/* ============================================
   Qiyu Air Conditioning - Professional HVAC Equipment
   Western-style clean and modern design
   ============================================ */

:root {
    --primary: #0066b3;
    --primary-dark: #004a82;
    --secondary: #00a8e8;
    --accent: #ff6b35;
    --dark: #1a1a2e;
    --gray: #666;
    --light-gray: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    --radius: 12px;
    --max-width: 1280px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--dark);
    line-height: 1.7;
    background: var(--white);
    font-size: 16px;
}

/* Language Switcher */
.lang-switcher {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1001;
    display: flex;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.lang-btn {
    padding: 10px 20px;
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: var(--dark);
    transition: all 0.3s;
}

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

.lang-btn:hover:not(.active) {
    background: var(--light-gray);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
    z-index: 1000;
    height: 72px;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-icon {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 18px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}

.logo-text span {
    display: block;
    font-size: 12px;
    font-weight: 400;
    color: var(--gray);
    letter-spacing: 0.5px;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    font-size: 15px;
    transition: color 0.3s;
    padding: 8px 0;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
}

.nav-phone {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--primary);
    font-weight: 600;
    font-size: 14px;
}

.nav-phone svg {
    width: 18px;
    height: 18px;
}

.mobile-menu {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.mobile-menu span {
    width: 24px;
    height: 2px;
    background: var(--dark);
    border-radius: 2px;
}

/* Page Wrapper */
.page-wrapper {
    padding-top: 72px;
}

/* Hero Section */
.hero {
    min-height: 90vh;
    background: linear-gradient(135deg, #0a1628 0%, #1a3a5c 50%, #0066b3 100%);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 80px 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    color: white;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.1);
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 13px;
    margin-bottom: 24px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero h1 {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
}

.hero h1 span {
    background: linear-gradient(135deg, var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-desc {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    padding: 14px 28px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #ff8f5a);
    color: white;
    box-shadow: 0 8px 25px rgba(255, 107, 53, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px rgba(255, 107, 53, 0.45);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

/* Product Showcase */
.products-showcase {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.showcase-card {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 16px;
    padding: 24px;
    transition: all 0.3s;
    cursor: pointer;
    text-decoration: none;
    color: white;
}

.showcase-card:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-4px);
}

.showcase-icon {
    width: 52px;
    height: 52px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    font-size: 24px;
}

.showcase-card h4 {
    font-size: 15px;
    margin-bottom: 6px;
}

.showcase-card p {
    font-size: 12px;
    opacity: 0.7;
}

/* Stats */
.stats {
    background: white;
    padding: 48px 24px;
    margin-top: -48px;
    position: relative;
    z-index: 10;
}

.stats-grid {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow);
}

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

.stat-value {
    font-size: 42px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 14px;
    color: var(--gray);
    margin-top: 8px;
}

/* Sections */
.section {
    padding: 100px 24px;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 102, 179, 0.1);
    color: var(--primary);
    padding: 8px 18px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 16px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.section-desc {
    font-size: 17px;
    color: var(--gray);
    max-width: 650px;
    margin: 0 auto;
}

/* Product Cards */
.products-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.product-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.4s;
    text-decoration: none;
    color: inherit;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.12);
}

.product-image {
    height: 240px;
    position: relative;
    overflow: hidden;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s;
}

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

.product-image .overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.6), transparent);
    display: flex;
    align-items: flex-end;
    padding: 24px;
}

.product-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--accent);
    color: white;
    padding: 6px 14px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 600;
    z-index: 2;
}

.product-info {
    padding: 28px;
}

.product-category {
    color: var(--primary);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.product-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 12px;
}

.product-desc {
    color: var(--gray);
    font-size: 14px;
    line-height: 1.7;
    margin-bottom: 20px;
}

.product-features {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.feature-tag {
    background: var(--light-gray);
    padding: 5px 12px;
    border-radius: 6px;
    font-size: 12px;
    color: var(--dark);
}

.product-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--primary);
    font-weight: 600;
    font-size: 14px;
    margin-top: 16px;
}

.product-link svg {
    width: 16px;
    height: 16px;
    transition: transform 0.3s;
}

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

/* Page Hero */
.page-hero {
    min-height: 45vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.page-hero.blue-gradient {
    background: linear-gradient(135deg, #0a1628 0%, #1a3a5c 50%, #0066b3 100%);
    color: white;
}

.page-hero-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 100px 24px 60px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
    width: 100%;
}

