/* ===== 前端样式 ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:14px}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;background:#f5f6fa;color:#2d3436;line-height:1.6}
a{color:#d85a30;text-decoration:none}
a:hover{color:#c04e28}
img{max-width:100%}
.fk-wrap{max-width:1400px;margin:0 auto;padding:0 24px}

/* 顶栏 */
.fk-header{background:#fff;border-bottom:1px solid #eef1f5;position:sticky;top:0;z-index:100}
.fk-header .fk-wrap{display:flex;align-items:center;height:68px;gap:50px}
.fk-logo{font-size:24px;font-weight:800;color:#2d3436}
.fk-logo span{color:#d85a30;font-weight:300;margin-left:4px}
.fk-nav{display:flex;gap:32px;flex:1}
.fk-nav a{font-size:15px;color:#636e72;padding:6px 0;border-bottom:2px solid transparent;transition:all .2s}
.fk-nav a:hover,.fk-nav a.active{color:#2d3436;border-bottom-color:#d85a30}
.fk-user{display:flex;align-items:center;gap:8px}
.fk-avatar{display:inline-block;border-radius:50%;overflow:hidden;flex-shrink:0}
.fk-avatar img{display:block;border-radius:50%}

/* 按钮 */
.fk-btn{display:inline-block;padding:8px 20px;border-radius:4px;background:#d85a30;color:#fff;font-size:13px;cursor:pointer;border:none;transition:background .2s}
.fk-btn:hover{background:#c04e28;color:#fff}
.fk-btn-outline{display:inline-block;padding:8px 20px;border-radius:4px;border:1px solid #e0e4e8;color:#636e72;font-size:13px;cursor:pointer;transition:all .2s}
.fk-btn-outline:hover{border-color:#d85a30;color:#d85a30}

/* 主内容 */
.fk-main{min-height:calc(100vh - 68px - 60px);padding:28px 0 60px}

/* 页脚 */
.fk-footer{background:#2d3436;color:#b2bec3;text-align:center;padding:20px 0;font-size:12px}

/* 轮播 */
.fk-banner{position:relative;height:420px;border-radius:5px;overflow:hidden;margin-bottom:40px;background:#eef1f5}
.fk-banner-inner{height:100%;width:100%;background-size:cover;background-position:center;display:flex;align-items:center;padding:70px}
.fk-banner-title{font-size:38px;font-weight:700;color:#fff;margin-bottom:12px;text-shadow:0 2px 8px rgba(0,0,0,.3)}
.fk-banner-desc{font-size:17px;color:rgba(255,255,255,.85);text-shadow:0 1px 4px rgba(0,0,0,.3)}
.fk-banner .fk-btn{margin-top:18px;font-size:16px;padding:12px 32px}
.fk-banner-dots{position:absolute;bottom:16px;left:50%;transform:translateX(-50%);display:flex;gap:8px}
.fk-banner-dot{width:8px;height:8px;border-radius:50%;background:rgba(255,255,255,.4);cursor:pointer;transition:all .2s}
.fk-banner-dot.active{background:#fff;width:24px;border-radius:4px}

/* 区域标题 */
.fk-section-title{font-size:20px;font-weight:600;color:#2d3436;margin-bottom:20px;display:flex;align-items:center;gap:8px}
.fk-section-title::before{content:'';display:block;width:3px;height:20px;background:#d85a30;border-radius:2px}

/* 课程网格 */
.fk-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;margin-bottom:40px}
@media(max-width:1100px){.fk-grid{grid-template-columns:repeat(3,1fr)}}
@media(max-width:900px){.fk-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:500px){.fk-grid{grid-template-columns:1fr}}

