* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: "Microsoft Yahei", sans-serif;
    color: #333;
    background-color: #f7f8fa;
    line-height: 1.6;
}
a {
    text-decoration: none;
    color: inherit;
}
ul {
    list-style: none;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}
.row {
    display: flex;
    flex-wrap: wrap;
    margin-left: -15px;
    margin-right: -15px;
}
.col {
    flex: 1 1 0%;
    padding: 0 15px;
}
.col-md-4 {
    width: 33.3333%;
    padding: 0 15px;
    margin-bottom:24px;
}
.col-12 {
    width:100%;
    padding:0 15px;
}
.py-5 {
    padding-top: 48px;
    padding-bottom: 48px;
}
.mb-4 {
    margin-bottom: 24px;
}
.mb-5 {
    margin-bottom: 40px;
}
.text-center {
    text-align: center;
}
.text-secondary {
    color:#666;
}
.text-danger {
    color:#e53935;
}
.fs-5 {
    font-size:1.25rem;
}
.d-flex {
    display:flex;
}
.justify-content-between {
    justify-content: space-between;
}
.align-items-center {
    align-items: center;
}
/* 导航栏 header */
.header-nav {
    background:#2b3b61;
    color:#fff;
}
.header-nav .container {
    display:flex;
    justify-content: space-between;
    align-items:center;
    height:64px;
}
.logo-text {
    font-size:20px;
    font-weight:bold;
    white-space: nowrap;
}
.nav-menu {
    display:flex;
    gap:28px;
}
.nav-menu a {
    color:#ffffffcc;
    transition: color 0.2s;
    white-space: nowrap;
}
.nav-menu a:hover {
    color:#fff;
}
/* 首页横幅优化 */
.banner {
    width:100%;
    height: 360px;
    position: relative;
    background: url("/banner.jpg") center center no-repeat;
    background-size: cover;
}
.banner-overlay {
    position:absolute;
    left:0;
    top:0;
    width:100%;
    height:100%;
    background-color:rgba(0,0,0,0.18);
}
.banner-bar {
    background:#2b3b61;
    color:#fff;
    padding:12px 0;
    font-size:15px;
}
/* 卡片样式美化 */
.card {
    background:#fff;
    border-radius:10px;
    overflow:hidden;
    box-shadow: 0 4px 16px rgba(0,0,0,0.07);
    height:100%;
    transition: 0.25s;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}
.card-body {
    padding:24px;
}
.card-title {
    font-size:18px;
    margin-bottom:12px;
    font-weight:600;
}
.card-text {
    margin-bottom:20px;
    min-height:44px;
    color:#555;
}
.btn {
    padding:9px 20px;
    border-radius:6px;
    border:none;
    cursor:pointer;
    font-size:14px;
}
.btn-primary {
    background:#2563eb;
    color:#fff;
}
.btn-primary:hover {
    background:#1d4ed8;
}
/* footer页脚 */
.footer {
    background:#1f2937;
    color:#aaa;
    padding:36px 0;
    margin-top:60px;
}
/* index.php首页额外样式 */
.content-section h2 {
    font-size: 28px;
    color:#222b45;
}
/* 响应式适配手机 */
@media(max-width:768px){
    .col-md-4 {
        width:100%;
    }
    .banner {
        height:240px;
    }
    .header-nav .container{
        height:auto;
        padding:12px 15px;
        flex-direction: column;
        gap:10px;
    }
    .nav-menu {
        gap:14px;
        flex-wrap: wrap;
        justify-content: center;
    }
    .content-section h2 {
        font-size:24px;
    }
}