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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
}

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

/* Navigation Bar */
.navbar {
    background: linear-gradient(135deg, #1a3a52 0%, #2c5aa0 100%);
    padding: 25px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 40px;
    padding: 0 60px;
}

.navbar-left {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    min-width: 350px;
}

.navbar-center {
    display: flex;
    align-items: center;
    flex: 0;
}

.navbar-right {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    margin-left: auto;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-shrink: 0;
}

.logo {
    width: 80px;
    height: 80px;
    object-fit: contain;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
    flex-shrink: 0;
}

.site-title {
    color: #ffc107;
    font-size: 26px;
    font-weight: bold;
    letter-spacing: 2px;
    white-space: nowrap;
    margin: 0;
    padding: 0;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 40px;
    align-items: center;
    margin: 0;
    padding: 0;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 8px 15px;
    border-radius: 5px;
}

.nav-links a:hover {
    background-color: #ffc107;
    color: #1a3a52;
}

.nav-links a.active {
    background-color: #ffc107;
    color: #1a3a52;
}

.btn-login {
    border: 2px solid #ffc107;
    background-color: transparent;
}

.btn-login:hover {
    background-color: #ffc107;
    color: #1a3a52;
}

.btn-signup {
    background-color: #ffc107;
    color: #1a3a52;
    font-weight: bold;
}

.btn-signup:hover {
    background-color: #ffb300;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #1a3a52 0%, #2c5aa0 100%);
    color: white;
    padding: 100px 20px;
    text-align: center;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-content h2 {
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-content p {
    font-size: 24px;
    margin-bottom: 40px;
    color: #ffc107;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

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

.btn {
    padding: 15px 40px;
    font-size: 16px;
    font-weight: bold;
    text-decoration: none;
    border-radius: 50px;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    display: inline-block;
    white-space: nowrap;
}

.btn-primary {
    background-color: #ffc107;
    color: #1a3a52;
}

.btn-primary:hover {
    background-color: #ffb300;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(255, 193, 7, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: white;
    color: #1a3a52;
    transform: translateY(-3px);
}

/* Features Section */
.features {
    padding: 80px 20px;
    background-color: #f8f9fa;
}

.features h2 {
    font-size: 36px;
    text-align: center;
    margin-bottom: 60px;
    color: #1a3a52;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border-top: 4px solid #ffc107;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: #1a3a52;
}

.feature-card p {
    color: #666;
    font-size: 14px;
}

/* Footer */
.footer {
    background: rgba(26, 58, 82, 0.9);
    color: white;
    padding: 12px 20px;
    text-align: center;
    margin-top: 60px;
    border-top: 2px solid #ffc107;
    font-size: 11px;
}

.footer p {
    margin: 0;
    padding: 0;
    line-height: 1.4;
}

.footer-links {
    margin-top: 6px;
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #ffc107;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 10px;
}

.footer-links a:hover {
    color: white;
    text-decoration: underline;
}

/* Responsive Design */

/* Tablet and Below (768px and down) */
@media (max-width: 768px) {
    .navbar {
        padding: 12px 0;
    }
    
    .navbar .container {
        flex-direction: column;
        gap: 12px;
        padding: 0 15px;
        justify-content: center;
    }

    .navbar-left {
        min-width: auto;
        width: 100%;
        justify-content: center;
    }

    .navbar-center {
        width: 100%;
        justify-content: center;
    }

    .navbar-right {
        margin-left: 0;
        width: 100%;
        justify-content: center;
    }

    .logo-section {
        gap: 8px;
    }

    .logo {
        width: 80px;
        height: 80px;
    }

    .site-title {
        font-size: 18px;
        letter-spacing: 1px;
    }

    .nav-links {
        gap: 8px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-links a {
        padding: 6px 10px;
        font-size: 13px;
    }

