/* =========================================================
   快连 KuaiLian - Global Stylesheet
   Theme: Light, Futuristic, Tech-forward
   Color Palette: #F8FAFC / #E2E8F0 / #00E5FF / #7C4DFF / #0F172A
   ========================================================= */

/* ---------- CSS Variables ---------- */
:root {
    --bg-primary: #F8FAFC;
    --bg-secondary: #FFFFFF;
    --bg-tertiary: #F1F5F9;
    --bg-glass: rgba(255, 255, 255, 0.7);
    --border-light: #E2E8F0;
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --accent-cyan: #00E5FF;
    --accent-purple: #7C4DFF;
    --accent-pink: #E040FB;
    --accent-gradient: linear-gradient(135deg, #00E5FF 0%, #7C4DFF 50%, #E040FB 100%);
    --gradient-hero: linear-gradient(135deg, #F0FDF4 0%, #EFF6FF 30%, #F5F3FF 60%, #FFF1F2 100%);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --font-main: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    position: relative;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

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

ul { list-style: none; }

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- Particles Background ---------- */
#particles-js {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 0.4;
}

/* ========== NAVBAR ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(248, 250, 252, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(248, 250, 252, 0.95);
    border-bottom-color: var(--border-light);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-img {
    width: 36px;
    height: 36px;
    object-fit: contain;
}

.logo-text {
    font-size: 1.4rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 8px;
    align-items: center;
}

.nav-links a {
    position: relative;
    padding: 10px 20px;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

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

.nav-links a.active {
    color: var(--accent-purple);
    background: rgba(124, 77, 255, 0.08);
}

.nav-links a.active .nav-underline {
    display: block;
}

.nav-underline {
    display: none;
    position: absolute;
    bottom: 0;
    left: 20%;
    width: 60%;
    height: 2px;
    background: var(--accent-purple);
    border-radius: 1px;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

@media (max-width: 768px) {
    .hamburger { display: flex; }
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 16px;
        border-bottom: 1px solid var(--border-light);
        box-shadow: var(--shadow-md);
    }
    .nav-links.open { display: flex; }
}

/* ========== HERO SECTION (首页首屏) ========== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: var(--gradient-hero);
    padding-top: 70px;
}

.hero-particles {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 24px;
    position: relative;
    z-index: 1;
    width: 100%;
}

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

.hero-left {
    max-width: 560px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 24px;
}

.gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    gap: 32px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.hero-right {
    position: relative;
}

.hero-image-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
}

.hero-main-img {
    max-width: 520px;
    width: 100%;
    filter: drop-shadow(0 20px 60px rgba(0, 229, 255, 0.15));
    animation: floatImg 6s ease-in-out infinite;
}

@keyframes floatImg {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-16px); }
}

.floating-card {
    position: absolute;
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.6);
    border-radius: var(--radius-md);
    padding: 10px 18px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--shadow-md);
    animation: floatCard 4s ease-in-out infinite;
}

.fc-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex-shrink: 0;
}

.fc-dot.green { background: #00E676; }
.fc-dot.blue { background: #2979FF; }
.fc-dot.purple { background: #7C4DFF; }

.card-1 { top: 15%; right: -20px; animation-delay: 0s; }
.card-2 { bottom: 30%; left: -30px; animation-delay: 1.5s; }
.card-3 { bottom: 10%; right: 10%; animation-delay: 3s; }

@keyframes floatCard {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    font-family: var(--font-main);
}

.btn-primary {
    background: var(--accent-gradient);
    color: #fff;
    border: none;
    box-shadow: 0 4px 20px rgba(0, 229, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 229, 255, 0.45);
}

.btn-outline {
    background: transparent;
    color: var(--accent-purple);
    border-color: var(--accent-purple);
}

.btn-outline:hover {
    background: var(--accent-purple);
    color: #fff;
}

.btn-full {
    width: 100%;
}

.btn-lg {
    padding: 16px 36px;
    font-size: 1.05rem;
    border-radius: var(--radius-lg);
}

