/* =============================================
   Global Styles & Variables
   ============================================= */

:root {
    --container: 1180px;
    --primary-color: #0066cc;
    --light-blue: #f0f5ff;
    --border-color: #e0e8f5;
    --text-dark: #1a1a1a;
    --text-light: #666666;
    --white: #ffffff;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 16px rgba(0, 102, 204, 0.15);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    width: min(100% - 32px, var(--container));
    margin-inline: auto;
}

/* Image Base Styles */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

.image-box img,
.hero-image img,
.section-image img,
.phone-card img,
.overview-image img,
.feature-image img,
.security-image img,
.tech-image img,
.use-case-image img,
.showcase-item img,
.footer-logo-img {
    width: 100%;
    max-width: 100%;
    height: auto;
    object-fit: contain;
}

/* =============================================
   Header & Navigation
   ============================================= */

.header {
    position: sticky;
    top: 0;
    background: #1a1a1a;
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 0;
}

.header-content {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--white);
    font-weight: 600;
    font-size: 18px;
    cursor: pointer;
}

.logo-img {
    width: 80px;
    height: 80px;
    object-fit: contain;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-cta {
    background: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.nav-cta:hover {
    background: #0052a3;
    box-shadow: var(--shadow-hover);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 6px;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--white);
    transition: var(--transition);
}

/* =============================================
   Hero Section
   ============================================= */

.hero {
    background: linear-gradient(135deg, var(--light-blue) 0%, #e6f0ff 100%);
    padding: 80px 0;
    position: relative;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 42px;
    line-height: 1.3;
    margin-bottom: 20px;
    color: var(--text-dark);
    font-weight: 700;
}

.hero-subtitle {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 32px;
}

.btn {
    padding: 12px 24px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

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

.btn-primary:hover {
    background: #0052a3;
    box-shadow: var(--shadow-hover);
}

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

.btn-secondary:hover {
    background: var(--light-blue);
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tag {
    background: var(--white);
    border: 1px solid var(--border-color);
    color: var(--text-dark);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

.hero-image {
    position: relative;
}

.hero-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
}

/* =============================================
   Highlight Bar Section
   ============================================= */

.highlight-bar {
    padding: 60px 0;
    background: var(--white);
}

.highlight-title {
    text-align: center;
    font-size: 28px;
    margin-bottom: 40px;
    color: var(--text-dark);
    font-weight: 700;
}

.highlight-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.highlight-card {
    background: var(--light-blue);
    padding: 28px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.highlight-card:hover {
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-color);
}

.highlight-card h3 {
    font-size: 16px;
    margin-bottom: 12px;
    color: var(--text-dark);
    font-weight: 600;
}

.highlight-card p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
}

/* =============================================
   Overview Section
   ============================================= */

.overview {
    padding: 80px 0;
    background: var(--white);
}

.overview > .container > h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
}

.overview-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.overview-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
}

.overview-text p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: 32px;
}

.overview-cards {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.overview-card {
    background: var(--light-blue);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.overview-card h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 6px;
}

.overview-card p {
    font-size: 13px;
    color: var(--text-light);
    margin: 0;
}

/* =============================================
   Features Section
   ============================================= */

.features {
    padding: 80px 0;
    background: var(--light-blue);
}

.features > .container > h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 60px;
}

.feature-card {
    background: var(--white);
    padding: 32px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 32px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
}

.feature-image {
    margin-bottom: 40px;
}

.feature-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    display: block;
}

/* =============================================
   Security Section
   ============================================= */

.security {
    padding: 80px 0;
    background: var(--white);
}

.security > .container > h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.security-image {
    margin-bottom: 48px;
    text-align: center;
}

.security-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 800px;
}

.security-tips {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.security-tip {
    background: var(--light-blue);
    padding: 24px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.security-tip h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.security-tip p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
    margin: 0;
}

/* =============================================
   Tech Section
   ============================================= */

.tech-section {
    padding: 80px 0;
    background: var(--light-blue);
}

.tech-section h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.tech-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.tech-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
}

.tech-text {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.tech-item h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.tech-item p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
    margin: 0;
}

/* =============================================
   Showcase Section
   ============================================= */

.showcase {
    padding: 80px 0;
    background: var(--white);
}

.showcase > .container > h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.showcase-controls {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 32px;
}

.showcase-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--white);
    cursor: pointer;
    font-size: 18px;
    font-weight: 600;
    color: var(--primary-color);
    transition: var(--transition);
}

