/* Main Styles - Jingtuo Alumina Website */

/* ============================================
   CSS Variables for Header
   ============================================ */
:root {
    /* Header 尺寸 */
    --header-height: 80px;
    --header-height-mobile: 64px;
    
    /* 品牌色 */
    --brand-primary: #2563eb;
    --brand-primary-dark: #1e40af;
    --brand-primary-light: #3b82f6;
    
    /* Header 背景 */
    --header-bg: #ffffff;
    --header-bg-scrolled: rgba(255, 255, 255, 0.98);
    
    /* 文字颜色 */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-white: #ffffff;
    
    /* 交互状态 */
    --nav-hover: #2563eb;
    --nav-active: #1e40af;
    --nav-active-bg: rgba(37, 99, 235, 0.08);
    
    /* 边框与阴影 */
    --border-light: #e2e8f0;
    --shadow-header: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-header-scrolled: 0 4px 20px rgba(0, 0, 0, 0.1);
    
    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    
    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

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

/* ============================================
   Header Styles - New Design
   ============================================ */

/* Skip Link (Accessibility) */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--brand-primary);
    color: var(--text-white);
    padding: 8px 16px;
    z-index: 9999;
    transition: top var(--transition-fast);
    text-decoration: none;
    font-weight: 500;
    border-radius: 0 0 4px 0;
}

.skip-link:focus {
    top: 0;
}

/* Header Container */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--header-bg);
    border-bottom: 1px solid var(--border-light);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.header.scrolled {
    background: var(--header-bg-scrolled);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-header-scrolled);
    border-bottom-color: transparent;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    height: 100%;
}

@media (max-width: 768px) {
    .header-container {
        padding: 0 var(--spacing-md);
    }
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    gap: var(--spacing-xl);
}

/* ============================================
   Logo Styles - Adaptive Sizing
   ============================================ */
.logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    text-decoration: none;
}

.logo img {
    width: auto;
    height: clamp(40px, 5vw, 52px);
    max-width: 180px;
    object-fit: contain;
    transition: transform var(--transition-fast);
}

.logo:hover img {
    transform: scale(1.02);
}

@media (max-width: 768px) {
    .logo img {
        height: 40px;
    }
}

/* ============================================
   Mobile Menu Toggle
   ============================================ */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    padding: 0;
    border: none;
    background: transparent;
    cursor: pointer;
    gap: 6px;
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
    border-radius: 1px;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ============================================
   Navigation Styles
   ============================================ */
.main-nav {
    flex: 1;
    display: flex;
    justify-content: center;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 16px;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    border-radius: 6px;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 16px;
    right: 16px;
    height: 2px;
    background: var(--brand-primary);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
    border-radius: 1px;
}

.nav-link:hover {
    color: var(--nav-hover);
    background: var(--nav-active-bg);
}

.nav-link:hover::after {
    transform: scaleX(1);
}

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

.nav-link.active::after {
    transform: scaleX(1);
}

/* ============================================
   Dropdown Menu
   ============================================ */
.dropdown {
    position: relative;
}

.dropdown-icon {
    transition: transform var(--transition-fast);
}

.nav-item.dropdown:hover .dropdown-icon {
    transform: rotate(180deg);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: var(--header-bg);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    padding: 8px 0;
    list-style: none;
    margin: 8px 0 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
}

.nav-item.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu a {
    display: block;
    padding: 10px 20px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    transition: all var(--transition-fast);
}

.dropdown-menu a:hover {
    background: var(--nav-active-bg);
    color: var(--nav-hover);
}

/* ============================================
   Language Switcher
   ============================================ */
.language-switcher {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    flex-shrink: 0;
}

.lang-btn {
    padding: 6px 12px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    border-radius: 4px;
    transition: all var(--transition-fast);
}

.lang-btn:hover {
    color: var(--nav-hover);
    background: var(--nav-active-bg);
}

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

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

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -2;
}

.hero-background img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.85) 0%, rgba(30, 41, 59, 0.75) 100%);
    z-index: -1;
}

