/* CSS Custom Properties */
:root {
    /* Colors */
    --color-dark-1: #0f0f23;
    --color-dark-2: #1a1a2e;
    --color-dark-3: #16213e;
    --color-accent: #00d4ff;
    --color-accent-hover: #0ea5e9;
    --color-bg-light: #f8fafc;
    --color-text-dark: #0b1218;
    --color-text-muted: #4a5568;
    --color-white: #ffffff;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    --font-logo: 'Montserrat', sans-serif;

    /* Layout */
    --max-width: 1200px;
    --header-height: 70px;
}

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

html {
    scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--color-text-dark);
    background-color: var(--color-bg-light);
}

/* Focus Styles */
:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

:focus:not(:focus-visible) {
    outline: none;
}

:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-sm);
    background: var(--color-dark-1);
    color: var(--color-white);
    padding: var(--spacing-xs) var(--spacing-sm);
    text-decoration: none;
    z-index: 1000;
    border-radius: 4px;
}

.skip-link:focus {
    top: var(--spacing-sm);
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--color-dark-1);
    z-index: 100;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.logo {
    text-decoration: none;
}

.logo-text {
    font-family: var(--font-logo);
    font-weight: 700;
    font-size: 1.5rem;
    text-transform: uppercase;
    color: var(--color-white);
    letter-spacing: -0.02em;
}

.logo-text span {
    font-weight: 600;
    color: var(--color-text-muted);
}

.logo-text-dark {
    color: var(--color-dark-1);
    font-size: inherit;
}

.nav-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    z-index: 101;
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-white);
    position: relative;
    transition: background 0.2s;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background: var(--color-white);
    left: 0;
    transition: transform 0.2s;
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

.nav-toggle[aria-expanded="true"] .hamburger {
    background: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
    transform: rotate(45deg) translate(5px, 6px);
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
    transform: rotate(-45deg) translate(5px, -6px);
}

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

.nav-links a {
    color: var(--color-white);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a:focus {
    color: var(--color-accent);
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        max-width: 300px;
        height: 100vh;
        background: var(--color-dark-2);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: var(--spacing-lg);
        transition: right 0.3s;
    }

    .nav-links.active {
        right: 0;
    }

    .nav-links a {
        font-size: 1.25rem;
    }
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: var(--header-height);
    background: linear-gradient(135deg, var(--color-dark-1) 0%, var(--color-dark-3) 100%);
    color: var(--color-white);
}

.hero-logo {
    max-width: 450px;
    width: 100%;
    height: auto;
    margin-bottom: var(--spacing-md);
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(90deg, var(--color-white), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-intro {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto var(--spacing-md);
    color: rgba(255, 255, 255, 0.8);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-dark-1);
}

.btn-primary:hover,
.btn-primary:focus {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 212, 255, 0.4);
}

/* About Section */
.about {
    padding: var(--spacing-xl) 0;
    background: var(--color-bg-light);
}

.about h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-dark-1);
}

.about-lead {
    text-align: center;
    font-size: 1.25rem;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
    color: var(--color-text-muted);
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.feature {
    background: var(--color-white);
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature h3 {
    color: var(--color-dark-1);
    margin-bottom: var(--spacing-xs);
    font-size: 1.25rem;
}

.feature p {
    color: var(--color-text-muted);
}

/* Models Section */
.models {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, var(--color-dark-2) 0%, var(--color-dark-1) 100%);
    color: var(--color-white);
}

.models h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
}

.model-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    max-width: 800px;
    margin: 0 auto;
}

.model-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: var(--spacing-md);
    transition: transform 0.2s, box-shadow 0.2s;
}

.model-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.model-card-featured {
    border-color: var(--color-accent);
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1) 0%, rgba(14, 165, 233, 0.05) 100%);
}

.model-card h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
}

.model-tagline {
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.model-features {
    list-style: none;
}

.model-features li {
    padding: var(--spacing-xs) 0;
    padding-left: 1.5rem;
    position: relative;
    color: rgba(255, 255, 255, 0.8);
}

.model-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
}

/* Contact Section */
.contact {
    padding: var(--spacing-xl) 0;
    background: var(--color-bg-light);
    text-align: center;
}

.contact h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-dark-1);
}

.contact > .container > p {
    color: var(--color-text-muted);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.contact-email {
    font-size: 1.5rem;
}

.contact-email a {
    color: var(--color-accent-hover);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.contact-email a:hover,
.contact-email a:focus {
    color: var(--color-accent);
    text-decoration: underline;
}

/* Social Links */
.social-links {
    margin-top: var(--spacing-md);
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 8px;
    transition: color 0.2s, background-color 0.2s;
}

.social-link:hover,
.social-link:focus {
    color: var(--color-dark-1);
    background-color: rgba(0, 0, 0, 0.05);
}

.social-link svg {
    flex-shrink: 0;
}

/* Footer */
.footer {
    background: var(--color-dark-1);
    color: rgba(255, 255, 255, 0.6);
    padding: var(--spacing-md) 0;
    text-align: center;
}

.footer p {
    font-size: 0.875rem;
}

/* Responsive adjustments */
@media (max-width: 480px) {
    :root {
        --spacing-md: 1.5rem;
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }

    .hero-logo {
        max-width: 280px;
    }

    .model-cards {
        grid-template-columns: 1fr;
    }
}