/* ============================================
   SUScube - Stainless Steel Water Tank Website
   Complete Stylesheet - Blue Ocean Theme
   ============================================ */

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ---------- Header & Navigation ---------- */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    flex-wrap: wrap;
}

.logo h1 {
    font-size: 1.8rem;
    color: #00b4d8;  /* 天蓝色 - 品牌主色 */
    letter-spacing: 1px;
}

nav ul {
    display: flex;
    gap: 30px;
    align-items: center;
}

nav ul li a {
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 8px 0;
    color: #2c3e50;
}

nav ul li a:hover,
nav ul li a.active {
    color: #0096c7;  /* 海蓝色 - 悬浮/激活状态 */
}

/* ---------- Dropdown Menu ---------- */
nav ul li {
    position: relative;
}

.dropdown {
    position: relative;
}

.dropdown-toggle {
    cursor: pointer;
}

.dropdown-toggle::after {
    content: ' ▼';
    font-size: 10px;
    color: #666;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 160px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    border-radius: 8px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 100;
    padding: 8px 0;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
}

.dropdown-menu li {
    display: block;
    width: 100%;
}

.dropdown-menu li a {
    display: block;
    padding: 10px 20px;
    color: #333;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.dropdown-menu li a:hover {
    background: #e0f7fa;  /* 浅天蓝背景 */
    color: #0096c7;
    padding-left: 25px;
}

.dropdown-menu li a.active {
    background: #00b4d8;
    color: white;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-block;
    background: #00b4d8;
    color: white;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background: #0096c7;
    transform: translateY(-2px);
}

.btn-light {
    background: white;
    color: #00b4d8;
    border: 2px solid #00b4d8;
}

.btn-light:hover {
    background: #e0f7fa;
    color: #0096c7;
    border-color: #0096c7;
}

/* ---------- Hero Section with Background Image ---------- */
.hero {
    color: white;
    text-align: center;
    padding: 100px 20px;
    min-height: 450px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(0, 180, 216, 0.85) 0%, rgba(0, 150, 199, 0.9) 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.95;
}

/* ---------- Material Section ---------- */
.material-section {
    display: flex;
    justify-content: space-between;
    gap: 40px;
    padding: 60px 20px;
    max-width: 1200px;
    margin: 0 auto;
    background: #f0f9ff;  /* 极浅天蓝背景 */
}

.material-text {
    flex: 1;
}

.material-text h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: #00b4d8;
}

.material-text p {
    line-height: 1.6;
    color: #333;
    font-size: 1rem;
}

.material-features {
    flex: 0.8;
    background: #fff;
    padding: 20px 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,180,216,0.1);
}

.material-features ul {
    list-style: none;
    padding: 0;
}

.material-features li {
    margin-bottom: 12px;
    font-size: 0.95rem;
    color: #2c3e50;
}

/* ---------- Focus Section ---------- */
.focus-section {
    text-align: center;
    padding: 60px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.focus-section h3 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 15px;
}

.focus-section > p {
    font-size: 1rem;
    color: #555;
    margin-bottom: 40px;
}

.product-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.product-item {
    background: #e0f7fa;
    padding: 15px 20px;
    border-radius: 6px;
    font-weight: 500;
    color: #0096c7;
    transition: all 0.3s ease;
}

.product-item:hover {
    background: #b2ebf2;
    transform: translateY(-2px);
}

/* ---------- Highlights Section ---------- */
.highlights {
    display: flex;
    gap: 30px;
    max-width: 1000px;
    margin: 60px auto;
    padding: 0 20px;
}

.highlight-card {
    flex: 1;
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid rgba(255,255,255,0.2);
    min-height: 280px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.highlight-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.highlight-card h3 {
    color: white;
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.highlight-card p {
    color: rgba(255,255,255,0.9);
    line-height: 1.5;
    margin-bottom: 20px;
}

.highlight-link {
    color: #ffb703;
    text-decoration: none;
    font-weight: 500;
}

