/* ========================================
   POEai - 聚合AI平台官网样式
   ======================================== */

/* CSS Variables */
:root {
    --primary: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #38bdf8;
    --secondary: #8b5cf6;
    --accent: #f59e0b;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    --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;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

ul {
    list-style: none;
}

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

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ========================================
   Navigation
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    transition: var(--transition);
}

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

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

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

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.nav-link {
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background: var(--gray-100);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.875rem;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(14, 165, 233, 0.39);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(14, 165, 233, 0.23);
}

.btn-secondary {
    background: var(--gray-100);
    color: var(--text-primary);
    border: 1px solid var(--gray-200);
}

.btn-secondary:hover {
    background: var(--gray-200);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--gray-300);
}

.btn-ghost:hover {
    background: var(--gray-100);
}

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

.btn-white:hover {
    background: var(--gray-100);
}

.btn-large {
    padding: 0.875rem 2rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 6rem 0 4rem;
    overflow: hidden;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

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

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.badge {
    padding: 0.375rem 0.75rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gradient-text-block {
    display: inline-block;
    margin-top: 10px;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
    max-width: 500px;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.stat-item {
    text-align: left;
}

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

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.hero-trust {
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
}

.hero-trust p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.trust-logos {
    display: flex;
    gap: 1.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-400);
}

/* Hero Visual */
.hero-visual {
    position: relative;
    z-index: 1;
}

.dashboard-preview {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid var(--gray-200);
}

.preview-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    background: var(--gray-50);
    border-bottom: 1px solid var(--gray-200);
}

.preview-dots {
    display: flex;
    gap: 0.5rem;
}

.preview-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--gray-300);
}

.preview-dots span:first-child {
    background: #ef4444;
}

.preview-dots span:nth-child(2) {
    background: #f59e0b;
}

.preview-dots span:nth-child(3) {
    background: #10b981;
}

.preview-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.preview-content {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.chat-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.chat-avatar {
    width: 2rem;
    height: 2rem;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.625rem;
    font-weight: 700;
    flex-shrink: 0;
}

.chat-bubble {
    background: var(--gray-100);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--text-primary);
}

.preview-input {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--gray-200);
    color: var(--text-light);
    font-size: 0.875rem;
}

.input-actions {
    display: flex;
    gap: 0.75rem;
}

/* Hero Background */
.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: var(--primary);
    top: -20%;
    right: -10%;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: var(--secondary);
    bottom: -10%;
    left: -5%;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: var(--accent);
    top: 40%;
    left: 30%;
    opacity: 0.2;
}

/* ========================================
   Sections
   ======================================== */
.section {
    padding: 6rem 0;
}

.section-dark {
    background: var(--bg-dark);
    color: white;
}

.section-dark .section-title,
.section-dark .section-subtitle {
    color: white;
}

.section-dark .section-subtitle {
    color: var(--gray-400);
}

.section-gradient {
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--gray-800) 100%);
    color: white;
}

.section-gradient .section-title,
.section-gradient .section-subtitle {
    color: white;
}

.section-gradient .section-subtitle {
    color: var(--gray-400);
}

.section-cta {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    text-align: center;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.section-tag {
    display: inline-block;
    padding: 0.375rem 1rem;
    background: var(--gray-100);
    color: var(--primary);
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.section-dark .section-tag,
.section-gradient .section-tag {
    background: rgba(255, 255, 255, 0.1);
    color: var(--primary-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* ========================================
   Features
   ======================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: var(--transition);
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-4px);
}

.feature-icon {
    width: 3rem;
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--gray-400);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ========================================
   Models
   ======================================== */
.models-tabs {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tab-btn {
    padding: 0.625rem 1.5rem;
    border-radius: var(--radius);
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-secondary);
    background: var(--gray-100);
    transition: var(--transition-fast);
}

