/* ============================================================
   拓星科技官网 - 全局样式
   浅色商务风 + 深色 Hero
   ============================================================ */

/* --- CSS Variables --- */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --accent: #0d9488;
    --accent-light: #ccfbf1;
    --dark: #0f172a;
    --dark-2: #1e293b;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --text: #1e293b;
    --text-secondary: #64748b;
    --bg: #ffffff;
    --bg-alt: #f8fafc;
    --border: #e2e8f0;
    --radius-sm: 8px;
    --radius: 16px;
    --radius-lg: 24px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 4px 16px rgba(0,0,0,0.06);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.08);
    --shadow-primary: 0 4px 24px rgba(37,99,235,0.12);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --max-width: 1200px;
}

/* --- Base --- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    color: var(--text);
    background: var(--bg);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    margin: 0;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--gray-900);
}

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* --- Section Spacing --- */
.section {
    padding: 6rem 0;
}

.section-alt {
    background: var(--bg-alt);
}

/* --- Container override --- */
.container {
    max-width: var(--max-width);
}

/* ============================================================
   HEADER & NAVIGATION
   ============================================================ */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: box-shadow var(--transition);
}

.site-header.scrolled {
    box-shadow: 0 1px 8px rgba(0,0,0,0.08);
}

.navbar { padding: 0; min-height: 68px; }

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--gray-900) !important;
    letter-spacing: -0.01em;
}

.brand-icon {
    width: 38px;
    height: 38px;
}

.navbar-nav { gap: 0.25rem; }

.nav-link {
    font-size: 0.925rem;
    font-weight: 500;
    color: var(--gray-600) !important;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary) !important;
    background: var(--primary-light);
}

/* Mobile menu */
.navbar-toggler {
    border: none;
    padding: 0.5rem;
    font-size: 1.25rem;
    color: var(--gray-700);
}

.navbar-toggler:focus {
    box-shadow: none;
    outline: none;
}

@media (max-width: 991px) {
    .navbar-collapse {
        background: #fff;
        padding: 1rem;
        border-radius: var(--radius);
        box-shadow: var(--shadow-lg);
        margin-top: 0.5rem;
    }
    .nav-link { padding: 0.75rem 1rem !important; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
    position: relative;
    min-height: 65vh;
    display: flex;
    align-items: center;
    background: var(--dark);
    overflow: hidden;
    padding-top: 68px;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 60% 50% at 50% 40%, rgba(37,99,235,0.15) 0%, transparent 70%),
        radial-gradient(ellipse 50% 40% at 80% 60%, rgba(13,148,136,0.1) 0%, transparent 70%);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(37,99,235,0.15);
    border: 1px solid rgba(37,99,235,0.3);
    color: #93c5fd;
    padding: 0.4rem 1rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    color: #f1f5f9;
    line-height: 1.15;
    margin-bottom: 1.25rem;
    letter-spacing: -0.03em;
}

.hero-title .highlight {
    background: linear-gradient(135deg, #60a5fa 0%, #2dd4bf 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: #94a3b8;
    line-height: 1.7;
    margin-bottom: 2.5rem;
    max-width: 480px;
}

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

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-visual canvas {
    width: 100%;
    max-width: 500px;
    height: auto;
}

@media (max-width: 991px) {
    .hero { min-height: auto; padding: 8rem 0 4rem; }
    .hero-grid { grid-template-columns: 1fr; gap: 2rem; }
    .hero-title { font-size: 2.25rem; }
    .hero-subtitle { font-size: 1rem; }
    .hero-visual { display: none; }
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.75rem 1.75rem;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    letter-spacing: 0.01em;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}

.btn-outline-light {
    border-color: rgba(255,255,255,0.3);
    color: #f1f5f9;
}

.btn-outline-light:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.5);
    color: #fff;
    transform: translateY(-2px);
}

.btn-outline-primary {
    border-color: var(--primary);
    color: var(--primary);
}

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

.btn-lg {
    padding: 0.9rem 2.25rem;
    font-size: 1rem;
}

/* ============================================================
   CAPABILITY CARDS
   ============================================================ */
.capability-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem 2rem;
    transition: all var(--transition);
    height: 100%;
    position: relative;
    overflow: hidden;
}

.capability-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity var(--transition);
}

.capability-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-primary);
    border-color: rgba(37,99,235,0.2);
}

.capability-card:hover::before {
    opacity: 1;
}

.capability-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 1.5rem;
    border-radius: 14px;
    margin-bottom: 1.5rem;
    transition: all var(--transition);
}

.capability-card:hover .capability-icon {
    background: var(--primary);
    color: #fff;
}

.capability-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.capability-card p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ============================================================
   ADVANTAGES / WHY CHOOSE US
   ============================================================ */
.advantage-card {
    text-align: center;
    padding: 2.5rem 1.5rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: all var(--transition);
    height: 100%;
}

.advantage-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37,99,235,0.15);
}

.advantage-image {
    width: 100%;
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    border-radius: var(--radius-sm);
    overflow: hidden;
    position: relative;
}

