/* =========================================
   VARIABLES & GLOBALS
========================================= */
:root {
    /* Eco-friendly Green Palette */
    --color-primary: #10B981; /* Emerald Green */
    --color-primary-dark: #059669;
    --color-secondary: #34D399; /* Light Green */
    --color-accent: #047857;
    
    /* Futuristic / Tech Palette */
    --color-bg-dark: #0f172a; /* Slate Dark */
    --color-surface: #1e293b;
    --color-text-main: #f8fafc;
    --color-text-muted: #94a3b8;
    
    /* Effects and Glassmorphism */
    --glass-bg: rgba(30, 41, 59, 0.6);
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(16, 185, 129, 0.3);
    
    /* Typography */
    --font-main: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    
    /* Layout */
    --transition-speed: 0.3s;
}

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

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

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

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
}

.gradient-text {
    background: linear-gradient(90deg, var(--color-secondary), var(--color-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--color-primary);
    color: #fff;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow-glow);
}

/* =========================================
   NAVIGATION
========================================= */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    padding: 1.5rem 0;
    transition: all var(--transition-speed) ease;
}

nav.scrolled {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 1rem 0;
    border-bottom: 1px solid var(--glass-border);
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 800;
}

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

.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--color-text-main);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-speed) ease;
}

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

/* =========================================
   HERO SECTION
========================================= */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

.background-effects {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.4;
    animation: float 10s infinite ease-in-out alternate;
}

.blob-1 {
    width: 400px;
    height: 400px;
    background-color: var(--color-accent);
    top: -100px;
    right: -100px;
}

.blob-2 {
    width: 500px;
    height: 500px;
    background-color: rgba(16, 185, 129, 0.2);
    bottom: -150px;
    left: -200px;
    animation-delay: 2s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(30px, 50px) scale(1.1); }
}

.hero-content {
    text-align: left;
    max-width: 800px;
}

.main-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: 1.5rem;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--color-text-muted);
    margin-bottom: 2.5rem;
    max-width: 700px;
}

/* =========================================
   SYSTEM INTRODUCTION SECTION
========================================= */
.system-section, .faq-section {
    padding: 6rem 0;
}

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

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.underline {
    height: 4px;
    width: 60px;
    background-color: var(--color-primary);
    margin: 0 auto;
    border-radius: 2px;
}

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

.system-text h3 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--color-secondary);
}

.system-text p {
    color: var(--color-text-muted);
    margin-bottom: 2rem;
}

.features-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.icon-box {
    background: rgba(16, 185, 129, 0.1);
    color: var(--color-primary);
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    flex-shrink: 0;
    box-shadow: inset 0 0 10px rgba(16, 185, 129, 0.2);
}

.feature-item h4 {
    margin-bottom: 0.3rem;
}

.feature-item p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

.glass-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-soft);
    overflow: hidden;
}

.image-placeholder {
    height: 500px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    color: var(--color-text-muted);
    transition: transform var(--transition-speed) ease;
}

.image-placeholder:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-glow);
    border-color: rgba(16, 185, 129, 0.3);
}

.image-icon {
    font-size: 5rem;
    color: var(--color-primary);
    opacity: 0.5;
}

/* =========================================
   FAQ SECTION
========================================= */
.faq-container {
    max-width: 800px;
}

.accordion {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.accordion-item {
    background: var(--color-surface);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    overflow: hidden;
    transition: all var(--transition-speed) ease;
}

.accordion-header {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    color: var(--color-text-main);
    font-size: 1.1rem;
    font-weight: 600;
    text-align: left;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: color var(--transition-speed) ease;
}

.accordion-header:hover {
    color: var(--color-primary);
}

.accordion-header .icon {
    transition: transform var(--transition-speed) ease;
    color: var(--color-primary);
}

.accordion-item.active .accordion-header .icon {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
    background: rgba(0, 0, 0, 0.2);
}

.accordion-content p {
    padding: 0 1.5rem 1.5rem 1.5rem;
    color: var(--color-text-muted);
}

/* =========================================
   FOOTER
========================================= */
footer {
    background-color: var(--color-surface);
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--glass-border);
}

footer p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

/* =========================================
   ANIMATIONS & REVEALS
========================================= */
.reveal {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease;
}

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

/* =========================================
   RESPONSIVE
========================================= */
@media (max-width: 900px) {
    .system-container {
        grid-template-columns: 1fr;
    }
    
    .system-image {
        order: -1; /* Move image above text on mobile */
    }
    
    .image-placeholder {
        height: 350px;
    }
}

@media (max-width: 600px) {
    .main-title {
        font-size: 2rem;
    }
    
    .nav-links {
        display: none; /* Can add hamburger menu logic later if needed */
    }
}