/* 北方钢铁网 - 主样式表 */
/* 天津兆泰钢铁有限公司 */

:root {
    --primary-color: #0d3b66;
    --secondary-color: #f4d35e;
    --accent-color: #ee964b;
    --dark-color: #1a1a2e;
    --light-color: #f8f9fa;
    --text-color: #333333;
    --text-light: #666666;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-color);
}

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

ul {
    list-style: none;
}

/* ==================== Header Styles ==================== */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--dark-color) 100%);
    color: var(--white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.header-top {
    background: rgba(0, 0, 0, 0.2);
    padding: 0.8rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--secondary-color);
}

.header-logo p {
    font-size: 0.85rem;
    opacity: 0.9;
    margin-top: 3px;
}

.header-contact {
    display: flex;
    gap: 25px;
    align-items: center;
}

.contact-phone,
.contact-address {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
}

.contact-phone i,
.contact-address i {
    color: var(--secondary-color);
}

.phone-number {
    font-weight: 700;
    color: var(--secondary-color);
    font-size: 1.1rem;
}

/* ==================== Navigation ==================== */
.modern-nav {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.modern-nav .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    display: flex;
    flex-direction: column;
}

.nav-logo h2 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

.nav-logo p {
    font-size: 0.8rem;
    color: var(--text-light);
}

.nav-menu ul {
    display: flex;
    gap: 5px;
}

.nav-menu li {
    position: relative;
}

.nav-menu li a {
    display: block;
    padding: 1rem 1.3rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
    border-radius: 4px;
}

.nav-menu li a:hover,
.nav-menu li a.active {
    color: var(--accent-color);
    background: rgba(238, 150, 75, 0.1);
}

.nav-menu li a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 3px;
    background: var(--accent-color);
}

/* Dropdown Menu */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--white);
    box-shadow: var(--shadow-lg);
    border-radius: 4px;
    min-width: 200px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    z-index: 1001;
}

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

.dropdown-menu li a {
    padding: 0.8rem 1.2rem;
    font-size: 0.95rem;
    border-bottom: 1px solid #f0f0f0;
}

.dropdown-menu li:last-child a {
    border-bottom: none;
}

.dropdown-menu li a:hover {
    background: var(--light-color);
}

.nav-contact .btn-call {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--secondary-color);
    color: var(--primary-color);
    padding: 0.7rem 1.3rem;
    border-radius: 25px;
    font-weight: 600;
    transition: var(--transition);
}

.nav-contact .btn-call:hover {
    background: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.mobile-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary-color);
}

/* ==================== Hero Section ==================== */
.hero {
    background: linear-gradient(rgba(13, 59, 102, 0.85), rgba(26, 26, 46, 0.9)),
                url('../images/hero-bg.jpg') center/cover no-repeat;
    color: var(--white);
    padding: 100px 0;
    text-align: center;
    position: relative;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: 2px;
}

.hero-content h2 {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.hero-content p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2.5rem;
    opacity: 0.95;
    line-height: 1.8;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 35px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: #e0c040;
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(244, 211, 94, 0.4);
}

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

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-color);
    transform: translateY(-3px);
}

/* ==================== Section Headers ==================== */
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 2px;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ==================== Featured Products ==================== */
.featured-products {
    padding: 80px 0;
    background: var(--white);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.product-card {
    background: var(--light-color);
    border-radius: 15px;
    padding: 35px 30px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid #e9ecef;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-color);
}

.product-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--dark-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--secondary-color);
}

.product-card h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 15px;
    font-weight: 600;
}

.product-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.7;
    font-size: 0.95rem;
}

.btn-link {
    color: var(--accent-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}

.btn-link:hover {
    color: var(--primary-color);
    gap: 10px;
}

/* ==================== Advantages Section ==================== */
.advantages {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 80px 0;
}

.advantages .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.advantage-item {
    text-align: center;
    padding: 35px 25px;
    background: var(--white);
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.advantage-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.advantage-item .icon {
    font-size: 3.5rem;
    margin-bottom: 20px;
    color: var(--accent-color);
}

.advantage-item h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 12px;
    font-weight: 600;
}

.advantage-item p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ==================== Testimonials ==================== */
.testimonials {
    padding: 80px 0;
    background: var(--white);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.testimonial-card {
    background: var(--light-color);
    padding: 30px;
    border-radius: 15px;
    border-left: 4px solid var(--accent-color);
    box-shadow: var(--shadow);
}

.testimonial-card blockquote {
    font-style: italic;
    color: var(--text-color);
    margin-bottom: 20px;
    line-height: 1.8;
    font-size: 1rem;
}

.testimonial-card cite {
    display: block;
    color: var(--primary-color);
    font-weight: 600;
    font-style: normal;
}

.testimonial-card cite span {
    display: block;
    color: var(--text-light);
    font-size: 0.9rem;
    font-weight: 400;
    margin-top: 5px;
}

/* ==================== Contact CTA ==================== */
.contact-cta {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--dark-color) 100%);
    color: var(--white);
    padding: 80px 0;
    text-align: center;
}

.contact-cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.contact-cta p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.contact-info-large {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}

.phone-large {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.phone-large:hover {
    color: var(--accent-color);
}

.address-large {
    font-size: 1.1rem;
    opacity: 0.9;
    display: flex;
    align-items: center;
    gap: 10px;
}

/* ==================== Footer ==================== */
.footer {
    background: var(--dark-color);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto 40px;
    padding: 0 20px;
}

.footer-logo h3 {
    font-size: 1.8rem;
    margin-bottom: 15px;
    color: var(--secondary-color);
    font-weight: 700;
}

.footer-logo p {
    opacity: 0.8;
    line-height: 1.7;
}

.footer-contact h4,
.footer-links h4 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
    font-weight: 600;
}

.footer-contact p {
    margin-bottom: 12px;
    opacity: 0.85;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-contact i {
    color: var(--accent-color);
}

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

.footer-links ul li a {
    color: var(--white);
    opacity: 0.85;
    transition: var(--transition);
}

.footer-links ul li a:hover {
    color: var(--secondary-color);
    opacity: 1;
    padding-left: 5px;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.7;
    font-size: 0.9rem;
}

/* ==================== Animations ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.hero-content,
.product-card,
.advantage-item,
.testimonial-card {
    animation: fadeInUp 0.6s ease-out forwards;
}

.product-card:nth-child(2) { animation-delay: 0.1s; }
.product-card:nth-child(3) { animation-delay: 0.2s; }
.product-card:nth-child(4) { animation-delay: 0.3s; }

/* ==================== Responsive Design ==================== */
@media (max-width: 992px) {
    .nav-menu {
        display: none;
    }
    
    .nav-contact {
        display: none;
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .hero-content h2 {
        font-size: 1.6rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .header-contact {
        flex-direction: column;
        gap: 10px;
    }
    
    .hero {
        padding: 60px 0;
    }
    
    .hero-content h1 {
        font-size: 1.8rem;
    }
    
    .hero-content h2 {
        font-size: 1.4rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
    
    .section-header h2 {
        font-size: 1.8rem;
    }
    
    .products-grid,
    .advantages-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .phone-large {
        font-size: 1.8rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-contact p {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.5rem;
    }
    
    .hero-content h2 {
        font-size: 1.2rem;
    }
    
    .section-header h2 {
        font-size: 1.5rem;
    }
    
    .product-card {
        padding: 25px 20px;
    }
    
    .product-icon {
        width: 60px;
        height: 60px;
        font-size: 1.5rem;
    }
}

/* ==================== Utility Classes ==================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

.hidden { display: none; }
.visible { display: block; }