:root,[data-theme=light]{--bg:#f8faf9;--bg-card:#fff;--fg:#1a2e2a;--fg-soft:#5b6b67;--primary:#0e7c66;--primary-hover:#0a6452;--primary-soft:#0e7c661a;--border:#e2e8e6;--warn-bg:#fff7ed;--warn-border:#fbbf24;--warn-fg:#92400e;--shadow-card:0 1px 3px #0e2e2a0a;--shadow-hover:0 2px 12px #0e7c6614;--mark-bg:#0e7c662e}[data-theme=dark]{--bg:#141d29;--bg-card:#1d2735;--fg:#f8fafc;--fg-soft:#aeb8c7;--primary:#389f9d;--primary-hover:#42bdbb;--primary-soft:#389f9d2e;--border:#414f62;--warn-bg:#493512;--warn-border:#775822;--warn-fg:#f8cb77;--shadow-card:0 1px 3px #0006;--shadow-hover:0 4px 18px #00000080;--mark-bg:#42bdbb52}*{box-sizing:border-box}html,body{background:var(--bg);color:var(--fg);margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,system-ui,sans-serif;font-size:16px;line-height:1.6}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:880px;margin:0 auto;padding:32px 24px 80px}.container-wide{max-width:1100px;margin:0 auto;padding:32px 24px 80px}.brand{border-bottom:1px solid var(--border);align-items:center;gap:12px;margin-bottom:32px;padding-bottom:20px;display:flex}.brand .logo{background:var(--primary);color:#fff;border-radius:8px;justify-content:center;align-items:center;width:36px;height:36px;font-size:18px;font-weight:700;display:flex}.brand .logo-img{object-fit:contain;width:40px;height:40px;display:block}.brand h1{margin:0;font-size:18px;font-weight:600}.brand .crumb{color:var(--fg-soft);font-size:14px}.lesson-grid{gap:14px;display:grid}.help-layout{grid-template-columns:240px 1fr;align-items:start;gap:36px;margin-top:28px;display:grid}.help-sidebar{background:var(--bg-card);border:1px solid var(--border);border-radius:14px;padding:14px 12px;position:sticky;top:24px;box-shadow:0 1px 3px #0e2e2a0a}.help-sidebar-label{text-transform:uppercase;letter-spacing:.06em;color:var(--fg-soft);margin:4px 10px 10px;font-size:11px;font-weight:600}.help-sidebar-nav{flex-direction:column;gap:2px;display:flex}.help-sidebar-item{text-align:left;width:100%;font:inherit;color:var(--fg-soft);cursor:pointer;background:0 0;border:none;border-radius:9px;justify-content:space-between;align-items:center;gap:10px;padding:9px 12px;font-size:14px;transition:background .12s,color .12s;display:flex}.help-sidebar-item:hover{background:var(--bg);color:var(--fg)}.help-sidebar-item.active{background:var(--primary-soft);color:var(--primary)}.help-sidebar-item.active .help-sidebar-item-count{background:var(--primary);color:#fff;border-color:var(--primary)}.help-sidebar-item-title{text-overflow:ellipsis;white-space:nowrap;min-width:0;font-weight:500;overflow:hidden}.help-sidebar-item-count{text-align:center;background:var(--bg);min-width:22px;color:var(--fg-soft);border:1px solid var(--border);border-radius:999px;flex:none;padding:2px 7px;font-size:11px;font-weight:600}.help-content{min-width:0}.help-search{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;align-items:center;gap:10px;margin:0 0 12px;padding:0 14px;transition:border-color .15s,box-shadow .15s;display:flex}.help-search:focus-within{border-color:var(--primary);box-shadow:0 0 0 3px #0e7c661f}.help-search svg{color:var(--fg-soft);flex:none}.help-search input{font:inherit;color:var(--fg);background:0 0;border:none;outline:none;flex:1;padding:12px 0;font-size:15px}.help-search input::-webkit-search-cancel-button{display:none}.help-search button{color:var(--fg-soft);cursor:pointer;background:0 0;border:none;border-radius:6px;padding:4px 6px;font-size:22px;line-height:1}.help-search button:hover{background:var(--bg);color:var(--fg)}.help-search-meta{color:var(--fg-soft);margin:-6px 0 14px;font-size:13px}.help-content .lesson-block:first-child{margin-top:0}.search-trigger{border:1px solid var(--border);background:var(--bg);color:var(--fg-soft);cursor:pointer;white-space:nowrap;border-radius:8px;align-items:center;gap:8px;padding:6px 12px;font-size:13px;transition:border-color .15s,box-shadow .15s;display:flex}.search-trigger:hover{border-color:var(--primary);box-shadow:var(--shadow-hover)}.search-trigger kbd{border:1px solid var(--border);background:var(--bg-card);color:var(--fg-soft);border-radius:4px;padding:1px 5px;font-family:inherit;font-size:11px}.search-overlay{z-index:1000;background:#0006;justify-content:center;align-items:flex-start;padding-top:min(20vh,160px);animation:.12s ease-out search-fade-in;display:flex;position:fixed;inset:0}@keyframes search-fade-in{0%{opacity:0}to{opacity:1}}.search-modal{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;flex-direction:column;width:min(560px,100vw - 32px);max-height:min(480px,100vh - 