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

        :root {
            --primary: #2c5aa0;
            --primary-dark: #1a3a6b;
            --primary-light: #4a7bc8;
            --secondary: #1e8449;
            --secondary-dark: #15763c;
            --secondary-light: #2ecc71;
            --accent: #e74c3c;
            --accent-dark: #c0392b;
            --accent-light: #ff6b5c;
            --light: #f8f9fa;
            --dark: #343a40;
            --gray: #607d8b;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
            --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            --radius: 20px;
        }

        body {
            font-family: 'Cairo', sans-serif;
            line-height: 1.7;
            color: var(--dark);
            background: linear-gradient(135deg, #f0f7ff 0%, #e3f2fd 100%);
            overflow-x: hidden;
            min-height: 100vh;
            direction: rtl;
        }

        /* خلفية متحركة بأشكال تعليمية */
        .bg-animation {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -3;
            overflow: hidden;
            pointer-events: none;
        }

        .edu-shape {
            position: absolute;
            opacity: 0.08;
            filter: blur(40px);
            animation: eduFloat 30s infinite linear;
        }

        .edu-shape:nth-child(1) {
            width: 300px;
            height: 300px;
            background: var(--primary);
            top: -150px;
            left: -150px;
            animation-delay: 0s;
            border-radius: 40% 60% 70% 30% / 40% 50% 60% 50%;
        }

        .edu-shape:nth-child(2) {
            width: 250px;
            height: 250px;
            background: var(--secondary);
            bottom: -125px;
            right: -125px;
            animation-delay: 10s;
            border-radius: 60% 40% 30% 70% / 60% 30% 70% 40%;
        }

        .edu-shape:nth-child(3) {
            width: 200px;
            height: 200px;
            background: var(--accent);
            top: 20%;
            right: 10%;
            animation-delay: 20s;
            border-radius: 30% 70% 50% 50% / 30% 50% 50% 70%;
        }

        @keyframes eduFloat {
            0%, 100% { 
                transform: translate(0, 0) rotate(0deg) scale(1); 
            }
            25% { 
                transform: translate(40px, 40px) rotate(90deg) scale(1.1); 
            }
            50% { 
                transform: translate(0, 80px) rotate(180deg) scale(1); 
            }
            75% { 
                transform: translate(-40px, 40px) rotate(270deg) scale(0.9); 
            }
        }

        .container {
            width: 90%;
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Header */
        header {
            background: rgba(255, 255, 255, 0.9); /* More transparent */
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08); /* Softer, deeper shadow */
            border-bottom: 1px solid rgba(255, 255, 255, 0.5); /* Subtle border */
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 0;
            animation: slideDown 0.8s ease;
        }

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

        .logo {
            display: flex;
            align-items: center;
            gap: 20px;
        }

        .logo-icon {
            width: 65px;
            height: 65px;
            background: linear-gradient(135deg, var(--primary), #4facfe);
            border-radius: 16px; /* Modern Squircle */
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 2.5rem;
            font-weight: 900;
            box-shadow: 0 10px 25px rgba(44, 90, 160, 0.3);
            position: relative;
            overflow: hidden;
            transition: all 0.4s ease;
            transform: rotate(-3deg);
        }
        
        .logo:hover .logo-icon {
            transform: rotate(0deg) scale(1.05);
            box-shadow: 0 15px 35px rgba(44, 90, 160, 0.4);
            border-radius: 50%;
        }

        @keyframes logoPulse {
            0%, 100% { 
                box-shadow: 0 10px 30px rgba(44, 90, 160, 0.4);
                transform: scale(1);
            }
            50% { 
                box-shadow: 0 15px 40px rgba(44, 90, 160, 0.6);
                transform: scale(1.05);
            }
        }

        .logo-text {
            display: flex;
            flex-direction: column;
        }

        .logo h1 {
            color: var(--primary);
            font-size: 2.4rem;
            line-height: 1.2;
            margin-bottom: 5px;
        }

        .logo span {
            color: var(--secondary);
            font-size: 2.2rem;
            font-weight: 900;
        }