.btn-sm {
    padding: 8px 18px;
    font-size: 0.85rem;
}

.btn-tiny {
    padding: 4px 12px;
    font-size: 0.78rem;
    background: rgba(124, 77, 255, 0.08);
    color: var(--accent-purple);
    border-radius: var(--radius-sm);
    font-weight: 500;
}

.btn-tiny:hover {
    background: var(--accent-purple);
    color: #fff;
}

.hero-download-btn {
    margin-top: 8px;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
    animation: bounceScroll 2s ease-in-out infinite;
}

.mouse {
    width: 24px;
    height: 38px;
    border: 2px solid var(--text-muted);
    border-radius: 12px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 8px;
    background: var(--text-muted);
    border-radius: 2px;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    animation: wheelScroll 1.5s ease-in-out infinite;
}

@keyframes wheelScroll {
    0% { opacity: 1; transform: translateX(-50%) translateY(0); }
    100% { opacity: 0; transform: translateX(-50%) translateY(12px); }
}

@keyframes bounceScroll {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* Reveal Animations */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* ========== SECTIONS COMMON ========== */
section {
    padding: 100px 0;
    position: relative;
    z-index: 1;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent-purple);
    background: rgba(124, 77, 255, 0.08);
    padding: 6px 16px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.8rem, 3.5vw, 2.5rem);
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.section-desc {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ========== FEATURES SECTION ========== */
.features-section {
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 28px;
}

.feature-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--accent-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(0, 229, 255, 0.2);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-icon-wrap {
    position: relative;
    width: 56px;
    height: 56px;
    margin-bottom: 20px;
}

.feature-icon-bg {
    position: absolute;
    inset: 0;
    background: rgba(0, 229, 255, 0.08);
    border-radius: var(--radius-md);
    transform: rotate(45deg);
}

.feature-icon {
    position: relative;
    z-index: 1;
    width: 56px;
    height: 56px;
}

.feature-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    margin-bottom: 16px;
    line-height: 1.7;
}

.feature-link {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--accent-purple);
}

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

/* ========== HOW IT WORKS ========== */
.how-it-works-section {
    background: var(--bg-tertiary);
}

.steps-container {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
    flex-wrap: wrap;
}

.step-step {
    text-align: center;
    max-width: 300px;
    padding: 20px;
}

.step-number-wrap {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 800;
    color: #fff;
    box-shadow: 0 4px 20px rgba(0, 229, 255, 0.25);
}

.step-step h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.step-step p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    margin-bottom: 12px;
}

.step-link, .step-cta .btn {
    font-size: 0.88rem;
    color: var(--accent-purple);
    font-weight: 600;
}

.step-line {
    flex: 1;
    max-width: 80px;
    min-width: 40px;
    height: 2px;
    background: var(--border-light);
    position: relative;
    margin: 32px 0;
}

.step-line-inner {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--accent-gradient);
    animation: shimmerLine 2s ease-in-out infinite;
}

@keyframes shimmerLine {
    0% { transform: scaleX(0); transform-origin: left; }
    50% { transform: scaleX(1); transform-origin: left; }
    51% { transform-origin: right; }
    100% { transform: scaleX(0); transform-origin: right; }
}

@media (max-width: 768px) {
    .step-line { display: none; }
    .steps-container { flex-direction: column; align-items: center; gap: 32px; }
}

/* ========== PLATFORM SECTION ========== */
.platform-section {
    background: var(--bg-secondary);
}

.platform-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
}

.platform-card {
    text-align: center;
    padding: 32px 20px;
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    cursor: default;
}

.platform-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: rgba(0, 229, 255, 0.3);
}

.pc-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pc-icon svg {
    width: 48px;
    height: 48px;
}