.fk-card{background:#fff;border-radius:5px;overflow:hidden;transition:transform .2s,box-shadow .2s;border:1px solid #eef1f5}
.fk-card:hover{transform:translateY(-4px);box-shadow:0 8px 30px rgba(0,0,0,.08)}
.fk-card-cover{position:relative;padding-bottom:75%;background:#f0f2f5;overflow:hidden}
.fk-card-cover img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.fk-card-cover .fk-tag{position:absolute;top:10px;left:10px;background:#d85a30;color:#fff;padding:2px 10px;border-radius:3px;font-size:11px}
.fk-card-body{padding:14px 16px}
.fk-card-title{font-size:15px;font-weight:600;color:#2d3436;margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.fk-card-meta{font-size:12px;color:#b2bec3;margin-bottom:8px}
.fk-card-price{font-size:18px;font-weight:700;color:#d85a30}
.fk-card-price del{font-size:12px;color:#b2bec3;font-weight:400;margin-left:6px}
.fk-card .fk-btn{width:100%;text-align:center;padding:7px;font-size:12px}

/* 分类导航 */
.fk-categories{display:flex;gap:10px;margin-bottom:24px;flex-wrap:wrap}
.fk-cat{display:inline-block;padding:6px 16px;border-radius:5px;border:1px solid #e0e4e8;color:#636e72;font-size:12px;cursor:pointer;transition:all .2s}
.fk-cat:hover,.fk-cat.active{border-color:#d85a30;color:#d85a30;background:rgba(216,90,48,.06)}

/* 详情页 */
.fk-detail-header{display:grid;grid-template-columns:minmax(320px,440px) 1fr;gap:48px;background:#fff;border-radius:5px;padding:36px;margin-bottom:24px}
@media(max-width:700px){.fk-detail-header{grid-template-columns:1fr}}
.fk-detail-cover{position:relative;padding-bottom:75%;background:#f0f2f5;border-radius:5px;overflow:hidden}
.fk-detail-cover img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.fk-detail-info{display:flex;flex-direction:column;justify-content:center;gap:12px}
.fk-detail-title{font-size:28px;font-weight:700;color:#2d3436;word-break:break-word}
.fk-detail-subtitle{font-size:15px;color:#636e72;word-break:break-word}
.fk-detail-price{font-size:30px;font-weight:700;color:#d85a30}
.fk-detail-price del{font-size:15px;color:#b2bec3;font-weight:400;margin-left:8px}
.fk-detail-meta{display:flex;gap:28px;font-size:14px;color:#636e72}
.fk-detail-meta span{display:flex;align-items:center;gap:4px}

/* 章节列表 */
.fk-chapter-list{background:#fff;border-radius:5px;padding:24px;margin-bottom:24px}
.fk-chapter-item{display:flex;align-items:center;padding:14px 0;border-bottom:1px solid #f0f2f5;cursor:pointer;transition:background .2s}
.fk-chapter-item:last-child{border-bottom:none}
.fk-chapter-item:hover{background:#f9fafb;margin:0 -16px;padding:14px 16px;border-radius:4px}
.fk-chapter-num{width:28px;height:28px;border-radius:50%;background:#f0f2f5;color:#636e72;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:600;margin-right:12px;flex-shrink:0}
.fk-chapter-title{flex:1;font-size:14px;color:#2d3436}
.fk-chapter-free{font-size:11px;color:#43a047;background:#e8f5e9;padding:2px 8px;border-radius:3px}
.fk-chapter-dur{font-size:12px;color:#b2bec3;margin-left:12px}

/* 讲师信息 */
.fk-teacher{background:#fff;border-radius:5px;padding:24px;margin-bottom:24px;display:flex;gap:20px;align-items:flex-start}
.fk-teacher-avatar{width:60px;height:60px;border-radius:50%;background:#f0f2f5;flex-shrink:0;overflow:hidden}
.fk-teacher-avatar img{width:100%;height:100%;object-fit:cover}
.fk-teacher-name{font-size:16px;font-weight:600;color:#2d3436}
.fk-teacher-title{font-size:12px;color:#636e72;margin-top:2px}
.fk-teacher-desc{font-size:13px;color:#636e72;margin-top:8px;line-height:1.7}

/* 分页 */
.fk-pages{display:flex;justify-content:center;gap:6px;margin-top:30px}
.fk-pages a{display:inline-flex;width:34px;height:34px;align-items:center;justify-content:center;border:1px solid #e0e4e8;border-radius:4px;font-size:13px;color:#636e72;transition:all .2s}
.fk-pages a:hover,.fk-pages a.active{border-color:#d85a30;color:#d85a30;background:rgba(216,90,48,.06)}