.page-hero-text h1 {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.page-hero-text .subtitle {
    font-size: 17px;
    opacity: 0.9;
    margin-bottom: 28px;
    line-height: 1.8;
}

.page-hero-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
}

.page-hero-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* Breadcrumb */
.breadcrumb {
    padding: 0;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.breadcrumb a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
}

.breadcrumb a:hover {
    color: white;
}

.breadcrumb span {
    color: rgba(255, 255, 255, 0.4);
}

/* Features Grid */
.features-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: white;
    border-radius: 16px;
    padding: 32px;
    transition: all 0.3s;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.08);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
    font-size: 26px;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--dark);
}

.feature-card p {
    color: var(--gray);
    font-size: 14px;
    line-height: 1.7;
}

/* Specs Table */
.specs-section {
    background: white;
}

.specs-wrapper {
    max-width: 1000px;
    margin: 0 auto;
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.specs-table th,
.specs-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.specs-table th {
    background: var(--primary);
    color: white;
    font-weight: 600;
    font-size: 14px;
}

.specs-table td {
    font-size: 14px;
    color: var(--dark);
}

.specs-table tr:last-child td {
    border-bottom: none;
}

.specs-table tr:hover td {
    background: var(--light-gray);
}

/* Product List */
.product-list {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.product-item {
    background: white;
    border-radius: 16px;
    padding: 28px;
    transition: all 0.3s;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.product-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.1);
}

.product-item-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: white;
    font-size: 24px;
}

.product-item h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--dark);
}

.product-item p {
    font-size: 13px;
    color: var(--gray);
    line-height: 1.6;
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    text-align: center;
    padding: 80px 24px;
}

.cta-section h2 {
    font-size: 34px;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-section p {
    font-size: 17px;
    opacity: 0.9;
    margin-bottom: 30px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

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

.cta-section .btn-secondary {
    border-color: white;
}

/* About Section */
.about-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: 30px;
    margin-bottom: 20px;
    color: var(--dark);
}

.about-text p {
    color: var(--gray);
    margin-bottom: 16px;
    line-height: 1.8;
}

.about-values {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 28px;
}

.value-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.value-icon {
    width: 40px;
    height: 40px;
    background: var(--light-gray);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    flex-shrink: 0;
    font-size: 20px;
}

.value-item h5 {
    font-size: 14px;
    color: var(--dark);
    margin-bottom: 4px;
}

.value-item p {
    font-size: 12px;
    color: var(--gray);
    margin: 0;
}

.about-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.about-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* Contact Section */
.contact-wrapper {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
}

.contact-info h3 {
    font-size: 26px;
    margin-bottom: 20px;
    color: var(--dark);
}

.contact-info > p {
    color: var(--gray);
    margin-bottom: 32px;
    font-size: 15px;
}

.contact-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: white;
}

.contact-icon svg {
    width: 22px;
    height: 22px;
}

.contact-item h5 {
    font-size: 12px;
    color: var(--gray);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.contact-item p {
    font-size: 16px;
    font-weight: 600;
    color: var(--dark);
}

.contact-form {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.contact-form h4 {
    font-size: 20px;
    margin-bottom: 24px;
    color: var(--dark);
}

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

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--dark);
    margin-bottom: 8px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.submit-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 102, 179, 0.3);
}

/* Footer */
.footer {
    background: #0a1628;
    color: white;
    padding: 80px 24px 30px;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand .logo {
    margin-bottom: 20px;
}

.footer-brand .logo-text {
    color: white;
}

.footer-brand .logo-text span {
    color: rgba(255, 255, 255, 0.6);
}

.footer-brand p {
    opacity: 0.7;
    font-size: 14px;
    line-height: 1.8;
}

.footer h4 {
    font-size: 15px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

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

.footer-bottom {
    max-width: var(--max-width);
    margin: 0 auto;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    opacity: 0.6;
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 1100px) {
    .products-showcase {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 900px) {
    .hero-content,
    .page-hero-content,
    .about-content,
    .contact-wrapper {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-buttons,
    .cta-buttons {
        justify-content: center;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid,
    .product-list {
        grid-template-columns: 1fr;
    }
    
    .about-values {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
    
    .nav-phone {
        display: none;
    }
    
    .mobile-menu {
        display: flex;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    .hero h1 {
        font-size: 32px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        padding: 24px;
    }
    
    .stat-value {
        font-size: 36px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    
    .page-hero-text h1 {
        font-size: 28px;
    }
    
    .products-showcase {
        grid-template-columns: 1fr;
    }
    
    .lang-switcher {
        top: 80px;
        right: 10px;
    }
}