/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 顶部导航栏样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    position: relative;
}

.logo img {
    height: 40px;
}

.nav {
    display: flex;
    align-items: center;
}

.nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
    margin: 0;
    padding: 0;
    position: relative;
    background: transparent;
    box-shadow: none;
}

.nav li {
    position: relative;
}

.nav li.dropdown > ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    flex-direction: column;
    gap: 0;
    padding: 8px 0;
    z-index: 1000;
}

.nav li.dropdown > ul > li > ul {
    left: 100%;
    top: 0;
}
@media (max-width: 1280px) {
    .navbar .dropdown .dropdown ul {left: -90%;}
    .navbar .dropdown .dropdown:hover > ul { left: -100%;}
    .nav-box{width:1026px;}
    .navbar a { padding: 10px 18px;}
}
.dropdown ul { display: block; position: absolute; left: 14px; top: calc(100% + 30px); margin: 0;  padding: 10px 0;  z-index: 99; opacity: 0; visibility: hidden; background: #fff; box-shadow: 0px 0px 30px rgba(127, 137, 161, 0.25); transition: 0.3s; border-radius: 3px;}
.dropdown ul li {min-width: 200px;height: 42px;display: flex;align-items: center;}
.dropdown ul a {padding: 8px 20px; font-size: 14px; text-transform: none; font-weight: 400;}
.dropdown ul a i { font-size: 12px;}
.dropdown ul a:hover, .dropdown ul .active:hover, .dropdown ul li:hover > a { color: #186AF2;}
.dropdown:hover > ul { opacity: 1; top: 100%; visibility: visible;}
.dropdown .dropdown ul { top: 0;left: calc(100% - 30px); visibility: hidden;}
.dropdown .dropdown:hover > ul { opacity: 1; top: 0; left: 100%; visibility: visible;}

.nav a {
    text-decoration: none;
    color: #333;
    font-size: 14px;
    padding: 8px 12px;
    border-radius: 4px;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.nav a:hover {
    color: #1890ff;
}

.btn-login, .btn-register {
    padding: 8px 20px !important;
}

.btn-login {
    color: #1890ff !important;
    border: 1px solid #1890ff;
}

.btn-register {
    background-color: #1890ff;
    color: #fff !important;
}

/* 主要内容区样式 */
.main {
    margin-top: 80px;
    padding: 40px 0;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background: #fff;
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.card-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    background-color: #1890ff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-icon i {
    font-size: 24px;
    color: #fff;
}

.card h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 18px;
}

.card-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 10px;
    text-align: left;
}

.card-features span {
    font-size: 12px;
    color: #666;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* 底部页脚样式 */
.footer {
    background-color: #24292e;
    color: #fff;
    padding: 50px 0 20px;
    /*margin-top: 50px;*/
    z-index: 1;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-column h4 {
    color: #fff;
    margin-bottom: 20px;
    font-size: 16px;
}

.footer-column ul {
    list-style: none;
}

.footer-column ul li {
    margin-bottom: 10px;
}

.footer-column a {
    color: #8b949e;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.footer-column a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #404448;
}

.footer-bottom p {
    color: #8b949e;
    font-size: 12px;
    margin: 5px 0;
}

/* 移动端导航按钮样式 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: #333;
    font-size: 24px;
    cursor: pointer;
    padding: 5px;
    margin-right: 10px;
    z-index: 1001;
}

.mobile-menu-btn:focus {
    outline: none;
}

/* 大屏幕hover显示 */
@media (min-width: 769px) {
    /*.nav li.dropdown:hover > ul {*/
    /*    display: flex;*/
    /*}*/

    .nav ul {
        display: flex !important;
    }

    .nav li.dropdown > ul {
        animation: fadeIn 0.3s ease;
    }

    @keyframes fadeIn {
        from {
            opacity: 0;
            transform: translateY(10px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header .container {
        padding: 0 15px;
    }

    .mobile-menu-btn {
        display: block;
    }

    .nav {
        order: 2;
    }

    .nav ul {
        display: none;
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background-color: #fff;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
        padding: 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        z-index: 999;
        max-height: calc(100vh - 60px);
        overflow-y: auto;
    }

    .nav li.dropdown > ul {
        position: static;
        box-shadow: none;
        background: #f8f9fa;
        padding-left: 20px;
        width: 100%;
    }

    .nav ul li {
        width: 100%;
    }

    .nav ul li a {
        display: block;
        padding: 12px 20px;
        border-radius: 0;
        border-bottom: 1px solid #eee;
    }

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

    .nav ul li a:hover {
        background-color: #f5f5f5;
    }

    .btn-login, .btn-register {
        margin: 5px 15px;
        width: calc(100% - 30px);
        text-align: center;
    }
}

@media (min-width: 769px) {
    .nav ul {
        display: flex !important;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}