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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: #1a1a1a;
    color: #e0e0e0;
    margin: 0;
    padding: 0;
}

/* 菜单栏固定 */
.nav-menu-fixed {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(30, 30, 35, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav-menu-bar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-menu-item {
    position: relative;
}

.nav-menu-btn {
    background: transparent;
    border: none;
    padding: 0.5rem 1rem;
    color: #aaa;
    font-size: 0.95rem;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.2s;
}

.nav-menu-btn:hover, .nav-menu-btn.active {
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.nav-sub-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: rgba(30,30,35,0.98);
    backdrop-filter: blur(10px);
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.1);
    padding: 0.5rem;
    min-width: 120px;
    display: none;
    flex-direction: column;
    gap: 0.25rem;
    z-index: 1001;
}

.nav-menu-item:hover .nav-sub-menu {
    display: flex;
}

.nav-sub-item {
    background: transparent;
    border: none;
    padding: 0.4rem 1rem;
    color: #aaa;
    font-size: 0.85rem;
    cursor: pointer;
    border-radius: 6px;
    text-align: left;
}

.nav-sub-item:hover {
    background: rgba(255,255,255,0.1);
    color: white;
}

/* 搜索区 */
.nav-search-section {
    padding: 2rem 1rem;
    background: linear-gradient(135deg, #1e1e2f 0%, #16162a 100%);
}

.nav-search-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

.nav-engine-group {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.nav-engine-btn {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    color: #ccc;
    cursor: pointer;
    font-size: 0.8rem;
}

.nav-engine-btn.active, .nav-engine-btn:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.nav-search-container {
    display: flex;
    gap: 0.5rem;
    background: rgba(255,255,255,0.1);
    border-radius: 50px;
    padding: 0.3rem 0.5rem 0.3rem 1rem;
    border: 1px solid rgba(255,255,255,0.2);
}

.nav-search-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: white;
    font-size: 1rem;
    padding: 0.5rem 0;
}

.nav-search-input::placeholder {
    color: #888;
}

.nav-search-btn {
    background: #667eea;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 卡片网格 */
.nav-card-grid {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 1rem;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
}

.nav-card {
    background: rgba(40,40,45,0.8);
    backdrop-filter: blur(5px);
    border-radius: 16px;
    padding: 1rem;
    transition: all 0.3s;
    cursor: pointer;
    border: 1px solid rgba(255,255,255,0.1);
}

.nav-card:hover {
    transform: translateY(-4px);
    background: rgba(55,55,65,0.9);
    border-color: #667eea;
    box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}

.nav-card-icon {
    width: 100%;
    height: 48px;
    border-radius: 12px;
    /* background: linear-gradient(135deg, #667eea, #764ba2); */
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.75rem;
    font-size: 28px;
}

.nav-card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: white;
}

.nav-card-desc {
    font-size: 0.8rem;
    color: #aaa;
    line-height: 1.4;
}

/* 页脚 */
.nav-footer {
    background: rgba(20,20,25,0.95);
    padding: 1.5rem;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-top: 2rem;
}

.nav-footer p {
    font-size: 0.8rem;
    color: #888;
}

@media (max-width: 768px) {
    .nav-card-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1rem;
    }
}