.tab-btn:hover {
    background: var(--gray-200);
}

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

.tab-panel {
    display: none;
}

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

.models-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 1rem;
}

.model-card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
}

.model-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: var(--primary);
}

.model-logo {
    width: 3rem;
    height: 3rem;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.75rem;
    font-weight: 700;
}

.model-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.model-card p {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.model-tag {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background: var(--gray-100);
    border-radius: var(--radius-sm);
    font-size: 0.625rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.models-cta {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--gray-200);
}

.models-cta p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* ========================================
   Core Features
   ======================================== */
.core-features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.core-feature-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    transition: var(--transition);
}

.core-feature-card:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-4px);
}

.core-feature-icon {
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.core-feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.core-feature-card p {
    font-size: 1rem;
    line-height: 1.5;
    margin-bottom: 1.5rem;
    color: var(--gray-400);
}

.feature-highlights {
    list-style: none;
    padding: 0;
    margin: 0;
}

.feature-highlights li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--gray-400);
}

.feature-highlights li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

/* ========================================
   Use Cases
   ======================================== */
.usecases-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.usecase-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: var(--transition);
}

.usecase-card:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-4px);
}

.usecase-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.usecase-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.usecase-card ul {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.usecase-card li {
    font-size: 0.875rem;
    color: var(--gray-400);
    padding-left: 1rem;
    position: relative;
}

.usecase-card li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--primary);
}

/* ========================================
   Pricing - Simple
   ======================================== */
.pricing-simple {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 3rem;
}

.pricing-highlight {
    margin-bottom: 2rem;
}

.price-tag {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.price-value {
    font-size: 4rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.price-unit {
    font-size: 1.25rem;
    color: var(--text-secondary);
}

.price-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.pricing-features-simple {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
    text-align: left;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--radius-lg);
}

.feature-item svg {
    color: var(--success);
    flex-shrink: 0;
}

.feature-item span {
    font-size: 0.9375rem;
    color: var(--text-primary);
}

.pricing-cta {
    margin-bottom: 1rem;
}

.pricing-note {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.pricing-calculator {
    max-width: 500px;
    margin: 0 auto;
    padding: 1.5rem;
    background: var(--gray-50);
    border-radius: var(--radius-xl);
}

.pricing-calculator h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-align: center;
    color: var(--text-secondary);
}

.calculator-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--gray-200);
    font-size: 0.9375rem;
}

.calculator-row:last-child {
    border-bottom: none;
}

.calculator-price {
    font-weight: 600;
    color: var(--primary);
}

/* ========================================
   FAQ
   ======================================== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: left;
    color: white;
    transition: var(--transition-fast);
}

.faq-question:hover {
    background: rgba(255, 255, 255, 0.05);
}

.faq-icon {
    flex-shrink: 0;
    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 1.5rem 1.25rem;
    color: var(--gray-400);
    line-height: 1.8;
}

/* ========================================
   CTA Section
   ======================================== */
.cta-content {
    max-width: 600px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* ========================================
   Footer - Horizontal
   ======================================== */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 2rem 0 1.5rem;
}

.footer-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 1.5rem;
}

.footer .logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer .logo-text {
    background: linear-gradient(135deg, white 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    font-size: 1.25rem;
}

.footer-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.footer-nav a {
    color: var(--gray-400);
    font-size: 0.875rem;
    font-weight: 500;
    transition: var(--transition-fast);
}

.footer-nav a:hover {
    color: white;
}

.footer-social {
    display: flex;
    gap: 0.75rem;
}

.footer-social a {
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    color: var(--gray-400);
    transition: var(--transition-fast);
}

.footer-social a:hover {
    background: var(--primary);
    color: white;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p {
    color: var(--gray-500);
    font-size: 0.875rem;
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-legal a {
    color: var(--gray-500);
    font-size: 0.875rem;
    transition: var(--transition-fast);
}

.footer-legal a:hover {
    color: white;
}

.footer-legal .divider {
    color: var(--gray-600);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        order: 1;
    }
    
    .hero-visual {
        order: 0;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .hero-trust {
        text-align: center;
    }
    
