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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #F6F7FB;
    min-height: 100vh;;
}

/* Header */
.header {
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.logo {
    color: #4255FF;
    font-size: 28px;
    font-weight: bold;
    text-decoration: none;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-item {
    color: black;
    text-decoration: none;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 4px;
    opacity: 0.9;
    transition: opacity 0.2s;
}

.nav-item:hover {
    opacity: 1;
}

.search-container {
    position: relative;
    flex: 1;
    max-width: 400px;
    margin: 0 32px;
}

.search-input {
    width: 100%;
    padding: 12px 16px 12px 40px;
    border: none;
    border-radius: 8px;
    background: rgba(157, 156, 156, 0.2);
    color: gainsboro;
    font-size: 16px;
    backdrop-filter: blur(10px);
}

.search-input::placeholder {
    color: rgba(128, 126, 126, 0.7);
}

.search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: rgba(25, 23, 23, 0.7);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.btn {
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

.btn-create {
    background: rgba(163, 162, 162, 0.2);
    color: #4255FF;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-login {
    background: #4255ff;
    color: white;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* Main Content */
.main-content {
    padding: 80px 24px;
    text-align: center;
    color: black;
}

.hero-title {
    font-size: 56px;
    font-weight: bold;
    margin-bottom: 24px;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 32px;
}

.btn-signup {
    background: #4255ff;
    color: white;
    padding: 16px 32px;
    font-size: 18px;
}

.teacher-link {
    color: #4255ff;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
}

/* Features Section */
.features {
    padding: 80px 24px;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
}

.carousel-container {
    position: relative;
    display: flex;
    align-items: center;
    gap: 20px;
}

.carousel-wrapper {
    flex: 1;
    overflow: hidden;
    border-radius: 16px;
}

.features-carousel {
    display: flex;
    transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    gap: 24px;
}

.carousel-btn {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
}

.carousel-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.carousel-btn:active {
    transform: scale(0.95);
}

.carousel-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.feature-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    color: rgb(14, 13, 13);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
    min-width: 280px;
    flex: 0 0 auto;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.2);
}

.feature-card.expert-solutions {
    background: #98E3FF;
}

.feature-card.learn {
    background: #EEAAFF;
}

.feature-card.study-guides {
    background: #4e49d5;
}

.feature-card.flashcards {
    background: #FFC38C;
}

.feature-card.test-prep {
    background: #98F1D1;
}

.feature-card.live-sessions {
    background: #98E3FF;
}

.feature-card.progress-tracking {
    background: #EEAAFF;
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
}

.feature-title {
    font-size: 24px;
    font-weight: bold;
    margin-bottom: 16px;
}

.feature-description {
    font-size: 16px;
    opacity: 0.9;
    line-height: 1.5;
}

/* Carousel Indicators */
.carousel-indicators {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-top: 32px;
}

.indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: all 0.3s ease;
}

.indicator.active {
    background: white;
    transform: scale(1.2);
}

.indicator:hover {
    background: rgba(255, 255, 255, 0.6);
    transform: scale(1.1);
}

/* Popular Flashcards */
.popular-section {
    padding: 80px 24px;
    max-width: 1200px;
    margin: 0 auto;
    color: rgb(8, 7, 7);
}

.section-title {
    font-size: 32px;
    font-weight: bold;
    text-align: center;
    margin-bottom: 48px;
}

.flashcard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.flashcard-item {
    background: white;
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 24px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform 0.2s;
}

.flashcard-item:hover {
    transform: translateY(-4px);
}

.flashcard-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}

.flashcard-meta {
    font-size: 14px;
    opacity: 0.7;
    margin-bottom: 16px;
}

.flashcard-author {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.author-avatar {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: #4255ff;
}

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

.hero-title {
    animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.cta-buttons {
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

/* Footer chung */
.quizlet-footer {
    background-color: #f7f8fa; /* Màu nền nhạt */
    padding: 40px 0;
    border-top: 1px solid #e6e9ed; /* Đường kẻ phía trên */
    margin-top: auto; /* Đẩy footer xuống cuối trang */
}

.footer-content {
    max-width: 1200px; /* Chiều rộng tối đa của nội dung footer */
    margin: 0 auto; /* Căn giữa */
    display: flex;
    justify-content: space-between; /* Đẩy các cột ra xa nhau */
    flex-wrap: wrap; /* Cho phép các cột xuống hàng nếu màn hình nhỏ */
    padding: 0 20px; /* Padding hai bên cho nội dung */
}

.footer-column {
    flex: 1; /* Mỗi cột sẽ chiếm không gian bằng nhau */
    min-width: 180px; /* Đảm bảo mỗi cột có chiều rộng tối thiểu */
    margin-bottom: 20px; /* Khoảng cách dưới mỗi cột khi xuống hàng */
}

.footer-column h3 {
    font-size: 1rem; /* Kích thước chữ tiêu đề cột */
    color: #586380; /* Màu chữ tiêu đề */
    margin-bottom: 15px;
    font-weight: bold;
    text-transform: uppercase; /* Chữ hoa */
}

