: -20px;
            left: 30px;
        }
        
        /* divider */
        .divider {
            width: 80px;
            height: 5px;
            background: #4caf50;
            margin: 20px 0;
            border-radius: 5px;
        }
        
        /* Reactive Design for mobiles */
        @media (max-width: 992px) {
            .card {
                flex-direction: column;
            }
            
            .card-title {
                position: relative;
                top: 0;
                left: 0;
                right: 0;
                text-align: center;
                border-radius: 0;
                margin-bottom: 20px;
            }
            
            .card-number {
                display: none;
            }
            
            .card-image {
                min-height: 300px;
            }
        }
        
        @media (max-width: 768px) {
            nav {
                flex-direction: column;
                gap: 1rem;
            }
            
            .nav-links {
                flex-wrap: wrap;
                justify-content: center;
            }

            h1 {
                font-size: 2.2rem;
            }
            
            .subtitle {
                font-size: 1.1rem;
            }
            
            .decoration {
                display: none;
            }
            
            .card-content {
                padding: 25px;
            }
            
            .grid-3, .grid-4 {
                grid-template-columns: 1fr;
            }
        }
        
        @media (max-width: 480px) {
            h1 {
                font-size: 1.8rem;
            }
            
            .card-title {
                font-size: 1.3rem;
                padding: 10px 20px;
            }
            
            .chinese-text {
                font-size: 1rem;
            }
            
            .english-text {
                font-size: 0.9rem;
            }
        }
        
        /* simple animation */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .card {
            animation: fadeIn 0.8s ease-out;
        }
        
        .card:nth-child(2) {
            animation-delay: 0.2s;
        }
        
        .card:nth-child(3) {
            animation-delay: 0.4s;
        }