    .trust-logos {
        justify-content: center;
    }
    
    .dashboard-preview {
        max-width: 500px;
        margin: 0 auto;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .models-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .usecases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .pricing-features-simple {
        grid-template-columns: 1fr;
    }
    
    .footer-top {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .footer-nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-links {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        gap: 0.5rem;
        border-bottom: 1px solid var(--gray-200);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        width: 100%;
        text-align: center;
        padding: 0.75rem;
    }
    
    .nav-actions {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }
    
    .stat-item {
        text-align: center;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .models-tabs {
        flex-wrap: wrap;
    }
    
    .models-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .usecases-grid {
        grid-template-columns: 1fr;
    }
    
    .cta-content h2 {
        font-size: 2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
    }
    
    .footer-top {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .footer-nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
    
    .footer-social {
        justify-content: center;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
        gap: 0.75rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero {
        padding: 5rem 0 3rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section {
        padding: 4rem 0;
    }
    
    .models-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.animate-fade-in {
    animation: fadeIn 0.6s ease forwards;
}

.animate-slide-in {
    animation: slideIn 0.6s ease forwards;
}

/* ========================================
   WeChat Float Button & Modal
   ======================================== */
.wechat-float-btn {
    position: fixed;
    right: 20px;
    bottom: 100px;
    z-index: 9999;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: linear-gradient(135deg, #07C160 0%, #05a350 100%);
    color: white;
    border-radius: 50px;
    box-shadow: 0 4px 20px rgba(7, 193, 96, 0.4);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: 14px;
    font-weight: 600;
    border: none;
    outline: none;
}

.wechat-float-btn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 30px rgba(7, 193, 96, 0.5);
}

.wechat-float-btn svg {
    width: 22px;
    height: 22px;
    flex-shrink: 0;
}

.wechat-float-btn .btn-text {
    white-space: nowrap;
}

@media (max-width: 768px) {
    .wechat-float-btn {
        right: 15px;
        bottom: 80px;
        padding: 10px 16px;
        font-size: 13px;
    }
    .wechat-float-btn svg {
        width: 20px;
        height: 20px;
    }
}

@media (max-width: 480px) {
    .wechat-float-btn {
        padding: 12px;
        border-radius: 50%;
    }
    .wechat-float-btn .btn-text {
        display: none;
    }
    .wechat-float-btn svg {
        width: 24px;
        height: 24px;
    }
}

/* Modal Overlay */
.wechat-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.wechat-modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.wechat-modal {
    background: white;
    border-radius: 20px;
    padding: 35px 30px;
    max-width: 380px;
    width: 90%;
    text-align: center;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.3);
    transform: scale(0.9) translateY(20px);
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
}

.wechat-modal-overlay.active .wechat-modal {
    transform: scale(1) translateY(0);
}

.wechat-modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #f5f5f5;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    color: #666;
}

.wechat-modal-close:hover {
    background: #e0e0e0;
    transform: rotate(90deg);
}

.wechat-modal-close svg {
    width: 18px;
    height: 18px;
}

.wechat-modal-header {
    margin-bottom: 20px;
}

.wechat-modal-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #07C160 0%, #05a350 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    box-shadow: 0 8px 25px rgba(7, 193, 96, 0.3);
}

.wechat-modal-icon svg {
    width: 32px;
    height: 32px;
    color: white;
}

.wechat-modal-title {
    font-size: 20px;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 8px;
}

.wechat-modal-subtitle {
    font-size: 14px;
    color: #666;
    line-height: 1.5;
}

.wechat-qr-container {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 16px;
    padding: 25px;
    margin: 20px 0;
    border: 2px dashed #dee2e6;
}

.wechat-qr-code {
    width: 200px;
    height: 200px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.wechat-qr-code img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.wechat-qr-hint {
    margin-top: 15px;
    font-size: 13px;
    color: #888;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.wechat-modal-footer {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.wechat-modal-benefit {
    font-size: 15px;
    color: #07C160;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.wechat-modal-benefit svg {
    width: 20px;
    height: 20px;
}

