/* 导航栏基础样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
    transition: background-color 0.4s ease, border-color 0.4s ease, color 0.4s ease, box-shadow 0.4s ease;
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.4s ease;
}

.navbar-brand:hover {
    color: var(--primary-hover);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--nav-link-color);
    font-weight: 500;
    display: flex;
    align-items: center;
    transition: color 0.2s, background-color 0.4s ease;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* 用户下拉菜单 */
.dropdown {
    position: relative;
    display: inline-block;
}

.nav-user {
    cursor: pointer;
    font-weight: 500;
    color: var(--nav-link-color);
    display: flex;
    align-items: center;
    gap: 0.15rem;
    padding: 0.5rem 0;
    transition: color 0.4s ease;
}

.nav-user:hover {
    color: var(--primary-color);
}

.nav-user svg {
    transition: transform 0.3s ease;
}

.dropdown:hover .nav-user svg {
    transform: rotate(180deg);
}

.dropdown-content {
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.4s ease;
    position: absolute;
    top: 100%; /* 确保它紧贴着父容器底部 */
    right: 0;
    background-color: var(--card-bg);
    min-width: 150px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    z-index: 100;
    overflow: hidden;
    padding: 0 0; /* 可以增加一点内边距，让菜单不那么拥挤 */
}

.dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    color: var(--text-color);
    padding: 10px 16px;
    text-decoration: none;
    display: flex;
    align-items: center;
    font-size: 0.875rem;
    transition: background-color 0.2s, color 0.4s ease;
    text-align: left;
}

.dropdown-content a:hover {
    background-color: var(--bg-color);
    color: var(--primary-color);
}

.dropdown-content a.delete-account {
    color: var(--muted-text);
}

.dropdown-content a.delete-account:hover {
    color: var(--error-color);
}

.logout-btn {
    background: none;
    border: none;
    color: var(--nav-link-color);
    font-weight: 500;
    cursor: pointer;
    font-size: 1rem;
    transition: color 0.4s ease;
}

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

/* 导航栏响应式 */
@media (max-width: 640px) {
    .navbar {
        position: fixed !important; /* 强制保持固定定位 */
        top: 0 !important;          /* 强制置顶，消除间隙 */
        left: 0 !important;
        right: 0 !important;
        padding: 0.5rem 1rem;
        justify-content: center;
        margin-top: 0 !important;    /* 消除任何可能的边距 */
    }

    .navbar-brand {
        display: none;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }
}