    .nav-links li {
        margin: 0;
    }

    .language-switcher {
        gap: 6px;
    }

    .language-switcher a {
        padding: 5px 10px;
        font-size: 12px;
    }

    .hero {
        padding: 60px 20px;
        min-height: 400px;
    }

    .hero-content h2 {
        font-size: 32px;
        margin-bottom: 15px;
    }

    .hero-content p {
        font-size: 18px;
        margin-bottom: 30px;
    }

    .hero-buttons {
        flex-wrap: wrap;
        gap: 15px;
    }

    .btn {
        padding: 12px 25px;
        font-size: 14px;
    }

    .features {
        padding: 60px 20px;
    }

    .features h2 {
        font-size: 28px;
        margin-bottom: 40px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .feature-card {
        padding: 30px 20px;
    }

    .feature-icon {
        font-size: 36px;
        margin-bottom: 15px;
    }

    .feature-card h3 {
        font-size: 18px;
        margin-bottom: 10px;
    }

    .feature-card p {
        font-size: 13px;
    }

    .footer {
        padding: 10px 20px;
        font-size: 10px;
    }

    .footer-links {
        gap: 10px;
    }

    .footer-links a {
        font-size: 9px;
    }

    /* Course Cards Responsive */
    .course-card {
        margin: 15px;
    }

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

/* Mobile (480px and down) */
@media (max-width: 480px) {
    .navbar {
        padding: 10px 0;
    }

    .navbar .container {
        flex-direction: column;
        gap: 8px;
        padding: 0 12px;
        justify-content: center;
    }

    .navbar-left {
        min-width: auto;
        width: 100%;
        justify-content: center;
    }

    .navbar-center {
        width: 100%;
        justify-content: center;
    }

    .navbar-right {
        margin-left: 0;
        width: 100%;
        justify-content: center;
    }

    .logo-section {
        gap: 6px;
    }

    .logo {
        width: 45px;
        height: 45px;
    }

    .site-title {
        font-size: 14px;
        letter-spacing: 0.5px;
    }

    .nav-links {
        gap: 6px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-links a {
        padding: 5px 8px;
        font-size: 11px;
    }

    .nav-links li {
        margin: 0;
    }

    .language-switcher {
        gap: 5px;
    }

    .language-switcher a {
        padding: 4px 8px;
        font-size: 10px;
    }

    .hero {
        padding: 40px 15px;
        min-height: 300px;
    }

    .hero-content h2 {
        font-size: 24px;
        margin-bottom: 12px;
    }

    .hero-content p {
        font-size: 16px;
        margin-bottom: 20px;
    }

    .hero-buttons {
        flex-direction: column;
        gap: 10px;
    }

    .btn {
        padding: 12px 20px;
        font-size: 13px;
        width: 100%;
        text-align: center;
    }

    .features {
        padding: 40px 15px;
    }

    .features h2 {
        font-size: 24px;
        margin-bottom: 30px;
    }

    .feature-card {
        padding: 20px 15px;
        margin: 10px 0;
    }

    .feature-icon {
        font-size: 30px;
        margin-bottom: 12px;
    }

    .feature-card h3 {
        font-size: 16px;
        margin-bottom: 8px;
    }

    .feature-card p {
        font-size: 12px;
    }

    .footer {
        padding: 8px 15px;
        font-size: 9px;
    }

    .footer p {
        line-height: 1.3;
    }

    .footer-links a {
        font-size: 8px;
    }

    /* Course Cards Mobile */
    .course-card {
        margin: 10px;
    }

    .course-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .course-thumbnail {
        height: 200px;
    }

    .course-info {
        padding: 15px;
    }

    .course-info h3 {
        font-size: 16px;
    }

    .course-info p {
        font-size: 12px;
    }
}

/* Large screens (1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1200px;
    }

    .hero-content h2 {
        font-size: 52px;
    }

    .hero-content p {
        font-size: 26px;
    }

    .features h2 {
        font-size: 40px;
    }

    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}