/* ========= 导航栏样式 ========= */
.navbar {
    width: 100%;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    border-bottom: 1px solid rgba(59, 130, 246, 0.15);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 0.7rem 2rem;
}

.nav-container {
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    text-decoration: none;
}

.logo-icon {
    background: linear-gradient(135deg, #1e3c72, #2a5298);
    width: 38px;
    height: 38px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease;
}

.nav-brand:hover .logo-icon {
    transform: scale(0.96);
}

.brand-name {
    font-weight: 700;
    font-size: 1.35rem;
    background: linear-gradient(135deg, #1f2b3c, #2c3e66);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    letter-spacing: -0.2px;
}

.nav-links {
    display: flex;
    gap: 1.8rem;
    align-items: center;
    flex-wrap: wrap;
}

/* 下拉菜单容器 */
.dropdown {
    position: relative;
}

/* 主链接按钮 */
.dropbtn {
    text-decoration: none;
    font-weight: 500;
    color: #2c3e66;
    transition: 0.2s;
    font-size: 0.95rem;
    padding: 0.3rem 0;
    border-bottom: 2px solid transparent;
    background: none;
    border: none;
    cursor: pointer;
    display: inline-block;
}

.dropbtn.active {
    color: #1e4b8f;
    border-bottom-color: #3b82f6;
}

/* 3行3列网格菜单 - 纯文字，无卡片装饰 */
.dropdown-content {
    position: absolute;
    top: calc(100% + 8px);
    left: -200%;
    background: white;
    border-radius: 0.5rem;
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08);
    padding: 0.5rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s ease;
    z-index: 200;
    border: 1px solid #eef2f8;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.25rem;
}

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

/* 网格中的每个菜单项 - 纯文字样式 */
.dropdown-content a {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0.6rem 1rem !important;
    color: #2c3e66;
    text-decoration: none;
    font-size: 0.75rem;
    font-weight: 500;
    transition: all 0.15s;
    background: transparent;
    border-radius: 0.3rem;
    white-space: nowrap;
}

.dropdown-content a:hover {
    background: #eef2ff;
    color: #1e4b8f;
}

/* 普通链接样式 */
.nav-links a:not(.dropbtn) {
    text-decoration: none;
    font-weight: 500;
    color: #2c3e66;
    transition: 0.2s;
    font-size: 0.95rem;
    padding: 0.3rem 0;
    border-bottom: 2px solid transparent;
}

.nav-links a:not(.dropbtn):hover {
    color: #1e4b8f;
    border-bottom-color: #3b82f6;
}

.nav-links a.active:not(.dropbtn) {
    color: #1e4b8f;
    border-bottom-color: #3b82f6;
}
@media (max-width: 780px) {
    .navbar {
        padding: 0.7rem 1rem;
    }
    .nav-container {
        flex-direction: column;
        align-items: center;
    }
    .nav-links {
        gap: 1.2rem;
        justify-content: center;
    }
    .dropdown-content {
        left: 50%;
        transform: translateX(-50%) translateY(-8px);
        grid-template-columns: none;
    }
    .dropdown:hover .dropdown-content {
        transform: translateX(-50%) translateY(0);
    }
}