:root{--color-bg: #F4F1EA;--color-bg-card: #FDFAF5;--color-bg-elevated: #FFFFFF;--color-primary: #D97757;--color-primary-hover: #C4623F;--color-primary-light: #F5E6DF;--color-text: #1A1410;--color-text-muted: #6B5E54;--color-text-faint: #A8998F;--color-border: #E0D9CF;--color-border-strong: #C8BFB2;--color-success: #4CAF50;--color-error: #E53935;--color-warning: #F59E0B;--font-serif: "Noto Serif SC", "Georgia", serif;--font-sans: "Noto Sans SC", -apple-system, "PingFang SC", sans-serif;--radius-sm: 6px;--radius-md: 12px;--radius-lg: 16px;--radius-full: 9999px;--shadow-sm: 0 1px 3px rgba(0,0,0,.08);--shadow-md: 0 4px 16px rgba(0,0,0,.1);--shadow-lg: 0 8px 32px rgba(0,0,0,.12);--transition: .15s ease}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--color-bg);color:var(--color-text);font-family:var(--font-sans);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}img{display:block;max-width:100%}button{cursor:pointer;font-family:inherit}.layout{min-height:100vh;display:flex;flex-direction:column}.navbar{background:var(--color-bg-elevated);border-bottom:1px solid var(--color-border);padding:0 24px;height:60px;display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:100;box-shadow:var(--shadow-sm)}.navbar-brand{display:flex;align-items:center;gap:8px;text-decoration:none}.brand-icon{color:var(--color-primary);font-size:20px}.brand-name{font-family:var(--font-serif);font-size:20px;font-weight:700;color:var(--color-text);letter-spacing:.02em}.navbar-nav{display:flex;align-items:center;gap:8px}.nav-link{padding:6px 14px;border-radius:var(--radius-full);font-size:14px;font-weight:500;color:var(--color-text-muted);transition:all var(--transition)}.nav-link:hover{background:var(--color-primary-light);color:var(--color-primary)}.nav-link.active{color:var(--color-primary);background:var(--color-primary-light)}.nav-badge{background:var(--color-primary);color:#fff;padding:5px 14px;border-radius:var(--radius-full);font-size:13px;font-weight:600;transition:background var(--transition)}.nav-link:hover .nav-badge{background:var(--color-primary-hover)}.main-content{flex:1;width:100%;max-width:1100px;margin:0 auto;padding:40px 24px}.footer{background:var(--color-bg-elevated);border-top:1px solid var(--color-border);padding:20px 24px;text-align:center;color:var(--color-text-faint);font-size:13px}.course-card{background:var(--color-bg-card);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden;transition:transform var(--transition),box-shadow var(--transition);display:flex;flex-direction:column;text-decoration:none;color:inherit}.course-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-md);border-color:var(--color-primary)}.course-cover{height:160px;display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden}.course-track-badge{position:absolute;top:12px;left:12px;background:#ffffff40;color:#fff;font-size:12px;font-weight:600;padding:3px 10px;border-radius:var(--radius-full);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.course-cover-emoji{font-size:52px;filter:drop-shadow(0 2px 8px rgba(0,0,0,.2))}.course-info{padding:18px;display:flex;flex-direction:column;gap:8px;flex:1}.course-title{font-family:var(--font-serif);font-size:17px;font-weight:700;color:var(--color-text);line-height:1.4}.course-intro{font-size:13px;color:var(--color-text-muted);line-height:1.6;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden;flex:1}.course-footer{display:flex;align-items:center;justify-content:space-between;padding-top:8px;border-top:1px solid var(--color-border);margin-top:4px}.course-price{font-family:var(--font-serif);font-size:22px;font-weight:700;color:var(--color-primary)}.course-chapters{font-size:12px;color:var(--color-text-faint);background:var(--color-bg);padding:3px 10px;border-radius:var(--radius-full)}.hero{text-align:center;padding:32px 0 40px}.hero-title{font-family:var(--font-serif);font-size:36px;font-weight:700;color:var(--color-text);margin-bottom:12px;letter-spacing:.02em}.hero-sub{font-size:16px;color:var(--color-text-muted);max-width:520px;margin:0 auto}.filter-bar{display:flex;gap:10px;margin-bottom:32px;flex-wrap:wrap}.filter-btn{padding:8px 20px;border-radius:var(--radius-full);border:1px solid