.platform-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.pc-ver {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* ========== STATS SECTION ========== */
.stats-section {
    position: relative;
    background: linear-gradient(135deg, #0a1628 0%, #0d1f3c 50%, #112240 100%);
    overflow: hidden;
    padding: 80px 0;
}

.stats-overlay {
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.stats-container {
    position: relative;
    z-index: 1;
    text-align: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 32px;
    margin-top: 40px;
}

.stat-block {
    text-align: center;
}

.stat-block-num {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-block-desc {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
    margin-top: 6px;
}

/* ========== TESTIMONIALS ========== */
.testimonials-section {
    background: var(--bg-tertiary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.testimonial-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: var(--transition);
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.tc-stars {
    color: #FFC107;
    font-size: 1rem;
    margin-bottom: 12px;
    letter-spacing: 2px;
}

.testimonial-card > p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    margin-bottom: 20px;
    font-style: italic;
    line-height: 1.7;
}

.tc-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.tc-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #fff;
    font-size: 1rem;
    flex-shrink: 0;
}

.tc-name {
    font-weight: 600;
    font-size: 0.92rem;
}

.tc-role {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ========== CTA Section ========== */
.cta-section {
    background: var(--accent-gradient);
    text-align: center;
    padding: 80px 0;
}

.cta-content {
    position: relative;
    z-index: 1;
}

.cta-content h2 {
    font-size: clamp(1.8rem, 3.5vw, 2.5rem);
    font-weight: 800;
    color: #fff;
    margin-bottom: 12px;
}

.cta-content > p {
    color: rgba(255, 255, 255, 0.85);
    font-size: 1.05rem;
    margin-bottom: 28px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.cta-buttons .btn-outline {
    color: #fff;
    border-color: #fff;
}

.cta-buttons .btn-outline:hover {
    background: #fff;
    color: var(--accent-purple);
}

/* ========== FAQ Section ========== */
.faq-section {
    background: var(--bg-secondary);
}

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

.faq-item {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    background: var(--bg-primary);
    transition: var(--transition);
    overflow: hidden;
}

.faq-item[open] {
    border-color: rgba(0, 229, 255, 0.3);
    box-shadow: var(--shadow-sm);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 24px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    user-select: none;
    transition: var(--transition);
}

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

.faq-arrow {
    font-size: 0.8rem;
    color: var(--text-muted);
    transition: transform 0.3s ease;
    flex-shrink: 0;
    margin-left: 12px;
}

.faq-item[open] .faq-arrow {
    transform: rotate(180deg);
    color: var(--accent-purple);
}

.faq-answer {
    padding: 0 24px 20px;
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.8;
}

.faq-answer p { margin-bottom: 8px; }
.faq-answer a { color: var(--accent-cyan); font-weight: 500; }
.faq-answer a:hover { text-decoration: underline; }

/* ========== FOOTER ========== */
.site-footer {
    background: #0a1628;
    color: rgba(255, 255, 255, 0.7);
    padding: 60px 0 24px;
    position: relative;
    z-index: 1;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

.footer-logo {
    width: 32px;
    height: 32px;
}

.footer-logo-text {
    font-size: 1.2rem;
    font-weight: 700;
    color: #fff;
}

.footer-desc {
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.7;
    margin-bottom: 16px;
}

.footer-col h4 {
    color: #fff;
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.88rem;
}

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

.footer-social {
    display: flex;
    gap: 8px;
}

.social-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.78rem;
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
}

.social-icon:hover {
    background: var(--accent-purple);
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 20px;
    text-align: center;
    font-size: 0.82rem;
    color: rgba(255, 255, 255, 0.35);
}

/* ========== DOWNLOAD PAGE STYLES ========== */
.page-hero {
    background: var(--gradient-hero);
    padding: 120px 0 80px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.page-hero-content {
    max-width: 700px;
    margin: 0 auto;
}

.page-hero-tag {
    display: inline-block;
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent-purple);
    background: rgba(124, 77, 255, 0.08);
    padding: 6px 16px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.page-hero-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    margin-bottom: 12px;
}

