/* Modern Minimalist Design System */
:root {
    /* Colors - Monochromatic with accent */
    --color-black: #000000;
    --color-white: #ffffff;
    --color-gray-100: #f8f8f8;
    --color-gray-200: #e8e8e8;
    --color-gray-300: #d0d0d0;
    --color-gray-400: #888888;
    --color-gray-500: #666666;
    --color-gray-600: #444444;
    --color-gray-700: #222222;
    --color-gray-900: #0a0a0a;
    
    /* Accent colors */
    --color-accent: #0071e3;
    --color-accent-hover: #0051a2;
    --color-accent-light: #e6f2ff;
    
    /* Gradients */
    --gradient-primary: linear-gradient(180deg, #000000 0%, #1a1a1a 100%);
    --gradient-accent: linear-gradient(135deg, #0071e3 0%, #0051a2 100%);
    --gradient-mesh: radial-gradient(at 27% 37%, hsla(215, 98%, 61%, 0.15) 0px, transparent 0%),
                     radial-gradient(at 97% 21%, hsla(125, 98%, 72%, 0.15) 0px, transparent 50%),
                     radial-gradient(at 52% 99%, hsla(354, 98%, 61%, 0.15) 0px, transparent 50%),
                     radial-gradient(at 10% 29%, hsla(256, 96%, 67%, 0.15) 0px, transparent 50%),
                     radial-gradient(at 97% 96%, hsla(38, 60%, 74%, 0.15) 0px, transparent 50%),
                     radial-gradient(at 33% 50%, hsla(222, 67%, 73%, 0.15) 0px, transparent 50%),
                     radial-gradient(at 79% 53%, hsla(343, 68%, 79%, 0.15) 0px, transparent 50%);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Inter', 'Helvetica Neue', sans-serif;
    --font-cn: 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
    --space-2xl: 12rem;
    
    /* Transitions */
    --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);
}

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

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

body {
    font-family: var(--font-primary);
    color: var(--color-gray-900);
    line-height: 1.6;
    background-color: var(--color-white);
    overflow-x: hidden;
}

body:lang(zh-CN) {
    font-family: var(--font-cn), var(--font-primary);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 { 
    font-size: clamp(2.5rem, 5vw, 5rem);
    font-weight: 700;
}

h2 { 
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 600;
}

h3 { 
    font-size: clamp(1.5rem, 3vw, 2.5rem);
}

h4 { 
    font-size: clamp(1.25rem, 2vw, 1.75rem);
}

p {
    margin-bottom: 1em;
    color: var(--color-gray-600);
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

.container-wide {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

.container-narrow {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-brand a {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-black);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-brand i {
    font-size: 1.25rem;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-gray-700);
    position: relative;
    padding: var(--space-xs) 0;
}

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

.nav-link.active {
    color: var(--color-black);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-black);
    transition: var(--transition-base);
}

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

.lang-switch {
    font-size: 0.875rem;
    font-weight: 500;
    background: transparent;
    border: 1px solid var(--color-gray-300);
    padding: 0.375rem 1rem;
    border-radius: 100px;
    cursor: pointer;
    transition: var(--transition-base);
}

.lang-switch:hover {
    border-color: var(--color-black);
    background: var(--color-black);
    color: var(--color-white);
}

/* Hero Section - Redesigned */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-black);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.6;
}

#particle-canvas {
    position: absolute;
    width: 100%;
    height: 100%;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--color-white);
    padding: var(--space-lg);
    max-width: 1000px;
}

.hero-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 0.5rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 100px;
    margin-bottom: var(--space-md);
    backdrop-filter: blur(10px);
}

.hero-title {
    font-size: clamp(3rem, 8vw, 7rem);
    font-weight: 700;
    line-height: 1;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-md);
    background: linear-gradient(180deg, #ffffff 0%, #999999 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
    font-weight: 400;
    opacity: 0.8;
    margin-bottom: var(--space-lg);
    line-height: 1.4;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons - Redesigned */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    border-radius: 100px;
    cursor: pointer;
    transition: var(--transition-base);
    border: none;
    outline: none;
    text-decoration: none;
}

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

.btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(255, 255, 255, 0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--color-white);
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

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

.btn-black:hover {
    background: var(--color-gray-700);
}

.btn-large {
    padding: 1.25rem 3rem;
    font-size: 1rem;
}

/* Sections */
.section {
    padding: var(--space-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.section-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-md);
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--color-gray-500);
    max-width: 600px;
    margin: 0 auto;
}

/* Feature Cards - New Design */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-xl);
}

.feature-card {
    position: relative;
    padding: var(--space-lg);
    background: var(--color-gray-100);
    border-radius: 24px;
    transition: var(--transition-base);
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-mesh);
    opacity: 0;
    transition: var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

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

.feature-icon {
    width: 64px;
    height: 64px;
    margin-bottom: var(--space-md);
    position: relative;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
    position: relative;
}

.feature-card p {
    position: relative;
    line-height: 1.8;
}

/* Image Containers */
.image-container {
    position: relative;
    overflow: hidden;
    border-radius: 16px;
    background: var(--color-gray-100);
}

.image-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.image-container:hover img {
    transform: scale(1.05);
}

/* Stats Section */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.stat-card {
    text-align: center;
    padding: var(--space-lg);
}

.stat-number {
    font-size: clamp(3rem, 5vw, 4rem);
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: var(--space-sm);
}

.stat-label {
    font-size: 1.125rem;
    color: var(--color-gray-600);
}

/* Footer - Minimal */
.footer {
    background: var(--color-black);
    color: var(--color-white);
    padding: var(--space-xl) 0 var(--space-lg);
    margin-top: var(--space-2xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
}

.footer-brand p {
    color: var(--color-gray-400);
    margin-bottom: var(--space-md);
}

.footer-section h4 {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-md);
    color: var(--color-gray-400);
}

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

.footer-section li {
    margin-bottom: var(--space-sm);
}

.footer-section a {
    color: var(--color-gray-300);
    font-size: 0.875rem;
}

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

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-gray-700);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--color-gray-400);
}

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

.bg-black { background-color: var(--color-black); }
.bg-white { background-color: var(--color-white); }
.bg-gray { background-color: var(--color-gray-100); }

.text-white { color: var(--color-white); }
.text-black { color: var(--color-black); }
.text-gray { color: var(--color-gray-500); }

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

.animate-in {
    animation: fade-in 0.8s ease-out forwards;
}

/* Mobile Navigation */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.nav-toggle span {
    display: block;
    width: 100%;
    height: 1.5px;
    background: var(--color-black);
    margin: 3px 0;
    transition: var(--transition-base);
}

/* Call to Action Section */
.cta-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-md);
}

.cta-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
}

.cta-text {
    font-size: 1.25rem;
    color: var(--color-gray-300);
    margin-bottom: var(--space-lg);
}

.cta-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Page Specific Styles */
.page-header {
    padding: calc(72px + var(--space-xl)) 0 var(--space-xl);
    background: var(--color-white);
    border-bottom: 1px solid var(--color-gray-200);
}

.page-header h1 {
    margin-bottom: var(--space-sm);
}

.page-header .subtitle {
    font-size: 1.25rem;
    color: var(--color-gray-500);
}