var(--color-border-strong);background:var(--color-bg-elevated);color:var(--color-text-muted);font-size:14px;font-weight:500;transition:all var(--transition);cursor:pointer}.filter-btn:hover{border-color:var(--color-primary);color:var(--color-primary)}.filter-btn.active{background:var(--color-primary);border-color:var(--color-primary);color:#fff}.courses-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}.loading-state{display:flex;flex-direction:column;align-items:center;gap:16px;padding:80px 0;color:var(--color-text-muted)}.spinner{width:36px;height:36px;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.back-link{display:inline-flex;align-items:center;gap:6px;color:var(--color-text-muted);font-size:14px;margin-bottom:24px;transition:color var(--transition)}.back-link:hover{color:var(--color-primary)}.detail-hero{display:grid;grid-template-columns:320px 1fr;gap:40px;margin-bottom:48px;align-items:start}@media(max-width:700px){.detail-hero{grid-template-columns:1fr}}.detail-cover{border-radius:var(--radius-lg);height:220px;display:flex;align-items:center;justify-content:center}.detail-cover-emoji{font-size:72px}.detail-meta{display:flex;flex-direction:column;gap:14px}.detail-track-tag{display:inline-block;background:var(--color-primary-light);color:var(--color-primary);font-size:13px;font-weight:600;padding:4px 12px;border-radius:var(--radius-full);width:fit-content}.detail-title{font-family:var(--font-serif);font-size:30px;font-weight:700;line-height:1.3}.detail-intro{color:var(--color-text-muted);font-size:15px;line-height:1.7}.detail-price-row{display:flex;align-items:baseline;gap:16px}.detail-price{font-family:var(--font-serif);font-size:32px;font-weight:700;color:var(--color-primary)}.detail-chapter-count{font-size:14px;color:var(--color-text-faint)}.btn-primary{display:inline-block;background:var(--color-primary);color:#fff;padding:12px 28px;border-radius:var(--radius-full);font-size:15px;font-weight:600;transition:background var(--transition);width:fit-content;text-decoration:none}.btn-primary:hover{background:var(--color-primary-hover)}.chapters-section{background:var(--color-bg-card);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden}.section-title{font-family:var(--font-serif);font-size:20px;font-weight:700;padding:20px 24px;border-bottom:1px solid var(--color-border)}.chapters-list{display:flex;flex-direction:column}.chapter-item{display:flex;align-items:center;gap:14px;padding:14px 24px;border-bottom:1px solid var(--color-border);cursor:pointer;transition:background var(--transition)}.chapter-item:last-child{border-bottom:none}.chapter-item:hover{background:var(--color-primary-light)}.chapter-item.locked{opacity:.7}.chapter-num{font-size:13px;color:var(--color-text-faint);font-variant-numeric:tabular-nums;min-width:24px}.chapter-kind-icon{font-size:14px;color:var(--color-text-muted);min-width:20px;text-align:center}.chapter-body{flex:1;display:flex;align-items:center;gap:12px;flex-wrap:wrap}.chapter-name{font-size:14px;font-weight:500}.chapter-duration{font-size:12px;color:var(--color-text-faint)}.chapter-status{flex-shrink:0}.tag-free{background:#e8f5e9;color:#2e7d32;font-size:12px;font-weight:600;padding:3px 10px;border-radius:var(--radius-full)}.tag-lock{font-size:14px;color:var(--color-text-faint)}.error-state{text-align:center;padding:80px 0;color:var(--color-text-muted)}.loading-state{display:flex;justify-content:center;padding:80px 0}.activate-page{display:flex;justify-content:center;padding:20px 0}.activate-card{background:var(--color-bg-elevated);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:40px;width:100%;max-width:500px;box-shadow:var(--shadow-md)}.activate-icon{font-size:48px;text-align:center;margin-bottom:16px}.activate-title{font-family:var(--font-serif);font-size:26px;font-weight:700;text-align:center;margin-bottom:10px}.activate-desc{color:var(--color-text-muted);font-size:14px;text-align:center;margin-bottom:32px;line-height:1.6}.activate-form{display:flex;flex-direction:column;gap:20px}.form-group{display:flex;flex-direction:column;gap:6px}.form-label{font-size:14px;font-weight:600;color:var(--color-text)}.form-input{padding:12px 16px;border:1.5px solid