/* CSS 样式文件 - 黑白灰简约博客设计 */

/* 基础重置和字体设置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #141414;
    background-color: #FFFFFF;
}

/* 间距系统 */
.space-xs { margin: 8px; }
.space-sm { margin: 16px; }
.space-md { margin: 24px; }
.space-lg { margin: 32px; }
.space-xl { margin: 48px; }
.space-xxl { margin: 64px; }

/* 顶部导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background-color: #FFFFFF;
    border-bottom: 1px solid #DEE2E6;
    z-index: 1000;
}

.nav-container {
    max-width: 800px;
    margin: 0 auto;
    height: 100%;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-icon {
    width: 32px;
    height: 32px;
    border-radius: 4px;
}

.brand-text {
    font-size: 16px;
    font-weight: 500;
    color: #141414;
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-link {
    font-size: 14px;
    font-weight: 400;
    color: #495057;
    text-decoration: none;
    transition: color 200ms linear;
}

.nav-link:hover {
    color: #141414;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 20px;
    height: 2px;
    background-color: #141414;
    transition: all 200ms ease;
}

/* 英雄区 */
.hero {
    width: 100%;
    height: 400px;
    background-image: linear-gradient(rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.4)), url('../imgs/blog_header_1.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    margin-top: 72px;
}

.hero-content {
    max-width: 600px;
    padding: 0 32px;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    color: #FFFFFF;
    line-height: 1.2;
    margin-bottom: 16px;
}

.hero-subtitle {
    font-size: 18px;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.5;
}

/* 主内容区 */
.main-content {
    padding: 64px 0;
    min-height: calc(100vh - 472px);
}

.content-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 32px;
}

.content-title {
    font-size: 24px;
    font-weight: 600;
    color: #141414;
    margin-bottom: 48px;
    text-align: center;
}

/* 文章列表 */
.articles-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.article-item {
    padding: 32px;
    border: 1px solid #DEE2E6;
    border-radius: 4px;
    background-color: #FFFFFF;
    transition: border-color 200ms linear;
    cursor: pointer;
}

.article-item:hover {
    border-color: #141414;
}

.article-title {
    font-size: 24px;
    font-weight: 600;
    color: #141414;
    line-height: 1.4;
    margin-bottom: 8px;
}

.article-time {
    font-size: 14px;
    font-weight: 400;
    color: #495057;
    line-height: 1.5;
}

/* 模态框 */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 200ms ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    width: 400px;
    background-color: #F8F9FA;
    border-radius: 4px;
    padding: 32px;
    transform: scale(0.95);
    transition: transform 250ms ease-out;
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
    color: #141414;
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    color: #495057;
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 200ms linear;
}

.modal-close:hover {
    color: #141414;
}

.modal-content {
    text-align: center;
}

.modal-email {
    font-size: 16px;
    font-weight: 400;
    color: #495057;
}

/* 移动端菜单 */
.mobile-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background-color: #FFFFFF;
    border-bottom: 1px solid #DEE2E6;
    padding: 24px;
    transform: translateY(-100%);
    transition: transform 200ms ease;
    z-index: 999;
}

.mobile-menu.active {
    transform: translateY(0);
}

.mobile-link {
    display: block;
    font-size: 16px;
    font-weight: 400;
    color: #495057;
    text-decoration: none;
    padding: 12px 0;
    border-bottom: 1px solid #DEE2E6;
    transition: color 200ms linear;
}

.mobile-link:last-child {
    border-bottom: none;
}

.mobile-link:hover {
    color: #141414;
}

/* 移动端响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        height: 250px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .nav-container,
    .content-container {
        padding-left: 24px;
        padding-right: 24px;
    }
    
    .content-title {
        font-size: 20px;
        margin-bottom: 32px;
    }
    
    .article-item {
        padding: 24px;
    }
    
    .article-title {
        font-size: 20px;
    }
    
    .main-content {
        padding: 48px 0;
    }
}

/* 超小屏幕优化 */
@media (max-width: 480px) {
    .nav-container,
    .content-container {
        padding-left: 16px;
        padding-right: 16px;
    }
    
    .article-item {
        padding: 20px;
    }
    
    .hero-content {
        padding: 0 24px;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 选中文本样式 */
::selection {
    background-color: #141414;
    color: #FFFFFF;
}

::-moz-selection {
    background-color: #141414;
    color: #FFFFFF;
}

/* 分类筛选样式 */
.category-filter {
    padding: 32px 0;
    background-color: #F8F9FA;
    border-bottom: 1px solid #DEE2E6;
}

.filter-tabs {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.filter-tab {
    padding: 12px 24px;
    background-color: #FFFFFF;
    border: 1px solid #DEE2E6;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    color: #495057;
    cursor: pointer;
    transition: all 200ms linear;
    white-space: nowrap;
}

.filter-tab:hover {
    border-color: #141414;
    color: #141414;
}

.filter-tab.active {
    background-color: #141414;
    border-color: #141414;
    color: #FFFFFF;
}

/* 加载状态样式 */
.loading-spinner {
    text-align: center;
    padding: 64px 32px;
    color: #495057;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid #DEE2E6;
    border-top: 3px solid #141414;
    border-radius: 50%;
    margin: 0 auto 16px auto;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-spinner p {
    font-size: 16px;
    margin: 0;
}

/* 无文章状态样式 */
.no-articles {
    text-align: center;
    padding: 64px 32px;
    color: #495057;
}

.no-articles p {
    font-size: 18px;
    margin: 0;
}

/* 分类标签样式 */
.article-item .category-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    color: #FFFFFF;
    margin-bottom: 8px;
}

.article-item .category-tag.programming {
    background-color: #141414;
}

.article-item .category-tag.reading {
    background-color: #495057;
}

.article-item .category-tag.essay {
    background-color: #6C757D;
}

.article-item .article-title {
    display: block;
    text-decoration: none;
    color: #141414;
}

.article-item .article-title:hover {
    color: #495057;
}

/* 移动端分类筛选优化 */
@media (max-width: 768px) {
    .category-filter {
        padding: 24px 0;
    }
    
    .filter-tabs {
        gap: 12px;
    }
    
    .filter-tab {
        padding: 10px 20px;
        font-size: 13px;
    }
    
    .loading-spinner,
    .no-articles {
        padding: 48px 24px;
    }
    
    .loading-spinner p,
    .no-articles p {
        font-size: 16px;
    }
}

/* 响应式文章网格 */
@media (max-width: 768px) {
    .articles-list {
        display: flex;
        flex-direction: column;
        gap: 16px;
    }
}