@charset "UTF-8";

/* ==========================================================================
   Variables & Theme
   ========================================================================== */
:root {
    /* Colors */
    --bg-primary: #FAFAFA;
    --bg-secondary: #F5F5F5;
    --bg-card: #FFFFFF;
    
    --text-primary: #111111;
    --text-secondary: #666666;
    --text-inverse: #FFFFFF;
    
    --border-subtle: #E8E8E8;
    --border-strong: #D1D1D1;
    
    /* Subtle Accent Color (Restrained, professional dark slate blue) */
    --accent: #252A36;
    --accent-hover: #171A21;
    --accent-light: rgba(37, 42, 54, 0.05);

    /* Typography */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    
    /* Spacing */
    --spacing-1: 4px;
    --spacing-2: 8px;
    --spacing-3: 16px;
    --spacing-4: 24px;
    --spacing-5: 32px;
    --spacing-6: 48px;
    --spacing-8: 64px;
    --spacing-12: 96px;
    --spacing-16: 128px;
    
    /* Layout */
    --max-width: 1240px;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 12px 24px rgba(0, 0, 0, 0.08);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *, ::before, ::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

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

html {
    scroll-behavior: smooth;
}

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

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

ul, ol {
    list-style: none;
}

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

button {
    font-family: inherit;
    border: none;
    background: none;
    cursor: pointer;
}

/* ==========================================================================
   Typography Hierarchy
   ========================================================================== */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

h1 {
    font-size: clamp(38px, 5vw, 72px);
    line-height: 1.05;
    letter-spacing: -0.03em;
}

h2 {
    font-size: clamp(28px, 4vw, 42px);
}

h3 {
    font-size: 20px;
    letter-spacing: -0.01em;
}

p {
    color: var(--text-secondary);
}

/* ==========================================================================
   Layout & Utilities
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-5);
}

@media (max-width: 1023px) {
    .container { padding: 0 var(--spacing-4); }
}

@media (max-width: 767px) {
    .container { padding: 0 18px; }
}

.section {
    padding: var(--spacing-12) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-3);
}

.section-desc {
    text-align: center;
    max-width: 600px;
    margin: 0 auto var(--spacing-8);
    font-size: 1.125rem;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 var(--spacing-4);
    height: 44px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 500;
    transition: all var(--transition-normal);
}

.btn:hover {
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background-color: var(--accent);
    color: var(--text-inverse);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    box-shadow: var(--shadow-md);
}

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

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

.btn-large {
    height: 52px;
    padding: 0 var(--spacing-6);
    font-size: 1.05rem;
}

.btn-full {
    width: 100%;
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background-color: rgba(250, 250, 250, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    z-index: 1000;
    transition: transform 0.3s ease;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.nav-logo-icon {
    width: 24px;
    height: 24px;
}

.nav-center {
    display: flex;
    gap: var(--spacing-5);
}

.nav-center a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.nav-center a:hover,
.nav-center a.active {
    color: var(--accent);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-1);
}

.hamburger svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-primary);
    stroke-width: 2;
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-subtle);
    padding: var(--spacing-4) var(--spacing-5);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

.mobile-menu.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
}

.mobile-menu a {
    display: block;
    padding: var(--spacing-3) 0;
    font-size: 1.1rem;
    font-weight: 500;
    border-bottom: 1px solid var(--border-subtle);
}

.mobile-menu .nav-actions {
    margin-top: var(--spacing-4);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

@media (max-width: 767px) {
    .nav-center, .nav-right .btn { display: none; }
    .hamburger { display: block; }
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    position: relative;
    padding-top: 150px;
    padding-bottom: var(--spacing-12);
    min-height: 75vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
}

.hero-bg-grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(to right, rgba(0, 0, 0, 0.03) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(0, 0, 0, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
    z-index: -1;
}

.hero-content {
    max-width: 760px;
    margin: 0 auto;
}

.eyebrow {
    display: inline-block;
    padding: 6px 12px;
    border-radius: var(--radius-full);
    background-color: var(--accent-light);
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: var(--spacing-4);
}

.hero-title {
    margin-bottom: var(--spacing-4);
}

.hero-desc {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-6);
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-3);
}

@media (max-width: 767px) {
    .hero { padding-top: 120px; min-height: auto; }
    .hero-desc { font-size: 1.1rem; }
    .hero-actions { flex-direction: column; width: 100%; }
}

/* ==========================================================================
   Trust Strip
   ========================================================================== */
.trust-strip {
    border-top: 1px solid var(--border-subtle);
    border-bottom: 1px solid var(--border-subtle);
    background-color: var(--bg-card);
    padding: var(--spacing-6) 0;
}

.trust-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-5);
    text-align: center;
}

.trust-item strong {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: var(--spacing-1);
    letter-spacing: -0.02em;
}

.trust-item span {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

@media (max-width: 767px) {
    .trust-grid { grid-template-columns: repeat(2, 1fr); gap: var(--spacing-6) var(--spacing-3); }
}

/* ==========================================================================
   Features Section
   ========================================================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-5);
}

.feature-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--spacing-5);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-strong);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    width: 40px;
    height: 40px;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-4);
}

.feature-icon svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
    stroke-width: 1.5;
    fill: none;
}

.feature-card h3 {
    margin-bottom: var(--spacing-2);
}

.feature-card p {
    font-size: 0.95rem;
}

@media (max-width: 1023px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 767px) {
    .features-grid { grid-template-columns: 1fr; }
}

/* ==========================================================================
   Network Showcase
   ========================================================================== */
.network-showcase {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
    border-bottom: 1px solid var(--border-subtle);
    overflow: hidden;
}

.network-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-8);
    align-items: center;
}

