/* ==================== CSS 变量和主题 ==================== */
:root {
    /* 莫兰迪配色 - 明亮模式 */
    --bg-primary: #f2f0eb;     /* 温暖的米灰色 */
    --bg-secondary: #ffffff;   /* 纯白卡片 */
    --text-primary: #545454;   /* 柔和深灰 */
    --text-secondary: #8c8c8c; /* 中性灰 */
    --border-color: #d9d6ce;   /* 浅卡其灰 */
    --accent-color: #7e9ca8;   /* 莫兰迪蓝灰 */
    --accent-hover: #5f7882;   /* 深蓝灰 */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s ease;
}

body.dark-mode {
    /* 莫兰迪配色 - 暗黑模式 */
    --bg-primary: #2c2e33;     /* 深Slate灰 */
    --bg-secondary: #363940;   /* 稍亮的Slate */
    --text-primary: #d8d8d8;   /* 灰白 */
    --text-secondary: #969696; /* 中灰 */
    --border-color: #484b52;   /* 深色边框 */
    --accent-color: #9fbbc7;   /* 亮莫兰迪蓝 */
    --accent-hover: #7e9ca8;   /* 莫兰迪蓝 */
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: var(--transition);
    line-height: 1.6;
}

/* ==================== 导航栏 ==================== */
.navbar {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
}

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

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

.nav-link:hover,
.nav-link.active {
    color: var(--accent-color);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.25rem;
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    padding: 0.5rem;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

/* ==================== 容器和页面 ==================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.page {
    display: none;
    animation: fadeIn 0.3s ease;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== 首页样式 ==================== */
.page-header {
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
}

/* 筛选和搜索 */
.filter-section {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.search-input,
.category-filter {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.search-input {
    flex: 1;
    min-width: 200px;
}

.search-input:focus,
.category-filter:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

/* 博客网格 */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.blog-card {
    background-color: var(--bg-secondary);
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    cursor: pointer;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.blog-card-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
}

.blog-card-content {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.blog-card-title {
    font-size: 1.3rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.blog-card-category {
    display: inline-block;
    background-color: var(--accent-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    margin-bottom: 0.75rem;
    width: fit-content;
}

.blog-card-excerpt {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    flex: 1;
}

.blog-card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ==================== 博客详情页 ==================== */
.back-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    margin-bottom: 2rem;
    font-size: 1rem;
    transition: var(--transition);
}

.back-btn:hover {
    background-color: var(--accent-hover);
}

.blog-detail {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
    margin-bottom: 2rem;
}

.blog-detail h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.blog-detail-meta {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.blog-detail-content {
    font-size: 1.05rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.blog-detail-content p {
    margin-bottom: 1.5rem;
    text-indent: 0;
}

.blog-img-wrapper {
    margin: 2rem 0;
    text-align: center;
}

.blog-content-img {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.blog-content-img:hover {
    transform: scale(1.02);
}

/* ==================== 评论部分 ==================== */
.comments-section {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
    margin-bottom: 2rem;
}

.comments-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.comment-form {
    background-color: var(--bg-primary);
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-input,
.form-textarea {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 100px;
}

.comments-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.comment-item {
    background-color: var(--bg-primary);
    padding: 1.5rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--accent-color);
}

.comment-author {
    font-weight: bold;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

.comment-time {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.comment-text {
    color: var(--text-primary);
}

/* ==================== 关于页面 ==================== */
.about-container {
    max-width: 800px;
    margin: 0 auto;
}

.about-container h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
}

.about-content {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
}

.about-avatar {
    font-size: 4rem;
    flex-shrink: 0;
}

.about-text h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.about-text h3 {
    font-size: 1.2rem;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.about-text ul {
    list-style-position: inside;
    gap: 0.5rem;
    display: flex;
    flex-direction: column;
}

.about-text li {
    color: var(--text-secondary);
}

/* ==================== 联系页面 ==================== */
.contact-container {
    max-width: 600px;
    margin: 0 auto;
}

.contact-container h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-align: center;
}

.contact-intro {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-form {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
    margin-bottom: 3rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.form-group label {
    font-weight: 500;
}

.contact-info {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
}

.contact-info h3 {
    margin-bottom: 1rem;
}

.contact-info p {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

/* ==================== 按钮样式 ==================== */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
}

