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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

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(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.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);
}

.logo a {
    color: inherit;
    text-decoration: none;
}

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

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

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

/* Hero Section */
.hero {
    padding: 6rem 0;
    background: linear-gradient(135deg, #2b5876 0%, #4e89ae 100%);
    color: white;
    text-align: center;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

.tag {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    backdrop-filter: blur(10px);
}

/* Articles Section */
.articles {
    padding: 4rem 0;
    background: var(--bg-secondary);
}

.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-color);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.article-card {
    background: var(--bg-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.article-card-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.article-card-excerpt {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.5;
}

.article-card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--text-light);
}

/* About Section */
.about {
    padding: 4rem 0;
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-intro {
    font-size: 1.2rem;
    color: var(--text-color);
    text-align: center;
    margin-bottom: 3rem;
    line-height: 1.8;
    font-weight: 500;
}

.about-details {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

.about-item {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 8px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.about-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.about-item h3 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.about-item p {
    color: var(--text-light);
    line-height: 1.6;
    margin: 0;
}

.tech-stack {
    margin-bottom: 2rem;
}

.tech-stack h3 {
    text-align: center;
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
}

.tech-tag {
    background: var(--bg-secondary);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.tech-tag:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.about-content p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--text-light);
}

.contact {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.contact-link {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    transition: background 0.3s;
}

.contact-link:hover {
    background: var(--secondary-color);
}

/* Article Detail */
.article-detail {
    padding: 4rem 0;
    min-height: calc(100vh - 200px);
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.article-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.article-meta {
    display: flex;
    gap: 2rem;
    color: var(--text-light);
    font-size: 0.9rem;
}

.article-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
}

.article-content h2 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.article-content h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.article-content p {
    margin-bottom: 1rem;
}

.article-content code {
    background: var(--bg-secondary);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.article-content pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 6px;
    overflow-x: auto;
    margin: 1rem 0;
}

.article-content pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.article-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.back-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .nav {
        gap: 1rem;
    }
    
    .articles-grid {
        grid-template-columns: 1fr;
    }
    
    .article-title {
        font-size: 1.75rem;
    }
    
    .about-details {
        grid-template-columns: 1fr;
    }
}


/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.3s ease;
}

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

.modal-content {
    background-color: var(--bg-color);
    margin: 15% auto;
    padding: 2rem;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    position: relative;
    animation: slideDown 0.3s ease;
}

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

.modal-close {
    position: absolute;
    right: 1rem;
    top: 1rem;
    font-size: 2rem;
    font-weight: 300;
    color: var(--text-light);
    cursor: pointer;
    transition: color 0.3s;
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-color);
}

.modal-title {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    text-align: center;
}

.wechat-info {
    text-align: center;
}

.wechat-label {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.wechat-id-box {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin: 1rem 0;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 8px;
    border: 2px dashed var(--border-color);
}

.wechat-id {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    letter-spacing: 1px;
}

.copy-btn {
    padding: 0.5rem 1.25rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s;
}

.copy-btn:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

.copy-btn:active {
    transform: translateY(0);
}

.copy-btn.copied {
    background: #10b981;
}

.wechat-tip {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-top: 1rem;
}

@media (max-width: 768px) {
    .modal-content {
        margin: 30% auto;
        width: 85%;
    }
    
    .wechat-id {
        font-size: 1.25rem;
    }
}