.advantage-image svg {
    width: 100%;
    height: 100%;
    max-width: 260px;
}

.advantage-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.advantage-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* ============================================================
   CLIENT LOGOS
   ============================================================ */
.client-strip {
    padding: 1rem 0;
}

.client-strip img {
    width: 100%;
    max-width: 1100px;
    height: auto;
    filter: grayscale(100%);
    transition: filter var(--transition);
}

.client-strip img:hover {
    filter: grayscale(0%);
}

/* ============================================================
   SERVICE CARDS
   ============================================================ */
.service-card {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 2rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem;
    margin-bottom: 1.5rem;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity var(--transition);
}

.service-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: rgba(37,99,235,0.15);
}

.service-card:hover::after {
    opacity: 1;
}

.service-icon {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 2rem;
    border-radius: var(--radius);
    flex-shrink: 0;
    transition: all var(--transition);
}

.service-card:hover .service-icon {
    background: var(--primary);
    color: #fff;
}

.service-body h3 {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
}

.service-body p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 0.95rem;
    line-height: 1.75;
}

.service-scenario {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--accent-light);
    color: var(--accent);
    padding: 0.35rem 0.9rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

@media (max-width: 640px) {
    .service-card { grid-template-columns: 1fr; gap: 1rem; padding: 1.5rem; }
    .service-icon { width: 56px; height: 56px; font-size: 1.5rem; }
}

/* ============================================================
   TECH MODULE CARDS (2x3 grid)
   ============================================================ */
.tech-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem 1.75rem;
    transition: all var(--transition);
    height: 100%;
}

.tech-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

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

.tech-card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 1.25rem;
    border-radius: 12px;
    flex-shrink: 0;
}

.tech-card h3 {
    font-size: 1.1rem;
    margin: 0;
}

.tech-keywords {
    font-size: 0.8rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 0.75rem;
}

.tech-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.25rem;
    line-height: 1.7;
}

.tech-maturity {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.tech-maturity-bar {
    flex: 1;
    height: 6px;
    background: var(--gray-200);
    border-radius: 3px;
    overflow: hidden;
}

.tech-maturity-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 3px;
    width: 0;
    transition: width 1.5s ease;
}

.tech-maturity-label {
    font-size: 0.75rem;
    color: var(--gray-500);
    font-weight: 500;
    min-width: 60px;
}

/* ============================================================
   SCENARIO CARDS
   ============================================================ */
.scenario-card {
    position: relative;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem 2rem;
    height: 100%;
    transition: all var(--transition);
    overflow: hidden;
}

.scenario-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: rgba(37,99,235,0.2);
}

.scenario-card .scenario-icon {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 1.25rem;
}

.scenario-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.scenario-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.75;
    margin: 0;
}

.scenario-index {
    position: absolute;
    top: 1.5rem;
    right: 2rem;
    font-size: 3rem;
    font-weight: 800;
    color: var(--gray-100);
    line-height: 1;
    pointer-events: none;
}

/* ============================================================
   ABOUT PAGE
   ============================================================ */
.about-intro {
    font-size: 1.15rem;
    line-height: 1.9;
    color: var(--text-secondary);
    max-width: 800px;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.5rem;
    bottom: 0.5rem;
    width: 2px;
    background: linear-gradient(180deg, var(--primary), var(--accent));
}

.timeline-item {
    position: relative;
    padding-bottom: 2.5rem;
}

.timeline-item:last-child { padding-bottom: 0; }

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.35rem;
    top: 0.4rem;
    width: 12px;
    height: 12px;
    background: var(--primary);
    border: 3px solid #fff;
    border-radius: 50%;
    box-shadow: 0 0 0 3px var(--primary-light);
}

.timeline-year {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.2rem;
}

.timeline-item h3 {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.timeline-item p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.95rem;
}

/* Team */
.team-card {
    text-align: center;
    padding: 2rem 1rem;
}

.team-avatar {
    width: 100px;
    height: 100px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.team-avatar svg {
    width: 100%;
    height: 100%;
}

.team-card h4 {
    font-size: 1rem;
    margin-bottom: 0.2rem;
}

.team-role {
    color: var(--primary);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.team-card p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin: 0;
}

/* Values */
.values-tagline {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 0.04em;
}

/* ============================================================
   CONTACT PAGE
   ============================================================ */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.3fr;
    gap: 3rem;
}

.contact-info-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.contact-info-list li {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border);
}

.contact-info-list li:last-child { border-bottom: none; }

.contact-info-icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 1rem;
    border-radius: 12px;
    flex-shrink: 0;
}

.contact-info-list h4 {
    font-size: 0.9rem;
    margin-bottom: 0.15rem;
}

.contact-info-list p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.9rem;
}

/* Form */
.contact-form {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem;
}

.form-label {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
}

.form-control {
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.7rem 1rem;
    font-size: 0.95rem;
    transition: all var(--transition);
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

/* Map */
.contact-map {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.75rem;
    box-shadow: var(--shadow);
}

