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

body {
    font-family: 'Poppins', sans-serif;
    color: #333;
    line-height: 1.6;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 40px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #0C6F8A;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #3DB6D3;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #333;
}

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 40px 60px;
    background: linear-gradient(135deg, #d5f0f7 0%, #e8f8fb 50%, #fdf8e1 100%);
}

.hero-content {
    max-width: 1000px;
    display: flex;
    align-items: center;
    gap: 60px;
}

.hero-photo img {
    width: 280px;
    height: 280px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid #fff;
    box-shadow: 0 10px 30px rgba(12, 111, 138, 0.2);
}

.hero-text h1 {
    font-size: 2.5rem;
    color: #0C6F8A;
    margin-bottom: 10px;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: #3DB6D3;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero-description {
    font-size: 1rem;
    color: #555;
    max-width: 500px;
}

/* Sección Clases */
.clases {
    padding: 80px 40px;
    text-align: center;
    background: #fff;
}

.clases h2 {
    font-size: 2rem;
    color: #0C6F8A;
    margin-bottom: 15px;
}

.clases-intro {
    color: #666;
    max-width: 600px;
    margin: 0 auto 40px;
    font-size: 1.05rem;
}

.clases-cards {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.clase-card {
    background: linear-gradient(135deg, #e8f8fb, #fdf8e1);
    border-radius: 16px;
    padding: 30px 40px;
    min-width: 220px;
    box-shadow: 0 4px 15px rgba(12, 111, 138, 0.1);
}

.clase-icon {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.clase-card h3 {
    font-size: 1.3rem;
    color: #0C6F8A;
    margin-bottom: 15px;
}

.clase-hora {
    font-size: 0.95rem;
    color: #555;
    margin-bottom: 5px;
}

/* Botones */
.btn {
    display: inline-block;
    padding: 16px 40px;
    border-radius: 50px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.btn-clase {
    background: linear-gradient(135deg, #0C6F8A, #3DB6D3);
    color: #fff;
}

.btn-paypal {
    background: #FAE46C;
    color: #333;
}

.btn-whatsapp {
    background: #25D366;
    color: #fff;
}

/* Sección Apóyame */
.apoyame {
    padding: 80px 40px;
    text-align: center;
    background: linear-gradient(135deg, #e8f8fb 0%, #fdf8e1 100%);
}

.apoyame h2 {
    font-size: 2rem;
    color: #0C6F8A;
    margin-bottom: 15px;
}

.apoyame-texto {
    color: #555;
    max-width: 600px;
    margin: 0 auto 30px;
    font-size: 1.05rem;
}

/* Sección italki */
.italki-section {
    padding: 80px 40px;
    text-align: center;
    background: #ffffff;
}

.italki-section h2 {
    font-size: 2rem;
    color: #0C6F8A;
    margin-bottom: 10px;
}

.italki-intro {
    color: #555;
    max-width: 700px;
    margin: 0 auto 20px;
    font-size: 1.05rem;
}

.italki-grid {
    display: flex;
    justify-content: center;
    gap: 30px;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.italki-card {
    max-width: 520px;
    text-align: left;
    background: #ffffff;
    padding: 22px;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(12, 111, 138, 0.08);
}

.italki-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}

.btn-italki {
    background: linear-gradient(135deg, #0C6F8A, #3DB6D3);
    color: #fff;
    padding: 14px 28px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
}

.btn-outline {
    background: transparent;
    border: 2px solid #0C6F8A;
    color: #0C6F8A;
    padding: 12px 26px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
}

.italki-note {
    color: #777;
    font-size: 0.95rem;
    margin-top: 10px;
}

/* Sección Videos */
.videos {
    padding: 80px 40px;
    text-align: center;
    background: #fff;
}

.videos h2 {
    font-size: 2rem;
    color: #0C6F8A;
    margin-bottom: 15px;
}

.videos-intro {
    color: #666;
    max-width: 600px;
    margin: 0 auto 40px;
    font-size: 1.05rem;
}

.videos-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    max-width: 1100px;
    margin: 0 auto;
}

.video-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    aspect-ratio: 16 / 9;
}

.video-item iframe {
    width: 100%;
    height: 100%;
    border: none;
}

/* Sección Comunidad (WhatsApp + Telegram) */
.comunidad {
    padding: 80px 40px;
    text-align: center;
    background: linear-gradient(135deg, #e8f8fb 0%, #eafbea 100%);
}

.comunidad h2 {
    font-size: 2rem;
    color: #0C6F8A;
    margin-bottom: 15px;
}

.comunidad-texto {
    color: #555;
    max-width: 600px;
    margin: 0 auto 30px;
    font-size: 1.05rem;
}

.comunidad-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.btn-telegram {
    background: #0088cc;
    color: #fff;
}

/* Footer */
.footer {
    padding: 30px 40px;
    text-align: center;
    background: #0C6F8A;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 15px;
}

.social-links a {
    color: #fff;
    transition: color 0.3s, transform 0.3s;
    display: flex;
    align-items: center;
}

