/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #ffffff;
    --bg-light: #f8f9fa;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 5px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--bg-color);
}

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

/* 导航栏 */
.navbar {
    background: var(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-brand h1 {
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 0.2rem;
}

.nav-brand .subtitle {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: normal;
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--secondary-color);
}

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--secondary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: var(--transition);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

.btn {
    padding: 0.8rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
    border: 2px solid transparent;
}

.btn-primary {
    background: white;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.hero-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    opacity: 0.1;
}

.decoration-circle {
    position: absolute;
    border-radius: 50%;
    background: white;
    animation: float 20s infinite ease-in-out;
}

.decoration-circle:nth-child(1) {
    width: 300px;
    height: 300px;
    top: -100px;
    left: -100px;
    animation-delay: 0s;
}

.decoration-circle:nth-child(2) {
    width: 200px;
    height: 200px;
    bottom: -50px;
    right: 10%;
    animation-delay: 5s;
}

.decoration-circle:nth-child(3) {
    width: 150px;
    height: 150px;
    top: 50%;
    right: -50px;
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
    }
    33% {
        transform: translate(30px, -30px) rotate(120deg);
    }
    66% {
        transform: translate(-20px, 20px) rotate(240deg);
    }
}

/* 特色介绍 */
.features {
    padding: 5rem 0;
    background: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* 内容预览 */
.preview {
    padding: 5rem 0;
}

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

.preview-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.preview-image {
    height: 200px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.preview-label {
    background: rgba(255, 255, 255, 0.9);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    color: var(--primary-color);
}

.preview-content {
    padding: 2rem;
}

.preview-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.preview-content p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.preview-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

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

/* 页脚 */
.footer {
    background: var(--primary-color);
    color: white;
    text-align: center;
    padding: 2rem 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: var(--transition);
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

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

    .nav-toggle {
        display: flex;
    }

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

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

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

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

    .features-grid,
    .preview-grid {
        grid-template-columns: 1fr;
    }
}

/* 通用页面样式 */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.page-content {
    padding: 3rem 0;
}

/* 卡片网格 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background: white;
    border-radius: 10px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.card-title {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.card-content {
    color: var(--text-light);
    line-height: 1.8;
}

.card-meta {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--text-light);
}