/* --- 全局与基础样式 --- */
:root {
    --primary-color-start: #4f46e5; /* 科技蓝 */
    --primary-color-end: #8b5cf6;   /* 科技紫 */
    --secondary-color: #e2e8f0;
    --text-color: #1e293b;
    --light-text-color: #64748b;
    --bg-color: #f8fafc;
    --card-bg-color: #ffffff;
    --border-radius: 12px;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.07), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', 'Helvetica Neue', 'Arial', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.7;
}

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

/* --- 头部导航 --- */
.main-header {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid #e2e8f0;
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
    color: var(--primary-color-start);
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
}

.main-nav a {
    text-decoration: none;
    color: var(--light-text-color);
    font-weight: 600;
    transition: color 0.3s ease;
}

.main-nav a:hover, .main-nav a:focus {
    color: var(--primary-color-start);
}

/* --- 主视觉区域 (Hero) --- */
.hero {
    padding-top: 100px; /* 为固定导航栏留出空间 */
    height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    /* background-image: url('URL_FOR_BACKGROUND_IMAGE'); 在这里替换您的背景图片URL */
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, rgba(248, 250, 252, 0.1), rgb(214 209 240 / 74%));
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    background: linear-gradient(90deg, var(--primary-color-start), var(--primary-color-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--light-text-color);
    margin-bottom: 40px;
}

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

.btn {
    padding: 15px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(90deg, var(--primary-color-start), var(--primary-color-end));
    color: white;
    box-shadow: 0 4px 15px rgba(79, 70, 229, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 7px 20px rgba(79, 70, 229, 0.5);
}

.btn-secondary {
    background-color: var(--card-bg-color);
    color: var(--primary-color-start);
    border: 1px solid #d1d5db;
}

.btn-secondary:hover {
    background-color: #f3f4f6;
    transform: translateY(-3px);
}

/* --- 通用区块样式 --- */
.features-section, .how-it-works-section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 60px;
    color: var(--text-color);
}

/* --- 特点网格 --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--card-bg-color);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    height: 100px;
    height: 100px;
    margin-bottom: 20px;
    /* 提示: 这里需要您提供图标图片的URL  
    content: url('URL_FOR_PLACEHOLDER_ICON');   这是一个占位符，请替换为您的图标 */
    background-color: #eef2ff;
    padding: 10px;
    border-radius: 50%;
}

.feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--light-text-color);
    font-size: 0.95rem;
}

/* --- 工作流程 --- */
.how-it-works-section {
    background-color: #ffffff;
}

.workflow-container {
    display: flex;
    align-items: center;
    justify-content: space-around;
    gap: 20px;
    flex-wrap: wrap;
}

.workflow-card {
    background-color: var(--bg-color);
    border: 1px solid #e2e8f0;
    border-radius: var(--border-radius);
    width: 30%;
    min-width: 300px;
    min-height: 350px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow);
}

.card-header {
    background-color: #eef2ff;
    color: var(--primary-color-start);
    padding: 15px 20px;
    font-weight: 600;
    border-top-left-radius: var(--border-radius);
    border-top-right-radius: var(--border-radius);
    border-bottom: 1px solid #e2e8f0;
}

.card-content {
    padding: 20px;
    flex-grow: 1;
}

.example-input {
    background-color: #fff;
    padding: 15px;
    border-radius: 8px;
    border: 1px dashed #cbd5e1;
    color: var(--light-text-color);
    font-style: italic;
}

.outline-list {
    list-style-type: none;
    padding-left: 0;
}

.outline-list li {
    padding: 8px 0;
    border-bottom: 1px solid #e2e8f0;
    color: var(--text-color);
}
.outline-list li:last-child {
    border-bottom: none;
}

.report-card {
    background-image: url('URL_FOR_REPORT_UI_IMAGE'); /* 在这里替换您的报告UI图片URL */
    background-size: cover;
    background-position: center;
    position: relative;
}

.report-card .card-content {
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(5px);
    border-radius: var(--border-radius);
    margin: 15px;
}

.fake-chart {
    display: flex;
    justify-content: space-around;
    align-items: flex-end;
    height: 80px;
    margin-top: 20px;
    padding: 10px;
    background-color: rgba(238, 242, 255, 0.7);
    border-radius: 8px;
}

.fake-chart .bar {
    width: 18%;
    background: linear-gradient(to top, var(--primary-color-start), var(--primary-color-end));
    border-radius: 4px 4px 0 0;
}

.workflow-arrow {
    font-size: 2.5rem;
    color: #cbd5e1;
    font-weight: 300;
}

/* --- 页脚 --- */
.main-footer {
    background-color: #0f172a;
    color: #94a3b8;
    padding: 80px 0 0;
    text-align: center;
}

.footer-content h2 {
    font-size: 2rem;
    color: #fff;
    margin-bottom: 15px;
}

.footer-content p {
    margin-bottom: 30px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.footer-bottom {
    border-top: 1px solid #1e293b;
    padding: 25px 0;
    margin-top: 60px;
    font-size: 0.9rem;
}

.footer-bottom a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-bottom a:hover {
    color: #fff;
}

/* --- 弹窗 (Modal) --- */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(15, 23, 42, 0.8);
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: var(--card-bg-color);
    margin: auto;
    padding: 40px;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 500px;
    position: relative;
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);
    animation: slideIn 0.4s ease;
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.close-button {
    color: #aaa;
    position: absolute;
    top: 15px;
    right: 25px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close-button:hover,
.close-button:focus {
    color: var(--text-color);
}

