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

:root {
    /* Telegram-like Colors - Black & Gray */
    --bg-primary: #0a0e27;
    --bg-secondary: #17212b;
    --bg-tertiary: #1e2732;
    --bg-card: #242f3d;
    --bg-hover: #2b3542;
    
    --text-primary: #ffffff;
    --text-secondary: #8a8a8a;
    --text-tertiary: #6b6b6b;
    
    --border-color: #2a2f3a;
    --border-light: #3a3f4a;
    
    /* Accent is kept strictly grayscale (no blue) */
    --accent: #3a3f4a;
    --accent-hover: #4a505c;
    
    --success: #4caf50;
    --error: #f44336;
    
    /* Spacing */
    --container-padding: 20px;
    --section-spacing: 100px;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    backdrop-filter: blur(10px);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-img {
    width: 36px;
    height: 36px;
    border-radius: 8px;
}

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

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    padding: 140px 0 var(--section-spacing);
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

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

.hero-text {
    max-width: 600px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-description {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 2.5rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-light);
}

.hero-stats {
    display: flex;
    gap: 3rem;
    flex-wrap: wrap;
}

.stat-item {
    text-align: left;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

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

/* Phone Mockup */
.phone-mockup {
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-card));
    border-radius: 30px;
    padding: 12px;
    aspect-ratio: 9/19;
    max-width: 320px;
    margin: 0 auto;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.phone-screen {
    background-color: var(--bg-secondary);
    border-radius: 25px;
    height: 100%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.chat-header {
    background-color: var(--bg-tertiary);
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--border-color);
}

.chat-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
}

.chat-info {
    flex: 1;
}

.chat-name {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-primary);
}

.chat-status {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.chat-messages {
    flex: 1;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow-y: auto;
}

.message {
    max-width: 75%;
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 0.9rem;
    line-height: 1.4;
}

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

.message-received {
    align-self: flex-start;
    background-color: var(--bg-card);
    color: var(--text-primary);
    border-bottom-left-radius: 4px;
}

.message-time {
    font-size: 0.7rem;
    opacity: 0.7;
    margin-top: 4px;
    text-align: right;
}

.message-received .message-time {
    text-align: left;
}

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

.section-header {
    text-align: center;
    margin-bottom: 4rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Feature Detail */
.feature-detail {
    margin-bottom: 6rem;
}

.feature-detail.reverse {
    direction: rtl;
}

.feature-detail.reverse .feature-detail-content {
    direction: ltr;
}

.feature-detail-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.feature-detail-text {
    max-width: 600px;
}

.feature-detail-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.feature-detail-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    padding: 0.75rem 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    position: relative;
    font-size: 1rem;
    line-height: 1.6;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

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

.feature-mockup {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    width: 100%;
    max-width: 400px;
    min-height: 200px;
}

.mockup-header {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.mockup-content {
    color: var(--text-secondary);
}

.messages-mockup .mockup-message {
    padding: 8px 12px;
    margin-bottom: 8px;
    border-radius: 8px;
    background-color: var(--bg-tertiary);
}

.messages-mockup .mockup-message.sent {
    background-color: var(--accent);
    color: white;
    margin-left: auto;
    max-width: 70%;
}

.voice-mockup {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.waveform {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    height: 60px;
}

.wave-bar {
    width: 4px;
    background-color: var(--accent);
    border-radius: 2px;
    animation: wave 1s ease-in-out infinite;
}

.wave-bar:nth-child(2) { animation-delay: 0.1s; }
.wave-bar:nth-child(3) { animation-delay: 0.2s; }
.wave-bar:nth-child(4) { animation-delay: 0.3s; }
.wave-bar:nth-child(5) { animation-delay: 0.4s; }
.wave-bar:nth-child(6) { animation-delay: 0.5s; }
.wave-bar:nth-child(7) { animation-delay: 0.6s; }

@keyframes wave {
    0%, 100% { transform: scaleY(0.5); }
    50% { transform: scaleY(1); }
}