.showcase-btn:hover {
    background: var(--light-blue);
    border-color: var(--primary-color);
}

.showcase-container {
    overflow: hidden;
    background: var(--light-blue);
    border-radius: 12px;
    padding: 24px;
}

.showcase-track {
    display: flex;
    gap: 16px;
    transition: transform 0.4s ease;
}

.showcase-item {
    flex: 0 0 calc(25% - 12px);
    min-height: 400px;
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.showcase-item img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 12px;
}

.showcase-dots {
    text-align: center;
    margin-top: 24px;
    display: flex;
    justify-content: center;
    gap: 8px;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background: var(--primary-color);
    width: 24px;
    border-radius: 4px;
}

/* =============================================
   Use Case Section
   ============================================= */

.use-case {
    padding: 80px 0;
    background: var(--light-blue);
}

.use-case h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.use-case-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.use-case-text {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.use-case-item h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.use-case-item p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
    margin: 0;
}

.use-case-image img {
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
}

/* =============================================
   Process Section
   ============================================= */

.process {
    padding: 80px 0;
    background: var(--white);
}

.process h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.process-step {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 24px;
    align-items: flex-start;
    padding: 32px;
    background: var(--light-blue);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.process-step:hover {
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-color);
}

.step-number {
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}

.process-step h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.process-step p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
    margin: 0;
}

/* =============================================
   FAQ Section
   ============================================= */

.faq {
    padding: 80px 0;
    background: var(--light-blue);
}

.faq h2 {
    font-size: 32px;
    margin-bottom: 48px;
    color: var(--text-dark);
    font-weight: 700;
    text-align: center;
}

.faq-items {
    max-width: none;
    margin: 0 auto;
}

.faq-item {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 16px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item.active {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-hover);
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    background: var(--white);
    border: none;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-dark);
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--light-blue);
}

.faq-icon {
    font-size: 18px;
    transition: var(--transition);
}

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

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

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px 24px;
    font-size: 14px;
    line-height: 1.7;
    color: var(--text-light);
    margin: 0;
}

/* =============================================
   Footer
   ============================================= */

.footer {
    background: #1a1a1a;
    border-top: 1px solid var(--border-color);
    padding: 60px 0 40px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 0.8fr 0.8fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    cursor: pointer;
}

.footer-logo-img {
    width: 28px;
    height: 28px;
    object-fit: contain;
}

.footer-logo span {
    font-size: 16px;
    font-weight: 700;
    color: var(--white);
}

.footer-section p {
    font-size: 13px;
    line-height: 1.6;
    color: #999;
    margin-bottom: 20px;
}

.footer-section h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 16px;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul a {
    font-size: 13px;
    color: #999;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section ul a:hover {
    color: var(--primary-color);
}

.footer-divider {
    height: 1px;
    background: var(--border-color);
    margin-bottom: 24px;
}

.footer-bottom {
    text-align: center;
}

.copyright {
    font-size: 12px;
    color: #999;
    margin-bottom: 8px;
}

.disclaimer {
    font-size: 12px;
    color: #999;
    margin: 0;
    line-height: 1.6;
}

/* =============================================
   Back to Top Button
   ============================================= */

.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 18px;
    font-weight: 600;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 99;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: #0052a3;
    box-shadow: var(--shadow-hover);
}

.footer-logo-img {
    width: 64px;
    height: 64px;
}

/* =============================================
   Responsive Design
   ============================================= */

@media (max-width: 1024px) {
    .nav-menu {
        gap: 20px;
    }

    .hero .container {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .hero-content h1 {
        font-size: 36px;
    }

    .highlight-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .overview-content,
    .tech-content,
    .use-case-content {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .security-tips {
        grid-template-columns: 1fr;
    }

    .process-steps {
        gap: 16px;
    }

    .process-step {
        padding: 24px;
    }

    .showcase-item {
        flex: 0 0 calc(33.333% - 11px);
        min-height: 350px;
    }
}

@media (max-width: 768px) {
    .header .container {
        padding: 10px 0;
    }

    .logo-img {
        width: 60px;
        height: 60px;
    }

    .nav-menu {
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: #1a1a1a;
        border-bottom: 1px solid var(--border-color);
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }

    .nav-menu.active {
        max-height: 400px;
    }

    .nav-link {
        padding: 12px 16px;
        display: block;
    }

    .nav-cta {
        position: absolute;
        top: 16px;
        right: 16px;
        padding: 8px 16px;
        font-size: 13px;
    }