.modal-content h3 {
    font-size: 1.8rem;
    margin-bottom: 25px;
    text-align: center;
}

.contact-info p {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--light-text-color);
}

.contact-info strong {
    color: var(--text-color);
    min-width: 60px;
    display: inline-block;
}

/* --- 响应式设计 --- */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

    .main-nav {
        display: none; /* 在移动端可以简化或隐藏导航 */
    }

    .workflow-container {
        flex-direction: column;
        gap: 30px;
    }

    .workflow-card {
        width: 100%;
    }

    .workflow-arrow {
        transform: rotate(90deg);
    }
}


/* --- 全局与变量定义 --- */
:root {
    --primary-color: #4f46e5; /* 主色调 - 科技蓝紫 */
    --secondary-color: #7c3aed; /* 辅助色 - 亮紫 */
    --accent-color: #10b981; /* 点缀色 - 绿色 */
    --bg-color: #f8fafc; /* 页面背景色 - 极浅灰 */
    --card-bg-color: #ffffff; /* 卡片背景色 - 纯白 */
    --text-color: #334155; /* 主要文本颜色 */
    --heading-color: #1e293b; /* 标题颜色 */
    --light-text-color: #64748b; /* 辅助文本颜色 */
    --white-color: #ffffff;
    --border-radius: 12px;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.07), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.7;
}

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

/* --- 头部导航 --- */
.main-header {
    background-color: var(--white-color);
    padding: 15px 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.main-nav a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 25px;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.cta-button-nav {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: var(--white-color);
    padding: 8px 18px;
    border-radius: 50px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cta-button-nav:hover {
    color: var(--white-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(79, 70, 229, 0.4);
}

/* --- 英雄区域 --- */
.hero-section {
    padding-top: 80px; /* 留出导航栏高度 */
    height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white-color);
    background-image: linear-gradient(rgba(20, 20, 40, 0.7), rgba(20, 20, 40, 0.7)), url('hero-background-placeholder-url.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 300;
    margin-bottom: 40px;
    opacity: 0.9;
}

.cta-button {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: var(--white-color);
    padding: 15px 35px;
    border-radius: 50px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: inline-block;
    border: none;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.5);
}

/* --- 通用区块样式 --- */
.features-section, .architecture-section, .use-cases-section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.5rem;
    color: var(--heading-color);
    text-align: center;
    margin-bottom: 15px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--light-text-color);
    text-align: center;
    max-width: 600px;
    margin: 0 auto 60px auto;
}

/* --- 产品特点 --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--card-bg-color);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid var(--primary-color);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 50px;
    height: 50px;
    margin-bottom: 20px;
    /* 提示: 您的SVG图标最好是单色的，这样可以用CSS控制颜色 */
    /* filter: invert(33%) sepia(82%) saturate(3483%) hue-rotate(235deg) brightness(95%) contrast(95%); */
}

.feature-card h3 {
    font-size: 1.4rem;
    color: var(--heading-color);
    margin-bottom: 10px;
}

/* --- 核心架构 --- */
.architecture-section {
    background-color: var(--white-color);
}

.architecture-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.architecture-image {
    flex: 1;
}

.architecture-image img {
    max-width: 100%;
    border-radius: var(--border-radius);
}

.architecture-text {
    flex: 1;
}

.model-description {
    margin-bottom: 30px;
}

.model-description h4 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.model-description h4 span {
    font-size: 2rem;
    margin-right: 10px;
}

/* --- 应用领域 --- */
.use-cases-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    list-style: none;
    padding: 0;
}

.use-cases-list li {
    background-color: var(--white-color);
    padding: 15px 30px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 500;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
}

.use-cases-list li:hover {
    background-color: var(--primary-color);
    color: var(--white-color);
    transform: translateY(-5px);
}

.use-cases-list li span {
    margin-right: 10px;
    font-size: 1.5rem;
}

/* --- 页脚 --- */
.main-footer {
    background-color: #1e293b; /* 深色背景 */
    color: #94a3b8; /* 浅色文字 */
    padding: 60px 0 0 0;
    text-align: center;
}

.footer-content {
    margin-bottom: 40px;
}

.footer-content h3 {
    font-size: 2rem;
    color: var(--white-color);
    margin-bottom: 15px;
}

.footer-content p {
    margin-bottom: 30px;
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding: 25px 0;
    font-size: 0.9rem;
}

.footer-bottom p {
    margin: 0;
}

.footer-bottom a {
    text-decoration: none;
    transition: color 0.3s ease;
}

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

/* --- 响应式设计 --- */
@media (max-width: 992px) {
    .architecture-content {
        flex-direction: column;
    }
    .architecture-image {
        margin-bottom: 40px;
    }
}

@media (max-width: 768px) {
    .main-nav {
        display: none; /* 简单处理，实际项目可换成汉堡菜单 */
    }
    .hero-title {
        font-size: 2.5rem;
    }
    .hero-subtitle {
        font-size: 1.1rem;
    }
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-section {
        height: 80vh;
    }
    .hero-title {
        font-size: 2rem;
    }
    .hero-subtitle {
        font-size: 1rem;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .use-cases-list {
        flex-direction: column;
        align-items: center;
    }
    .use-cases-list li {
        width: 80%;
        justify-content: center;
    }
}