/* CSS Variables for Theme Colors */
:root {
    /* Primary Colors - Water & Nature Theme */
    --primary-blue: #1a6fb0;
    --secondary-blue: #2a9dcc;
    --light-blue: #e3f2fd;
    --dark-blue: #0d4a7a;
    
    /* Supporting Colors */
    --primary-green: #2ecc71;
    --secondary-green: #27ae60;
    --light-green: #d5f4e6;
    
    /* Neutral Colors */
    --white: #ffffff;
    --light-gray: #f8f9fa;
    --medium-gray: #e9ecef;
    --dark-gray: #343a40;
    --black: #212529;
    
    /* Status Colors */
    --safe: #27ae60;
    --warning: #f39c12;
    --critical: #e74c3c;
    
    /* Typography */
    --heading-font: 'Poppins', sans-serif;
    --body-font: 'Roboto', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-round: 50%;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--body-font);
    font-size: 16px;
    line-height: 1.6;
    color: var(--dark-gray);
    background-color: var(--white);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--heading-font);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    color: var(--dark-blue);
}

p {
    margin-bottom: var(--spacing-sm);
}

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

ul, ol {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-lg) 0;
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-sm);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--primary-green));
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.1rem;
    text-align: center;
    color: var(--secondary-blue);
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    font-family: var(--heading-font);
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--dark-blue), var(--primary-blue));
}

.btn-secondary {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-secondary:hover {
    background-color: var(--light-blue);
    transform: translateY(-2px);
}

.btn-large {
    padding: 16px 36px;
    font-size: 1.1rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    font-family: var(--heading-font);
    font-weight: 700;
    font-size: 1.8rem;
    color: var(--dark-blue);
}

.logo i {
    margin-right: 10px;
    font-size: 2rem;
    color: var(--primary-blue);
}

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

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
}

.nav-link {
    position: relative;
    font-weight: 500;
    padding: 8px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-blue);
    transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link.active {
    color: var(--primary-blue);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--dark-blue);
    cursor: pointer;
}

/* Hero Section */
.hero {
    position: relative;
    padding-top: 120px;
    padding-bottom: 80px;
    background: linear-gradient(135deg, var(--light-blue) 0%, #d4eaf7 100%);
    overflow: hidden;
}

.hero-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    gap: var(--spacing-lg);
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-title {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--dark-blue);
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-lg);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.robot-visual {
    position: relative;
    width: 400px;
    height: 300px;
}

.robot-base {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 120px;
    background: linear-gradient(135deg, #4a90e2, #2a9dcc);
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

.solar-panel {
    width: 180px;
    height: 40px;
    background: linear-gradient(135deg, #2c3e50, #34495e);
    border-radius: 8px;
    margin-bottom: 15px;
    position: relative;
    overflow: hidden;
}

.solar-panel::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: solar-shine 3s infinite;
}

@keyframes solar-shine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.sensor-array {
    display: flex;
    gap: 15px;
}

.sensor {
    width: 30px;
    height: 30px;
    border-radius: var(--radius-round);
    background-color: var(--primary-green);
    box-shadow: 0 0 10px rgba(46, 204, 113, 0.5);
    animation: sensor-pulse 2s infinite;
}

.sensor:nth-child(2) {
    animation-delay: 0.5s;
    background-color: var(--warning);
}

.sensor:nth-child(3) {
    animation-delay: 1s;
    background-color: var(--secondary-blue);
}

@keyframes sensor-pulse {
    0%, 100% { opacity: 0.7; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