.btn-primary:active {
    transform: scale(0.98);
}

/* ==================== Toast提示 ==================== */
.toast {
    position: fixed;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #333;
    color: white;
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    z-index: 1000;
    transition: var(--transition);
}

.toast.show {
    bottom: 2rem;
}

.toast.success {
    background-color: #4caf50;
}

.toast.error {
    background-color: #f44336;
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    .nav-container {
        padding: 1rem;
    }

    .nav-brand {
        font-size: 1.2rem;
    }

    .nav-menu {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .container {
        padding: 1rem;
    }

    .page-header h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 1rem;
    }

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

    .filter-section {
        flex-direction: column;
    }

    .search-input {
        min-width: 100%;
    }

    .about-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .about-avatar {
        font-size: 3rem;
    }

    .blog-detail {
        padding: 1rem;
    }

    .comment-form {
        padding: 1rem;
    }

    .nav-link {
        padding: 0;
        border-bottom: none;
    }

    .nav-link:hover,
    .nav-link.active {
        color: var(--accent-color);
        border-bottom: none;
    }
}

@media (max-width: 480px) {
    .page-header h1 {
        font-size: 1.5rem;
    }

    .blog-detail-meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .blog-detail h1 {
        font-size: 1.5rem;
    }

    .nav-menu {
        gap: 0.5rem;
    }

    .blog-card-image {
        height: 150px;
        font-size: 2rem;
    }
}

/* ==================== 关于页面 ==================== */
.about-container {
    max-width: 900px;
    margin: 0 auto;
}

.about-section {
    background-color: var(--bg-secondary);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.about-section h2 {
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.5rem;
}

/* 单栏目 About 页面布局 */
.about-content.single-column {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.section-title {
    font-size: 1.2rem;
    color: var(--accent-color);
    margin: 0.5rem 0 0.5rem 0;
}

.about-item {
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    padding: 0.6rem 1rem;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
}

.about-item summary {
    list-style: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 600;
    color: var(--text-primary);
}

.about-item summary::-webkit-details-marker { display:none; }

.about-item summary::after {
    content: '\25BE';
    margin-left: auto;
    color: var(--accent-color);
    font-size: 0.85rem;
    transition: transform 0.25s ease;
}

.about-item[open] summary::after {
    transform: rotate(180deg);
}

.about-body {
    margin-top: 0.75rem;
    color: var(--text-primary);
    line-height: 1.7;
}

@media (min-width: 900px) {
    .about-container { max-width: 900px; }
}

/* 时间线样式 */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.4rem; /* 2rem padding + 0.4rem offset */
    top: 0.3rem;
    width: 0.8rem;
    height: 0.8rem;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 3px solid var(--bg-secondary);
    box-shadow: 0 0 0 1px var(--border-color);
}

.timeline-header {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
    margin-bottom: 0.8rem;
}

.timeline-header h3 {
    margin: 0;
    color: var(--text-primary);
    font-size: 1.25rem;
}

.timeline-header .company {
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 1rem;
}

.timeline-header .date {
    font-size: 0.9rem;
    color: var(--text-secondary);
    background-color: var(--bg-primary);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
}

.timeline-content h4 {
    margin: 0.5rem 0;
    color: var(--accent-color);
    font-size: 1.05rem;
    font-weight: 600;
}

.timeline-content p {
    color: var(--text-primary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    text-align: justify;
    line-height: 1.7;
}

/* 项目卡片 */
.project-item {
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 1.5rem;
    transition: var(--transition);
    background-color: var(--bg-primary); /* 轻微背景区别 */
}

.project-item:hover {
    border-color: var(--accent-color);
    background-color: var(--bg-secondary);
    box-shadow: var(--shadow-md);
}

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

.project-title {
    flex: 1;
}

.project-title h3 {
    margin: 0 0 0.3rem 0;
    font-size: 1.2rem;
}

.project-badge {
    display: inline-block;
    font-size: 0.8rem;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    background-color: var(--accent-color);
    color: #fff;
    margin-left: 0.5rem;
    vertical-align: middle;
}

.project-detail {
    margin-bottom: 0.8rem;
    font-size: 0.95rem;
}

.project-detail strong {
    color: var(--accent-color);
    font-weight: 600;
    margin-right: 0.3rem;
}

@media (max-width: 768px) {
    .timeline-header {
        flex-direction: column;
        gap: 0.3rem;
    }
    
    .timeline-header .date {
        margin-left: 0;
    }
}