/* ========================================
   DeVPN-AI Landing Page - Responsive Styles
======================================== */

/* ===== Extra Large Devices (1440px and up) ===== */
@media (min-width: 1440px) {
    .container {
        max-width: 1320px;
    }
    
    .hero-title {
        font-size: 56px;
    }
    
    .section-title {
        font-size: 48px;
    }
}

/* ===== Large Devices (1024px to 1439px) ===== */
@media (max-width: 1439px) {
    .hero-title {
        font-size: 44px;
    }
    
    .section-title {
        font-size: 38px;
    }
}

/* ===== Medium Devices (768px to 1023px) ===== */
@media (max-width: 1023px) {
    /* Header */
    .navbar {
        padding: 15px 0;
    }
    
    .navbar-brand {
        font-size: 20px;
    }
    
    /* Hero Section */
    .hero-section {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn-primary-large,
    .btn-secondary-large {
        width: 100%;
        justify-content: center;
    }
    
    .network-visualization {
        height: 400px;
        margin-top: 40px;
    }
    
    /* Sections */
    section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .section-subtitle {
        font-size: 16px;
    }
    
    /* Architecture */
    .architecture-layer {
        padding: 20px;
    }
    
    .layer-number {
        font-size: 28px;
    }
    
    .layer-content h4 {
        font-size: 18px;
    }
    
    /* Roadmap */
    .roadmap-timeline::before {
        left: 40px;
    }
    
    .timeline-item {
        flex-direction: row !important;
        padding-left: 80px;
    }
    
    .timeline-marker {
        position: absolute;
        left: 0;
        min-width: 60px;
        height: 60px;
        font-size: 20px;
    }
    
    /* Comparison Table */
    .comparison-table {
        font-size: 14px;
    }
    
    .comparison-table th,
    .comparison-table td {
        padding: 12px 10px;
    }
    
    /* CTA */
    .cta-title {
        font-size: 36px;
    }
    
    .cta-subtitle {
        font-size: 18px;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: stretch;
        max-width: 400px;
        margin: 0 auto;
    }
    
    .btn-cta-primary,
    .btn-cta-secondary,
    .btn-cta-tertiary {
        width: 100%;
        justify-content: center;
    }
}

/* ===== Small Devices (576px to 767px) ===== */
@media (max-width: 767px) {
    /* Global */
    :root {
        --section-padding: 60px 0;
        --card-padding: 20px;
    }
    
    /* Header */
    .navbar {
        padding: 12px 0;
    }
    
    .navbar-collapse {
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(10px);
        padding: 20px;
        border-radius: var(--border-radius-small);
        margin-top: 15px;
        border: 1px solid rgba(0, 217, 255, 0.2);
    }
    
    .nav-item {
        margin: 5px 0;
    }
    
    .language-switcher {
        margin: 15px 0;
        justify-content: center;
    }
    
    .navbar .btn-primary-glow {
        width: 100%;
        text-align: center;
        margin-top: 10px;
    }
    
    /* Hero Section */
    .hero-section {
        padding: 80px 0 40px;
        min-height: auto;
    }
    
    .hero-title {
        font-size: 28px;
        line-height: 1.3;
    }
    
    .hero-subtitle {
        font-size: 16px;
        margin-bottom: 30px;
    }
    
    .btn-primary-large,
    .btn-secondary-large {
        font-size: 16px;
        padding: 14px 28px;
    }
    
    .network-visualization {
        height: 300px;
    }
    
    /* Sections */
    section {
        padding: 50px 0;
    }
    
    .section-title {
        font-size: 28px;
        margin-bottom: 15px;
    }
    
    .section-subtitle {
        font-size: 15px;
    }
    
    /* Problem Section */
    .problem-card {
        margin-bottom: 20px;
    }
    
    .problem-icon {
        font-size: 40px;
    }
    
    .problem-card h3 {
        font-size: 20px;
    }
    
    /* Feature Cards */
    .feature-card,
    .usecase-card,
    .security-card {
        margin-bottom: 20px;
    }
    
    .feature-icon,
    .usecase-icon {
        font-size: 42px;
    }
    
    .feature-card h3,
    .usecase-card h4,
    .security-card h4 {
        font-size: 18px;
    }
    
    /* Architecture */
    .architecture-layer {
        padding: 18px;
        margin-bottom: 12px;
    }
    
    .architecture-layer::before {
        left: -15px;
        width: 8px;
        height: 8px;
    }
    
    .layer-number {
        font-size: 24px;
        min-width: 40px;
    }
    
    .layer-content h4 {
        font-size: 16px;
    }
    
    .layer-content p {
        font-size: 13px;
    }
    
    /* Reset staggered alignments on mobile */
    .solution-section .row > .col-md-6.col-lg-3:nth-child(1),
    .solution-section .row > .col-md-6.col-lg-3:nth-child(2),
    .solution-section .row > .col-md-6.col-lg-3:nth-child(3),
    .solution-section .row > .col-md-6.col-lg-3:nth-child(4) {
        margin-top: 0 !important;
    }
    
    .architecture-layer[data-layer="1"],
    .architecture-layer[data-layer="2"],
    .architecture-layer[data-layer="3"],
    .architecture-layer[data-layer="4"],
    .architecture-layer[data-layer="5"] {
        padding-left: 18px !important;
    }
    