        .logo p {
            color: var(--gray);
            font-size: 1rem;
            margin-top: 8px;
            font-weight: 600;
        }

        nav ul {
            display: flex;
            list-style: none;
            gap: 8px; /* Compact gap */
            background: rgba(0, 0, 0, 0.04); /* Subtle pill container */
            padding: 6px;
            border-radius: 50px;
        }

        nav a {
            text-decoration: none;
            color: var(--dark);
            font-weight: 700;
            font-size: 1.05rem;
            transition: all 0.3s ease;
            position: relative;
            padding: 10px 22px;
            border-radius: 25px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        nav a i {
            font-size: 1.2rem;
            transition: all 0.3s ease;
            color: var(--gray);
        }

        nav a:hover {
            color: var(--primary);
            background: white;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            transform: translateY(-2px);
        }

        nav a:hover i {
            color: var(--secondary);
            transform: scale(1.1);
        }

        /* Removed underline animation for a pill style */

        .auth-buttons {
            display: flex;
            gap: 15px;
        }

        .btn {
            padding: 12px 24px;
            border-radius: 50px;
            font-weight: 700;
            font-size: 1rem;
            cursor: pointer;
            transition: var(--transition);
            border: none;
            font-family: 'Cairo', sans-serif;
            position: relative;
            overflow: hidden;
            letter-spacing: 0.5px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            text-decoration: none;
        }

        .btn::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(45deg, 
                transparent 30%, 
                rgba(255, 255, 255, 0.4) 50%, 
                transparent 70%);
            transform: translateX(-100%);
            transition: transform 0.8s ease;
        }

        .btn:hover::before {
            transform: translateX(100%);
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
            color: white;
            box-shadow: 0 8px 25px rgba(30, 132, 73, 0.4);
        }

        .btn-primary:hover {
            transform: translateY(-5px) scale(1.05);
            box-shadow: 0 15px 40px rgba(30, 132, 73, 0.6);
        }

        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
            box-shadow: 0 8px 25px rgba(44, 90, 160, 0.2);
        }

        .btn-outline:hover {
            transform: translateY(-5px) scale(1.05);
            box-shadow: 0 15px 40px rgba(44, 90, 160, 0.3);
            background: var(--primary);
            color: white;
        }

        /* Hero Section */
        .hero {
            padding: 140px 0 120px;
            position: relative;
            overflow: hidden;
            background: linear-gradient(rgba(44, 90, 160, 0.85), rgba(30, 132, 73, 0.9)), 
                url('https://images.unsplash.com/photo-1523240795612-9a054b0db644?ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            color: white;
            animation: heroReveal 1.2s ease;
        }

        @keyframes heroReveal {
            from {
                opacity: 0;
                transform: translateY(50px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 100%;
            height: 100%;
            background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%23ffffff' fill-opacity='0.1' fill-rule='evenodd'/%3E%3C/svg%3E");
            opacity: 0.1;
            pointer-events: none;
        }

        .hero-content {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 80px;
            position: relative;
            z-index: 2;
        }

        .hero-text {
            flex: 1;
            animation: textSlideIn 1s ease 0.3s both;
        }

        @keyframes textSlideIn {
            from {
                opacity: 0;
                transform: translateX(50px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        .hero-title {
            font-size: 2.5rem;
            margin-bottom: 25px;
            line-height: 1.3;
            position: relative;
            text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.3);
        }

        .hero-subtitle {
            font-size: 1.25rem;
            margin-bottom: 35px;
            line-height: 1.8;
            opacity: 0.95;
            font-weight: 500;
            animation: subtitleFade 1s ease 0.6s both;
        }

        @keyframes subtitleFade {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .hero-buttons {
            display: flex;
            gap: 25px;
            flex-wrap: wrap;
            animation: buttonsFloat 1s ease 0.9s both;
        }

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

        .btn-hero {
            padding: 18px 40px;
            font-size: 1.2rem;
            border-radius: 60px;
            box-shadow: 0 12px 35px rgba(0, 0, 0, 0.3);
        }

        .hero-image {
            flex: 1;
            position: relative;
            animation: imageFloat 3s ease-in-out infinite alternate;
        }

