/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Typography */
    --font-primary: 'Inter', sans-serif;
    --font-display: 'Playfair Display', serif;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 700;
}

.logo-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.2) 0%, transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: var(--spacing-lg) 0;
}

.hero-subtitle {
    display: block;
    font-size: 1.125rem;
    font-weight: 400;
    margin-bottom: var(--spacing-sm);
    opacity: 0.95;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.hero-highlight {
    background: linear-gradient(to right, #fbbf24, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
    opacity: 0.95;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-md);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: white;
    opacity: 0.7;
    animation: bounce 2s infinite;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
}

/* Section Styles */
section {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
}

.section-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    border-radius: 2rem;
    font-weight: 600;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* About Section */
.about {
    background: var(--bg-light);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.about-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.about-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    color: white;
}

.about-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.about-card p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* Courses Section */
.courses {
    background: white;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.course-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.course-card-featured {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
}

.course-card-featured .course-title,
.course-card-featured .course-description,
.course-card-featured .course-features {
    color: white;
}

.course-card-featured .course-icon {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.course-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.course-icon-pm {
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: white;
}

.course-icon-ai {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.course-icon-advanced {
    background: linear-gradient(135deg, #8b5cf6, #7c3aed);
    color: white;
}

.course-badge {
    padding: 0.375rem 0.875rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    border-radius: 2rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.course-badge-featured {
    background: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
}

.course-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.course-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.course-features {
    list-style: none;
    margin-bottom: var(--spacing-md);
    flex-grow: 1;
}

.course-features li {
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.course-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

.course-card-featured .course-features li {
    color: rgba(255, 255, 255, 0.9);
}

.course-card-featured .course-features li::before {
    color: #fbbf24;
}

/* Contact Section */
.contact {
    background: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.contact-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.contact-card p {
    color: var(--text-secondary);
}

.contact-card a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.contact-card a:hover {
    color: var(--primary-dark);
}

.contact-form-wrapper {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    padding: 0.875rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

/* Form Messages */
#formMessages {
    margin-bottom: var(--spacing-md);
}

.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.alert-success svg {
    flex-shrink: 0;
    color: #059669;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.alert-error svg {
    flex-shrink: 0;
    color: #dc2626;
}

/* Button Loading State */
.button-loader {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

#submitButton:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.footer-tagline {
    color: var(--text-light);
    max-width: 300px;
}

.footer-social {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: white;
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-section h4 {
    margin-bottom: var(--spacing-sm);
    font-size: 1.125rem;
}

.footer-links,
.footer-contact {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.footer-links a {
    color: var(--text-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-contact {
    color: var(--text-light);
}

.footer-contact a {
    color: var(--text-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: var(--text-light);
}

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition-base);
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }
    
    .hero {
        min-height: 80vh;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
}