.hero-content {
    max-width: 800px;
    padding: var(--space-2xl);
}

.hero-title {
    font-size: var(--text-5xl);
    font-weight: var(--font-bold);
    line-height: var(--leading-tight);
    margin-bottom: var(--space-lg);
}

.hero-subtitle {
    font-size: var(--text-xl);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-2xl);
    opacity: 0.9;
}

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

/* Hero Stats */
.hero-stats {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding: var(--space-xl) 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
}

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

.stat-number {
    display: block;
    font-size: var(--text-4xl);
    font-weight: var(--font-bold);
    color: var(--accent-color);
    margin-bottom: var(--space-xs);
}

.stat-label {
    font-size: var(--text-sm);
    opacity: 0.9;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-md) var(--space-xl);
    font-size: var(--text-base);
    font-weight: var(--font-semibold);
    text-align: center;
    text-decoration: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    border: 2px solid transparent;
}

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

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

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

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

.btn-large {
    padding: var(--space-lg) var(--space-2xl);
    font-size: var(--text-lg);
}

/* Section Styles */
section {
    padding: var(--space-4xl) 0;
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto var(--space-3xl);
}

.section-title {
    font-size: var(--text-4xl);
    font-weight: var(--font-bold);
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

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

/* Products Section - 暖色调设计 */
.products-section {
    background: linear-gradient(135deg, #faf9f7 0%, #f5f3ef 50%, #faf8f5 100%);
    position: relative;
}

.products-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(ellipse at 30% 20%, rgba(245, 158, 11, 0.05) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(245, 158, 11, 0.03) 0%, transparent 50%);
    pointer-events: none;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
    position: relative;
    z-index: 1;
}

.product-card {
    background: linear-gradient(145deg, #ffffff 0%, #fdfcfa 100%);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.04), 0 2px 4px -1px rgba(0, 0, 0, 0.02);
    border: 1px solid rgba(245, 158, 11, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.product-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #f59e0b, #fbbf24);
    transform: scaleX(0);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.product-card:hover {
    transform: translateY(-12px);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.1), 0 12px 24px -8px rgba(245, 158, 11, 0.15);
    border-color: rgba(245, 158, 11, 0.2);
}

.product-card:hover::after {
    transform: scaleX(1);
}

.product-image {
    height: 200px;
    overflow: hidden;
    position: relative;
}

.product-image::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, transparent 60%, rgba(0, 0, 0, 0.05) 100%);
    z-index: 1;
    pointer-events: none;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.product-card:hover .product-image img {
    transform: scale(1.08);
}

.product-content {
    padding: var(--space-xl);
    background: linear-gradient(180deg, #ffffff 0%, #fdfcfa 100%);
}

.product-name {
    font-size: var(--text-xl);
    font-weight: var(--font-semibold);
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    transition: color 0.3s ease;
}

.product-card:hover .product-name {
    color: #d97706;
}

.product-description {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    line-height: var(--leading-relaxed);
}

.product-link {
    font-weight: var(--font-medium);
    color: #f59e0b;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.product-link::after {
    content: '→';
    transition: transform 0.3s ease;
}

.product-card:hover .product-link {
    color: #d97706;
}

.product-card:hover .product-link::after {
    transform: translateX(4px);
}

/* Animation Classes - Disabled for performance */
.animate-on-scroll,
.animate-on-scroll.animated {
    opacity: 1;
    transform: none;
}

/* Applications Section - 深色玻璃拟态设计 */
.applications-section {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 50%, #1e293b 100%);
    position: relative;
    overflow: hidden;
}

.applications-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(59, 130, 246, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 80% 70%, rgba(99, 102, 241, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 50% 50%, rgba(139, 92, 246, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.applications-section .section-title {
    color: #ffffff;
}

.applications-section .section-subtitle {
    color: rgba(255, 255, 255, 0.7);
}

.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-xl);
    position: relative;
    z-index: 1;
}

.application-card {
    text-align: center;
    padding: var(--space-2xl);
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.application-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