.footer-column ul {
    list-style: none; /* Bỏ dấu chấm đầu dòng */
    padding: 0;
    margin: 0;
}

.footer-column ul li {
    margin-bottom: 10px; /* Khoảng cách giữa các mục danh sách */
}

.footer-column ul li a {
    text-decoration: none; /* Bỏ gạch chân link */
    color: #333; /* Màu chữ link */
    font-size: 0.875rem; /* Kích thước chữ link */
}

.footer-column ul li a:hover {
    color: #4257b2; /* Màu chữ khi hover */
}

/* Cột ngôn ngữ và QR Code */
.language-qr-column {
    min-width: 150px; /* Điều chỉnh chiều rộng cho cột này */
    text-align: right; /* Căn phải nội dung trong cột này */
}

.language-selector {
    display: flex;
    align-items: center;
    justify-content: flex-end; /* Căn phải */
    border: 1px solid #ccc;
    padding: 8px 12px;
    border-radius: 5px;
    cursor: pointer;
    width: fit-content; /* Điều chỉnh chiều rộng theo nội dung */
    margin-left: auto; /* Đẩy sang phải */
    margin-bottom: 20px;
    color: #333;
    font-size: 0.875rem;
}

.language-selector svg {
    margin-left: 8px;
    color: #888;
}

.qr-code-section {
    text-align: center; /* Căn giữa nội dung trong phần QR */
    background-color: #fff; /* Nền trắng cho phần QR */
    border: 1px solid #e6e9ed;
    border-radius: 8px;
    padding: 15px;
    display: inline-block; /* Để có thể căn giữa khối này */
    margin-left: auto;
    margin-right: auto;
}

.qr-code {
    width: 100px; /* Kích thước QR code */
    height: 100px;
    display: block; /* Đảm bảo ảnh chiếm một dòng riêng */
    margin: 0 auto 10px auto; /* Căn giữa ảnh và tạo khoảng cách dưới */
    /* Bạn cần thay thế 'qr_code_placeholder.png' bằng ảnh QR code thực tế của bạn */
}

.qr-code-section p {
    font-size: 0.75rem; /* Kích thước chữ "Tải ứng dụng" */
    color: #586380;
    margin: 0;
}

/* Thanh dưới cùng của footer */
.footer-bottom-bar {
    text-align: left; /* Căn trái */
    padding: 20px 20px 0; /* Padding trên và hai bên, không padding dưới */
    max-width: 1200px;
    margin: 0 auto;
    border-top: 1px solid #e6e9ed; /* Đường kẻ phía trên */
    margin-top: 20px; /* Khoảng cách từ nội dung footer chính */
}

.footer-bottom-bar a {
    color: #586380;
    text-decoration: none;
    font-size: 0.75rem;
}

.footer-bottom-bar a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    /* Header adjustments */
    .header {
        flex-direction: column; /* Stack header items vertically */
        gap: 12px; /* Reduced gap between stacked items */
        padding: 12px 15px; /* Adjusted padding for mobile header */
        align-items: stretch; /* Stretch items to fill column width */
    }

    .nav-left {
        display: none; /* Hide main navigation items on mobile header */
    }

    .logo {
        text-align: center; /* Center logo on mobile */
        font-size: 22px; /* Slightly smaller logo */
        margin-bottom: 5px; /* Small margin below logo */
    }

    .search-container {
        margin: 0;
        max-width: none; /* Allow search bar to take full width */
        width: 100%; /* Ensure it takes 100% width */
        order: 1; /* Place search bar after logo */
    }

    .search-input {
        padding: 9px 12px 9px 34px; /* Smaller padding for search input */
        font-size: 13px; /* Smaller font size for input */
    }

    .search-icon {
        left: 10px;
        font-size: 13px; /* Smaller search icon */
    }

    .nav-right {
        gap: 8px; /* Reduced gap between right nav buttons */
        justify-content: center; /* Center buttons */
        width: 100%; /* Ensure buttons span full width */
        flex-wrap: wrap; /* Allow buttons to wrap to next line if space is tight */
    }

    .btn {
        padding: 7px 14px; /* Smaller button padding */
        font-size: 13px; /* Smaller font for buttons */
        min-width: unset; /* Allow buttons to shrink */
    }

    /* Main Content adjustments */
    .main-content {
        padding: 50px 15px; /* Adjusted padding for mobile content */
    }

    .hero-title {
        font-size: 32px; /* Smaller hero title */
        margin-bottom: 12px;
    }

    .hero-subtitle {
        font-size: 15px; /* Smaller subtitle */
        margin-bottom: 25px;
        padding: 0 5px; /* Slightly less horizontal padding */
    }

    .cta-buttons {
        flex-direction: column; /* Stack buttons vertically */
        align-items: center; /* Center stacked buttons */
        gap: 10px; /* Reduced gap between buttons */
    }

    .btn-signup {
        width: 90%; /* Make signup button relatively wider */
        max-width: 300px; /* Limit max width for very large phones */
        padding: 12px 25px; /* Smaller padding */
        font-size: 15px; /* Smaller font */
    }

