/* ========================================
   全站导航栏样式 - site-nav.css
   供所有学习笔记页面引用
   ======================================== */

/* ---- 导航栏容器 ---- */
.site-nav {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    width: 100%;
}

.site-nav .nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

/* ---- Logo ---- */
.site-nav .nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    flex-shrink: 0;
}

.site-nav .nav-logo img {
    height: 32px;
    width: auto;
    display: block;
}

.site-nav .nav-logo span {
    font-size: 1.1em;
    font-weight: 600;
    color: #2c3e50;
}

/* ---- 菜单 ---- */
.site-nav .nav-menu {
    display: flex;
    list-style: none;
    gap: 2px;
    margin: 0;
    padding: 0;
}

.site-nav .nav-menu li a {
    display: block;
    padding: 8px 14px;
    color: #555;
    text-decoration: none;
    font-size: 0.93em;
    border-radius: 6px;
    transition: all 0.2s;
    white-space: nowrap;
}

.site-nav .nav-menu li a:hover,
.site-nav .nav-menu li a.active {
    background: #f0f7ff;
    color: #3498db;
}

/* ---- 汉堡按钮 ---- */
.site-nav .nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.4em;
    color: #555;
    cursor: pointer;
    padding: 8px;
    line-height: 1;
}

/* ---- 响应式 ---- */
@media (max-width: 768px) {
    .site-nav .nav-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 10px 20px;
        box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        gap: 0;
    }

    .site-nav .nav-menu.open {
        display: flex;
    }

    .site-nav .nav-menu li a {
        padding: 12px 16px;
        border-radius: 0;
        border-bottom: 1px solid #f0f0f0;
    }

    .site-nav .nav-menu li:last-child a {
        border-bottom: none;
    }

    .site-nav .nav-toggle {
        display: block;
    }
}

/* ---- 学习笔记子导航 ---- */
.nav-bar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 8px;
    margin: 20px 0 30px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 8px;
}

.nav-button {
    display: inline-block;
    padding: 8px 16px;
    background-color: #3498db;
    color: #fff;
    text-decoration: none;
    border-radius: 5px;
    font-size: 0.9em;
    font-weight: bold;
    transition: background-color 0.2s;
    white-space: nowrap;
}

.nav-button:hover {
    background-color: #2980b9;
    color: #fff;
}

.nav-button.current {
    background-color: #c0392b;
}

.nav-button.current:hover {
    background-color: #a93226;
}

@media (max-width: 768px) {
    .nav-bar {
        flex-direction: column;
        align-items: center;
    }
    .nav-button {
        width: 100%;
        text-align: center;
    }
}