/* Critical CSS for above-the-fold content */
/* Reset and Base Styles */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

/* 页面加载完成后显示内容，防止闪烁 */
body.loaded {
    opacity: 1;
}

/* CSS Variables */
:root {
    /* Colors */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --accent: #f59e0b;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    --bg-overlay: rgba(15, 23, 42, 0.8);
    
    /* Border Colors */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-dark: #64748b;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Typography */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    
    /* Layout */
    --container-max-width: 1200px;
    --container-padding: var(--space-4);
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.375rem;
    --border-radius-lg: 0.5rem;
    --border-radius-xl: 0.75rem;
    --border-radius-2xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    
    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* Utility Classes */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Header Styles */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: var(--z-fixed);
    transition: all var(--transition-normal);
}

.navbar {
    padding: var(--space-4) 0;
}

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

.navbar-brand {
    flex-shrink: 0;
}

.brand-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.brand-title {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--primary);
    margin: 0;
    line-height: 1.2;
}

.brand-subtitle {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
    margin-top: var(--space-1);
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: var(--space-6);
    margin: 0;
    padding: 0;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: var(--font-weight-medium);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background-color: rgba(37, 99, 235, 0.1);
}

/* Floating Contact Component Styles */
.floating-contact {
    position: relative;
    z-index: 1000;
}

.floating-contact-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: linear-gradient(135deg, #4CAF50, #45a049);
    color: white;
    border: none;
    border-radius: 30px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(76, 175, 80, 0.3);
    opacity: 0.9;
}

.floating-contact-btn:hover {
    background: linear-gradient(135deg, #45a049, #4CAF50);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
    opacity: 1;
}

.floating-contact-btn i {
    font-size: 1.2rem;
}

.floating-contact-btn .contact-text {
    white-space: nowrap;
    font-weight: 600;
}

/* Contact Menu Styles */
.contact-menu {
    position: absolute;
    bottom: 100%;
    right: 0;
    margin-bottom: 10px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px) scale(0.95);
    transition: all 0.3s ease;
    min-width: 160px;
    overflow: hidden;
}

.floating-contact.active .contact-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

.contact-menu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    border-bottom: 1px solid #f0f0f0;
}

.contact-menu-item:last-child {
    border-bottom: none;
}

.contact-menu-item:hover {
    background: #f8f9fa;
    color: #4CAF50;
}

.contact-menu-item i {
    font-size: 1.1rem;
    width: 20px;
    text-align: center;
    color: #666;
}

.contact-menu-item:hover i {
    color: #4CAF50;
}

.contact-menu-item span {
    font-size: 0.9rem;
    font-weight: 500;
    color: #333;
}

.contact-menu-item:hover span {
    color: #4CAF50;
}

/* Mobile responsive */
@media (max-width: 768px) {
    .floating-buttons {
        bottom: 15px;
        right: 15px;
        gap: 10px;
    }
    
    .floating-contact-btn {
        width: 50px;
        height: 50px;
        border-radius: 50%;
        justify-content: center;
        padding: 0;
        font-size: 0.8rem;
    }
    
    .floating-contact-btn .contact-text {
        display: none;
    }
    
    .contact-menu {
        right: -10px;
        min-width: 140px;
    }
    
    .contact-menu-item {
        padding: 0.6rem 0.8rem;
    }
    
    .contact-menu-item span {
        font-size: 0.8rem;
    }
}

.language-switch {
    display: flex;
    gap: var(--space-2);
    background: var(--bg-secondary);
    padding: var(--space-1);
    border-radius: var(--border-radius-lg);
}

.lang-btn {
    padding: var(--space-2) var(--space-3);
    text-decoration: none;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
}

.lang-btn.active,
.lang-btn:hover {
    background: var(--bg-primary);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: var(--space-1);
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
}

.hamburger-line {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
    border-radius: 1px;
}

.menu-text {
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
    margin-top: var(--space-1);
}

.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-overlay);
    z-index: var(--z-modal-backdrop);
}

/* Main Content */
#main-content {
    position: relative;
    z-index: 1;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 85vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    padding-top: 83px;
}

.hero-background {
    position: absolute;
    top: 83px;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    z-index: 1;
}

.hero-shapes {
    position: absolute;
    top: 83px;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
}

.shape {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    animation: float 6s ease-in-out infinite;
}

.shape-1 {
    width: 200px;
    height: 200px;
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 150px;
    height: 150px;
    top: 60%;
    right: 15%;
    animation-delay: 2s;
}

.shape-3 {
    width: 100px;
    height: 100px;
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(180deg);
    }
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--text-inverse);
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--space-6);
    line-height: 1.1;
}

.combined-title {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.gradient-text {
    background: linear-gradient(135deg, #ffffff, #e2e8f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    font-weight: var(--font-weight-bold);
}

.title-accent {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.8em;
    font-weight: var(--font-weight-medium);
    opacity: 0.95;
    position: relative;
}

.title-accent::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    right: 0;
    height: 1px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 1px;
}



.hero-subtitle {
    font-size: var(--font-size-xl);
    margin-bottom: var(--space-8);
    color: rgba(255, 255, 255, 0.9);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-8);
    margin-bottom: var(--space-10);
}

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

.stat-number {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-inverse);
    display: block;
}

.stat-label {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.8);
    margin-top: var(--space-1);
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
    flex-wrap: wrap;
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-3) var(--space-6);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    text-decoration: none;
    border-radius: var(--border-radius-lg);
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-normal);
    min-width: 120px;
}

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

.btn-primary:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--text-inverse);
    border-color: var(--text-inverse);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .navbar-menu {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .combined-title {
        flex-direction: column;
        gap: var(--space-2);
        margin-top: 20px;
    }
    
    .gradient-text {
        font-size: 0.9em;
    }
    
    .title-accent {
        font-size: 0.7em;
    }
    
    .hero-stats {
        gap: var(--space-4);
    }
    
    .stat-number {
        font-size: var(--font-size-2xl);
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
        margin-bottom: 20px;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
    }
}

@media (max-width: 480px) {
    .hero-stats {
        flex-direction: column;
        gap: var(--space-4);
    }
    
    .container {
        padding: 0 var(--space-3);
    }
    
    .navbar {
        padding: var(--space-3) 0;
    }
    
    .brand-title {
        font-size: var(--font-size-xl);
    }
    
    .brand-subtitle {
        font-size: var(--font-size-xs);
    }
}