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

:root {
    --black: #000000;
    --white: #ffffff;
    --gray-light: #f5f5f5;
    --gray-medium: #666666;
    --gray-dark: #333333;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-dark);
    background: var(--white);
}

/* Header */
.header {
    background: var(--black);
    padding: 0.5rem 0;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--white);
    text-align: center;
}

.icon-btn {
    background: none;
    border: none;
    color: var(--white);
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.2s;
}

.icon-btn:hover {
    opacity: 0.7;
}

.icon-btn svg {
    width: 24px;
    height: 24px;
}

/* Navigation */
.nav {
    background: var(--white);
    border-bottom: 1px solid #e0e0e0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-list {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    gap: 3rem;
    list-style: none;
    padding: 1rem 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--gray-dark);
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    transition: color 0.2s;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1rem;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--black);
}

/* Hero */
.hero {
    position: relative;
    width: 100%;
    height: 600px;
    overflow: hidden;
}

.hero-image {
    width: 100%;
    height: 100%;
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

/* Sections */
.section {
    padding: 4rem 2rem;
}

.section:nth-child(even) {
    background: var(--gray-light);
}

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

h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.lead {
    font-size: 1.25rem;
    color: var(--gray-medium);
    margin-bottom: 2rem;
}

/* Visual Grid */
.visual-grid,
.aviation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.visual-card,
.aviation-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.visual-card h3,
.aviation-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.visual-card p,
.aviation-card p {
    color: var(--gray-medium);
    margin-bottom: 1rem;
}

/* Button */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--black);
    color: var(--white);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.btn:hover {
    opacity: 0.8;
}

/* Footer */
.footer {
    background: var(--black);
    color: var(--white);
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

.footer p {
    margin: 0.5rem 0;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-list {
        gap: 1rem;
        padding: 1rem;
        flex-wrap: wrap;
    }

    .nav-link {
        font-size: 0.8rem;
    }

    .logo {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 2rem;
    }

    .hero {
        height: 400px;
    }

    .section {
        padding: 3rem 1rem;
    }
}