:root {
    --primary-color: #007bff;
    --primary-dark: #0056b3;
    --secondary-color: #28a745;
    --text-color: #333;
    --light-text: #666;
    --bg-color: #ffffff;
    --alt-bg-color: #f8f9fa;
    --white: #ffffff;
    --spacing-unit: 1rem;
    --border-radius: 8px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
    padding: 1rem 0;
}

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

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

.logo img {
    height: 40px;
    width: auto;
}

.logo span {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 1px;
    margin-left: 0.8rem;
}

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

.nav-links a {
    font-weight: 500;
    transition: var(--transition);
}

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

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 0.6rem 1.2rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    color: var(--white);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 0.6rem 1.2rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

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

.hamburger {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
}

/* Hero Section */
.hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #e0f7fa 0%, #ffffff 100%);
    min-height: 80vh;
    display: flex;
    align-items: center;
}

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

.hero-content h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    color: var(--text-color);
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--light-text);
    margin-bottom: 2rem;
}

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

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

.phone-frame {
    width: 340px;
    height: 640px;
    background-color: #333;
    border: 12px solid #333;
    border-radius: 40px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
    overflow: hidden;
    position: relative;
}

.phone-frame img {
    width: 100%;
    height: 100%;
    object-fit: fill;
    display: block;
}

/* Sections */
.section {
    padding: 5rem 0;
}

.alt-bg {
    background-color: var(--alt-bg-color);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 4rem;
}

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

.section-header p {
    font-size: 1.1rem;
    color: var(--light-text);
}

/* About Grid */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.about-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-5px);
}

.about-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

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

/* How It Works */
.how-it-works-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.how-it-works-image {
    display: flex;
    justify-content: center;
}

.step {
    position: relative;
    padding: 2rem;
}

.step-number {
    font-size: 3rem;
    font-weight: 900;
    color: rgba(0, 123, 255, 0.1);
    position: absolute;
    top: -1.5rem;
    left: 1rem;
    z-index: 0;
}

.step-content {
    position: relative;
    z-index: 1;
}

.step-content h3 {
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

/* Research Section */
.research-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-top: 2rem;
}

.stat-item {
    text-align: center;
    padding: 1rem;
    background-color: var(--alt-bg-color);
    border-radius: var(--border-radius);
}

.stat-number {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--light-text);
}

.research-text h3 {
    margin-bottom: 1rem;
}

.research-text ul {
    list-style: disc;
    padding-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.research-text li {
    margin-bottom: 0.5rem;
}

.concept-diagram {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.diagram-box {
    padding: 1rem 2rem;
    border: 2px solid #ccc;
    border-radius: var(--border-radius);
    background-color: #fff;
    width: 100%;
    text-align: center;
    font-weight: 600;
}

.diagram-box.highlight {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background-color: rgba(0, 123, 255, 0.05);
}

.arrow {
    font-size: 1.5rem;
    color: #ccc;
}

/* Footer */
footer {
    background-color: #1a1a1a;
    color: #fff;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.footer-brand-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.footer-logo {
    height: 50px;
    width: auto;
    margin-bottom: 0;
}

.footer-brand h3 {
    font-size: 1.5rem;
    color: var(--white);
    margin-bottom: 0;
}

.footer-brand p {
    color: #aaa;
}

.footer-links, .footer-contact {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links h4, .footer-contact h4 {
    margin-bottom: 1rem;
    color: var(--white);
}

.footer-links a {
    color: #aaa;
    transition: var(--transition);
}

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

.socials {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.socials a {
    color: #aaa;
    font-size: 1.2rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #333;
    color: #666;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--white);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow);
    }

    .nav-links.active {
        display: flex;
    }

    .hamburger {
        display: block;
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-btns {
        justify-content: center;
    }

    .hero-content h1 {
        font-size: 2.2rem;
    }

    .research-content {
        grid-template-columns: 1fr;
    }

    .how-it-works-wrapper {
        grid-template-columns: 1fr;
    }
}