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

/* ---------- Why Choose Section ---------- */
.why-choose {
    background: #e0f7fa;
    padding: 60px 20px;
    text-align: center;
}

.why-choose h3 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 40px;
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.benefit {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,180,216,0.1);
}

.benefit h4 {
    color: #0096c7;
    margin-bottom: 10px;
}

.benefit p {
    color: #555;
    font-size: 0.9rem;
}

/* ---------- CTA Section ---------- */
.cta-section {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(135deg, #00b4d8 0%, #0077b6 100%);
    color: white;
}

.cta-section h2 {
    font-size: 1.8rem;
    margin-bottom: 15px;
}

.cta-section p {
    max-width: 600px;
    margin: 0 auto 25px;
    opacity: 0.9;
}

/* ---------- Product Page Styles ---------- */
.page-title {
    text-align: center;
    padding: 60px 20px 40px;
    background: linear-gradient(135deg, #00b4d8 0%, #0077b6 100%);
    color: white;
}

.page-title h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.page-title p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Product Hero Section */
.product-hero {
    color: white;
    text-align: center;
    padding: 80px 20px;
    min-height: 350px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(0, 180, 216, 0.7) 0%, rgba(0, 119, 182, 0.8) 100%);
}

.product-hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.product-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.product-hero p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Product Toggle Buttons */
.product-toggle {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 40px 20px 0;
}

.toggle-btn {
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 500;
    border: 2px solid #00b4d8;
    background: transparent;
    color: #00b4d8;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.toggle-btn.active {
    background: #00b4d8;
    color: white;
}

.toggle-btn:hover {
    background: #00b4d8;
    color: white;
    transform: translateY(-2px);
}

/* Product Detail Layout */
.product-detail {
    display: flex;
    gap: 40px;
    padding: 60px 20px;
    max-width: 1200px;
    margin: 0 auto;
    border-bottom: 1px solid #e0e0e0;
    align-items: flex-start;
}

.product-detail.alt {
    background: #f0f9ff;
}

/* Product Image Small */
.product-image-small {
    flex: 0.7;
    min-width: 200px;
    max-width: 280px;
    background: #e0f7fa;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid #b2ebf2;
    aspect-ratio: 1 / 1;
}

.product-image-small img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.product-info {
    flex: 1.5;
}

.product-info h2 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 5px;
}

.product-tag {
    color: #0096c7;
    font-weight: 500;
    margin-bottom: 20px;
}

.product-info h3 {
    font-size: 1.2rem;
    color: #2c3e50;
    margin: 20px 0 10px 0;
}

.feature-list {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.feature-list li {
    font-size: 0.9rem;
    color: #444;
}

/* Spec Table */
.spec-table {
    width: 100%;
    border-collapse: collapse;
    background: #f0f9ff;
    border-radius: 8px;
    overflow: hidden;
    margin: 15px 0;
}

.spec-table th,
.spec-table td {
    padding: 10px 15px;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

.spec-table th {
    width: 35%;
    background: #e0f7fa;
    font-weight: 600;
    color: #0096c7;
}

.spec-table td {
    background: white;
}

/* Product Container */
.product-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* ---------- Solutions Page - 8 Industries Grid ---------- */
.solutions-grid {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.solution-card {
    border-radius: 16px;
    padding: 35px 25px;
    transition: all 0.3s ease;
    border: 1px solid rgba(255,255,255,0.2);
    color: white;
    min-height: 280px;
    display: flex;
    flex-direction: column;
    text-align: center;
}

.solution-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.2);
}

.solution-card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: white;
    font-weight: 600;
}

.industry-tag {
    font-size: 0.85rem;
    margin-bottom: 15px;
    opacity: 0.9;
    line-height: 1.4;
    color: white;
}

.industry-desc {
    font-size: 0.85rem;
    line-height: 1.5;
    opacity: 0.9;
    margin-top: 5px;
    color: white;
}