.page-hero-sub {
    font-size: 1.05rem;
    color: var(--text-secondary);
}

.download-main-section {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.os-tabs {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.os-tab {
    padding: 12px 24px;
    font-size: 0.92rem;
    font-weight: 600;
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-main);
    color: var(--text-secondary);
}

.os-tab:hover {
    border-color: var(--accent-cyan);
    color: var(--text-primary);
}

.os-tab.active {
    background: var(--accent-gradient);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 4px 20px rgba(0, 229, 255, 0.25);
}

.os-tab svg {
    vertical-align: middle;
    margin-right: 6px;
}

.download-panel {
    display: none;
}

.download-panel.active {
    display: block;
}

.download-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.download-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 28px;
    position: relative;
    transition: var(--transition);
}

.download-card.featured {
    border-color: rgba(0, 229, 255, 0.3);
    box-shadow: 0 4px 24px rgba(0, 229, 255, 0.08);
}

.dc-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--accent-gradient);
    color: #fff;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 12px;
}

.dc-platform-icon {
    width: 56px;
    height: 56px;
    margin-bottom: 16px;
}

.dc-platform-icon svg {
    width: 56px;
    height: 56px;
}

.download-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.dc-desc {
    color: var(--text-secondary);
    font-size: 0.88rem;
    margin-bottom: 12px;
}

.dc-info {
    display: flex;
    gap: 12px;
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.dc-download-link, .btn-outline {
    margin-bottom: 12px;
}

.dc-alt-links {
    display: flex;
    gap: 8px;
    font-size: 0.82rem;
    color: var(--text-muted);
    align-items: center;
    flex-wrap: wrap;
}

.dc-alt-links a {
    color: var(--accent-purple);
}

.dc-alt-links a:hover {
    text-decoration: underline;
}

/* History Table */
.history-version-section {
    background: var(--bg-tertiary);
    padding: 80px 0;
}

.history-table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-secondary);
}

.history-table th {
    background: var(--bg-tertiary);
    font-size: 0.85rem;
    font-weight: 600;
    text-align: left;
    padding: 14px 18px;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-light);
    white-space: nowrap;
}

.history-table td {
    padding: 14px 18px;
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-primary);
}

.history-table tr:last-child td {
    border-bottom: none;
}

.history-table tr:hover td {
    background: rgba(0, 229, 255, 0.03);
}

/* Install Guide */
.install-guide-section {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.install-steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.install-step-card {
    text-align: center;
    padding: 32px 24px;
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.install-step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.is-step-num {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 800;
    color: #fff;
}

.install-step-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.install-step-card p {
    color: var(--text-secondary);
    font-size: 0.88rem;
}

.install-note {
    text-align: center;
    padding: 20px;
    background: rgba(0, 229, 255, 0.05);
    border-radius: var(--radius-md);
    border: 1px solid rgba(0, 229, 255, 0.1);
    font-size: 0.92rem;
    color: var(--text-secondary);
}

.install-note a {
    color: var(--accent-cyan);
    font-weight: 500;
}

/* ========== HELP PAGE STYLES ========== */
.help-search-box {
    max-width: 520px;
    margin: 24px auto 0;
    display: flex;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--bg-secondary);
    box-shadow: var(--shadow-md);
}

.help-search-box input {
    flex: 1;
    padding: 14px 20px;
    border: none;
    outline: none;
    font-size: 0.95rem;
    font-family: var(--font-main);
    background: transparent;
    color: var(--text-primary);
}

.help-search-box input::placeholder {
    color: var(--text-muted);
}

.help-search-btn {
    padding: 14px 20px;
    background: var(--accent-gradient);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

/* Categories */
.categories-overview {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.help-categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
}

.help-cat-card {
    text-align: center;
    padding: 28px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    cursor: default;
}

