/* ============================================
   重力解放 GRAVITY LIBERATION - 主样式文件
   设计风格：简约科技感（蓝色/紫色系）
   ============================================ */

/* CSS变量定义 */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #7B68EE;
    --accent-color: #5D4F85;
    --text-primary: #2C3E50;
    --text-secondary: #7F8C8D;
    --bg-light: #F8F9FA;
    --bg-dark: #1A1A2E;
    --white: #FFFFFF;
    --gradient-primary: linear-gradient(135deg, #4A90E2 0%, #7B68EE 100%);
    --gradient-dark: linear-gradient(135deg, #1A1A2E 0%, #16213E 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
    --transition: all 0.3s ease;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    overflow-x: hidden;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 1.2rem;
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 600;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
}

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

.lang-switcher {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.lang-btn {
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
}

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

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

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* Hero区域 */
.hero {
    min-height: 100vh;
    background: var(--gradient-dark);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.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 1200 600"><circle cx="200" cy="150" r="100" fill="rgba(74,144,226,0.1)"/><circle cx="800" cy="400" r="150" fill="rgba(123,104,238,0.1)"/></svg>');
    opacity: 0.5;
}

.hero-content {
    text-align: center;
    color: white;
    z-index: 1;
    max-width: 800px;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 3rem;
    opacity: 0.8;
    line-height: 1.8;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-cta {
    display: inline-flex;
    gap: 1rem;
    animation: fadeInUp 1s ease 0.6s both;
}

.btn {
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

/* Section通用样式 */
.section {
    padding: 5rem 2rem;
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 3rem;
}

/* 特性卡片 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    text-align: center;
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 1.5rem;
}

.feature-title {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* 产品展示 */
.products-section {
    background: var(--bg-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.product-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.product-image {
    width: 100%;
    height: 250px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
}

.product-info {
    padding: 1.5rem;
}

.product-name {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.product-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.product-price {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
}

/* 科学原理 */
.science-section {
    background: white;
}

.science-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    margin-top: 3rem;
}

.science-text h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.science-text p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.science-visual {
    background: var(--gradient-primary);
    border-radius: 12px;
    padding: 3rem;
    color: white;
    text-align: center;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.research-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.research-card {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
}

.research-card h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.research-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 用户评价 */
.reviews-section {
    background: var(--bg-light);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.review-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.review-stars {
    color: #FFD700;
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.review-text {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1rem;
    font-style: italic;
}

.review-author {
    color: var(--text-primary);
    font-weight: 600;
}

/* 媒体报道 */
.media-section {
    background: white;
}

.media-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.media-card {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 12px;
    transition: var(--transition);
}

.media-card:hover {
    box-shadow: var(--shadow-md);
}

.media-source {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.media-title {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.media-excerpt {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 资质认证 */
.qualifications-section {
    background: var(--bg-light);
}

.qualifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.qualification-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.qualification-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
}

.qualification-title {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.qualification-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 联系我们 */
.contact-section {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 3rem;
}

.contact-info h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.contact-text h4 {
    color: var(--text-primary);
    margin-bottom: 0.3rem;
}

.contact-text p {
    color: var(--text-secondary);
}

.contact-form {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 12px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

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

.submit-btn {
    width: 100%;
    padding: 1rem;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 3rem 2rem 1rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section p,
.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    line-height: 1.8;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
}

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

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-md);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .science-content,
    .contact-content {
        grid-template-columns: 1fr;
    }

    .features-grid,
    .products-grid,
    .reviews-grid,
    .media-grid,
    .qualifications-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }
}