.solution-content p {
    font-size: 0.85rem;
    line-height: 1.5;
    opacity: 0.9;
    margin-top: 5px;
    color: white;
}

/* ---------- Why Use Us Section ---------- */
.why-use-us {
    max-width: 1000px;
    margin: 0 auto;
    padding: 60px 20px;
    text-align: center;
    background: #e0f7fa;
    border-radius: 20px;
}

.why-use-us h2 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 25px;
}

.why-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

.why-text p {
    line-height: 1.7;
    color: #333;
    font-size: 1rem;
    max-width: 850px;
    margin: 0 auto;
}

.why-text strong {
    color: #0096c7;
}

.why-images {
    display: flex;
    justify-content: center;
    gap: 50px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.why-image-item {
    text-align: center;
    width: 180px;
}

.why-image-item img {
    width: 100%;
    height: auto;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,180,216,0.2);
    border: 2px solid white;
    background: white;
}

.why-image-item p {
    margin-top: 12px;
    font-weight: 600;
    color: #0096c7;
    font-size: 0.9rem;
}

/* ---------- Case Study / CTA Section ---------- */
.case-cta {
    background: linear-gradient(135deg, #00b4d8 0%, #0077b6 100%);
    color: white;
    text-align: center;
    padding: 60px 20px;
}

.case-content {
    max-width: 800px;
    margin: 0 auto;
}

.case-content h2 {
    font-size: 1.8rem;
    margin-bottom: 15px;
}

.case-content > p {
    font-size: 1rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.case-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 35px;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: bold;
    color: #ffb703;
}

.stat-label {
    font-size: 0.85rem;
    opacity: 0.8;
}

/* ---------- Contact Page Styles ---------- */
.contact-section {
    display: flex;
    gap: 50px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
}

.contact-info {
    flex: 1;
    background: #f0f9ff;
    padding: 30px;
    border-radius: 16px;
}

.contact-info h2 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 15px;
}

.contact-info > p {
    color: #555;
    margin-bottom: 30px;
    line-height: 1.6;
}

.info-details {
    margin-bottom: 30px;
}

.info-item {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    align-items: flex-start;
}

.info-icon {
    font-size: 1.5rem;
}

.info-item h3 {
    font-size: 1rem;
    color: #0096c7;
    margin-bottom: 5px;
}

.info-item p {
    color: #555;
}

.info-item a {
    color: #0096c7;
    text-decoration: none;
}

.info-item a:hover {
    text-decoration: underline;
}

.business-hours {
    margin-bottom: 30px;
    padding-top: 20px;
    border-top: 1px solid #b2ebf2;
}

.business-hours h3 {
    font-size: 1rem;
    color: #0096c7;
    margin-bottom: 10px;
}

.business-hours p {
    color: #555;
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.social-links h3 {
    font-size: 1rem;
    color: #0096c7;
    margin-bottom: 10px;
}

.social-icons {
    display: flex;
    gap: 15px;
}

.social-icon {
    color: #00b4d8;
    text-decoration: none;
    font-size: 0.9rem;
}

.social-icon:hover {
    color: #0096c7;
}

/* Contact Map inside Get In Touch */
.contact-map {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #b2ebf2;
}

.contact-map h3 {
    font-size: 1rem;
    color: #0096c7;
    margin-bottom: 15px;
}

.map-placeholder-small {
    background: #e0f7fa;
    border-radius: 12px;
    padding: 10px;
    border: 1px solid #b2ebf2;
}

.map-placeholder-small svg {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
}

/* Contact Form */
.contact-form {
    flex: 1.5;
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,180,216,0.1);
    border: 1px solid #e0f7fa;
}

.contact-form h2 {
    font-size: 1.8rem;
    color: #00b4d8;
    margin-bottom: 10px;
}

