* {
    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: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

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

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

/* Header */
.header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 1px;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--secondary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 6rem 0;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

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

/* Articles Section */
.articles {
    padding: 4rem 0;
}

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

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--secondary-color);
    border-radius: 2px;
}

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

.article-card {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

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

.article-header {
    margin-bottom: 1rem;
}

.article-date {
    font-size: 0.9rem;
    color: var(--text-light);
    display: block;
    margin-bottom: 0.5rem;
}

.article-title {
    font-size: 1.4rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    line-height: 1.4;
}

.article-excerpt {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.article-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.article-link:hover {
    color: var(--accent-color);
}

/* About Section */
.about {
    padding: 4rem 0;
    background: var(--white);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.about-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
    text-align: left;
}

.about-list li {
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
    color: var(--text-color);
    position: relative;
    padding-left: 2rem;
}

.about-list li::before {
    content: '✓';
    position: absolute;
    left: 0.8rem;
    color: var(--secondary-color);
    font-weight: bold;
}

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

.footer-text {
    font-size: 0.9rem;
    opacity: 0.9;
}

.icp-link {
    color: var(--white);
    text-decoration: none;
    transition: opacity 0.3s;
}

.icp-link:hover {
    opacity: 0.8;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav {
        gap: 1rem;
    }

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

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

    .article-grid {
        grid-template-columns: 1fr;
    }

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

    .about-list {
        grid-template-columns: 1fr;
    }
}