.application-card:hover::before {
    left: 100%;
}

.application-card:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.3), 0 8px 32px rgba(0, 0, 0, 0.3);
    transform: translateY(-8px);
}

.application-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-lg);
    padding: var(--space-lg);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(59, 130, 246, 0.2) 100%);
    border-radius: var(--radius-2xl);
    border: 1px solid rgba(99, 102, 241, 0.3);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: center;
}

.application-card:hover .application-icon {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.4) 0%, rgba(59, 130, 246, 0.4) 100%);
    border-color: rgba(99, 102, 241, 0.6);
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.4);
    transform: scale(1.1) rotate(5deg);
}

.application-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    filter: brightness(0) invert(1);
    transition: transform 0.3s ease;
}

.application-card:hover .application-icon img {
    transform: scale(1.1);
}

.application-card h3 {
    font-size: var(--text-xl);
    font-weight: var(--font-semibold);
    color: #ffffff;
    margin-bottom: var(--space-sm);
    transition: color 0.3s ease;
}

.application-card:hover h3 {
    color: #818cf8;
}

.application-card p {
    font-size: var(--text-sm);
    color: rgba(255, 255, 255, 0.7);
    line-height: var(--leading-relaxed);
    transition: color 0.3s ease;
}

.application-card:hover p {
    color: rgba(255, 255, 255, 0.9);
}

/* Why Us Section */
.why-us-section {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 50%, #f1f5f9 100%);
    position: relative;
    overflow: hidden;
}

.why-us-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(59, 130, 246, 0.06) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(59, 130, 246, 0.04) 0%, transparent 40%);
    pointer-events: none;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
    position: relative;
    z-index: 1;
}

.feature-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: var(--space-2xl);
    background: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius-2xl);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.8);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.feature-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transform: scaleX(0);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    background: rgba(255, 255, 255, 1);
}

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

.feature-icon {
    width: 72px;
    height: 72px;
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    border-radius: var(--radius-xl);
    box-shadow: 0 10px 15px -3px rgba(59, 130, 246, 0.3);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-item:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 20px 25px -5px rgba(59, 130, 246, 0.4);
}

.feature-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    filter: brightness(0) invert(1);
    transition: transform 0.3s ease;
}

.feature-item:hover .feature-icon img {
    transform: scale(1.05);
}

.feature-item h3 {
    font-size: var(--text-xl);
    font-weight: var(--font-semibold);
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    transition: color 0.3s ease;
}

.feature-item:hover h3 {
    color: var(--primary-color);
}

.feature-item p {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: var(--leading-relaxed);
    transition: color 0.3s ease;
}

.feature-item:hover p {
    color: var(--text-primary);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--text-inverse);
    text-align: center;
}

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

.cta-content h2 {
    font-size: var(--text-4xl);
    font-weight: var(--font-bold);
    margin-bottom: var(--space-md);
}

.cta-content p {
    font-size: var(--text-lg);
    margin-bottom: var(--space-2xl);
    opacity: 0.9;
}

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

.cta-section .btn-secondary {
    border-color: var(--text-inverse);
}

.cta-section .btn-secondary:hover {
    background-color: var(--text-inverse);
    color: var(--primary-color);
}

/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: var(--text-inverse);
    padding: var(--space-4xl) 0 var(--space-xl);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-2xl);
    margin-bottom: var(--space-3xl);
}

.footer-section h3 {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    margin-bottom: var(--space-lg);
    color: var(--text-inverse);
}

.footer-section ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-section a {
    color: var(--text-secondary);
    transition: color var(--transition-normal);
}

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

.footer-section address {
    font-style: normal;
    color: var(--text-secondary);
}

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

.social-links {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    transition: all var(--transition-normal);
}

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

.social-links img {
    width: 20px;
    height: 20px;
    filter: brightness(0) invert(1);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-bottom p {
    color: var(--text-secondary);
    font-size: var(--text-sm);
}

.footer-legal {
    display: flex;
    gap: var(--space-lg);
}

.footer-legal a {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: color var(--transition-normal);
}

.footer-legal a:hover {
    color: var(--text-inverse);
}