.network-text h2 {
    margin-bottom: var(--spacing-4);
}

.network-text p {
    margin-bottom: var(--spacing-4);
    font-size: 1.05rem;
}

.network-visual {
    position: relative;
    width: 100%;
    height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.network-line {
    position: absolute;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-strong), transparent);
    width: 100%;
}

.network-nodes {
    display: flex;
    justify-content: space-between;
    width: 100%;
    position: relative;
    z-index: 2;
}

.node {
    width: 12px;
    height: 12px;
    background-color: var(--bg-card);
    border: 2px solid var(--accent);
    border-radius: 50%;
    position: relative;
}

.node::after {
    content: attr(data-label);
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    font-weight: 500;
}

@media (max-width: 767px) {
    .network-grid { grid-template-columns: 1fr; gap: var(--spacing-6); }
    .network-visual { height: 150px; }
}

/* ==========================================================================
   Pricing Section
   ========================================================================== */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-5);
    align-items: stretch;
}

.pricing-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--spacing-5);
    display: flex;
    flex-direction: column;
}

.pricing-card.recommended {
    border-color: var(--accent);
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-md);
    position: relative;
}

.badge-recommended {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--accent);
    color: var(--text-inverse);
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    letter-spacing: 0.05em;
}

.pricing-header {
    margin-bottom: var(--spacing-4);
}

.pricing-name {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-2);
}

.pricing-price {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1;
    color: var(--text-primary);
    letter-spacing: -0.03em;
}

.pricing-period {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.pricing-features {
    margin-bottom: var(--spacing-6);
    flex-grow: 1;
}

.pricing-features li {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-2);
    margin-bottom: var(--spacing-2);
    font-size: 0.95rem;
}

.pricing-features li svg {
    width: 18px;
    height: 18px;
    stroke: var(--accent);
    flex-shrink: 0;
    margin-top: 3px;
}

.pricing-card .btn {
    margin-top: auto;
}

@media (max-width: 1023px) {
    .pricing-grid { grid-template-columns: repeat(2, 1fr); }
    .pricing-card:last-child { grid-column: span 2; max-width: 50%; margin: 0 auto; }
}

@media (max-width: 767px) {
    .pricing-grid { grid-template-columns: 1fr; gap: var(--spacing-6); }
    .pricing-card:last-child { grid-column: auto; max-width: 100%; }
}

/* ==========================================================================
   Testimonials (Marquee)
   ========================================================================== */
.testimonials {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-subtle);
    overflow: hidden;
}

.test-marquee-wrapper {
    position: relative;
    width: 100%;
    overflow: hidden;
    mask-image: linear-gradient(to right, transparent, black 5%, black 95%, transparent);
    -webkit-mask-image: linear-gradient(to right, transparent, black 5%, black 95%, transparent);
    padding: var(--spacing-2) 0;
}

.test-marquee-content {
    display: flex;
    gap: var(--spacing-5);
    width: max-content;
    animation: marquee-scroll 40s linear infinite;
}

.test-marquee-content:hover {
    animation-play-state: paused;
}

@keyframes marquee-scroll {
    0% { transform: translateX(0); }
    100% { transform: translateX(calc(-50% - (var(--spacing-5) / 2))); }
}

.test-card {
    width: 400px;
    flex-shrink: 0;
    padding: var(--spacing-5);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    background-color: var(--bg-card);
}

.test-stars {
    color: var(--text-primary);
    font-size: 0.9rem;
    letter-spacing: 2px;
    margin-bottom: var(--spacing-3);
}

.test-text {
    font-size: 1.05rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-4);
    font-weight: 500;
}

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

@media (max-width: 767px) {
    .test-card { width: 300px; }
}

/* ==========================================================================
   Customer Support
   ========================================================================== */
.support {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
}

.support-options {
    display: flex;
    justify-content: center;
    gap: var(--spacing-5);
    flex-wrap: wrap;
}

.support-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-4);
    background-color: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-full);
    font-weight: 500;
    font-size: 0.95rem;
}

.support-item:hover {
    border-color: var(--border-strong);
}

.support-item svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
    fill: none;
    stroke-width: 1.5;
}

/* ==========================================================================
   Bottom CTA
   ========================================================================== */
.bottom-cta {
    border-top: 1px solid var(--border-subtle);
    background-color: var(--bg-card);
}

.bottom-cta .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.bottom-cta h2 {
    margin-bottom: var(--spacing-2);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    border-top: 1px solid var(--border-subtle);
    padding: var(--spacing-8) 0 var(--spacing-6);
    background-color: var(--bg-primary);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-4);
}

.footer-left .brand {
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: var(--spacing-1);
    display: block;
}

.footer-copyright {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: var(--spacing-4);
}

.footer-links a {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

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

@media (max-width: 767px) {
    .footer-container { flex-direction: column; text-align: center; }
    .footer-links { justify-content: center; flex-wrap: wrap; }
}

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-hero > * {
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
}

.animate-hero > *:nth-child(1) { animation-delay: 0.1s; }
.animate-hero > *:nth-child(2) { animation-delay: 0.2s; }
.animate-hero > *:nth-child(3) { animation-delay: 0.3s; }
.animate-hero > *:nth-child(4) { animation-delay: 0.4s; }

/* Scroll Reveal Classes */
.reveal-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.faq-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all var(--transition-fast);
}

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

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-4);
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
    list-style: none; /* Hide default triangle */
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-icon {
    width: 20px;
    height: 20px;
    stroke: var(--text-secondary);
    stroke-width: 2;
    fill: none;
    transition: transform var(--transition-fast);
}

.faq-item[open] .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 var(--spacing-4) var(--spacing-4);
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}