/* ============ 点线-CG 培训官网 共享样式 ============ */
/* 主题：暗黑底色 + 橙色主色，延续原社区页视觉风格 */
/* 文件作用：全站 5 个页面（首页/教程列表/教程详情/实训营详情/关于/联系）共用的全局样式表，
   由各页通过 <link rel="stylesheet" href="css/style.css?v=..."> 引入；页面专属样式仍写在各页 <style> 内。 */
/* 主题色板（全站统一约定，便于维护）：
   主色橙 #ff7824，hover/高亮橙 #ff9442，蓝色辅助 #82b8e8；
   页面底色 #1b1e24，卡片/导航底 #242830 / #2c313a，边框 #3a3f4b / #2d323d；
   正文 #c5c8ce，次级文字 #a9adb8，弱化文字 #888c96。 */
/* 全局重置：清零默认 margin/padding，统一 border-box 盒模型与中文字体栈 */
*{margin:0;padding:0;box-sizing:border-box;font-family:"Microsoft YaHei","PingFang SC",sans-serif;}
body{background-color:#1b1e24;color:#c5c8ce;line-height:1.6;}
a{text-decoration:none;color:#c5c8ce;}
a:hover{color:#ff7824;}
img{display:block;}
ul{list-style:none;}

/* ---------- 顶部导航 ---------- */
.header{background:#242830;position:sticky;top:0;z-index:99;box-shadow:0 1px 4px rgba(0,0,0,.3);}
.header-inner{max-width:1200px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;padding:0 16px;height:54px;}
.logo{font-size:20px;font-weight:bold;color:#ff7824;letter-spacing:1px;}
.logo span{color:#e2e5eb;font-weight:normal;font-size:12px;margin-left:6px;}
.nav-list{display:flex;gap:26px;font-size:14px;}
.nav-list a.active{color:#ff7824;}
/* 全部课程下拉菜单（一级 + 二级） */
.nav-list .nav-item{position:relative;}
.nav-list .nav-item>a{color:#c5c8ce;display:block;}
.nav-list .nav-item>a:hover{color:#ff7824;}
.nav-list .submenu{position:absolute;top:100%;left:-8px;background:#242830;border:1px solid #3a3f4b;border-radius:6px;min-width:160px;padding:6px 0;display:none;z-index:200;box-shadow:0 8px 20px rgba(0,0,0,.45);}
.nav-list .has-sub.open>.submenu{display:block;}
.nav-list .submenu>a,.nav-list .submenu .sub-head{display:block;padding:8px 16px;font-size:13px;color:#c5c8ce;}
.nav-list .submenu>a:hover{color:#ff7824;background:#2c313a;}
.nav-list .submenu .sub-head{color:#888c96;font-size:12px;cursor:default;}
.nav-list .submenu .has-sub2{position:relative;}
.nav-list .submenu .sub2{left:100%;top:-6px;min-width:130px;}
.nav-list .has-sub2:hover>.sub2{display:block;}
.user-btn{display:flex;gap:12px;align-items:center;}
.btn{padding:6px 14px;border-radius:4px;font-size:13px;border:1px solid #444852;cursor:pointer;background:transparent;color:#c5c8ce;}
.btn:hover{border-color:#ff7824;color:#ff7824;}
.btn-consult{background:#ff7824;color:#fff;border:none;}
.btn-consult:hover{background:#ff9442;color:#fff;}

/* ---------- 页面标题区 ---------- */
.page-head{max-width:1200px;margin:0 auto;padding:28px 16px 6px;}
.page-head h1{color:#fff;font-size:26px;}
.page-head p{color:#888c96;font-size:14px;margin-top:6px;}

/* ---------- Banner ---------- */
.banner-wrap{max-width:1200px;margin:24px auto;padding:0 16px;}
.banner{height:300px;background:#2c313a;border-radius:8px;overflow:hidden;position:relative;display:flex;align-items:center;}
.banner-img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.4;}
.banner-overlay{position:absolute;inset:0;background:linear-gradient(90deg,rgba(20,22,28,.85) 20%,rgba(20,22,28,.35) 70%,transparent);}
.banner-text{position:relative;z-index:2;padding:0 48px;max-width:640px;color:#fff;}
.banner-text h1{font-size:clamp(24px,4vw,36px);line-height:1.3;margin-bottom:14px;}
.banner-text p{font-size:16px;color:#d7d9df;margin-bottom:22px;}
.banner-text .banner-btn{background:#ff7824;padding:11px 26px;border:none;border-radius:4px;color:#fff;font-size:15px;cursor:pointer;font-family:inherit;}
.banner-text .banner-btn:hover{background:#ff9442;}
.banner-tags{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px;}
.banner-tags span{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.2);padding:3px 10px;border-radius:20px;font-size:12px;color:#e2e5eb;}

/* ---------- 主体双栏 ---------- */
.main-container{max-width:1200px;margin:0 auto;display:grid;grid-template-columns:830px 340px;gap:24px;padding:0 16px;}
.left-area{min-width:0;}
.right-sidebar{min-width:0;}

/* 区块标题 */
.section-title{font-size:20px;color:#fff;margin-bottom:16px;padding-left:10px;border-left:4px solid #ff7824;display:flex;align-items:center;justify-content:space-between;}
.section-title .more{font-size:13px;color:#ff7824;font-weight:normal;}

/* Tab 分类 */
.tab-bar{display:flex;background:#242830;border-radius:6px;margin-bottom:18px;overflow-x:auto;scrollbar-width:none;}
.tab-bar::-webkit-scrollbar{display:none;}
.tab-item{padding:11px 18px;font-size:14px;cursor:pointer;white-space:nowrap;color:#888c96;}
.tab-item.active{color:#ff7824;border-bottom:2px solid #ff7824;}

/* ---------- 课程卡片 ---------- */
.course-list{display:flex;flex-direction:column;gap:14px;}
.course-card{background:#242830;border-radius:8px;padding:14px;display:grid;grid-template-columns:170px 1fr;gap:16px;transition:transform .15s,box-shadow .15s;}
.course-card:hover{transform:translateY(-2px);box-shadow:0 6px 18px rgba(0,0,0,.35);}
.course-thumb{width:170px;aspect-ratio:16/9;border-radius:6px;overflow:hidden;background:linear-gradient(135deg,#333a45,#232730);position:relative;}
.course-thumb img{width:100%;height:100%;object-fit:cover;}
.course-thumb .thumb-fallback{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:#6b7280;font-size:13px;}
.course-info{display:flex;flex-direction:column;justify-content:center;}
.course-title{font-size:17px;color:#e2e5eb;margin-bottom:6px;font-weight:600;}
.course-desc{font-size:13px;color:#a9adb8;margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;}
.course-meta{display:flex;flex-wrap:wrap;gap:14px;font-size:12px;color:#888c96;margin-bottom:10px;}
.course-meta b{color:#82b8e8;font-weight:normal;}
.course-link{font-size:14px;color:#ff7824;}
.course-link:hover{color:#ff9442;}

/* ---------- 侧边栏 ---------- */
.side-block{background:#242830;border-radius:8px;padding:16px;margin-bottom:18px;}
.side-title{font-size:15px;color:#fff;margin-bottom:12px;padding-left:8px;border-left:4px solid #ff7824;}

/* 表单 */
.form-item{margin-bottom:12px;}
.form-item input,.form-item textarea{width:100%;background:#2c313a;border:1px solid #3a3f4b;border-radius:4px;color:#fff;padding:10px 12px;font-size:13px;outline:none;font-family:inherit;resize:vertical;}
.form-item input:focus,.form-item textarea:focus{border-color:#ff7824;}
.submit-btn{width:100%;background:#ff7824;color:#fff;border:none;padding:11px;border-radius:4px;cursor:pointer;font-size:14px;font-family:inherit;}
.submit-btn:hover{background:#ff9442;}
.form-tip{font-size:12px;color:#888c96;margin-top:8px;text-align:center;}

/* 师资卡片 */
.teacher-item{display:flex;gap:12px;padding:10px 0;border-bottom:1px solid #2d323d;align-items:center;}
.teacher-item:last-child{border-bottom:none;}
.teacher-avatar{width:48px;height:48px;border-radius:50%;background:linear-gradient(135deg,#3a414e,#2a2f3a);flex-shrink:0;display:flex;align-items:center;justify-content:center;color:#ff7824;font-size:20px;}
.teacher-info h4{color:#e2e5eb;font-size:14px;margin-bottom:2px;}
.teacher-info p{font-size:12px;color:#888c96;}

/* 联系信息 */
.contact-line{display:flex;align-items:center;gap:10px;padding:9px 0;font-size:13px;color:#c5c8ce;}
.contact-line .ico{color:#ff7824;font-size:16px;width:18px;text-align:center;}

/* ---------- 页脚 ---------- */
.footer{max-width:1200px;margin:44px auto 26px;padding:18px 16px;border-top:1px solid #2d323d;text-align:center;font-size:12px;color:#666;line-height:1.9;}
.footer a{color:#888c96;}
.footer a:hover{color:#ff7824;}

/* ---------- 关于页 / 课程详情 通用 ---------- */
.content-block{background:#242830;border-radius:8px;padding:22px;margin-bottom:18px;}
.content-block h2{color:#fff;font-size:19px;margin-bottom:14px;padding-left:10px;border-left:4px solid #ff7824;}
.content-block h3{color:#ff9442;font-size:15px;margin:14px 0 8px;}
.content-block p{font-size:14px;color:#a9adb8;margin-bottom:8px;}
.content-block ul{list-style:none;}
.content-block ul li{font-size:14px;color:#a9adb8;padding:6px 0 6px 20px;position:relative;}
.content-block ul li::before{content:"•";color:#ff7824;position:absolute;left:4px;}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px;}

/* 里程碑 */
.timeline{position:relative;padding-left:22px;}

/* 【1.8】课程介绍单列段落排版：文字左对齐（三列仅用于实训案例章节） */
.intro-columns{text-align:left;}
.intro-columns p{margin-bottom:8px;}
.timeline::before{content:"";position:absolute;left:6px;top:4px;bottom:4px;width:2px;background:#3a3f4b;}
.timeline-item{position:relative;padding:0 0 18px;}
.timeline-item::before{content:"";position:absolute;left:-20px;top:6px;width:9px;height:9px;border-radius:50%;background:#ff7824;}
.timeline-item h4{color:#e2e5eb;font-size:15px;}
.timeline-item p{font-size:13px;color:#888c96;margin-top:4px;}

/* 课程详情 hero */
.detail-hero{background:#242830;border-radius:8px;padding:24px;margin-bottom:18px;display:flex;gap:22px;align-items:center;}
.detail-hero .dh-thumb{width:200px;aspect-ratio:16/9;border-radius:6px;overflow:hidden;background:#2c313a;flex-shrink:0;}
.detail-hero .dh-thumb img{width:100%;height:100%;object-fit:cover;}
.detail-hero h1{color:#fff;font-size:24px;margin-bottom:10px;}
.detail-hero .dh-desc{color:#a9adb8;font-size:14px;margin-bottom:12px;}
.detail-hero .dh-meta{display:flex;flex-wrap:wrap;gap:12px;font-size:13px;color:#888c96;}
.detail-hero .dh-meta b{color:#82b8e8;font-weight:normal;}
.detail-hero .dh-btn{margin-top:14px;}

/* ---------- 移动端适配 ---------- */
/* 响应式断点①：≤1100px 时，主体双栏（830px+340px）降为单栏，避免侧栏过窄 */
@media(max-width:1100px){
.main-container{grid-template-columns:1fr;}
}
/* 响应式断点②：≤768px 移动端——导航纵向堆叠、Banner 降高、课程卡/详情卡/师资双列均改单列 */
@media(max-width:768px){
.header-inner{height:auto;padding:10px 16px;flex-direction:column;gap:10px;}
.nav-list{flex-wrap:wrap;justify-content:center;gap:14px;}
.banner{height:240px;}
.banner-text{padding:0 24px;}
.course-card{grid-template-columns:1fr;}
.course-thumb{width:100%;aspect-ratio:16/9;}
.grid-2{grid-template-columns:1fr;}
.detail-hero{flex-direction:column;align-items:flex-start;}
.detail-hero .dh-thumb{width:100%;aspect-ratio:16/9;}
}

/* ============ 首页视频卡片网格 ============ */
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:18px;}
.video-card{background:#242830;border-radius:8px;overflow:hidden;transition:transform .15s,box-shadow .15s;cursor:pointer;}
.video-card:hover{transform:translateY(-2px);box-shadow:0 6px 18px rgba(0,0,0,.35);}
.video-thumb{position:relative;aspect-ratio:16/9;background:linear-gradient(135deg,#333a45,#232730);overflow:hidden;}
.video-thumb img{width:100%;height:100%;object-fit:cover;}
.video-thumb .play{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,.28);opacity:0;transition:opacity .15s;}
.video-card:hover .video-thumb .play{opacity:1;}
.video-play-icon{width:46px;height:46px;border-radius:50%;background:rgba(255,120,36,.92);display:flex;align-items:center;justify-content:center;color:#fff;font-size:16px;}
.video-info{padding:12px;}
.video-title{font-size:15px;color:#e2e5eb;font-weight:600;margin-bottom:5px;min-height:40px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;}
.video-desc{font-size:12px;color:#888c96;margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:1;-webkit-box-orient:vertical;overflow:hidden;}
.video-author{font-size:12px;color:#ff9442;margin-bottom:8px;}
.video-stats{display:flex;gap:16px;font-size:12px;color:#888c96;border-top:1px solid #2d323d;padding-top:8px;}
.video-stats .vs{display:flex;align-items:center;gap:4px;}
.video-empty{color:#888c96;padding:20px 0;text-align:center;}