/* Trigger Modal Variant */
.wechat-trigger-modal .wechat-modal {
    max-width: 420px;
}

.wechat-trigger-modal .wechat-modal-header {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    margin: -35px -30px 25px;
    padding: 30px 30px 25px;
    border-radius: 20px 20px 0 0;
}

.wechat-trigger-modal .wechat-modal-icon {
    width: 70px;
    height: 70px;
}

.wechat-trigger-modal .wechat-modal-icon svg {
    width: 36px;
    height: 36px;
}

.wechat-trigger-modal .wechat-modal-title {
    font-size: 22px;
}

.wechat-not-show {
    margin-top: 15px;
    font-size: 13px;
    color: #999;
    cursor: pointer;
    text-decoration: underline;
    transition: color 0.2s;
}

.wechat-not-show:hover {
    color: #666;
}

@keyframes wechat-pulse {
    0%, 100% {
        box-shadow: 0 4px 20px rgba(7, 193, 96, 0.4);
    }
    50% {
        box-shadow: 0 4px 30px rgba(7, 193, 96, 0.6);
    }
}

.wechat-float-btn.pulse {
    animation: wechat-pulse 2s infinite;
}

.wechat-tooltip {
    position: absolute;
    right: 100%;
    top: 50%;
    transform: translateY(-50%);
    margin-right: 12px;
    background: #333;
    color: white;
    padding: 8px 14px;
    border-radius: 8px;
    font-size: 13px;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    pointer-events: none;
}

.wechat-tooltip::after {
    content: '';
    position: absolute;
    left: 100%;
    top: 50%;
    transform: translateY(-50%);
    border: 6px solid transparent;
    border-left-color: #333;
}

.wechat-float-btn:hover .wechat-tooltip {
    opacity: 1;
    visibility: visible;
}

@media (max-width: 480px) {
    .wechat-tooltip {
        display: none;
    }
    .wechat-modal {
        padding: 25px 20px;
        margin: 20px;
    }
    .wechat-modal-title {
        font-size: 18px;
    }
    .wechat-qr-code {
        width: 180px;
        height: 180px;
    }
}

/* ========================================
   General Modal Styles
   ======================================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: white;
    border-radius: 20px;
    padding: 40px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.3);
    transform: scale(0.9) translateY(20px);
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
}

.modal-overlay.active .modal-content {
    transform: scale(1) translateY(0);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #f5f5f5;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    color: #666;
}

.modal-close:hover {
    background: #e0e0e0;
    transform: rotate(90deg);
}

.modal-close svg {
    width: 18px;
    height: 18px;
}

.modal-header {
    margin-bottom: 30px;
    text-align: center;
}

.modal-title {
    font-size: 24px;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 10px;
}

.modal-subtitle {
    font-size: 16px;
    color: #666;
    line-height: 1.5;
}

.modal-body {
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1);
}

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

.btn-block {
    width: 100%;
}

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

.mb-2 {
    margin-bottom: 8px;
}

.mb-4 {
    margin-bottom: 16px;
}

.text-sm {
    font-size: 14px;
}

.text-gray {
    color: #666;
}

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

.link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.link:hover {
    text-decoration: underline;
}

@media (max-width: 480px) {
    .modal-content {
        padding: 30px 20px;
        margin: 20px;
    }
    .modal-title {
        font-size: 20px;
    }
}

.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid #f3f3f3;
    border-top: 2px solid var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* ========================================
   Accessibility - Skip Link
   ======================================== */
.skip-link {
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 12px 24px;
    border-radius: 0 0 8px 8px;
    font-weight: 600;
    z-index: 99999;
    transition: top 0.3s ease;
    text-decoration: none;
}

.skip-link:focus {
    top: 0;
    outline: 2px solid var(--primary-dark);
    outline-offset: 2px;
}