.social-links a:hover {
    color: #FAE46C;
    transform: scale(1.15);
}

.social-icon {
    width: 32px;
    height: 32px;
    object-fit: contain;
    filter: brightness(0) invert(1);
    transition: filter 0.3s;
}

.social-links a:hover .social-icon {
    filter: brightness(0) invert(1) sepia(1) saturate(5) hue-rotate(10deg);
}

/* Página Practica - Hero */
.practica-hero {
    padding: 120px 40px 50px;
    text-align: center;
    background: linear-gradient(135deg, #d5f0f7 0%, #fdf8e1 100%);
}

.practica-hero h1 {
    font-size: 2.5rem;
    color: #0C6F8A;
    margin-bottom: 10px;
}

.practica-hero-desc {
    color: #555;
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto 25px;
}

.btn-start {
    background: linear-gradient(135deg, #0C6F8A, #3DB6D3);
    color: #fff;
}

.active-link {
    color: #0C6F8A !important;
    font-weight: 700 !important;
}

/* Practica Layout */
.practica-layout {
    display: flex;
    min-height: calc(100vh - 200px);
}

/* Sidebar */
.sidebar {
    width: 260px;
    flex-shrink: 0;
    position: sticky;
    top: 70px;
    height: calc(100vh - 70px);
    background: #f5f5f5;
    border-right: 2px solid #e0e0e0;
    z-index: 100;
}

.sidebar-toggle {
    display: none;
    width: 100%;
    padding: 15px 20px;
    background: #0C6F8A;
    color: #fff;
    border: none;
    cursor: pointer;
    font-family: 'Poppins', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    align-items: center;
    gap: 10px;
}

.sidebar-nav {
    padding: 25px 20px;
    overflow-y: auto;
    height: 100%;
}

.sidebar-nav h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #3DB6D3;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #FAE46C;
}

.sidebar-nav ul {
    list-style: none;
}

.sidebar-nav li {
    margin-bottom: 5px;
}

.sidebar-link {
    display: block;
    padding: 10px 15px;
    color: #555;
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: background 0.3s, color 0.3s;
}

.sidebar-link:hover {
    background: #e8f8fb;
    color: #0C6F8A;
}

.sidebar-link.active {
    background: #0C6F8A;
    color: #fff;
    font-weight: 600;
}

/* Practica Content */
.practica-content {
    flex: 1;
    padding: 40px;
    max-width: 850px;
}

/* Topic sections */
.quiz-topic {
    margin-bottom: 60px;
    scroll-margin-top: 90px;
}

.topic-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.topic-header h2 {
    font-size: 1.8rem;
    color: #0C6F8A;
}

.topic-badge {
    background: #FAE46C;
    color: #333;
    padding: 3px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 700;
}

.topic-desc {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid #eee;
}

/* Topic visual aids */
.topic-image-box {
    margin-bottom: 25px;
    border-radius: 12px;
    overflow: hidden;
    background: #f0fafb;
    border: 2px solid #e0eff3;
    padding: 20px;
}

.grammar-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.grammar-table th {
    background: #0C6F8A;
    color: #fff;
    padding: 10px 15px;
    text-align: left;
    font-weight: 600;
}

.grammar-table td {
    padding: 10px 15px;
    border-bottom: 1px solid #dceef3;
}

.grammar-table tr:last-child td {
    border-bottom: none;
}

.grammar-table tr:nth-child(even) td {
    background: #e8f8fb;
}

/* Image placeholder for didactic images */
.image-placeholder {
    text-align: center;
}

.image-placeholder img {
    max-width: 100%;
    border-radius: 8px;
}

.placeholder-text {
    padding: 15px;
    font-size: 1rem;
    line-height: 2;
    color: #0C6F8A;
}

/* Vocabulary cards */
.vocab-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.vocab-card {
    background: #fff;
    border: 2px solid #e0eff3;
    border-radius: 10px;
    padding: 12px 16px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.vocab-en {
    font-weight: 700;
    color: #0C6F8A;
    font-size: 0.95rem;
}

.vocab-es {
    color: #777;
    font-size: 0.85rem;
}

/* Dialogue box */
.dialogue-box {
    background: #fff;
    border-radius: 10px;
    padding: 20px;
    border-left: 4px solid #3DB6D3;
}

.dialogue-title {
    font-weight: 700;
    color: #0C6F8A;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.dialogue-box p {
    margin-bottom: 6px;
    font-size: 0.93rem;
    line-height: 1.7;
}

.dialogue-box strong {
    color: #0C6F8A;
}

/* Quiz questions */
.quiz-question {
    background: #f9f9f9;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.quiz-question p {
    font-size: 1.05rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.quiz-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.quiz-option {
    padding: 12px 18px;
    border: 2px solid #ddd;
    border-radius: 8px;
    background: #fff;
    cursor: pointer;
    font-size: 0.95rem;
    font-family: 'Poppins', sans-serif;
    transition: border-color 0.3s, background 0.3s;
    text-align: left;
}

.quiz-option:hover {
    border-color: #3DB6D3;
    background: #f0fafb;
}

.quiz-option.correct {
    border-color: #25D366;
    background: #e6f9ee;
    color: #1a7a3a;
    font-weight: 600;
}

