/* --- 1. 全局变量与重置 --- */
:root {
    --primary: #0078d7;     
    --primary-dark: #005a9e;  
    --bg-body: #f3f3f3;       
    --bg-tile: #ffffff;       
    --text-main: #2b2b2b;
    --text-light: #767676;
    --grid-gap: 12px;
}

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

body {
    font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    height: 100vh;
    overflow: hidden;
    display: flex;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- 2. 侧边栏 (Sidebar) --- */
.sidebar {
    width: 280px;
    background-color: var(--bg-tile);
    border-right: 1px solid #e5e5e5;
    display: flex;
    flex-direction: column;
    padding: 40px 20px;
    flex-shrink: 0;
}

.profile {
    margin-bottom: 40px;
}

.profile-name {
    font-size: 24px;
    font-weight: 300;
    color: var(--primary);
    margin-bottom: 5px;
}

.profile-desc {
    font-size: 14px;
    color: var(--text-light);
}

.nav-menu li {
    margin-bottom: 2px;
}

.nav-link {
    display: block;
    padding: 12px 15px;
    font-size: 15px;
    transition: all 0.1s linear;
    border-left: 4px solid transparent;
}

.nav-link:hover, .nav-link.active {
    background-color: #e6f2fa;
    color: var(--primary);
    border-left-color: var(--primary);
}

/* --- 3. 主内容区 (Main Content) --- */
.main-content {
    flex-grow: 1;
    padding: 30px 40px;
    overflow-y: auto;
}

.page-header {
    margin-bottom: 30px;
}

.page-title {
    font-size: 32px;
    font-weight: 300;
}

/* --- 4. 磁贴网格 (Tiles) --- */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--grid-gap);
}

.tile {
    background-color: var(--bg-tile);
    padding: 20px;
    height: 220px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 0.1s linear, outline 0.1s;
    cursor: pointer;
    border: 1px solid transparent;
    position: relative;
    /* 初始透明，为了动画 */
    opacity: 0; 
}

.tile:hover {
    border: 2px solid var(--primary);
    background-color: #fcfcfc;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05); 
}

.tile:active {
    transform: scale(0.99);
}

.tile-date {
    font-size: 12px;
    color: var(--text-light);
    text-transform: uppercase;
    margin-bottom: 10px;
}

tile-title {
    font-size: 20px;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 10px;
    color: #000000;
    color: var(--text-main) !important;
}

/* 针对手机端增加一段强制补丁 */
@media (prefers-color-scheme: dark) {
    .tile-title {
        color: #ffffff !important; /* 直接写死纯白颜色值，不给手机浏览器出错的机会 */
    }
}


.tile-excerpt {
    font-size: 14px;
    color: #555;
    line-height: 1.5;
    flex-grow: 1;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}

.tile-tag {
    align-self: flex-start;
    background-color: var(--primary);
    color: white;
    font-size: 12px;
    padding: 4px 8px;
    margin-top: 15px;
    display: inline-block;
}

/* --- 5. 滚动条与动画 --- */
::-webkit-scrollbar { width: 12px; }
::-webkit-scrollbar-track { background: #f1f1f1; }
::-webkit-scrollbar-thumb { background: #cdcdcd; }
::-webkit-scrollbar-thumb:hover { background: #a6a6a6; }

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

/* 响应式 */
@media (max-width: 768px) {
    body { flex-direction: column; overflow: auto; }
    .sidebar { width: 100%; height: auto; border-right: none; border-bottom: 1px solid #ddd; padding: 20px; }
    .main-content { overflow: visible; padding: 20px; }
    .tile { height: auto; min-height: 200px; }
}

/* --- 6. 404 错误页样式 (Win10 蓝屏风格) --- */
.error-container {
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start; /* Win10 错误信息通常靠左 */
    animation: fadeIn 0.4s ease forwards;
}

.error-face {
    font-size: 100px;
    font-weight: 300;
    margin-bottom: 20px;
    color: var(--primary); /* 使用蓝色笑脸/哭脸 */
}

.error-code {
    font-size: 24px;
    font-weight: 300;
    margin-bottom: 10px;
}

.error-desc {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 30px;
    max-width: 500px;
    line-height: 1.5;
}

.btn-home {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 15px;
    cursor: pointer;
    transition: background 0.2s;
    display: inline-block;
}

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

/* --- 7. 系统级深色模式适配 (Dark Mode) --- */
/* 当系统设置为深色时，自动覆盖上面的变量 */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-body: #202020;       /* 深灰背景，护眼且高级 */
        --bg-tile: #2b2b2b;       /* 磁贴颜色稍亮一点 */
        --text-main: #ffffff;     /* 文字变白 */
        --text-light: #a0a0a0;    /* 辅助文字变灰白 */
        /* --primary 保持蓝色，或者你可以微调成 #4cc2ff 这种更亮的蓝 */
    }

    /* 侧边栏边框在深色下需要调整 */
    .sidebar {
        border-right: 1px solid #333333;
    }

    /* 磁贴悬停效果调整 */
    .tile:hover {
        background-color: #333333;
        border-color: var(--primary);
    }
    
    /* 导航栏悬停背景变深 */
    .nav-link:hover, .nav-link.active {
        background-color: #333333;
    }
}