/* BA-inspired design system */
:root {
    /* Colors */
    --background: hsl(0, 0%, 98%);
    --foreground: hsl(220, 26%, 14%);
    --card: hsl(0, 0%, 100%);
    --card-foreground: hsl(220, 26%, 14%);
    --primary: hsl(220, 70%, 24%);
    --primary-foreground: hsl(0, 0%, 100%);
    --primary-light: hsl(220, 60%, 35%);
    --primary-dark: hsl(220, 80%, 18%);
    --secondary: hsl(210, 20%, 95%);
    --secondary-foreground: hsl(220, 26%, 14%);
    --muted: hsl(210, 20%, 96%);
    --muted-foreground: hsl(220, 13%, 60%);
    --accent: hsl(220, 15%, 92%);
    --accent-foreground: hsl(220, 26%, 14%);
    --border: hsl(220, 13%, 88%);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, hsl(220, 70%, 24%), hsl(220, 60%, 35%));
    --gradient-hero: linear-gradient(135deg, hsl(220, 80%, 18%), hsl(220, 70%, 24%));
    --gradient-subtle: linear-gradient(180deg, hsl(0, 0%, 98%), hsl(210, 20%, 96%));
    
    /* Shadows */
    --shadow-soft: 0 2px 8px -2px hsl(220, 70%, 24%, 0.08);
    --shadow-medium: 0 8px 25px -5px hsl(220, 70%, 24%, 0.12);
    --shadow-strong: 0 20px 40px -12px hsl(220, 70%, 24%, 0.18);
    
    /* Transitions */
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease-out;
}

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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.6;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.nav-bar {
    background-color: rgba(248, 250, 252, 0.95);
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 50;
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    font-weight: 700;
    font-size: 1.25rem;
    text-decoration: none;
}

.plane-icon {
    width: 1.5rem;
    height: 1.5rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted-foreground);
    text-decoration: none;
    transition: var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-external {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-left: 1.5rem;
    padding-left: 1.5rem;
    border-left: 1px solid var(--border);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--foreground);
    cursor: pointer;
}

.menu-icon {
    width: 1.25rem;
    height: 1.25rem;
}

.mobile-nav {
    display: none;
    padding: 1rem 0;
    border-top: 1px solid var(--border);
    flex-direction: column;
    gap: 0.75rem;
}

.mobile-nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted-foreground);
    text-decoration: none;
    transition: var(--transition-fast);
}

.mobile-nav-link:hover {
    color: var(--primary);
}

.mobile-nav-external {
    padding-top: 0.75rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition-fast);
    cursor: pointer;
    border: none;
}

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

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

.btn-outline {
    background-color: transparent;
    color: var(--foreground);
    border: 1px solid var(--border);
}

.btn-outline:hover {
    background-color: var(--accent);
}

.btn-hero {
    background-color: white;
    color: var(--primary);
    font-weight: 600;
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-hero:hover {
    background-color: rgba(255, 255, 255, 0.9);
}

.btn-outline-hero {
    background-color: transparent;
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    font-weight: 600;
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-outline-hero:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.btn-cta {
    background-color: white;
    color: var(--primary);
    font-weight: 600;
    padding: 1rem 2rem;
}

.btn-cta:hover {
    background-color: rgba(255, 255, 255, 0.9);
}

.btn-outline-cta {
    background-color: transparent;
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    font-weight: 600;
    padding: 1rem 2rem;
}

.btn-outline-cta:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.btn-full {
    width: 100%;
}

.arrow-icon,
.btn-icon {
    width: 1.25rem;
    height: 1.25rem;
}

/* Hero Section */
.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background-image: url('src/assets/ba-aircraft-hero.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
    opacity: 0.75;
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    color: white;
    padding: 0 1rem;
    max-width: 80rem;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-highlight {
    color: var(--primary-light);
}

.hero-subtitle {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    margin-bottom: 2rem;
    color: rgba(255, 255, 255, 0.9);
    max-width: 48rem;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    max-width: 32rem;
    margin: 0 auto;
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Sections */
.features,
.quick-links {
    padding: 5rem 0;
}

.features {
    background: var(--gradient-subtle);
}

.quick-links {
    background-color: var(--background);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    font-weight: 700;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--muted-foreground);
    max-width: 48rem;
    margin: 0 auto;
}

/* Feature Cards */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

.feature-card {
    background-color: var(--card);
    border-radius: 0.75rem;
    padding: 2rem 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-medium);
    transition: var(--transition-smooth);
}

.feature-card:hover {
    box-shadow: var(--shadow-strong);
}

.feature-icon {
    width: 4rem;
    height: 4rem;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
}

.feature-icon svg {
    width: 2rem;
    height: 2rem;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.feature-description {
    color: var(--muted-foreground);
}

/* Quick Links */
.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

.quick-link-card {
    background-color: var(--card);
    border-radius: 0.75rem;
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-medium);
    transition: var(--transition-smooth);
}

.quick-link-card:hover {
    box-shadow: var(--shadow-strong);
}

.quick-link-icon {
    width: 4rem;
    height: 4rem;
    background-color: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
}

.quick-link-icon.primary-light {
    background-color: var(--primary-light);
}

.quick-link-icon.accent {
    background-color: var(--accent);
    color: var(--primary);
}

.quick-link-icon svg {
    width: 2rem;
    height: 2rem;
}

.quick-link-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.quick-link-description {
    color: var(--muted-foreground);
    margin-bottom: 1.5rem;
}

/* CTA Section */
.cta {
    padding: 5rem 0;
    background: var(--gradient-primary);
    text-align: center;
}

.cta .container {
    max-width: 64rem;
}

.cta-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    font-weight: 700;
    color: white;
    margin-bottom: 1.5rem;
}

.cta-subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    max-width: 32rem;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    justify-content: center;
}

/* Responsive Design */
@media (min-width: 640px) {
    .hero-buttons,
    .cta-buttons {
        flex-direction: row;
    }
    
    .hero-stats {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (min-width: 768px) {
    .nav-links {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: none;
    }
}

@media (max-width: 767px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .mobile-nav.show {
        display: flex;
    }
}