var(--color-border-strong);border-radius:var(--radius-md);font-family:inherit;font-size:15px;background:var(--color-bg);color:var(--color-text);transition:border-color var(--transition);outline:none}.form-input:focus{border-color:var(--color-primary);background:var(--color-bg-elevated)}.form-input:disabled{opacity:.6}.code-input{font-family:SF Mono,Fira Code,monospace;letter-spacing:.05em;font-size:16px}.form-hint{font-size:12px;color:var(--color-text-faint)}.activate-result{display:flex;align-items:center;gap:10px;padding:12px 16px;border-radius:var(--radius-md);font-size:14px;font-weight:500}.activate-result.ok{background:#e8f5e9;color:#2e7d32}.activate-result.error{background:#ffebee;color:#c62828}.result-icon{font-weight:700;font-size:16px}.btn-activate{background:var(--color-primary);color:#fff;border:none;padding:14px;border-radius:var(--radius-full);font-size:16px;font-weight:600;transition:background var(--transition);letter-spacing:.02em}.btn-activate:hover:not(:disabled){background:var(--color-primary-hover)}.btn-activate:disabled{opacity:.5;cursor:not-allowed}.activate-tips{margin-top:32px;padding-top:24px;border-top:1px solid var(--color-border)}.tips-title{font-size:14px;font-weight:600;color:var(--color-text-muted);margin-bottom:10px}.tips-list{list-style:none;display:flex;flex-direction:column;gap:6px}.tips-list li{font-size:13px;color:var(--color-text-faint);padding-left:16px;position:relative}.tips-list li:before{content:"·";position:absolute;left:4px;color:var(--color-primary)}.my-courses-page{max-width:800px;margin:0 auto}.page-header{margin-bottom:32px}.page-title{font-family:var(--font-serif);font-size:30px;font-weight:700;margin-bottom:6px}.page-sub{color:var(--color-text-muted);font-size:14px}.empty-state{text-align:center;padding:80px 0;display:flex;flex-direction:column;align-items:center;gap:12px}.empty-icon{font-size:56px;margin-bottom:8px}.empty-title{font-family:var(--font-serif);font-size:22px;font-weight:700}.empty-desc{color:var(--color-text-muted);font-size:14px;margin-bottom:8px}.btn-go-activate{background:var(--color-primary);color:#fff;padding:10px 24px;border-radius:var(--radius-full);font-size:14px;font-weight:600;text-decoration:none;transition:background var(--transition)}.btn-go-activate:hover{background:var(--color-primary-hover)}.my-courses-list{display:flex;flex-direction:column;gap:16px}.my-course-card{background:var(--color-bg-elevated);border:1px solid var(--color-border);border-radius:var(--radius-lg);display:flex;overflow:hidden;transition:box-shadow var(--transition)}.my-course-card:hover{box-shadow:var(--shadow-md)}.my-course-cover{width:140px;flex-shrink:0;display:flex;align-items:center;justify-content:center}.my-course-emoji{font-size:42px}.my-course-body{flex:1;padding:20px 24px;display:flex;flex-direction:column;gap:8px}.my-course-track{font-size:12px;font-weight:600;color:var(--color-primary);background:var(--color-primary-light);padding:2px 10px;border-radius:var(--radius-full);width:fit-content}.my-course-title{font-family:var(--font-serif);font-size:19px;font-weight:700}.my-course-stats{display:flex;gap:16px;flex-wrap:wrap;font-size:13px;color:var(--color-text-faint)}.my-course-acquired{color:var(--color-success)}.my-course-actions{display:flex;align-items:center;gap:12px;margin-top:4px}.btn-go-course{background:var(--color-primary);color:#fff;padding:8px 20px;border-radius:var(--radius-full);font-size:14px;font-weight:600;text-decoration:none;transition:background var(--transition)}.btn-go-course:hover{background:var(--color-primary-hover)}.my-course-status{font-size:13px;padding:4px 10px;border-radius:var(--radius-full)}.my-course-status.active{background:#e8f5e9;color:#2e7d32;font-weight:600}.watch-page{max-width:100%}.watch-breadcrumb{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--color-text-muted);margin-bottom:20px;flex-wrap:wrap}.watch-breadcrumb a{color:var(--color-text-muted);transition:color var(--transition)}.watch-breadcrumb a:hover{color:var(--color-primary)}.watch-breadcrumb .current{color:var(--color-text);font-weight:500}.watch-layout{display:grid;grid-template-columns:1fr 