        @keyframes imageFloat {
            from {
                transform: translateY(0);
            }
            to {
                transform: translateY(-20px);
            }
        }

        .hero-image img {
            width: 100%;
            border-radius: var(--radius);
            box-shadow: 0 40px 80px rgba(0, 0, 0, 0.4);
            border: 10px solid rgba(255, 255, 255, 0.2);
            backdrop-filter: blur(5px);
        }

        /* قسم عن الأستاذ */
        .teacher-section {
            padding: 100px 0;
            background: white;
            position: relative;
            overflow: hidden;
        }

        .section-title {
            text-align: center;
            margin-bottom: 60px;
            position: relative;
            z-index: 2;
        }

        .section-title h2 {
            font-size: 2.2rem;
            color: var(--primary);
            margin-bottom: 25px;
            position: relative;
            display: inline-block;
        }

        .section-title h2::after {
            content: '';
            position: absolute;
            width: 120px;
            height: 6px;
            background: linear-gradient(to left, var(--primary), var(--secondary));
            bottom: -20px;
            right: 50%;
            transform: translateX(50%);
            border-radius: 3px;
            animation: lineGrow 2s ease;
        }

        @keyframes lineGrow {
            from {
                width: 0;
            }
            to {
                width: 120px;
            }
        }

        .teacher-profile {
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
            max-width: 800px;
            margin: 0 auto;
        }

        .teacher-avatar {
            width: 200px;
            height: 200px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary-light), var(--primary));
            margin-bottom: 30px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 4rem;
            color: white;
            overflow: hidden;
            box-shadow: 0 20px 40px rgba(44, 90, 160, 0.3);
            animation: avatarFloat 4s ease-in-out infinite;
        }

        @keyframes avatarFloat {
            0%, 100% {
                transform: translateY(0);
            }
            50% {
                transform: translateY(-15px);
            }
        }

        .teacher-avatar img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .teacher-bio {
            margin-bottom: 2rem;
            text-align: right;
            font-size: 1.2rem;
            line-height: 1.9;
            color: var(--gray);
        }

        .teacher-bio h3 {
            color: var(--primary);
            font-size: 1.5rem;
            margin-bottom: 20px;
        }

        /* قسم الكتب */
        .books-section {
            padding: 100px 0;
            background: linear-gradient(135deg, #f8fafc 0%, #e8eaf6 100%);
            position: relative;
            overflow: hidden;
        }

        .books-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: 30px;
            margin-top: 40px;
            position: relative;
            z-index: 2;
            max-width: 1000px;
            margin-left: auto;
            margin-right: auto;
        }

        .book-card {
            background: white;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow-lg);
            transition: var(--transition);
            animation: bookSlideIn 1s ease;
        }

        @keyframes bookSlideIn {
            from {
                opacity: 0;
                transform: translateX(50px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        .book-card:hover {
            transform: translateY(-20px) scale(1.03);
            box-shadow: 0 40px 80px rgba(0, 0, 0, 0.15);
        }

        .book-header {
            padding: 40px 30px;
            text-align: center;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: white;
            position: relative;
            overflow: hidden;
        }

        .book-header::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(45deg, 
                transparent 30%, 
                rgba(255, 255, 255, 0.2) 50%, 
                transparent 70%);
            animation: shine 3s infinite;
        }

        @keyframes shine {
            0% { transform: translateX(-100%); }
            100% { transform: translateX(100%); }
        }

        .book-icon {
            font-size: 4rem;
            margin-bottom: 30px;
            display: inline-block;
            animation: bookIconSpin 10s linear infinite;
        }

        @keyframes bookIconSpin {
            from {
                transform: rotate(0deg);
            }
            to {
                transform: rotate(360deg);
            }
        }

        .book-title {
            font-size: 1.5rem;
            margin-bottom: 15px;
        }

        .book-content {
            padding: 40px;
        }

        .features-list {
            list-style: none;
            margin-bottom: 30px;
        }

        .features-list li {
            padding: 15px 0;
            border-bottom: 2px solid rgba(0, 0, 0, 0.05);
            display: flex;
            align-items: center;
            gap: 15px;
            transition: var(--transition);
            animation: listItemSlide 0.5s ease;
        }