.voice-time {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.group-mockup .group-member,
.channel-mockup .channel-post {
    padding: 8px 12px;
    margin-bottom: 8px;
    background-color: var(--bg-tertiary);
    border-radius: 8px;
}

.channel-stats {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 8px;
}

.call-mockup {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    min-height: 250px;
}

.call-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
}

.call-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.call-status {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.media-mockup .media-item {
    padding: 10px 12px;
    margin-bottom: 8px;
    background-color: var(--bg-tertiary);
    border-radius: 8px;
    border-left: 3px solid var(--accent);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
}

.feature-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    transition: all 0.3s ease;
}

.feature-card:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-light);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Platforms Section */
.platforms {
    padding: var(--section-spacing) 0;
    background-color: var(--bg-primary);
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.platform-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    transition: all 0.3s ease;
}

.platform-card:hover {
    background-color: var(--bg-hover);
    border-color: var(--accent);
    transform: translateY(-4px);
}

.platform-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.platform-icon {
    font-size: 2.5rem;
}

.platform-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.platform-version {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.platform-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.platform-features {
    list-style: none;
    margin-bottom: 1.5rem;
}

.platform-features li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    position: relative;
    font-size: 0.9rem;
}

.platform-features li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

.platform-link {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: color 0.3s ease;
    display: inline-block;
}

.platform-link:hover {
    color: var(--accent-hover);
}

/* Download Section */
.download {
    padding: var(--section-spacing) 0;
    background-color: var(--bg-secondary);
    text-align: center;
}

.download-content {
    max-width: 800px;
    margin: 0 auto;
}

.download-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 3rem;
}

.btn-download {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.25rem 2rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    text-decoration: none;
    transition: all 0.3s ease;
    min-width: 200px;
    justify-content: flex-start;
}

.btn-download:hover {
    background-color: var(--bg-hover);
    border-color: var(--accent);
    transform: translateY(-2px);
}

.btn-icon {
    font-size: 2rem;
}

.btn-title {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.btn-subtitle {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

/* FAQ Section */
.faq {
    padding: var(--section-spacing) 0;
    background-color: var(--bg-primary);
}

.faq-items {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-bottom: 1rem;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: var(--border-light);
}

.faq-item.active {
    border-color: var(--accent);
}

.faq-question {
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
    font-weight: 600;
    color: var(--text-primary);
    transition: color 0.3s ease;
}

.faq-item:hover .faq-question {
    color: var(--accent);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--accent);
    transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 1.5rem;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-column {
    max-width: 250px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 1rem;
}

.footer-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-top: 1rem;
}

.footer-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1rem;
}

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

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero-content,
    .feature-detail-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .feature-detail.reverse {
        direction: ltr;
    }

    .hero-text {
        text-align: center;
        max-width: 100%;
    }

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

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

    .feature-detail-text {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--bg-secondary);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.active {
        transform: translateX(0);
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-description {
        font-size: 1rem;
    }

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

    .btn {
        width: 100%;
        justify-content: center;
    }

    .features-grid,
    .platforms-grid {
        grid-template-columns: 1fr;
    }

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

    .btn-download {
        width: 100%;
    }

    .section-spacing {
        --section-spacing: 60px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .feature-detail-title {
        font-size: 1.5rem;
    }

    .platform-card,
    .feature-card {
        padding: 1.5rem;
    }
}

/* Smooth Scroll */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

/* Animation on Scroll */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.platform-card {
    animation: fadeInUp 0.6s ease-out backwards;
}

.feature-card:nth-child(1) { animation-delay: 0.1s; }
.feature-card:nth-child(2) { animation-delay: 0.2s; }
.feature-card:nth-child(3) { animation-delay: 0.3s; }
.feature-card:nth-child(4) { animation-delay: 0.4s; }
.feature-card:nth-child(5) { animation-delay: 0.5s; }
.feature-card:nth-child(6) { animation-delay: 0.6s; }