/* 全局样式重置 */
* {
    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);
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* 头部样式 */
.header {
    background-color: var(--bg-color);
    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 h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

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

.nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: 6px;
}

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

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 3px 0;
    transition: var(--transition);
    border-radius: 3px;
}

/* 主横幅 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.btn-primary {
    display: inline-block;
    padding: 0.875rem 2rem;
    background-color: white;
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

/* 文章列表 */
.articles-section {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-color);
}

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

.article-card {
    background-color: var(--bg-color);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

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

.article-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.article-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.article-date {
    color: var(--text-light);
    font-size: 0.875rem;
}

.article-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-color);
    line-height: 1.4;
}

.article-excerpt {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.7;
    flex-grow: 1;
}

.article-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.btn-read-more {
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.btn-read-more:hover {
    background-color: var(--secondary-color);
}

.read-time {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* 关于部分 */
.about-section {
    padding: 4rem 0;
    background-color: var(--bg-color);
}

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

.about-text p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.about-text strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s ease;
}

.modal.active {
    display: flex;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: var(--bg-color);
    border-radius: 12px;
    max-width: 900px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.3s ease;
}

.modal-close {
    position: sticky;
    top: 0;
    right: 0;
    float: right;
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-light);
    background: none;
    border: none;
    cursor: pointer;
    padding: 1rem;
    z-index: 1;
}

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

.modal-body {
    padding: 2rem;
}

.article-detail h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.article-detail h3 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.article-detail p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

.article-detail code {
    background-color: var(--bg-secondary);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

.article-detail pre {
    background-color: var(--bg-secondary);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0;
}

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

.footer-content p {
    margin: 0.5rem 0;
}

.footer-icp a {
    color: #9ca3af;
    text-decoration: none;
    transition: var(--transition);
}

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

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

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

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

/* 响应式设计 - 平板 */
@media (max-width: 768px) {
    .header .container {
        flex-wrap: wrap;
    }

    .nav {
        display: none;
        width: 100%;
        order: 3;
    }

    .nav.active {
        display: block;
    }

    .nav ul {
        flex-direction: column;
        gap: 0;
        padding-top: 1rem;
    }

    .nav a {
        display: block;
        padding: 0.75rem 1rem;
    }

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

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

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

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

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

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

/* 响应式设计 - 手机 */
@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 4rem 0;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    .btn-primary {
        padding: 0.75rem 1.5rem;
        font-size: 0.95rem;
    }

    .articles-section {
        padding: 3rem 0;
    }

    .section-title {
        font-size: 1.75rem;
        margin-bottom: 2rem;
    }

    .article-card {
        padding: 1.25rem;
    }

    .article-title {
        font-size: 1.25rem;
    }

    .modal-content {
        width: 95%;
    }

    .modal-body {
        padding: 1.5rem;
    }

    .article-detail h2 {
        font-size: 1.5rem;
    }

    .about-text p {
        font-size: 1rem;
    }
}