:root{--primary-color: #eeaba6;--bg-color: #f7f7f7;--white: #ffffff;--text-primary: #333333;--text-secondary: #666666;--text-tertiary: #999999;--border-color: #eeeeee}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--bg-color);color:var(--text-primary)}*{box-sizing:border-box}a{text-decoration:none;color:inherit}button{border:none;background:none;cursor:pointer;font-family:inherit}.container{max-width:800px;margin:0 auto;min-height:100vh;background-color:var(--bg-color);display:flex;flex-direction:column;box-shadow:0 0 20px #0000000d}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#ccc;border-radius:3px}.home-container{padding:20px;background-color:var(--bg-color);min-height:100vh}.home-header{text-align:center;margin-bottom:30px;padding:40px 0;background:#fff;border-radius:16px;box-shadow:0 4px 12px #00000008}.home-header h1{margin:0;color:var(--text-primary);font-size:24px}.home-header p{margin:10px 0 0;color:var(--text-secondary);font-size:14px}.course-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}.course-card{background:var(--white);border-radius:12px;overflow:hidden;box-shadow:0 4px 12px #0000000d;transition:transform .2s,box-shadow .2s;display:flex;flex-direction:column}.course-card:hover{transform:translateY(-4px);box-shadow:0 8px 20px #00000014}.card-image{width:100%;aspect-ratio:16/9;background-color:#eee}.card-image img{width:100%;height:100%;object-fit:cover}.card-content{padding:16px;flex:1;display:flex;flex-direction:column}.card-content h3{margin:0 0 8px;font-size:16px;color:var(--text-primary)}.card-desc{font-size:13px;color:var(--text-secondary);margin:0 0 16px;line-height:1.5;flex:1;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.card-footer{display:flex;justify-content:space-between;align-items:center;margin-top:auto}.learner-count{font-size:12px;color:var(--text-tertiary)}.price{font-size:16px;color:var(--primary-color);font-weight:700}.detail-container{display:flex;flex-direction:column;min-height:100vh;background-color:var(--bg-color);width:100%;max-width:100%;margin:0 auto;box-shadow:0 0 20px #0000001a}.video-area{width:100%;height:240px;background-color:#000;position:relative}.preview-container{width:100%;height:100%;background-size:cover;background-position:center;position:relative}.play-overlay{position:absolute;top:0;left:0;right:0;bottom:0;background:#0000004d;display:flex;justify-content:center;align-items:center;cursor:pointer}.play-btn{width:60px;height:60px;background:#ffffffe6;border-radius:50%;display:flex;justify-content:center;align-items:center;font-size:24px;color:var(--primary-color);padding-left:4px}.video-placeholder{width:100%;height:100%;display:flex;flex-direction:column;justify-content:center;align-items:center;color:#fff}.content-scroll{flex:1;overflow-y:auto}.info-section{background-color:var(--white);padding:16px;margin-bottom:10px}.title{font-size:18px;font-weight:700;color:var(--text-primary);margin:0 0 12px}.meta-row{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}.learners{font-size:13px;color:var(--text-tertiary)}.price{font-size:18px;color:var(--primary-color);font-weight:700}.desc{font-size:14px;color:var(--text-secondary);line-height:1.6;margin:0}.review-section{background-color:var(--white);padding:16px;margin-bottom:10px;cursor:pointer}.section-header{display:flex;justify-content:space-between;align-items:center}.section-title{font-size:16px;font-weight:700;color:var(--text-primary)}.more-reviews{display:flex;align-items:center;font-size:13px;color:var(--text-tertiary)}.arrow{margin-left:5px}.chapter-section{background-color:var(--white);padding:16px 16px 80px}.section-title-bar{margin-bottom:16px;padding-left:10px;border-left:4px solid var(--primary-color)}.chapter-item{display:flex;justify-content:space-between;align-items:center;padding:16px 0;border-bottom:1px solid var(--border-color);cursor:pointer}.chapter-item:last-child{border-bottom:none}.chapter-item.active,.chapter-item.active .chapter-name{color:var(--primary-color)}.chapter-item.locked{color:var(--text-tertiary);cursor:not-allowed}.chapter-info{display:flex;align-items:center;flex:1;overflow:hidden}.chapter-num{font-size:14px;margin-right:12px;font-weight:700}.chapter-name{font-size:15px;flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--text-primary)}.chapter-status{font-size:12px;margin-left:10px}.playing-tag{color:var(--primary-color);border:1px solid var(--primary-color);padding:2px 6px;border-radius:4px;font-size:11px}.play-icon{color:var(--text-tertiary);font-size:14px}.bottom-bar{position:fixed;bottom:0;left:50%;transform:translate(-50%);width:100%;max-width:600px;background-color:var(--white);padding:10px 16px;display:flex;justify-content:space-between;align-items:center;box-shadow:0 -2px 10px #0000000d;z-index:10}.amount{font-size:20px;color:var(--primary-color);font-weight:700}.buy-btn{background:var(--primary-color);color:var(--white);padding:10px 30px;border-radius:20px;font-size:16px;font-weight:700}.video-player-wrapper{width:100%;height:100%;background:#000;position:relative;display:flex;justify-content:center;align-items:center}.real-video-player{width:100%;height:100%;object-fit:contain}.close-video-btn{position:absolute;top:10px;right:10px;color:#fff;font-size:24px;background:#00000080;width:40px;height:40px;border-radius:50%;display:flex;justify-content:center;align-items:center;z-index:10}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:#0009;display:flex;justify-content:center;align-items:center;z-index:100;padding:20px}.modal-content{background:#fff;width:100%;max-width:320px;padding:24px;border-radius:16px;text-align:center;box-shadow:0 4px 20px #0003}.modal-content h3{margin:0 0 10px;color:var(--text-primary)}.modal-content p{color:var(--text-secondary);font-size:14px;margin-bottom:20px}.redeem-input{width:100%;padding:12px;border:1px solid var(--border-color);border-radius:8px;margin-bottom:10px;font-size:16px;outline:none}.redeem-input:focus{border-color:var(--primary-color)}.error-msg{color:#ff4d4f;font-size:12px;margin-bottom:10px}.modal-actions{display:flex;justify-content:space-between;gap:10px}.modal-actions button{flex:1;padding:10px;border-radius:8px;font-size:14px;font-weight:700}.cancel-btn{background:#f5f5f5;color:#666}.confirm-btn{background:var(--primary-color);color:#fff}.confirm-btn:disabled{opacity:.7;cursor:not-allowed}