.contact-form > p {
    color: #666;
    margin-bottom: 25px;
}

.form-row {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
}

.form-group {
    flex: 1;
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: #333;
    font-size: 0.9rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 0.95rem;
    font-family: inherit;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #00b4d8;
    box-shadow: 0 0 0 3px rgba(0, 180, 216, 0.1);
}

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

.checkbox {
    margin: 20px 0;
}

.checkbox label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-weight: normal;
}

.checkbox input {
    width: auto;
    margin: 0;
}

.submit-btn {
    width: 100%;
    padding: 14px;
    font-size: 1rem;
    margin-top: 10px;
}

.form-note {
    font-size: 0.8rem;
    color: #888;
    text-align: center;
    margin-top: 15px;
}

/* FAQ Section */
.faq-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
    background: #f0f9ff;
    border-radius: 16px;
    margin-bottom: 40px;
}

.faq-section h2 {
    font-size: 1.8rem;
    color: #00b4d8;
    text-align: center;
    margin-bottom: 40px;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.faq-item {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,180,216,0.05);
}

.faq-item h3 {
    font-size: 1.1rem;
    color: #0096c7;
    margin-bottom: 10px;
}

.faq-item p {
    color: #555;
    line-height: 1.5;
    font-size: 0.9rem;
}

/* ---------- Footer ---------- */
footer {
    background: #023e8a;
    color: #aaa;
    padding: 40px 20px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-info h4 {
    color: white;
    margin-bottom: 5px;
}

.footer-links a {
    color: #aaa;
    text-decoration: none;
    margin: 0 10px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #00b4d8;
}

/* ---------- Responsive Design ---------- */
@media (max-width: 1024px) {
    .material-section {
        flex-direction: column;
    }
    
    .solutions-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
}

@media (max-width: 900px) {
    .solutions-grid {
        gap: 25px;
    }
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 15px;
        padding: 15px 20px;
    }
    
    nav ul {
        gap: 20px;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero {
        min-height: 350px;
        padding: 60px 20px;
    }
    
    .hero h2 {
        font-size: 1.8rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .highlights {
        flex-direction: column;
    }
    
    .highlight-card {
        min-height: auto;
        padding: 30px 20px;
    }
    
    .product-detail {
        flex-direction: column;
        align-items: center;
    }
    
    .product-image-small {
        max-width: 250px;
        width: 100%;
        margin-bottom: 20px;
    }
    
    .feature-list {
        grid-template-columns: 1fr;
    }
    
    .spec-table th,
    .spec-table td {
        font-size: 0.85rem;
    }
    
    .page-title h1 {
        font-size: 1.8rem;
    }
    
    .product-hero {
        min-height: 280px;
        padding: 50px 20px;
    }
    
    .product-hero h1 {
        font-size: 1.8rem;
    }
    
    .product-hero p {
        font-size: 0.9rem;
    }
    
    .case-stats {
        gap: 20px;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .dropdown-menu {
        left: -20px;
    }
    
    .contact-section {
        flex-direction: column;
    }
    
    .form-row {
        flex-direction: column;
        gap: 0;
    }
    
    .faq-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .solutions-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .solution-card {
        min-height: auto;
        padding: 25px 20px;
    }
    
    .why-use-us {
        margin: 20px;
        padding: 40px 20px;
    }
    
    .why-content p {
        font-size: 0.9rem;
    }
    
    .why-images {
        gap: 30px;
    }
    
    .why-image-item {
        width: 140px;
    }
    
    .why-image-item p {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .product-toggle {
        flex-direction: column;
        align-items: center;
    }
    
    .toggle-btn {
        width: 80%;
        text-align: center;
    }
    
    .btn {
        padding: 10px 20px;
    }
    
    .contact-info,
    .contact-form {
        padding: 20px;
    }
    
    .info-item {
        flex-direction: column;
        gap: 5px;
    }
    
    .faq-item {
        padding: 20px;
    }
    
    .solution-card {
        padding: 20px;
    }
}