.help-cat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: rgba(0, 229, 255, 0.2);
}

.hc-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 14px;
    background: rgba(0, 229, 255, 0.08);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transform: rotate(45deg);
}

.hc-icon svg {
    transform: rotate(-45deg);
    width: 24px;
    height: 24px;
    color: hsl(var(--hue), 100%, 50%);
}

.help-cat-card h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.help-cat-card p {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.hc-count {
    font-size: 0.75rem;
    color: var(--accent-purple);
    font-weight: 600;
}

/* Featured Articles */
.featured-articles-section {
    background: var(--bg-tertiary);
    padding: 80px 0;
}

.featured-articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.featured-article-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: var(--transition);
}

.featured-article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.fa-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 12px;
    margin-bottom: 12px;
}

.featured-article-card h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.featured-article-card p {
    color: var(--text-secondary);
    font-size: 0.88rem;
    margin-bottom: 16px;
    line-height: 1.7;
}

.article-read-more {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--accent-purple);
}

.article-read-more:hover {
    color: var(--accent-cyan);
}

/* Popular QAs */
.popular-qas-section {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.help-faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.help-faq-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
}

.help-faq-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.hfc-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 10px;
    background: hsla(var(--hue), 80%, 60%, 0.1);
    color: hsl(var(--hue), 80%, 45%);
}

.hfc-body {
    padding: 24px;
}

.hfc-body h4 {
    font-size: 1.02rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.hfc-body p {
    color: var(--text-secondary);
    font-size: 0.88rem;
    margin-bottom: 12px;
    line-height: 1.7;
}

.hfc-meta {
    display: flex;
    gap: 16px;
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* Help Docs */
.help-docs-section {
    background: var(--bg-tertiary);
    padding: 80px 0;
}

.help-doc-group {
    margin-bottom: 48px;
}

.help-doc-group:last-child {
    margin-bottom: 0;
}

.hdg-title {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.hdg-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    background: var(--bg);
}

.hdg-icon svg {
    width: 20px;
    height: 20px;
    color: #fff;
}

.help-doc-list {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    overflow: hidden;
}

.help-doc-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-light);
    transition: var(--transition);
}

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

.help-doc-item:hover {
    background: rgba(0, 229, 255, 0.03);
    padding-left: 28px;
}

.hd-item-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(0, 229, 255, 0.06);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.hd-item-icon svg {
    width: 18px;
    height: 18px;
    color: var(--accent-cyan);
}

.hd-item-icon svg circle,
.hd-item-icon svg polyline {
    stroke: var(--accent-cyan);
}

.help-doc-item strong {
    display: block;
    font-size: 0.95rem;
    margin-bottom: 4px;
}

.help-doc-item > div > p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.hd-arrow {
    margin-left: auto;
    font-size: 1.2rem;
    color: var(--text-muted);
    flex-shrink: 0;
}

.help-doc-item:hover .hd-arrow {
    color: var(--accent-purple);
}

/* Submit Ticket Form */
.submit-ticket-section {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.ticket-form-wrapper {
    max-width: 700px;
    margin: 0 auto;
}

.ticket-form {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 36px;
}

.tf-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}

@media (max-width: 560px) {
    .tf-row {
        grid-template-columns: 1fr;
    }
}

.tf-field {
    display: flex;
    flex-direction: column;
    margin-bottom: 16px;
}

.tf-field-wide {
    margin-bottom: 16px;
}

.tf-field label {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.tf-field input,
.tf-field select,
.tf-field textarea {
    padding: 12px 16px;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    font-size: 0.92rem;
    font-family: var(--font-main);
    background: var(--bg-secondary);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition);
}

.tf-field input:focus,
.tf-field select:focus,
.tf-field textarea:focus {
    border-color: var(--accent-cyan);
    box-shadow: 0 0 0 3px rgba(0, 229, 255, 0.1);
}

