/* ========================================
   长沙泰鸣贸易有限公司 - 主样式文件
   版本：v3.0 - 专业美化版
   ======================================== */

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

:root {
    /* 主色调 - 深海蓝 */
    --primary: #1e40af;
    --primary-dark: #1e3a8a;
    --primary-light: #3b82f6;
    --primary-gradient: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    
    /* 中性色 */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 强调色 */
    --accent: #f59e0b;
    --accent-light: #fbbf24;
    
    /* 阴影系统 */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 2px 4px 0 rgba(0, 0, 0, 0.06);
    --shadow: 0 4px 8px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 8px 16px -2px rgba(0, 0, 0, 0.1), 0 4px 8px -2px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 12px 24px -3px rgba(0, 0, 0, 0.12), 0 6px 12px -3px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 20px 32px -4px rgba(0, 0, 0, 0.14), 0 8px 16px -4px rgba(0, 0, 0, 0.1);
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
    line-height: 1.8;
    color: var(--gray-700);
    background-color: var(--white);
    font-weight: 400;
    letter-spacing: -0.01em;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========== 导航栏 ========== */
.navbar {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(12px);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--gray-200);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 24px;
    height: 76px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 14px;
    cursor: pointer;
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 22px;
    font-family: 'Arial', sans-serif;
    box-shadow: 0 4px 12px rgba(30, 64, 175, 0.3);
    transition: transform 0.3s ease;
}

.logo:hover .logo-icon {
    transform: scale(1.05);
}

.logo-text {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.logo-text .cn {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-dark);
    line-height: 1.3;
    letter-spacing: 0.5px;
}

.logo-text .en {
    font-size: 0.65rem;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: 600;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--gray-600);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 10px 0;
    position: relative;
    transition: color 0.3s ease;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 6px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 2px;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    transform: scaleX(1);
}

/* 语言切换按钮 */
.lang-switch {
    display: flex;
    gap: 10px;
    margin-left: 2rem;
    align-items: center;
    padding-left: 2rem;
    border-left: 1px solid var(--gray-200);
}

.lang-btn {
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    padding: 8px 20px !important;
    border: 1.5px solid #d1d5db !important;
    border-radius: 25px !important;
    font-size: 0.85rem !important;
    font-weight: 600 !important;
    cursor: pointer !important;
    background: #ffffff !important;
    color: #374151 !important;
    text-decoration: none !important;
    white-space: nowrap !important;
    min-width: 70px !important;
    transition: all 0.3s ease !important;
}

.lang-btn:hover {
    background: #f9fafb !important;
    border-color: #9ca3af !important;
    color: #111827 !important;
    transform: translateY(-1px) !important;
}

.lang-btn.active {
    background: #1e40af !important;
    color: #ffffff !important;
    border-color: #1e40af !important;
    box-shadow: 0 3px 10px rgba(30, 64, 175, 0.3) !important;
}

.lang-btn.active:hover {
    background: #1e3a8a !important;
    border-color: #1e3a8a !important;
    box-shadow: 0 5px 15px rgba(30, 64, 175, 0.4) !important;
}

/* ========== Hero Section ========== */
.hero {
    background: linear-gradient(135deg, rgba(30,58,138,0.85) 0%, rgba(30,64,175,0.85) 50%, rgba(59,130,246,0.85) 100%),
                url('../images/hero-bg.jpg') no-repeat center center;
    background-size: cover;
    color: var(--white);
    padding: 180px 0 120px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(255,255,255,0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255,255,255,0.08) 0%, transparent 50%);
    opacity: 0.4;
}

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

.hero h1 {
    font-size: 3.2rem;
    margin-bottom: 1.5rem;
    font-weight: 800;
    letter-spacing: -1px;
    line-height: 1.2;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.9;
    font-weight: 300;
}

.hero-btns {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 16px 36px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: none;
    text-align: center;
}

.btn-primary {
    background: var(--white);
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
    background: var(--gray-50);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.6);
}

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

/* ========== Section Styles ========== */
section {
    padding: 100px 0;
}

section.alt-bg {
    background: var(--gray-50);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--gray-900);
    margin-bottom: 0.75rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.section-header .subtitle {
    color: var(--gray-500);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 3px;
    font-weight: 600;
}

.section-header .divider {
    width: 70px;
    height: 4px;
    background: var(--primary-gradient);
    margin: 1.75rem auto 0;
    border-radius: 2px;
}

/* ========== 业务卡片 ========== */
.business-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 2rem;
}

.business-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--gray-200);
    position: relative;
    overflow: hidden;
}

.business-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.business-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.business-card:hover::before {
    transform: scaleX(1);
}

.business-card .icon {
    width: 64px;
    height: 64px;
    background: var(--primary-gradient);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.75rem;
    font-size: 30px;
    box-shadow: 0 6px 16px rgba(30, 64, 175, 0.25);
}

.business-card h3 {
    color: var(--gray-900);
    margin-bottom: 1.25rem;
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.3;
}

