/* ============================================
   导航栏样式 - 统一设计系统
   ============================================ */

@import url('variables.css');

/* ========== 主导航栏 ========== */
.main-nav {
    background: linear-gradient(180deg, #FFFFFF 0%, var(--bg-light-orange) 100%);
    padding: var(--spacing-md) 0;
    text-align: center;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    width: 100%;
    border-bottom: 1px solid rgba(255, 167, 38, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.main-nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
}

.main-nav ul li {
    position: relative;
}

.main-nav ul li a {
    color: var(--text-primary);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-medium);
    padding: var(--spacing-sm) var(--spacing-md);
    position: relative;
    display: inline-block;
    transition: color var(--transition-base);
}

/* 导航链接底部指示线 */
.main-nav ul li a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 4px;
    background-color: transparent;
    transition: width var(--transition-base), background-color var(--transition-base);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.main-nav ul li a:hover::after,
.main-nav ul li a.active::after {
    width: 100%;
}

/* 不同导航项的颜色主题 */
.main-nav ul li a.nav-home:hover,
.main-nav ul li a.nav-home.active {
    color: var(--primary-orange);
}

.main-nav ul li a.nav-home:hover::after,
.main-nav ul li a.nav-home.active::after {
    background-color: var(--primary-orange);
}

.main-nav ul li a.nav-about:hover,
.main-nav ul li a.nav-about.active {
    color: var(--primary-orange-light);
}

.main-nav ul li a.nav-about:hover::after,
.main-nav ul li a.nav-about.active::after {
    background-color: var(--primary-orange-light);
}

.main-nav ul li a.nav-events:hover,
.main-nav ul li a.nav-events.active {
    color: var(--accent-yellow);
}

.main-nav ul li a.nav-events:hover::after,
.main-nav ul li a.nav-events.active::after {
    background-color: var(--accent-yellow);
}

.main-nav ul li a.nav-join:hover,
.main-nav ul li a.nav-join.active {
    color: var(--accent-green);
}

.main-nav ul li a.nav-join:hover::after,
.main-nav ul li a.nav-join.active::after {
    background-color: var(--accent-green);
}

.main-nav ul li a.nav-contact:hover,
.main-nav ul li a.nav-contact.active {
    color: var(--accent-purple);
}

.main-nav ul li a.nav-contact:hover::after,
.main-nav ul li a.nav-contact.active::after {
    background-color: var(--accent-purple);
}

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

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(180deg, #FFFFFF 0%, var(--bg-light-orange) 100%);
    min-width: 200px;
    box-shadow: var(--shadow-xl);
    border-radius: var(--radius-xl);
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: var(--z-dropdown);
    margin-top: var(--spacing-sm);
    border: 1px solid rgba(255, 167, 38, 0.15);
}

.dropdown-menu a {
    color: var(--text-primary);
    padding: var(--spacing-md) var(--spacing-lg);
    display: block;
    text-align: left;
    transition: all var(--transition-base);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
}

.dropdown-menu a:hover {
    background: linear-gradient(135deg, var(--primary-orange-light) 0%, var(--primary-orange) 100%);
    color: white;
    transform: translateX(5px);
    padding-left: var(--spacing-xl);
}

.dropdown:hover .dropdown-menu {
    display: block;
    opacity: 1;
    visibility: visible;
}

/* ========== 子菜单（用于join页面） ========== */
.main-nav .submenu {
    list-style: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--bg-cream);
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-md);
    min-width: 150px;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
    z-index: var(--z-dropdown);
    padding: var(--spacing-sm) 0;
    white-space: nowrap;
    margin-top: var(--spacing-sm);
}

.main-nav li.has-submenu:hover .submenu {
    opacity: 1;
    visibility: visible;
}

.main-nav .submenu li {
    display: block;
    text-align: center;
}

.main-nav .submenu li a {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
    color: var(--text-primary);
    display: block;
    transition: background-color var(--transition-base), color var(--transition-base);
}

.main-nav .submenu li a:hover,
.main-nav .submenu li a.active {
    background-color: var(--primary-orange-light);
    color: white;
}

.main-nav .submenu li a::after {
    display: none;
}

/* ========== 固定Logo ========== */
.fixed-logo {
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    z-index: var(--z-cursor);
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.98), rgba(255, 243, 224, 0.98));
    padding: var(--spacing-sm);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-colored);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    transition: all var(--transition-base);
    border: 2px solid rgba(255, 167, 38, 0.2);
}

.fixed-logo img {
    width: 80px;
    height: 80px;
    object-fit: contain;
    display: block;
    border-radius: var(--radius-full);
}

.fixed-logo:hover {
    transform: scale(1.08) rotate(5deg);
    box-shadow: var(--shadow-2xl);
    border-color: var(--primary-orange-light);
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
    .main-nav {
        padding: var(--spacing-sm) 0;
    }
    
    .main-nav ul {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .dropdown-menu {
        left: 0;
        transform: none;
        width: 100%;
        position: static;
        margin-top: var(--spacing-sm);
    }
    
    .main-nav .submenu {
        position: static;
        transform: none;
        width: 100%;
        box-shadow: none;
        border-radius: 0;
        padding: 0;
        min-width: auto;
        background-color: transparent;
    }
    
    .main-nav .submenu li a {
        background-color: var(--primary-orange-light);
        margin: var(--spacing-xs) var(--spacing-lg);
        border-radius: var(--radius-md);
    }
    
    .fixed-logo {
        top: var(--spacing-sm);
        left: var(--spacing-sm);
    }
    
    .fixed-logo img {
        width: 60px;
        height: 60px;
    }
}