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

:root {
    --primary-color: #25D366;
    --secondary-color: #128C7E;
    --dark-color: #075E54;
    --light-color: #DCF8C6;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --bg-light: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    overflow-x: hidden;
}

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

/* Navbar */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 2rem;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 100px 0;
}

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

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.85;
}

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

.download-info {
    margin-bottom: 2rem;
    opacity: 0.9;
}

.download-info small {
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn {
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-download {
    animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        box-shadow: 0 0 20px rgba(255, 255, 255, 0.5);
    }
    50% {
        box-shadow: 0 0 30px rgba(255, 255, 255, 0.8);
    }
}

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

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

.btn-large {
    width: 100%;
    padding: 15px 30px;
    justify-content: center;
    font-size: 1.1rem;
}

.hero-stats {
    display: flex;
    gap: 2rem;
}

.stat {
    display: flex;
    align-items: center;
    gap: 8px;
}

.stat i {
    font-size: 1.5rem;
}

/* Phone Mockup */
.phone-mockup {
    background: var(--white);
    border-radius: 30px;
    padding: 40px 30px;
    box-shadow: var(--shadow-lg);
    text-align: center;
    position: relative;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.phone-mockup i {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.message-preview {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.message {
    background: var(--light-color);
    color: var(--text-dark);
    padding: 10px 15px;
    border-radius: 10px;
    text-align: left;
    animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Features Section */
.features {
    padding: 80px 0;
    background: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

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

.feature-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    text-align: center;
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.feature-icon i {
    font-size: 2rem;
    color: var(--white);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
}

/* Download Section */
.download {
    padding: 80px 0;
    background: var(--white);
}

.download-options {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.download-option {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.download-option:hover {
    transform: translateY(-5px);
}

.download-option.featured {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    box-shadow: var(--shadow-lg);
}

.platform-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.download-option.featured .platform-icon {
    background: rgba(255, 255, 255, 0.3);
}

.platform-icon i {
    font-size: 2.5rem;
    color: var(--white);
}

.download-option:not(.featured) .platform-icon i {
    color: var(--primary-color);
}

.download-option h3 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.version {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 1rem;
}

.download-option p {
    margin-bottom: 1.5rem;
}

.download-option:not(.featured) p {
    color: var(--text-light);
}

.feature-list {
    list-style: none;
    margin: 1.5rem 0;
}

.feature-list li {
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature-list i {
    color: rgba(255, 255, 255, 0.9);
}

.download-size {
    display: block;
    text-align: center;
    margin-top: 1rem;
    opacity: 0.8;
}

.code-block {
    background: var(--text-dark);
    color: var(--white);
    padding: 1.5rem;
    border-radius: 10px;
    margin: 1.5rem 0;
    position: relative;
}

.code-block code {
    font-family: 'Courier New', monospace;
    white-space: pre-line;
    display: block;
    font-size: 0.9rem;
}

.copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s;
    font-size: 0.85rem;
}

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

.requirements {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: 15px;
}

.requirements h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.requirement {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 1rem;
    background: var(--white);
    border-radius: 10px;
}

.requirement i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

/* How It Works */
.how-it-works {
    padding: 80px 0;
    background: var(--bg-light);
}

.steps {
    display: grid;
    gap: 2rem;
}

.step {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.step-content p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.step-content code {
    background: var(--white);
    padding: 10px 15px;
    border-radius: 5px;
    display: inline-block;
    font-family: 'Courier New', monospace;
    color: var(--secondary-color);
}

/* FAQ Section */
.faq {
    padding: 80px 0;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.faq-item {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary-color);
}

.faq-item h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 10px;
}

.faq-item h3 i {
    color: var(--primary-color);
}

.faq-item p {
    color: var(--text-light);
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: var(--white);
    padding: 60px 0 20px;
}

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

.footer-section h3, .footer-section h4 {
    margin-bottom: 1rem;
}

.footer-section p {
    opacity: 0.8;
    margin-bottom: 1rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    text-decoration: none;
    transition: background 0.3s;
}

.social-links a:hover {
    background: var(--secondary-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-section ul li a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.8;
}

/* Responsive */
@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .nav-links {
        display: none;
    }

    .download-options {
        grid-template-columns: 1fr;
    }

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

    .hero-buttons {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

    .requirements-grid {
        grid-template-columns: 1fr;
    }
}