        @keyframes listItemSlide {
            from {
                opacity: 0;
                transform: translateX(20px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        .features-list li:nth-child(1) { animation-delay: 0.1s; }
        .features-list li:nth-child(2) { animation-delay: 0.2s; }
        .features-list li:nth-child(3) { animation-delay: 0.3s; }
        .features-list li:nth-child(4) { animation-delay: 0.4s; }
        .features-list li:nth-child(5) { animation-delay: 0.5s; }

        .features-list li:hover {
            transform: translateX(-10px);
            background: rgba(44, 90, 160, 0.05);
            border-radius: 15px;
            padding: 15px 20px;
        }

        .features-list i {
            color: var(--success);
            font-size: 1.3rem;
            width: 35px;
            height: 35px;
            background: rgba(30, 132, 73, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition);
            animation: checkPulse 2s infinite;
        }

        @keyframes checkPulse {
            0%, 100% {
                transform: scale(1);
            }
            50% {
                transform: scale(1.2);
            }
        }

        /* نظام الاشتراك */
        .pricing-section {
            padding: 100px 0;
            background: white;
            position: relative;
            overflow: hidden;
        }

        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 40px;
            margin-top: 60px;
        }

        .pricing-card {
            background: white;
            border-radius: var(--radius);
            padding: 50px 40px;
            text-align: center;
            box-shadow: var(--shadow-lg);
            transition: var(--transition);
            position: relative;
            overflow: hidden;
            border: 3px solid transparent;
        }

        .pricing-card.featured {
            border-color: var(--secondary);
            transform: scale(1.05);
            background: linear-gradient(135deg, white, #e8f5e9);
        }

        .pricing-card:hover {
            transform: translateY(-20px) scale(1.05);
            box-shadow: 0 40px 80px rgba(0, 0, 0, 0.15);
        }

        .price {
            font-size: 3rem;
            font-weight: bold;
            color: var(--primary);
            margin: 30px 0;
        }

        .price span {
            font-size: 1.2rem;
            color: var(--gray);
        }

        /* نظام الدفع */
        .payment-methods {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-top: 40px;
            flex-wrap: wrap;
        }

        .payment-method {
            background: white;
            padding: 15px 30px;
            border-radius: var(--radius);
            display: flex;
            align-items: center;
            gap: 15px;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }

        .payment-method:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
        }

        .bank-icon {
            font-size: 2rem;
            color: var(--primary);
        }

        /* contact-info من الكود الأصلي */
        .contact-info {
            background: white;
            padding: 2rem;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            width: 100%;
            max-width: 500px;
            margin: 30px auto 0;
        }

        .contact-form {
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }

        .form-group {
            display: flex;
            flex-direction: column;
            text-align: right;
        }

        .form-group label {
            margin-bottom: 0.5rem;
            font-weight: bold;
            color: var(--primary);
        }

        .form-control {
            padding: 0.75rem;
            border: 2px solid #e0e0e0;
            border-radius: 15px;
            font-size: 1rem;
            transition: var(--transition);
            font-family: 'Cairo', sans-serif;
        }

        .form-control:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(44, 90, 160, 0.1);
        }

        textarea.form-control {
            min-height: 150px;
            resize: vertical;
        }

        /* Footer */
        footer {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            color: white;
            padding: 80px 0 30px;
            position: relative;
            overflow: hidden;
        }

        footer::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 100%;
            height: 6px;
            background: linear-gradient(to left, var(--secondary), var(--accent));
            box-shadow: 0 4px 20px rgba(231, 76, 60, 0.5);
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 40px;
            margin-bottom: 60px;
            position: relative;
            z-index: 2;
        }

        .footer-column h3 {
            font-size: 1.8rem;
            margin-bottom: 25px;
            color: white;
            position: relative;
            padding-bottom: 15px;
        }

        .footer-column h3::after {
            content: '';
            position: absolute;
            width: 60px;
            height: 4px;
            background: var(--accent);
            bottom: 0;
            right: 0;
            border-radius: 2px;
        }

        .footer-column p {
            margin-bottom: 25px;
            line-height: 1.8;
            opacity: 0.9;
        }

