/* 
   Sentra Vision - Manajemen Surat Landing Page
   Design System: Forest Green & Cream Premium
*/

:root {
    --primary: #133E38;
    --secondary: #F3F0E0;
    --accent: #2A5D56;
    --text-dark: #1a1a1a;
    --text-light: #ffffff;
    --glass: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--secondary);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3 {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
}

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

section {
    padding: 8rem 0;
}

/* Header & Nav */
header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(19, 62, 56, 0.8);
    backdrop-filter: blur(10px);
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--glass-border);
}

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

.logo {
    font-family: 'Playfair Display', serif;
    font-size: 1.5rem;
    color: var(--secondary);
    font-weight: 700;
    text-decoration: none;
}

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

.nav-links a {
    color: var(--secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    opacity: 0.8;
    transition: var(--transition);
}

.nav-links a:hover {
    opacity: 1;
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--primary) 0%, #0a2320 100%);
    color: var(--text-light);
    position: relative;
    overflow: hidden;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -50px;
    left: 0;
    width: 100%;
    height: 100px;
    background: var(--secondary);
    transform: skewY(-2deg);
}

.hero-content {
    max-width: 700px;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

/* Preview Section */
.preview {
    background-color: var(--secondary);
}

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

.section-title h2 {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 3rem;
}

.gallery-item {
    background: white;
    padding: 1rem;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.05);
    transition: var(--transition);
    cursor: pointer;
}

.gallery-item:hover {
    transform: scale(1.02);
}

.gallery-item img {
    width: 100%;
    border-radius: 10px;
    display: block;
}

.gallery-item p {
    text-align: center;
    margin-top: 1rem;
    font-weight: 600;
    color: var(--primary);
}

/* Features Section */
.features {
    background-color: #fff;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 2.5rem;
    background: var(--secondary);
    border-radius: 30px;
    transition: var(--transition);
}

.feature-card:hover {
    background: var(--primary);
    color: white;
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

/* Download Section */
.cta {
    background: var(--primary);
    color: white;
    text-align: center;
    padding: 10rem 0;
}

.cta h2 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Footer */
footer {
    padding: 4rem 0;
    background: #0a2320;
    color: white;
    text-align: center;
}

.footer-logo {
    font-family: 'Playfair Display', serif;
    font-size: 2rem;
    margin-bottom: 1rem;
}

/* Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .gallery {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
}