.business-card p {
    color: var(--gray-600);
    line-height: 1.9;
    font-size: 0.95rem;
}

/* ========== 产品卡片 ========== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
    gap: 2rem;
}

.product-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--gray-200);
}

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

.product-image {
    height: 200px;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    font-weight: 700;
    color: var(--white);
    text-shadow: 0 2px 8px rgba(0,0,0,0.6);
}

/* 产品图片 - 钨 */
.product-card:nth-child(1) .product-image {
    background-image: url('../images/product-tungsten.jpg') !important;
    background-color: #6b7280;
}

/* 产品图片 - 钴 */
.product-card:nth-child(2) .product-image {
    background-image: url('../images/product-cobalt.jpg') !important;
    background-color: #4b5563;
}

/* 产品图片 - 镍 */
.product-card:nth-child(3) .product-image {
    background-image: url('../images/product-nickel.jpg') !important;
    background-color: #374151;
}

/* 产品图片 - 锑 */
.product-card:nth-child(4) .product-image {
    background-image: url('../images/product-antimony.jpg') !important;
    background-color: #1f2937;
}

.product-card .content {
    padding: 1.75rem;
}

.product-card h3 {
    color: var(--gray-900);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
    font-weight: 700;
}

.product-card .en-name {
    color: var(--gray-500);
    font-size: 0.8rem;
    margin-bottom: 1.25rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.product-card p {
    color: var(--gray-600);
    font-size: 0.9rem;
    line-height: 1.8;
    margin-bottom: 1.25rem;
}

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

.tag {
    padding: 5px 12px;
    background: var(--gray-100);
    border-radius: 20px;
    font-size: 0.75rem;
    color: var(--gray-600);
    font-weight: 600;
    border: 1px solid var(--gray-200);
}

/* ========== 新闻中心 ========== */
.news-list {
    display: grid;
    gap: 1.75rem;
}

.news-item {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2.5rem;
    padding: 2rem;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.news-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.news-date {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--gray-100), var(--gray-200));
    border-radius: var(--radius);
    padding: 1.5rem;
    min-width: 140px;
}

.news-date .day {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
}

.news-date .month {
    font-size: 0.8rem;
    color: var(--gray-600);
    text-transform: uppercase;
    font-weight: 600;
    margin-top: 0.5rem;
    letter-spacing: 1px;
}

.news-content h3 {
    color: var(--gray-900);
    margin-bottom: 1rem;
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.5;
}

.news-content p {
    color: var(--gray-600);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    line-height: 1.8;
}

.news-meta {
    font-size: 0.8rem;
    color: var(--gray-500);
    font-weight: 500;
}

/* ========== 合作伙伴 ========== */
.partners-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 2rem;
}

.partner-card {
    background: var(--white);
    padding: 2.5rem;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.partner-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-6px);
}

.partner-card h4 {
    color: var(--gray-900);
    margin-bottom: 0.75rem;
    font-size: 1.15rem;
    font-weight: 700;
}

.partner-card p {
    font-size: 0.9rem;
    color: var(--gray-600);
    line-height: 1.7;
}

/* ========== 页脚 ========== */
footer {
    background: var(--gray-900);
    color: var(--gray-400);
    padding: 70px 0 35px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 3.5rem;
    margin-bottom: 3.5rem;
}

.footer-section h4 {
    margin-bottom: 1.75rem;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.3px;
}

.footer-section p,
.footer-section a {
    color: var(--gray-400);
    line-height: 2.4;
    font-size: 0.9rem;
}

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

.footer-contact p {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 1rem;
}

.footer-contact .icon {
    font-size: 1.2rem;
    margin-top: 2px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
    color: var(--gray-500);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    gap: 2.5rem;
}

.footer-links a {
    color: var(--gray-500);
    font-size: 0.875rem;
}

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

/* ========== 响应式设计 ========== */
@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .section-header h2 {
        font-size: 2.2rem;
    }
}

@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        height: auto;
        padding: 1.25rem 24px;
        gap: 1.25rem;
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
    
    .lang-switch {
        margin-left: 0;
        margin-top: 1rem;
        padding-left: 0;
        border-left: none;
    }
    
    .hero {
        padding: 140px 0 80px;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1.05rem;
    }
    
    .hero-btns {
        flex-direction: column;
        align-items: center;
    }
    
    section {
        padding: 60px 0;
    }
    
    .section-header h2 {
        font-size: 1.9rem;
    }
    
    .business-grid {
        grid-template-columns: 1fr;
    }
    
    .products-grid {
        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    }
    
    .news-item {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .news-date {
        flex-direction: row;
        gap: 1.5rem;
        min-width: auto;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .container {
        padding: 0 20px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-header h2 {
        font-size: 1.65rem;
    }
    
    .business-card {
        padding: 1.75rem;
    }
    
    .btn {
        padding: 14px 28px;
        font-size: 0.95rem;
    }
    
    .logo-text .cn {
        font-size: 1.15rem;
    }
}