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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #2563eb;
    font-weight: 700;
    font-size: 1.25rem;
    gap: 0.5rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #374151;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-link:hover,
.nav-link.active {
    color: #2563eb;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 3px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #374151;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #2563eb;
    color: white;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: #2563eb;
    border: 2px solid #2563eb;
}

.btn-secondary:hover {
    background: #2563eb;
    color: white;
}

.btn-outline {
    background: transparent;
    color: #374151;
    border: 2px solid #d1d5db;
}

.btn-outline:hover {
    background: #f9fafb;
    border-color: #9ca3af;
}

/* Hero Section */
.hero {
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('/assets/hero-bg.svg') center/cover;
    opacity: 0.1;
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Features */
.features {
    padding: 5rem 0;
    background: #f8fafc;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

/* Courses */
.featured-courses {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #1f2937;
}

.section-header p {
    font-size: 1.125rem;
    color: #6b7280;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.course-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: #f3f4f6;
}

.course-content {
    padding: 1.5rem;
}

.course-tag {
    display: inline-block;
    background: #dbeafe;
    color: #1e40af;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.course-description {
    color: #6b7280;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: #6b7280;
}

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #059669;
    margin-bottom: 1rem;
}

.section-footer {
    text-align: center;
}

/* Course Detail */
.course-detail {
    padding: 2rem 0;
}

.course-header {
    background: #f8fafc;
    padding: 3rem 0;
    margin-bottom: 3rem;
}

.course-info {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.course-sidebar {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    height: fit-content;
}

.course-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid #e5e7eb;
}

.tab-button {
    background: none;
    border: none;
    padding: 1rem 0;
    font-size: 1rem;
    font-weight: 600;
    color: #6b7280;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.3s;
}

.tab-button.active {
    color: #2563eb;
    border-bottom-color: #2563eb;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.curriculum-list {
    list-style: none;
}

.curriculum-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid #f3f4f6;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.curriculum-list li:before {
    content: "▶";
    color: #2563eb;
    font-size: 0.75rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #374151;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: #2563eb;
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

.form-checkbox {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.form-checkbox input {
    margin-top: 0.25rem;
}

.form-error {
    color: #dc2626;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Checkout */
.checkout {
    padding: 2rem 0;
}

.checkout-header {
    text-align: center;
    margin-bottom: 3rem;
}

.checkout-steps {
    display: flex;
    justify-content: center;
    margin-bottom: 3rem;
    gap: 2rem;
}

.step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    background: #f3f4f6;
    color: #6b7280;
}

.step.active {
    background: #dbeafe;
    color: #1e40af;
}

.step.completed {
    background: #d1fae5;
    color: #065f46;
}

.checkout-content {
    max-width: 800px;
    margin: 0 auto;
}

.checkout-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.order-summary {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 1rem;
    height: fit-content;
}

.trust-badges {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
    align-items: center;
}

.trust-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: white;
    border-radius: 0.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
    font-size: 1.25rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: #f9fafb;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 2rem;
    text-align: center;
    color: #9ca3af;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0,0,0,0.05);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

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

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

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

    .trust-badges {
        flex-wrap: wrap;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }