/* --- 全局基础样式 --- */
* { margin: 0; padding: 0; box-sizing: border-box; font-family: "Microsoft YaHei", "PingFang SC", sans-serif; }
body { background-color: #f8f9fa; color: #333; line-height: 1.6; }
a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

:root {
    --primary-red: #B71C1C;
    --accent-gold: #D4AF37;
    --text-dark: #333;
}

/* 布局容器 */
.container { width: 1200px; margin: 0 auto; max-width: 95%; }

/* --- Header & Top Bar --- */
.top-bar { background-color: #eee; padding: 8px 0; font-size: 14px; color: #666; }
.top-bar .container { display: flex; justify-content: space-between; }
.header-main { background: #fff; padding: 20px 0; }
.header-main .container { display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 28px; font-weight: bold; color: var(--primary-red); display: flex; align-items: center; }
.logo span { font-size: 14px; color: #666; margin-left: 10px; font-weight: normal; border-left: 1px solid #ddd; padding-left: 10px; }
.logo-main { width: 40px; margin-right: 8px; }
.hotline h3 { color: var(--primary-red); font-size: 24px; font-weight: bold; text-align: right; }

/* --- 导航栏 (PC端默认) --- */
.main-nav { 
    background-color: var(--primary-red); 
    position: sticky; 
    top: 0; 
    z-index: 9999; 
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}
.nav-list { display: flex; justify-content: space-between; }
.nav-list li { flex: 1; text-align: center; }
.nav-list li a { display: block; color: #fff; padding: 15px 5px; font-size: 15px; font-weight: 500; }
.nav-list li a:hover, .nav-list li.active a { background-color: #8e1212; color: var(--accent-gold); }
.mobile-menu-btn { display: none; color: #fff; font-size: 24px; padding: 10px; cursor: pointer; /*text-align: center;*/ }

/* --- 名师团队页面样式 --- */
.page-title { text-align: center; padding: 40px 0 20px; }
.page-title h1 { font-size: 32px; color: var(--primary-red); margin-bottom: 10px; }
.page-title p { font-size: 16px; color: #666; }

.teachers-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    padding: 40px 0;
}

.teacher-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    text-align: center;
    transition: 0.3s;
    border-top: 5px solid var(--accent-gold);
    display: block;
}
.teacher-card:hover { transform: translateY(-8px); box-shadow: 0 10px 25px rgba(0,0,0,0.15); }
.teacher-photo { height: 250px; overflow: hidden; }
.teacher-photo img { width: 100%; height: 100%; object-fit: cover; }
.teacher-info { padding: 20px 15px; }
.teacher-name { font-size: 20px; font-weight: bold; color: var(--primary-red); margin-bottom: 5px; }
.teacher-title { display: inline-block; background: var(--primary-red); color: #fff; padding: 4px 10px; border-radius: 4px; font-size: 12px; margin-bottom: 10px; }
.teacher-expertise { font-size: 14px; color: #666; height: 45px; overflow: hidden; margin-bottom: 15px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.view-detail { color: var(--accent-gold); font-weight: bold; font-size: 14px; }

/* --- 底部 Footer (PC端默认) --- */
footer { background: #222; color: #fff; padding: 60px 0 30px; }
.footer-grid { 
    display: grid; 
    grid-template-columns: 2.5fr 1fr 1fr 1.5fr; 
    gap: 40px; 
    border-bottom: 1px solid #444; 
    padding-bottom: 40px; 
    margin-bottom: 25px; 
}
.footer-about h4, .footer-link h4 { color: #fff; margin-bottom: 20px; font-size: 18px; }
.footer-about p { color: #aaa; font-size: 14px; line-height: 1.8; }
.footer-phone { margin-top: 20px; color: var(--accent-gold); font-size: 20px; font-weight: bold; }
.footer-link ul li { margin-bottom: 10px; }
.footer-link ul li a { color: #aaa; font-size: 14px; }
.footer-link ul li a:hover { color: #fff; padding-left: 5px; }
.qr-box { text-align: center; }
.qr-img { width: 120px; height: 120px; background: #fff; margin: 0 auto 10px; display: flex; align-items: center; justify-content: center; }
.qr-img img { width: 110px; height: 110px; }
.copyright { text-align: center; color: #666; font-size: 13px; }

/* --- 响应式适配 (移动端) --- */
@media (max-width: 1024px) {
    .teachers-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
    /* 移动端导航 */
    .mobile-menu-btn { display: block; background: #a31919; }
    .nav-list { 
        display: none; 
        flex-direction: column; 
        position: absolute; 
        top: 100%; 
        left: 0; 
        width: 100%; 
        background: var(--primary-red); 
        box-shadow: 0 5px 10px rgba(0,0,0,0.2);
    }
    .nav-list.show { display: flex; }
    .nav-list li { border-top: 1px solid #8e1212; }
    
    .header-main .container { flex-direction: column; text-align: center; gap: 15px; }
    .hotline { text-align: center; }
    .logo { justify-content: center; }

    /* 移动端名师列表 */
    .teachers-grid { grid-template-columns: repeat(2, 1fr); gap: 15px; }

    /* 移动端页脚 */
    .footer-grid { 
        grid-template-columns: 1fr; 
       /* text-align: center; */
        gap: 30px;
    }
    .footer-link { display: inline-block; width: 45%; vertical-align: top; }
    .footer-about, .qr-box { width: 100%; }
    .footer-about h4::after { content: ''; display: block; width: 40px; height: 2px; background: var(--accent-gold); margin: 10px 0 0; }
}

@media (max-width: 480px) {
    .teachers-grid { grid-template-columns: 1fr; }
    .footer-link { width: 100%; }
}