@media (max-width: 768px) {
    .contact-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
    background: var(--dark);
    color: #94a3b8;
    padding: 4rem 0 2rem;
    font-size: 0.9rem;
}

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

.footer-logo {
    font-size: 1.3rem;
    font-weight: 800;
    color: #f1f5f9;
    margin-bottom: 0.75rem;
}

.footer-desc {
    max-width: 420px;
    line-height: 1.8;
}

.footer-links h4,
.footer-contact h4 {
    color: #f1f5f9;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.footer-links ul,
.footer-contact ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links ul li { margin-bottom: 0.5rem; }
.footer-contact ul li { margin-bottom: 0.6rem; }

.footer-links a {
    color: #94a3b8;
    transition: color var(--transition);
}

.footer-links a:hover { color: #fff; }

.footer-contact i {
    width: 18px;
    color: var(--primary);
    margin-right: 0.25rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 1.5rem;
    text-align: center;
    font-size: 0.85rem;
}

.footer-bottom p { margin-bottom: 0.25rem; }

.icp { font-size: 0.8rem; color: #64748b; }

@media (max-width: 768px) {
    .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
}

/* ============================================================
   AI BADGE
   ============================================================ */
.ai-badge-section {
    background: linear-gradient(135deg, rgba(37,99,235,0.04) 0%, rgba(13,148,136,0.04) 100%);
    padding: 2.5rem 0;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.ai-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary-light);
    color: var(--primary);
    padding: 0.6rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: all var(--transition);
    z-index: 999;
    box-shadow: 0 4px 16px rgba(37,99,235,0.3);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(37,99,235,0.4);
}

/* ============================================================
   SCROLL ANIMATIONS
   ============================================================ */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ============================================================
   HERO CANVAS (particle background)
   ============================================================ */
#heroCanvas {
    width: 100%;
    max-width: 480px;
    aspect-ratio: 1;
}

/* ============================================================
   PAGE HEADER BANNER
   ============================================================ */
.page-header {
    background: var(--dark);
    padding: 8rem 0 4rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 50% 50% at 50% 50%, rgba(37,99,235,0.1) 0%, transparent 70%);
}

.page-header h1 {
    color: #f1f5f9;
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
    position: relative;
}

.page-header .subtitle {
    color: #94a3b8;
    font-size: 1.1rem;
    position: relative;
}

/* ============================================================
   UTILITY
   ============================================================ */
.text-center { text-align: center; }

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

/* ============================================
   Product Download Page
   ============================================ */
.product-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    max-width: 880px;
    margin: 0 auto;
}

.product-card {
    background: #fff;
    border: 1px solid #e4e4ec;
    border-radius: 12px;
    padding: 2rem 2.5rem;
    transition: box-shadow 0.3s ease, transform 0.2s ease;
}
.product-card:hover {
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.product-card-header {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-bottom: 1rem;
}
.product-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: rgba(63, 86, 206, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #3F56CE;
    flex-shrink: 0;
}
.product-title-group {
    display: flex;
    align-items: baseline;
    gap: 0.75rem;
    flex-wrap: wrap;
}
.product-name {
    font-size: 1.35rem;
    font-weight: 700;
    color: #1e1e2e;
    margin: 0;
}
.product-version {
    display: inline-block;
    background: #3F56CE;
    color: #fff;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.15rem 0.6rem;
    border-radius: 4px;
    letter-spacing: 0.03em;
}
.product-desc {
    color: #3c3c50;
    line-height: 1.7;
    margin-bottom: 1.25rem;
    font-size: 0.95rem;
}

.product-highlights {
    margin-bottom: 1.5rem;
}
.product-highlights h4 {
    font-size: 0.8rem;
    font-weight: 700;
    color: #78788c;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}
.product-highlights ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.4rem 1.5rem;
}
.product-highlights li {
    font-size: 0.88rem;
    color: #3c3c50;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.product-highlights li i {
    color: #3F56CE;
    font-size: 0.75rem;
    flex-shrink: 0;
}

.product-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding-top: 1.25rem;
    border-top: 1px solid #e4e4ec;
    flex-wrap: wrap;
}
.product-meta {
    display: flex;
    gap: 1.5rem;
    font-size: 0.82rem;
    color: #78788c;
}
.product-meta i {
    margin-right: 0.3rem;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.75rem;
    background: #3F56CE;
    color: #fff;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.95rem;
    text-decoration: none;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
}
.btn-download:hover {
    background: #374AAA;
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(63, 86, 206, 0.35);
}

@media (max-width: 768px) {
    .product-card { padding: 1.5rem; }
    .product-highlights ul { grid-template-columns: 1fr; }
    .product-card-footer { flex-direction: column; align-items: flex-start; }
    .product-meta { flex-direction: column; gap: 0.35rem; }
    .btn-download { width: 100%; justify-content: center; }
}

.mb-0 { margin-bottom: 0; }

@media (max-width: 768px) {
    .section { padding: 4rem 0; }
    .section-title { font-size: 1.75rem; }
    .page-header h1 { font-size: 1.75rem; }
}

.demo-video-section {
    padding-top: 100px;
}