        .social-links {
            display: flex;
            gap: 15px;
            margin-top: 20px;
        }

        .social-links a {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 50px;
            height: 50px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 50%;
            color: white;
            text-decoration: none;
            font-size: 1.2rem;
            transition: var(--transition);
        }

        .social-links a:hover {
            background: var(--accent);
            transform: rotate(15deg) scale(1.2);
        }

        .footer-links {
            list-style: none;
        }

        .footer-links li {
            margin-bottom: 15px;
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .footer-links i {
            color: var(--accent);
            width: 20px;
        }

        .footer-links a {
            color: #ddd;
            text-decoration: none;
            transition: color 0.3s;
        }

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

        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: #a5b1c2;
            position: relative;
            z-index: 2;
        }

        /* زر العودة للأعلى */
        .back-to-top {
            position: fixed;
            bottom: 40px;
            left: 40px;
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: 0 10px 30px rgba(44, 90, 160, 0.4);
            z-index: 998;
            opacity: 0;
            visibility: hidden;
            transform: translateY(20px);
        }

        .back-to-top.show {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }

        .back-to-top:hover {
            transform: scale(1.2) !important;
        }

        /* رسالة للزوار غير المسجلين */
        .guest-message {
            text-align: center;
            margin-bottom: 40px;
            padding: 30px;
            background: white;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            animation: messageFloat 3s ease-in-out infinite;
        }

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

        .guest-message h3 {
            color: var(--primary);
            margin-bottom: 15px;
            font-size: 1.8rem;
        }

        /* Responsive Design */
        @media (max-width: 1200px) {
            .hero-content {
                flex-direction: column;
                text-align: center;
                gap: 60px;
            }
            
            .hero-title {
                font-size: 3rem;
            }
        }

        @media (max-width: 992px) {
            .header-container {
                flex-direction: column;
                gap: 25px;
            }
            
            nav ul {
                gap: 25px;
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .hero-title {
                font-size: 2.5rem;
            }
            
            .hero-subtitle {
                font-size: 1.3rem;
            }
            
            .section-title h2 {
                font-size: 2.5rem;
            }
            
            .books-grid, .pricing-grid {
                grid-template-columns: 1fr;
                max-width: 600px;
                margin-left: auto;
                margin-right: auto;
            }
        }

        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.2rem;
            }
            
            .hero-subtitle {
                font-size: 1.1rem;
            }
            
            .hero-buttons {
                flex-direction: column;
                align-items: center;
                gap: 20px;
            }
            
            .btn-hero {
                width: 100%;
                max-width: 400px;
            }
            
            .section-title h2 {
                font-size: 2.2rem;
            }
            
            .pricing-card.featured {
                transform: scale(1);
            }
            
            .teacher-avatar {
                width: 150px;
                height: 150px;
                font-size: 3rem;
            }
            
            .teacher-bio h3 {
                font-size: 1.8rem;
            }
            
            .back-to-top {
                left: 20px;
                bottom: 20px;
                width: 50px;
                height: 50px;
                font-size: 1.3rem;
            }
        }

        @media (max-width: 576px) {
            .logo {
                flex-direction: column;
                text-align: center;
                gap: 15px;
            }
            
            .logo-icon {
                width: 60px;
                height: 60px;
                font-size: 2rem;
            }
            
            .logo h1 {
                font-size: 2rem;
            }
            
            .logo span {
                font-size: 1.9rem;
            }
            
            nav ul {
                gap: 15px;
            }
            
            nav a {
                font-size: 1rem;
                padding: 5px 0;
            }
            
            .auth-buttons {
                flex-direction: column;
                width: 100%;
                max-width: 350px;
                gap: 15px;
            }
            
            .btn {
                width: 100%;
                justify-content: center;
            }
            
            .hero-title {
                font-size: 2rem;
            }
            
            .hero-subtitle {
                font-size: 1rem;
            }
            
            .books-grid {
                grid-template-columns: 1fr;
            }
            
            .book-card, .pricing-card {
                padding: 30px 20px;
            }
            
            .book-title {
                font-size: 1.8rem;
            }
        }