    .teacher-link {
        font-size: 14px; /* Smaller teacher link font */
    }

    /* Features Section adjustments (Carousel) */
    .features {
        padding: 30px 15px; /* Adjusted padding for features section */
    }

    .carousel-container {
        flex-direction: column; /* Stack carousel elements vertically */
        gap: 15px; /* Reduced gap */
    }

    .carousel-btn {
        display: none; /* Hide navigation buttons on mobile for scrollable carousel */
    }

    .carousel-wrapper {
        width: 100%; /* Ensure wrapper takes full width for scrolling */
    }

    .features-carousel {
        overflow-x: auto; /* Enable horizontal scrolling */
        scroll-snap-type: x mandatory; /* Snap to cards */
        scrollbar-width: none; /* Hide scrollbar for Firefox */
        -ms-overflow-style: none; /* Hide scrollbar for IE/Edge */
        padding-bottom: 8px; /* Reduced padding if scrollbar area is desired */
        gap: 15px; /* Reduced gap between cards for mobile scroll */
    }

    .features-carousel::-webkit-scrollbar {
        display: none; /* Hide scrollbar for Webkit browsers */
    }

    .feature-card {
        scroll-snap-align: start; /* Snap to the start of each card */
        min-width: 240px; /* Set a slightly smaller minimum width for cards */
        flex-shrink: 0; /* Prevent cards from shrinking */
        padding: 20px 15px; /* Adjusted card padding */
    }

    .feature-icon {
        width: 55px; /* Smaller icons */
        height: 55px;
        margin-bottom: 15px;
        font-size: 22px;
    }

    .feature-title {
        font-size: 18px; /* Smaller feature title */
        margin-bottom: 10px;
    }

    .feature-description {
        font-size: 13px; /* Smaller feature description */
    }

    .carousel-indicators {
        display: none; /* Hide indicators on mobile if using scroll snap */
    }

    /* Popular Flashcards section adjustments */
    .popular-section {
        padding: 30px 15px; /* Adjusted padding */
    }

    .section-title {
        font-size: 26px; /* Smaller section title */
        margin-bottom: 30px;
    }

    .flashcard-grid {
        grid-template-columns: 1fr; /* Single column layout for flashcards */
        gap: 15px; /* Reduced gap */
    }

    .flashcard-item {
        padding: 18px; /* Adjusted padding for flashcard items */
    }

    .flashcard-title {
        font-size: 15px; /* Smaller flashcard title */
    }

    .flashcard-meta {
        font-size: 12px; /* Smaller meta text */
    }

    .flashcard-author {
        font-size: 13px; /* Smaller author text */
    }

    .author-avatar {
        width: 20px; /* Smaller avatar */
        height: 20px;
    }

    /* Footer adjustments */
    .quizlet-footer {
        padding: 30px 0; /* Reduced footer padding */
    }

    .footer-content {
        flex-direction: column; /* Stack footer columns vertically */
        align-items: flex-start; /* Align columns to the left */
        padding: 0 15px; /* Adjusted horizontal padding */
    }

    .footer-column {
        min-width: unset; /* Remove min-width constraint */
        width: 100%; /* Make columns take full width */
        text-align: left; /* Align text to the left */
        margin-bottom: 18px; /* Space between stacked columns */
    }

    .footer-column h3 {
        font-size: 0.9rem; /* Smaller column title */
        margin-bottom: 10px;
    }

    .footer-column ul li {
        margin-bottom: 8px; /* Reduced space between list items */
    }

    .footer-column ul li a {
        font-size: 0.8rem; /* Smaller link font */
    }

    .language-qr-column {
        text-align: left; /* Align content to the left */
        order: -1; /* Move this column to the top on mobile */
        margin-bottom: 20px; /* Ensure space below it */
    }

    .language-selector {
        margin-left: 0; /* Remove auto left margin */
        justify-content: flex-start; /* Align selector to the left */
        margin-bottom: 10px; /* Reduced space below it */
        padding: 6px 10px; /* Adjusted padding */
        font-size: 0.8rem; /* Smaller font */
    }

    .qr-code-section {
        text-align: center; /* Keep QR code section centered */
        margin-left: 0;
        margin-right: auto; /* Allow auto right margin to center if needed */
        width: 140px; /* Slightly smaller width for the QR section */
        padding: 12px; /* Adjusted padding */
    }

    .qr-code {
        width: 90px; /* Smaller QR code image */
        height: 90px;
        margin: 0 auto 8px auto; /* Adjusted margin */
    }

    .qr-code-section p {
        font-size: 0.7rem; /* Smaller text below QR */
    }

    .footer-bottom-bar {
        text-align: center; /* Center copyright/links */
        padding: 12px 15px 0; /* Adjusted padding */
        margin-top: 15px; /* Adjusted margin */
    }

    .footer-bottom-bar a {
        font-size: 0.7rem; /* Smaller font for bottom links */
    }
}

a[href*="somee.com"],
iframe[src*="somee.com"],
img[src*="somee.com"],
script[src*="somee.com"],
link[href*="somee.com"],
div[style*="z-index: 2147483647"][style*="position: fixed"][style*="background-color: #202020"] {
    display: none !important;
}