280px;gap:24px;align-items:start}@media(max-width:900px){.watch-layout{grid-template-columns:1fr}.watch-sidebar{order:-1}}.watch-main{display:flex;flex-direction:column;gap:16px}.player-wrapper{border-radius:var(--radius-lg);overflow:hidden;background:#1a1410;aspect-ratio:16/9;position:relative}.player-cover{position:absolute;top:0;right:0;bottom:0;left:0;cursor:pointer;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:12px}.player-cover-bg{position:absolute;top:0;right:0;bottom:0;left:0;z-index:0}.player-play-btn{position:relative;z-index:1;width:72px;height:72px;background:#d97757e6;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:28px;color:#fff;padding-left:4px;transition:transform var(--transition),background var(--transition);box-shadow:0 4px 24px #0006}.player-cover:hover .player-play-btn{background:var(--color-primary);transform:scale(1.05)}.player-cover-info{position:relative;z-index:1;text-align:center;display:flex;flex-direction:column;gap:4px}.player-cover-title{color:#fff;font-size:16px;font-weight:600}.player-cover-dur{color:#fff9;font-size:13px}.player-free-badge{position:absolute;z-index:2;top:12px;right:12px;background:#4caf50;color:#fff;font-size:12px;font-weight:600;padding:4px 10px;border-radius:var(--radius-full)}.player-active{position:absolute;top:0;right:0;bottom:0;left:0;background:#0a0705;display:flex;align-items:center;justify-content:center}.player-placeholder{position:relative;z-index:1;text-align:center;color:#fff6;display:flex;flex-direction:column;align-items:center;gap:8px}.player-logo{font-size:40px;color:#fff3}.player-asset-key{font-family:monospace;font-size:11px;opacity:.5}.watermark-container{position:absolute;top:0;right:0;bottom:0;left:0;pointer-events:none;z-index:10;overflow:hidden}.watermark-canvas{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%}.watch-meta{display:flex;flex-direction:column;gap:6px}.watch-title{font-family:var(--font-serif);font-size:22px;font-weight:700}.watch-meta-row{display:flex;align-items:center;justify-content:space-between;font-size:13px;color:var(--color-text-muted);flex-wrap:wrap;gap:8px}.watch-user{background:var(--color-primary-light);color:var(--color-primary);padding:3px 10px;border-radius:var(--radius-full);font-weight:500}.watch-sidebar{background:var(--color-bg-elevated);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden}.sidebar-title{font-family:var(--font-serif);font-size:15px;font-weight:700;padding:14px 16px;border-bottom:1px solid var(--color-border)}.sidebar-chapters{max-height:480px;overflow-y:auto}.sidebar-chapter{display:flex;align-items:center;gap:10px;padding:10px 16px;border-bottom:1px solid var(--color-border);font-size:13px;color:var(--color-text-muted);text-decoration:none;transition:background var(--transition)}.sidebar-chapter:last-child{border-bottom:none}.sidebar-chapter:hover{background:var(--color-primary-light);color:var(--color-primary)}.sidebar-chapter.active{background:var(--color-primary-light);color:var(--color-primary);font-weight:600}.sidebar-num{min-width:20px;font-size:11px;color:var(--color-text-faint);font-variant-numeric:tabular-nums}.sidebar-name{flex:1;line-height:1.4}.sidebar-playing{color:var(--color-primary);font-size:10px}.sidebar-lock{font-size:11px;opacity:.5}.watch-locked{text-align:center;padding:80px 0;display:flex;flex-direction:column;align-items:center;gap:12px}.locked-icon{font-size:56px;margin-bottom:8px}.locked-title{font-family:var(--font-serif);font-size:24px;font-weight:700}.locked-desc{color:var(--color-text-muted);font-size:14px;margin-bottom:8px}.locked-actions{display:flex;gap:12px;flex-wrap:wrap;justify-content:center}.btn-primary-sm{background:var(--color-primary);color:#fff;padding:10px 22px;border-radius:var(--radius-full);font-size:14px;font-weight:600;text-decoration:none;transition:background var(--transition)}.btn-primary-sm:hover{background:var(--color-primary-hover)}.btn-ghost-sm{background:transparent;color:var(--color-text-muted);padding:10px 22px;border-radius:var(--radius-full);font-size:14px;font-weight:500;text-decoration:none;border:1px solid var(--color-border-strong);transition:all var(--transition)}.btn-ghost-sm:hover{border-color:var(--color-primary);color:var(--color-primary)}.watch-loading{display:flex;justify-content:center;padding:80px 0}.watch-error{text-align:center;padding:80px 0;color:var(--color-text-muted)}