    /* Tabs */
    .features-tabs .nav-pills {
        flex-direction: column;
    }
    
    .features-tabs .nav-link {
        width: 100%;
        text-align: center;
    }
    
    .tab-content {
        padding: 25px 20px;
    }
    
    .tab-pane h3 {
        font-size: 22px;
    }
    
    .feature-list li {
        font-size: 14px;
    }
    
    .tech-diagram {
        min-height: 200px;
    }
    
    .diagram-box {
        padding: 40px 20px;
    }
    
    .diagram-box i {
        font-size: 60px;
    }
    
    .diagram-box p {
        font-size: 16px;
    }
    
    /* Roadmap */
    .roadmap-timeline::before {
        left: 30px;
    }
    
    .timeline-item {
        padding-left: 70px;
    }
    
    .timeline-marker {
        min-width: 50px;
        height: 50px;
        font-size: 18px;
    }
    
    .timeline-content {
        padding: 20px;
    }
    
    .timeline-content h3 {
        font-size: 20px;
    }
    
    .timeline-content ul li {
        font-size: 14px;
    }
    
    /* Comparison Table */
    .table-responsive {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    .comparison-table {
        min-width: 700px;
        font-size: 13px;
    }
    
    .comparison-table th,
    .comparison-table td {
        padding: 10px 8px;
    }
    
    .comparison-table .fa-check-circle,
    .comparison-table .fa-times-circle,
    .comparison-table .fa-minus-circle {
        font-size: 16px;
    }
    
    /* CTA */
    .cta-section {
        padding: 50px 0;
    }
    
    .cta-title {
        font-size: 28px;
    }
    
    .cta-subtitle {
        font-size: 16px;
    }
    
    .btn-cta-primary,
    .btn-cta-secondary,
    .btn-cta-tertiary {
        font-size: 16px;
        padding: 14px 28px;
    }
    
    /* Footer */
    .footer {
        padding: 40px 0 20px;
    }
    
    .footer-brand {
        font-size: 20px;
    }
    
    .footer h5 {
        font-size: 16px;
        margin-top: 20px;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .footer-bottom {
        margin-top: 30px;
        padding-top: 20px;
    }
}

/* ===== Extra Small Devices (320px to 575px) ===== */
@media (max-width: 575px) {
    /* Hero */
    .hero-title {
        font-size: 24px;
    }
    
    .hero-subtitle {
        font-size: 14px;
    }
    
    .btn-primary-large,
    .btn-secondary-large {
        font-size: 14px;
        padding: 12px 24px;
    }
    
    .network-visualization {
        height: 250px;
    }
    
    /* Sections */
    section {
        padding: 40px 0;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .section-subtitle {
        font-size: 14px;
    }
    
    /* Cards */
    .feature-card,
    .usecase-card,
    .security-card,
    .problem-card {
        padding: 20px;
    }
    
    /* Architecture */
    .architecture-layer {
        padding: 15px;
    }
    
    .layer-content {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .layer-number {
        margin-bottom: 10px;
    }
    
    /* Roadmap */
    .roadmap-timeline::before {
        left: 25px;
    }
    
    .timeline-item {
        padding-left: 60px;
    }
    
    .timeline-marker {
        min-width: 45px;
        height: 45px;
        font-size: 16px;
    }
    
    .timeline-content {
        padding: 18px;
    }
    
    .timeline-content h3 {
        font-size: 18px;
    }
    
    /* CTA */
    .cta-title {
        font-size: 24px;
    }
    
    .cta-subtitle {
        font-size: 14px;
    }
    
    .btn-cta-primary,
    .btn-cta-secondary,
    .btn-cta-tertiary {
        font-size: 14px;
        padding: 12px 24px;
    }
    
    /* Footer */
    .footer {
        text-align: center;
    }
    
    .footer-links {
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
        flex-wrap: wrap;
    }
}

/* ===== Landscape Orientation (Mobile) ===== */
@media (max-height: 500px) and (orientation: landscape) {
    .hero-section {
        min-height: auto;
        padding: 100px 0 60px;
    }
    
    .network-visualization {
        height: 300px;
    }
}

/* ===== Print Styles ===== */
@media print {
    .navbar,
    .cta-section,
    .footer,
    .animated-background {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .hero-title,
    .section-title {
        color: black;
    }
}

/* ===== Touch Device Optimizations ===== */
@media (hover: none) and (pointer: coarse) {
    /* Increase tap targets */
    .nav-link {
        padding: 12px 16px !important;
    }
    
    .btn-primary-glow,
    .btn-primary-large,
    .btn-secondary-large {
        min-height: 48px;
    }
    
    /* Remove hover effects on touch devices */
    .feature-card:hover,
    .usecase-card:hover,
    .security-card:hover,
    .problem-card:hover {
        transform: none;
    }
    
    /* Simplify animations on touch */
    * {
        animation-duration: 0.5s !important;
    }
}

/* ===== High DPI Displays ===== */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    /* Sharper text rendering */
    body {
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
}

/* ===== Dark Mode Support ===== */
@media (prefers-color-scheme: dark) {
    /* Already in dark theme, but can add overrides if needed */
}

/* ===== Light Mode Override (if user prefers light) ===== */
@media (prefers-color-scheme: light) {
    /* Keep dark theme as primary design */
}