/* --- CSS Variables & Theming --- */
:root {
    /* Neutral Premium Color Palette */
    --color-bg-primary: #FAF9F6; /* Off-white / warm neutral */
    --color-bg-secondary: #FFFFFF;
    --color-text-primary: #1F2937; /* Dark gray */
    --color-text-secondary: #4B5563; /* Medium gray */
    --color-border: #E5E7EB;
    
    --color-accent-primary: #374151; /* Dark charcoal */
    --color-accent-hover: #111827; /* Almost black */
    
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
}

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

html {
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* --- Typography --- */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-text-primary);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2rem, 3vw, 2.5rem);
    margin-bottom: 1rem;
}

h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

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

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--color-accent-primary);
    color: #FFFFFF;
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background-color: var(--color-bg-secondary);
    border-color: var(--color-text-primary);
}

/* --- Navigation --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(250, 249, 246, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(229, 231, 235, 0.5);
    z-index: 1000;
    padding: 1rem 0;
    transition: all var(--transition-fast);
}

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

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    width: 200px;
    height: 80px;
    max-width: 100%;
    margin: 0;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.lang-selector {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.lang-selector a {
    color: var(--color-text-secondary);
}

.lang-selector a:hover {
    color: var(--color-accent-primary);
}

.lang-selector .active {
    color: var(--color-text-primary);
    font-weight: 700;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
}

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

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

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

/* --- Hero Section --- */
.hero {
    padding-top: 8rem;
    padding-bottom: 6rem;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content {
    max-width: 540px;
}

.hero-content p {
    font-size: 1.125rem;
    margin-top: 1.5rem;
    margin-bottom: 2.5rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

/* App Mockup Image */
.app-mockup-img {
    width: 100%;
    max-width: 400px;
    height: auto;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    display: block;
    margin: 0 auto;
    transform: perspective(1000px) rotateY(-5deg) rotateX(5deg);
    transition: transform var(--transition-smooth);
}

.app-mockup-img:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

/* --- Mission / About Section --- */
.mission {
    padding: 5rem 0;
    background-color: var(--color-accent-primary);
    color: #FFFFFF;
    text-align: center;
}

.mission h2 {
    color: #FFFFFF;
}

.mission-text {
    color: #E5E7EB;
    font-size: 1.25rem;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
}

/* --- Features Section --- */
.features {
    padding: 6rem 0;
    background-color: var(--color-bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 4rem;
}

.section-header p {
    font-size: 1.125rem;
    margin-top: 1rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
}

.feature-card {
    padding: 2.5rem;
    border-radius: 12px;
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    transition: all var(--transition-smooth);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: #D1D5DB;
}

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    background-color: var(--color-text-primary);
    color: #FFFFFF;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

/* --- Footer --- */
.footer {
    background-color: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
    padding-top: 4rem;
    padding-bottom: 2rem;
}

.footer-container {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 4rem;
}

.footer-brand p {
    margin-top: 1rem;
    max-width: 300px;
}

.footer-links h4 {
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

.footer-links a:hover {
    color: var(--color-text-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* --- Animations --- */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUpAnim 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

@keyframes fadeUpAnim {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* --- Responsive --- */
@media (max-width: 900px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 3rem;
    }
    
    .hero-content {
        margin: 0 auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }

    .footer-container {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-links, .nav-btn {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    h1 {
        font-size: 2rem;
    }

    .footer-container {
        grid-template-columns: 1fr;
    }
}