    .menu-toggle {
        display: flex;
    }

    .hero {
        padding: 60px 0;
    }

    .hero-content h1 {
        font-size: 28px;
    }

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

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

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

    .highlight-title {
        font-size: 22px;
    }

    .highlight-cards {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .overview,
    .features,
    .security,
    .tech-section,
    .showcase,
    .use-case,
    .process,
    .faq {
        padding: 60px 0;
    }

    .overview > .container > h2,
    .features > .container > h2,
    .security > .container > h2,
    .tech-section h2,
    .showcase > .container > h2,
    .use-case h2,
    .process h2,
    .faq h2 {
        font-size: 24px;
        margin-bottom: 32px;
    }

    .overview-content {
        gap: 32px;
    }

    .overview-text p {
        margin-bottom: 24px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .feature-card {
        padding: 20px;
    }

    .showcase-item {
        flex: 0 0 calc(50% - 8px);
        min-height: 300px;
    }

    .showcase-controls {
        gap: 12px;
        margin-bottom: 24px;
    }

    .showcase-btn {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .back-to-top {
        bottom: 24px;
        right: 24px;
        width: 36px;
        height: 36px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .header .container {
        padding: 8px 0;
    }

    .logo-img {
        width: 56px;
        height: 56px;
    }

    .nav-cta {
        padding: 8px 14px;
        font-size: 12px;
    }

    .hero {
        padding: 40px 0;
    }

    .hero-content h1 {
        font-size: 24px;
        margin-bottom: 16px;
    }

    .hero-subtitle {
        font-size: 14px;
        margin-bottom: 24px;
    }

    .hero-buttons {
        gap: 12px;
    }

    .btn {
        padding: 10px 20px;
        font-size: 13px;
    }

    .highlight-cards {
        gap: 12px;
    }

    .highlight-card {
        padding: 20px;
    }

    .highlight-card h3 {
        font-size: 14px;
    }

    .highlight-card p {
        font-size: 12px;
    }

    .overview,
    .features,
    .security,
    .tech-section,
    .showcase,
    .use-case,
    .process,
    .faq {
        padding: 40px 0;
    }

    .overview > .container > h2,
    .features > .container > h2,
    .security > .container > h2,
    .tech-section h2,
    .showcase > .container > h2,
    .use-case h2,
    .process h2,
    .faq h2 {
        font-size: 20px;
        margin-bottom: 24px;
    }

    .overview-cards {
        gap: 12px;
    }

    .overview-card {
        padding: 16px;
    }

    .overview-card h4 {
        font-size: 13px;
    }

    .overview-card p {
        font-size: 12px;
    }

    .feature-card {
        padding: 16px;
    }

    .feature-icon {
        font-size: 28px;
    }

    .feature-card h3 {
        font-size: 14px;
    }

    .feature-card p {
        font-size: 12px;
    }

    .security-tip {
        padding: 16px;
    }

    .security-tip h3 {
        font-size: 13px;
    }

    .security-tip p {
        font-size: 12px;
    }

    .tech-item h3 {
        font-size: 13px;
    }

    .tech-item p {
        font-size: 12px;
    }

    .showcase-item {
        flex: 0 0 calc(72%);
        min-height: 280px;
    }

    .showcase-container {
        padding: 16px;
    }

    .showcase-track {
        gap: 12px;
    }

    .use-case-item h3 {
        font-size: 13px;
    }

    .use-case-item p {
        font-size: 12px;
    }

    .process-step {
        grid-template-columns: auto 1fr;
        gap: 12px;
        padding: 16px;
    }

    .step-number {
        width: 36px;
        height: 36px;
        font-size: 14px;
        flex-shrink: 0;
    }

    .process-step h3 {
        font-size: 13px;
        margin-bottom: 4px;
    }

    .process-step p {
        font-size: 12px;
        margin: 0;
    }

    .process-steps {
        gap: 12px;
    }

    .faq-question {
        padding: 16px;
        font-size: 13px;
    }

    .faq-answer p {
        padding: 0 16px 16px 16px;
        font-size: 13px;
    }

    .footer-section h4 {
        font-size: 13px;
    }

    .footer-logo-img {
        width: 48px;
        height: 48px;
    }

    .footer-section p,
    .footer-section ul a {
        font-size: 12px;
    }

    .copyright,
    .disclaimer {
        font-size: 11px;
    }
}