.quiz-option.incorrect {
    border-color: #FF0000;
    background: #ffe6e6;
    color: #cc0000;
}

.quiz-option.disabled {
    pointer-events: none;
    opacity: 0.7;
}

/* Quiz result */
.quiz-result {
    text-align: center;
    padding: 40px;
    background: linear-gradient(135deg, #e8f8fb, #fdf8e1);
    border-radius: 16px;
    margin-top: 30px;
}

.quiz-result h2 {
    color: #0C6F8A;
    margin-bottom: 10px;
}

.quiz-result .score {
    font-size: 3rem;
    font-weight: 700;
    color: #3DB6D3;
}

.quiz-result p {
    color: #555;
    margin-top: 10px;
}

.btn-restart {
    margin-top: 20px;
    padding: 12px 30px;
    background: linear-gradient(135deg, #0C6F8A, #3DB6D3);
    color: #fff;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    font-family: 'Poppins', sans-serif;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn-restart:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

/* Página Material */
.material-hero {
    padding: 120px 40px 50px;
    text-align: center;
    background: linear-gradient(135deg, #d5f0f7 0%, #fdf8e1 100%);
}

.material-hero h1 {
    font-size: 2.5rem;
    color: #0C6F8A;
    margin-bottom: 10px;
}

.material-hero-desc {
    color: #555;
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

.material-grid-section {
    padding: 60px 40px;
    background: #fff;
    min-height: 40vh;
}

.material-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    max-width: 1100px;
    margin: 0 auto;
}

.material-card {
    background: #fff;
    border: 2px solid #e0eff3;
    border-radius: 16px;
    padding: 30px 25px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.material-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(12, 111, 138, 0.15);
}

.material-card-icon {
    margin-bottom: 15px;
}

.material-card h3 {
    font-size: 1.1rem;
    color: #0C6F8A;
    margin-bottom: 10px;
}

.material-card-desc {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 20px;
    line-height: 1.5;
}

.material-card-actions {
    display: flex;
    justify-content: center;
    gap: 10px;
}

.btn-preview,
.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 600;
    font-family: 'Poppins', sans-serif;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
}

.btn-preview {
    background: #fff;
    color: #0C6F8A;
    border: 2px solid #0C6F8A;
}

.btn-preview:hover {
    background: #e8f8fb;
    transform: translateY(-2px);
}

.btn-download {
    background: linear-gradient(135deg, #0C6F8A, #3DB6D3);
    color: #fff;
    border: none;
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(12, 111, 138, 0.3);
}

/* Empty state */
.material-empty {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 20px;
}

.material-empty h3 {
    font-size: 1.5rem;
    color: #0C6F8A;
    margin: 20px 0 10px;
}

.material-empty p {
    color: #888;
    font-size: 1.05rem;
}

/* PDF Modal */
.pdf-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.pdf-modal.active {
    display: flex;
}

.pdf-modal-content {
    background: #fff;
    border-radius: 12px;
    width: 96%;
    max-width: 1200px;
    height: 95vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pdf-modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 25px;
    background: #0C6F8A;
    color: #fff;
}

.pdf-modal-header h3 {
    font-size: 1rem;
    text-transform: capitalize;
}

.pdf-modal-close {
    background: none;
    border: none;
    color: #fff;
    font-size: 1.8rem;
    cursor: pointer;
    line-height: 1;
    padding: 0 5px;
}

.pdf-modal-close:hover {
    color: #FAE46C;
}

.pdf-modal-body {
    flex: 1;
    overflow: hidden;
}

.pdf-modal-body iframe {
    width: 100%;
    height: 100%;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 65px;
        left: 0;
        width: 100%;
        background: rgba(255, 255, 255, 0.98);
        padding: 20px 40px;
        gap: 15px;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-text h1 {
        font-size: 1.8rem;
    }

    .hero-photo img {
        width: 200px;
        height: 200px;
    }

    .hero-description {
        margin: 0 auto;
    }

    .videos-grid {
        grid-template-columns: 1fr;
    }

    .quiz-options {
        grid-template-columns: 1fr;
    }

    .practica-hero h1 {
        font-size: 1.8rem;
    }

    /* Sidebar responsive */
    .practica-layout {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: relative;
        top: 0;
        height: auto;
        border-right: none;
        border-bottom: 2px solid #e0e0e0;
    }

    .sidebar-toggle {
        display: flex;
    }

    .sidebar-nav {
        display: none;
        padding: 15px 20px;
        height: auto;
    }

    .sidebar-nav.open {
        display: block;
    }

    .practica-content {
        padding: 25px 20px;
    }

    .vocab-grid {
        grid-template-columns: 1fr;
    }

    .grammar-table {
        font-size: 0.85rem;
    }

    .grammar-table th,
    .grammar-table td {
        padding: 8px 10px;
    }

    .material-hero h1 {
        font-size: 1.8rem;
    }

    .material-grid {
        grid-template-columns: 1fr;
    }

    .material-grid-section {
        padding: 40px 20px;
    }

    .pdf-modal-content {
        width: 95%;
        height: 80vh;
    }
}