.wave-animation {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M0,0V46.29c47.79,22.2,103.59,32.17,158,28,70.36-5.37,136.33-33.31,206.8-37.5C438.64,32.43,512.34,53.67,583,72.05c69.27,18,138.3,24.88,209.4,13.08,36.15-6,69.85-17.84,104.45-29.34C989.49,25,1113-14.29,1200,52.47V0Z" opacity=".25" fill="%232a9dcc"/><path d="M0,0V15.81C13,36.92,27.64,56.86,47.69,72.05,99.41,111.27,165,111,224.58,91.58c31.15-10.15,60.09-26.07,89.67-39.8,40.92-19,84.73-46,130.83-49.67,36.26-2.85,70.9,9.42,98.6,31.56,31.77,25.39,62.32,62,103.63,73,40.44,10.79,81.35-6.69,119.13-24.28s75.16-39,116.92-43.05c59.73-5.85,113.28,22.88,168.9,38.84,30.2,8.66,59,6.17,87.09-7.5,22.43-10.89,48-26.93,60.65-49.24V0Z" opacity=".5" fill="%232a9dcc"/><path d="M0,0V5.63C149.93,59,314.09,71.32,475.83,42.57c43-7.64,84.23-20.12,127.61-26.46,59-8.63,112.48,12.24,165.56,35.4C827.93,77.22,886,95.24,951.2,90c86.53-7,172.46-45.71,248.8-84.81V0Z" fill="%232a9dcc"/></svg>');
    background-size: 1200px 100px;
    animation: wave 20s linear infinite;
    z-index: 1;
}

@keyframes wave {
    0% { background-position-x: 0; }
    100% { background-position-x: 1200px; }
}

.wave-divider {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    line-height: 0;
}

.wave-divider svg {
    position: relative;
    display: block;
    width: calc(100% + 1.3px);
    height: 80px;
    fill: var(--white);
}

/* How It Works Section */
.how-it-works {
    background-color: var(--white);
}

.steps-container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.step {
    flex: 1;
    min-width: 300px;
    text-align: center;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    background-color: var(--light-gray);
    transition: transform var(--transition-normal);
    position: relative;
}

.step:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.step-number {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background-color: var(--primary-blue);
    color: var(--white);
    border-radius: var(--radius-round);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.2rem;
}

.step-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    border-radius: var(--radius-round);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 2rem;
}

.step-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.step-description {
    color: var(--dark-gray);
}

/* Features Section */
.features {
    background-color: var(--light-blue);
}

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

.feature-card {
    padding: var(--spacing-md);
    background-color: var(--white);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-green), var(--secondary-green));
    border-radius: var(--radius-round);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.8rem;
}

.feature-title {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
}

.feature-description {
    color: var(--dark-gray);
}

/* CTA Section */
.cta {
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    text-align: center;
}

.cta .section-title {
    color: var(--white);
}

.cta .section-title::after {
    background: var(--white);
}

.cta-description {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
    color: rgba(255, 255, 255, 0.9);
}

/* Footer */
.footer {
    background-color: var(--dark-blue);
    color: var(--white);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-sm);
    display: inline-block;
}

.footer-description {
    margin-bottom: var(--spacing-md);
    color: rgba(255, 255, 255, 0.8);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-round);
    color: var(--white);
    font-size: 1.2rem;
    transition: all var(--transition-normal);
}

.social-links a:hover {
    background-color: var(--primary-blue);
    transform: translateY(-3px);
}

.footer-heading {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-md);
    color: var(--white);
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer-contact li {
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.8);
}

.footer-contact i {
    margin-right: 10px;
    color: var(--primary-green);
    width: 20px;
}

.footer-bottom {
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.9);
}

.footer-bottom a:hover {
    color: var(--white);
    text-decoration: underline;
}

/* Responsive Styles */
@media (max-width: 992px) {
    .hero-container {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .robot-visual {
        width: 350px;
        height: 250px;
    }
    
    .section-title {
        font-size: 2.2rem;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        padding: var(--spacing-md) 0;
        box-shadow: var(--shadow-md);
        transition: left var(--transition-normal);
        z-index: 999;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .steps-container,
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .step,
    .feature-card {
        min-width: 100%;
    }
}

@media (max-width: 576px) {
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .btn {
        padding: 10px 20px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .robot-visual {
        width: 280px;
        height: 200px;
    }
    
    .robot-base {
        width: 160px;
        height: 100px;
    }
}