/* ============================================
   湖南善元门古方健康产业研究院有限公司 - 官网样式
   风格：大气简约、传统与现代结合
   适配：PC端 + 移动端
   ============================================ */

/* CSS变量定义 */
:root {
    /* 主色调 - 传统中国红与金色 */
    --primary-color: #8B1E1E;
    --primary-dark: #6B1515;
    --primary-light: #A82E2E;
    --accent-color: #C9A962;
    --accent-light: #D9BC7A;
    
    /* 中性色 */
    --text-dark: #2C2C2C;
    --text-medium: #555555;
    --text-light: #888888;
    --bg-white: #FFFFFF;
    --bg-light: #F8F6F3;
    --bg-dark: #1A1A1A;
    --border-color: #E5E5E5;
    
    /* 字体 */
    --font-serif: 'Noto Serif SC', 'SimSun', serif;
    --font-sans: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
    
    /* 间距 */
    --section-padding: 100px;
    --container-max-width: 1200px;
    
    /* 过渡 */
    --transition: all 0.3s ease;
    --transition-slow: all 0.5s ease;
}

/* 重置样式 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

/* 容器 */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ============================================
   导航栏
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.1);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-serif);
    font-size: 24px;
    font-weight: 700;
    box-shadow: 0 4px 15px rgba(139, 30, 30, 0.3);
}

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

.logo-main {
    font-family: var(--font-serif);
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 2px;
}

.logo-sub {
    font-size: 11px;
    color: var(--text-light);
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    gap: 40px;
}

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-dark);
    position: relative;
    padding: 5px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

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

/* 移动端菜单按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* ============================================
   首页横幅
   ============================================ */
.hero {
    position: relative;
    height: 100vh;
    min-height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(201,169,98,0.1)" stroke-width="0.5"/></svg>');
    background-size: 200px 200px;
    opacity: 0.5;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.4);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    padding: 0 20px;
    max-width: 900px;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 56px;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 20px;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--accent-color);
    margin-bottom: 15px;
    letter-spacing: 3px;
    animation: fadeInUp 1s ease 0.2s backwards;
}

.hero-desc {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 40px;
    line-height: 1.8;
    animation: fadeInUp 1s ease 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    animation: fadeInUp 1s ease 0.6s backwards;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 36px;
    font-size: 15px;
    font-weight: 500;
    border-radius: 30px;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 20px rgba(139, 30, 30, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(139, 30, 30, 0.5);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
    background: white;
    color: var(--text-dark);
    border-color: white;
}

.btn-full {
    width: 100%;
}

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.6);
    font-size: 12px;
    text-align: center;
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid rgba(255, 255, 255, 0.6);
    border-bottom: 2px solid rgba(255, 255, 255, 0.6);
    transform: rotate(45deg);
    margin: 10px auto 0;
}

/* ============================================
   通用区块样式
   ============================================ */
.section {
    padding: var(--section-padding) 0;
}

.section-dark {
    background: var(--bg-dark);
    color: white;
}

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

.section-tag {
    display: inline-block;
    padding: 8px 24px;
    background: rgba(139, 30, 30, 0.1);
    color: var(--primary-color);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 2px;
    border-radius: 20px;
    margin-bottom: 20px;
}

.section-dark .section-tag {
    background: rgba(201, 169, 98, 0.2);
    color: var(--accent-color);
}

.section-title {
    font-family: var(--font-serif);
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.section-dark .section-title {
    color: white;
}

.section-desc {
    font-size: 17px;
    color: var(--text-medium);
}

.section-dark .section-desc {
    color: rgba(255, 255, 255, 0.7);
}

/* ============================================
   关于我们
   ============================================ */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-image {
    position: relative;
}

.image-frame {
    position: relative;
    padding: 20px;
    background: var(--bg-light);
    border-radius: 10px;
}

.image-frame::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 20px;
    bottom: 20px;
    border: 2px solid var(--accent-color);
    border-radius: 10px;
    z-index: 1;
}

.image-placeholder {
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, #e8e4df, #d4cfc7);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 18px;
    position: relative;
    z-index: 2;
}

.about-text h3 {
    font-family: var(--font-serif);
    font-size: 28px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.about-text p {
    font-size: 16px;
    color: var(--text-medium);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px;
    background: var(--bg-light);
    border-radius: 8px;
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 24px;
}

.feature-text {
    font-weight: 500;
    color: var(--text-dark);
}

/* ============================================
   核心业务
   ============================================ */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.service-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 40px 30px;
    text-align: center;
    transition: var(--transition);
}

.service-card:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-5px);
    border-color: var(--accent-color);
}