.tf-field textarea {
    resize: vertical;
}

.tf-submit {
    text-align: center;
}

.tf-note {
    margin-top: 12px;
    font-size: 0.82rem;
    color: var(--text-muted);
}

.tf-note strong {
    color: var(--text-primary);
}

/* Page hero for Help page specific */
.page-hero-content-help {
    position: relative;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    section {
        padding: 60px 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

    .hero-left {
        max-width: 100%;
    }

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

    .hero-main-img {
        max-width: 360px;
    }

    .floating-card {
        display: none;
    }

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

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

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

    .os-tabs {
        gap: 6px;
    }

    .os-tab {
        padding: 10px 16px;
        font-size: 0.85rem;
    }

    .download-cards-grid {
        grid-template-columns: 1fr;
    }

    .help-search-box {
                margin-top: 20px;
            }
        }

        @media (max-width: 480px) {
            .platform-cards {
                grid-template-columns: repeat(2, 1fr);
            }

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

            .featured-articles-grid,
            .help-faq-grid {
                grid-template-columns: 1fr;
            }

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

        /* ========== Particle Canvas Styling ========== */
        #particles-js canvas {
            display: block;
            width: 100%;
            height: 100%;
        }

        /* ========== Smooth Scroll Padding for Fixed Nav ========== */
        [id] {
            scroll-margin-top: 80px;
        }

        /* ========== Selection Color ========== */
        ::selection {
            background: rgba(0, 229, 255, 0.2);
            color: var(--text-primary);
        }

        ::-moz-selection {
            background: rgba(0, 229, 255, 0.2);
            color: var(--text-primary);
        }

        /* ========== Loading Animation for Download ========== */
        .loading-spinner {
            display: inline-block;
            width: 18px;
            height: 18px;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-top-color: #fff;
            border-radius: 50%;
            animation: spin 0.8s linear infinite;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        /* ========== Custom Scrollbar ========== */
        ::-webkit-scrollbar {
            width: 8px;
        }

        ::-webkit-scrollbar-track {
            background: var(--bg-primary);
        }

        ::-webkit-scrollbar-thumb {
            background: var(--border-light);
            border-radius: 4px;
        }

        ::-webkit-scrollbar-thumb:hover {
            background: var(--text-muted);
        }

        /* ========== Glow Effect for Interactive Elements ========== */
        .glow-on-hover {
            transition: var(--transition);
        }

        .glow-on-hover:hover {
            filter: drop-shadow(0 0 12px rgba(0, 229, 255, 0.3));
        }

        /* ========== Card Hover Shine Effect ========== */
        .shine-effect {
            position: relative;
            overflow: hidden;
        }

        .shine-effect::after {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: linear-gradient(to right, transparent 0%, rgba(255, 255, 255, 0.05) 50%, transparent 100%);
            transform: rotate(45deg);
            transition: transform 0.6s ease;
            transform: translateX(-100%) rotate(45deg);
        }

        .shine-effect:hover::after {
            transform: translateX(100%) rotate(45deg);
        }

        /* ========== Back to Top Button ========== */
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 44px;
            height: 44px;
            background: var(--accent-gradient);
            border: none;
            border-radius: 50%;
            color: #fff;
            font-size: 1.2rem;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 999;
            box-shadow: var(--shadow-md);
            transition: var(--transition);
        }

        .back-to-top.show {
            display: flex;
        }

        .back-to-top:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-lg);
        }

        /* ========== Tooltip ========== */
        [data-tooltip] {
            position: relative;
        }

        [data-tooltip]::after {
            content: attr(data-tooltip);
            position: absolute;
            bottom: 120%;
            left: 50%;
            transform: translateX(-50%);
            padding: 6px 12px;
            background: var(--text-primary);
            color: #fff;
            font-size: 0.75rem;
            border-radius: 6px;
            white-space: nowrap;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.2s ease;
        }

        [data-tooltip]:hover::after {
            opacity: 1;
        }