:root {
    --whatsapp-green: #25D366;
    --whatsapp-dark-green: #128C7E;
    --whatsapp-darker-green: #075E54;
    --whatsapp-light-green: #DCF8C6;
    --text-dark: #1F2937;
    --text-gray: #6B7280;
    --bg-light: #F9FAFB;
    --bg-white: #FFFFFF;
}

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

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-dark);
    background-color: var(--bg-white);
    line-height: 1.6;
}

/* Header Styles */
.main-header {
    background-color: var(--bg-white);
    border-bottom: 1px solid #E5E7EB;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.navbar {
    padding: 1rem 0;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
}

.navbar-brand:hover {
    color: var(--whatsapp-green);
}

.brand-icon {
    width: 45px;
    height: 45px;
    min-width: 45px;
    min-height: 45px;
    border-radius: 50%;
    object-fit: cover;
    display: block !important;
    flex-shrink: 0;
    border: 2px solid rgba(0, 0, 0, 0.05);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    visibility: visible !important;
    opacity: 1 !important;
}

.brand-text {
    margin-left: 0;
}

.navbar-nav .nav-link {
    color: var(--text-dark);
    font-weight: 500;
    padding: 0.5rem 1rem;
    transition: color 0.3s ease;
}

.navbar-nav .nav-link:hover {
    color: var(--whatsapp-green);
}

.language-selector .nav-link {
    color: var(--whatsapp-green);
}

.dropdown-menu {
    border: none;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    padding: 0.5rem 0;
}

.dropdown-item {
    padding: 0.5rem 1.5rem;
    transition: background-color 0.2s ease;
}

.dropdown-item:hover {
    background-color: var(--bg-light);
    color: var(--whatsapp-green);
}

/* Hero Section */
.hero-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    min-height: 600px;
    display: flex;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

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

.btn {
    padding: 0.75rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-download {
    background-color: var(--whatsapp-green);
    color: white;
}

.btn-download:hover {
    background-color: var(--whatsapp-dark-green);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 211, 102, 0.4);
}

.btn-desktop {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

.btn-desktop:hover {
    background-color: white;
    color: var(--whatsapp-green);
}

.btn-outline {
    background-color: transparent;
    color: var(--whatsapp-green);
    border: 2px solid var(--whatsapp-green);
}

.btn-outline:hover {
    background-color: var(--whatsapp-green);
    color: white;
}

.phone-mockup {
    position: relative;
    max-width: 300px;
    margin: 0 auto;
}

.phone-screen {
    background: linear-gradient(180deg, #ECE5DD 0%, #DCF8C6 100%);
    border-radius: 30px;
    padding: 2rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.chat-interface {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    min-height: 400px;
}

.chat-header {
    background-color: var(--whatsapp-dark-green);
    height: 60px;
    border-radius: 20px 20px 0 0;
}

.chat-messages {
    padding: 1rem;
    min-height: 340px;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    padding: 0.75rem 1rem;
    border-radius: 12px;
    max-width: 70%;
    font-size: 0.9rem;
}

.message.received {
    background-color: #E5E5E5;
    align-self: flex-start;
    border-bottom-left-radius: 4px;
}

.message.sent {
    background-color: var(--whatsapp-light-green);
    align-self: flex-end;
    border-bottom-right-radius: 4px;
}

/* Features Section */
.features-section {
    padding: 5rem 0;
    background-color: var(--bg-white);
}

.section-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 4rem;
}

.intro-text {
    font-size: 1.5rem;
    color: var(--text-gray);
    line-height: 1.8;
}

.feature-item {
    margin-bottom: 6rem;
}

.feature-item.reverse .row {
    flex-direction: row-reverse;
}

.feature-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.feature-description {
    font-size: 1.125rem;
    color: var(--text-gray);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.feature-image {
    text-align: center;
}

.feature-mockup {
    width: 100%;
    max-width: 500px;
    height: 400px;
    margin: 0 auto;
    border-radius: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.feature-mockup::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="rgba(255,255,255,0.1)"/></svg>');
    background-size: cover;
    opacity: 0.3;
}

.polls-mockup {
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
}

.events-mockup {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.pin-mockup {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.hd-mockup {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.screenshare-mockup {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.files-mockup {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

/* Privacy Section */
.privacy-section {
    padding: 5rem 0;
    background-color: var(--bg-light);
}

.privacy-image {
    text-align: center;
}

.encryption-mockup {
    width: 100%;
    max-width: 400px;
    height: 400px;
    margin: 0 auto;
    border-radius: 20px;
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 40px rgba(37, 211, 102, 0.2);
    position: relative;
}

.encryption-mockup::before {
    content: '🔒';
    font-size: 5rem;
    opacity: 0.8;
}

.privacy-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.privacy-description {
    font-size: 1.125rem;
    color: var(--text-gray);
    margin-bottom: 2rem;
    line-height: 1.8;
}

/* Footer */
.main-footer {
    background-color: var(--text-dark);
    color: white;
    padding: 3rem 0 1.5rem;
}

.main-footer h5 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--whatsapp-green);
}

.footer-links {
    list-style: none;
    padding: 0;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
    font-size: 0.9rem;
}

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

.footer-bottom {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
    margin: 0;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

.footer-link {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.footer-link:hover {
    color: var(--whatsapp-green);
}

/* Social Media Buttons */
.social-media {
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.social-media-button {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all 0.3s ease;
    color: white;
    font-size: 1.2rem;
}

.social-media-button:hover {
    background-color: var(--whatsapp-green);
    border-color: var(--whatsapp-green);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(37, 211, 102, 0.4);
}

.social-media-button svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

/* Social Media Icons */
.social-icon {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

/* Responsive Design */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .feature-title {
        font-size: 2rem;
    }
    
    .feature-item.reverse .row {
        flex-direction: column;
    }
}

/* Feature Cards */
.feature-card {
    padding: 2rem;
    border-radius: 12px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.feature-card h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-gray);
    line-height: 1.6;
    font-size: 0.95rem;
}

.feature-icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* FAQ Section */
.faq-item {
    padding: 1.5rem;
    border-bottom: 1px solid #E5E7EB;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-item h5 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.faq-item p {
    color: var(--text-gray);
    line-height: 1.8;
    margin: 0;
}

@media (max-width: 768px) {
    .hero-section {
        padding: 2rem 0;
        min-height: auto;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .features-section,
    .privacy-section {
        padding: 3rem 0;
    }
    
    .feature-title,
    .privacy-title {
        font-size: 1.75rem;
    }
    
    .intro-text {
        font-size: 1.25rem;
    }
    
    .feature-mockup,
    .encryption-mockup {
        height: 300px;
    }

    .feature-card {
        padding: 1.5rem;
    }

    .feature-card h4 {
        font-size: 1.125rem;
    }

    .social-media {
        margin-top: 1.5rem;
        margin-bottom: 1rem;
    }

    .social-media-button {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    /* Responsive brand-icon untuk tablet */
    .brand-icon {
        width: 40px !important;
        height: 40px !important;
        min-width: 40px !important;
        min-height: 40px !important;
    }
}

/* Responsive brand-icon untuk mobile kecil */
@media (max-width: 576px) {
    .brand-icon {
        width: 35px !important;
        height: 35px !important;
        min-width: 35px !important;
        min-height: 35px !important;
    }
}