.service-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    font-size: 32px;
}

.service-card h3 {
    font-family: var(--font-serif);
    font-size: 22px;
    margin-bottom: 15px;
    color: white;
}

.service-card p {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

/* ============================================
   产品中心
   ============================================ */
.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.product-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.product-image {
    aspect-ratio: 4/3;
    overflow: hidden;
}

.product-img-1 { background: linear-gradient(135deg, #e8d5b7, #d4c4a8); }
.product-img-2 { background: linear-gradient(135deg, #c9d6df, #b8c9d9); }
.product-img-3 { background: linear-gradient(135deg, #d4e2d4, #c5d9c5); }
.product-img-4 { background: linear-gradient(135deg, #e2d4d4, #d9c5c5); }

.product-image .image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-medium);
    font-size: 16px;
}

.product-info {
    padding: 25px;
}

.product-info h3 {
    font-family: var(--font-serif);
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.product-info p {
    font-size: 14px;
    color: var(--text-medium);
    margin-bottom: 15px;
    line-height: 1.6;
}

.product-link {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 14px;
}

.product-link:hover {
    color: var(--primary-dark);
}

/* ============================================
   科研实力
   ============================================ */
.research-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.research-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.stat-item {
    text-align: center;
    padding: 30px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-number {
    display: block;
    font-family: var(--font-serif);
    font-size: 48px;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 10px;
}

.stat-label {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.7);
}

.research-features {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.research-item {
    padding: 25px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    border-left: 3px solid var(--accent-color);
}

.research-item h4 {
    font-size: 18px;
    margin-bottom: 10px;
    color: white;
}

.research-item p {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

/* ============================================
   联系我们
   ============================================ */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 25px;
    background: var(--bg-light);
    border-radius: 10px;
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.contact-icon {
    font-size: 28px;
    width: 50px;
    height: 50px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.contact-item h4 {
    font-size: 16px;
    color: var(--text-dark);
    margin-bottom: 5px;
}

.contact-item p {
    font-size: 15px;
    color: var(--text-medium);
}

/* 联系表单 */
.contact-form-wrapper {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 15px;
    font-family: var(--font-sans);
    transition: var(--transition);
    background: var(--bg-light);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(139, 30, 30, 0.1);
}

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

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

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-serif);
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 15px;
}

.footer-logo .logo-icon {
    width: 40px;
    height: 40px;
    font-size: 20px;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
    line-height: 1.7;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 16px;
    margin-bottom: 20px;
    color: var(--accent-color);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
}

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

.footer-contact p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 13px;
    margin-bottom: 5px;
}

/* ============================================
   返回顶部按钮
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 20px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: 0 4px 15px rgba(139, 30, 30, 0.4);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ============================================
   响应式设计 - 移动端适配
   ============================================ */
@media screen and (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media screen and (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    /* 导航栏移动端 */
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        align-items: center;
        padding: 30px 0;
        gap: 20px;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
        transform: translateY(-150%);
        transition: transform 0.3s ease;
    }
    
    .nav-menu.active {
        transform: translateY(0);
    }
    
    .nav-link {
        font-size: 16px;
    }
    
    /* 首页横幅移动端 */
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-desc {
        font-size: 15px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 15px;
    }
    
    .btn {
        padding: 12px 30px;
        font-size: 14px;
    }
    
    /* 区块标题移动端 */
    .section-title {
        font-size: 28px;
    }
    
    .section-desc {
        font-size: 15px;
    }
    
    /* 关于我们移动端 */
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .about-text h3 {
        font-size: 24px;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    /* 核心业务移动端 */
    .services-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .service-card {
        padding: 30px 20px;
    }
    
    /* 产品中心移动端 */
    .products-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    /* 科研实力移动端 */
    .research-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .research-stats {
        gap: 15px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    /* 联系我们移动端 */
    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .contact-form-wrapper {
        padding: 30px 20px;
    }
    
    /* 页脚移动端 */
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .footer-logo {
        justify-content: center;
    }
    
    .footer-links ul {
        align-items: center;
    }
}

@media screen and (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
        letter-spacing: 2px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .logo-main {
        font-size: 18px;
    }
    
    .logo-sub {
        font-size: 10px;
    }
    
    .navbar {
        height: 70px;
    }
    
    .nav-menu {
        top: 70px;
    }
}

/* 打印样式 */
@media print {
    .header,
    .scroll-indicator,
    .back-to-top,
    .hero-buttons {
        display: none;
    }
    
    .hero {
        height: auto;
        padding: 60px 0;
    }
    
    .section {
        padding: 40px 0;
    }
}