200px);animation:.12s ease-out search-slide-in;display:flex;overflow:hidden;box-shadow:0 16px 48px #0003}@keyframes search-slide-in{0%{opacity:0;transform:translateY(-8px)scale(.98)}to{opacity:1;transform:translateY(0)scale(1)}}.search-input-row{border-bottom:1px solid var(--border);align-items:center;gap:10px;padding:12px 16px;display:flex}.search-icon{color:var(--fg-soft);flex-shrink:0}.search-input{color:var(--fg);background:0 0;border:none;outline:none;flex:1;font-family:inherit;font-size:15px}.search-input::placeholder{color:var(--fg-soft)}.search-kbd{border:1px solid var(--border);background:var(--bg);color:var(--fg-soft);border-radius:4px;flex-shrink:0;padding:2px 6px;font-family:inherit;font-size:11px}.search-unmatched{color:var(--fg-soft);border-bottom:1px solid var(--border);align-items:center;gap:6px;padding:6px 16px;font-size:12px;display:flex}.search-unmatched-word{color:var(--warn-fg);background:var(--warn-bg);border-radius:3px;padding:1px 5px;text-decoration:line-through}.search-unmatched-label{font-style:italic}.search-results{flex:1;overflow-y:auto}.search-result{text-align:left;width:100%;color:var(--fg);cursor:pointer;background:0 0;border:none;border-bottom:1px solid #0000;padding:10px 16px;font-family:inherit;font-size:14px;transition:background 80ms;display:block}.search-result[data-active=true]{background:var(--primary-soft)}.search-result-title{align-items:center;gap:8px;margin-bottom:2px;font-weight:600;display:flex}.search-result-block{background:var(--primary-soft);color:var(--primary);white-space:nowrap;border-radius:4px;padding:1px 6px;font-size:11px;font-weight:500}.search-result-snippet{color:var(--fg-soft);text-overflow:ellipsis;-webkit-line-clamp:2;-webkit-box-orient:vertical;font-size:13px;line-height:1.4;display:-webkit-box;overflow:hidden}.search-result mark,.search-result-snippet mark{background:var(--mark-bg);color:inherit;border-radius:2px;padding:0 1px}.search-empty,.search-hint{text-align:center;color:var(--fg-soft);padding:24px 16px;font-size:14px}@media (max-width:820px){.help-layout{grid-template-columns:1fr;gap:20px}.help-sidebar{position:static}.help-sidebar-nav{flex-flow:wrap}.help-sidebar-item{width:auto}}.lesson-block{margin-top:28px}.lesson-block h2{text-transform:uppercase;color:var(--fg-soft);letter-spacing:.04em;margin:0 0 12px;font-size:13px}.lesson-card{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;align-items:center;gap:16px;padding:16px 20px;transition:all .15s;display:flex}.lesson-card:hover{border-color:var(--primary);box-shadow:var(--shadow-hover);text-decoration:none}.lesson-card .num{background:var(--bg);height:36px;color:var(--primary);border-radius:8px;flex:0 0 36px;justify-content:center;align-items:center;font-weight:600;display:flex}.lesson-card .body{flex:1;min-width:0}.lesson-card .title{color:var(--fg);margin:0 0 2px;font-size:15px;font-weight:600}.lesson-card .meta{color:var(--fg-soft);font-size:13px}.lesson-card .pending-pill{background:var(--warn-bg);color:var(--warn-fg);border:1px solid var(--warn-border);border-radius:6px;flex:none;padding:4px 8px;font-size:11px;font-weight:600}.lesson-page h1{margin:0 0 8px;font-size:28px;line-height:1.25}.lesson-page .lead{color:var(--fg-soft);margin:0 0 28px;font-size:15px}.video-frame{color:#fff;aspect-ratio:16/9;text-align:center;background:#0b1d1a;border-radius:12px;justify-content:center;align-items:center;margin:0 0 32px;padding:24px;font-size:14px;display:flex}.warn-banner{background:var(--warn-bg);border:1px solid var(--warn-border);color:var(--warn-fg);border-radius:10px;margin:0 0 24px;padding:14px 18px;font-size:14px}.warn-banner strong{margin-bottom:4px;display:block}.markdown h2{margin:32px 0 12px;font-size:22px}.markdown h3{margin:24px 0 8px;font-size:17px}.markdown p{margin:0 0 14px}.markdown ul,.markdown ol{margin:0 0 16px;padding-left:22px}.markdown li{margin-bottom:6px}.markdown code{background:var(--bg);border:1px solid var(--border);border-radius:4px;padding:1px 6px;font-size:.92em}.markdown blockquote{border-left:3px solid var(--primary);color:var(--fg-soft);margin:16px 0;padding:4px 0 4px 16px;font-style:italic}.markdown img{border:1px solid var(--border);border-radius:8px;max-width:100%;height:auto;margin:20px 0;display:block}.shots{grid-template-columns:1fr;gap:16px;margin:28px 0;display:grid}.shot figure{margin:0}.shot img{border:1px solid var(--border);border-radius:8px;width:100%;display:block}.shot figcaption{color:var(--fg-soft);text-align:center;margin-top:6px;font-size:13px}.tabs{border-bottom:1px solid var(--border);gap:4px;margin:32px 0 20px;display:flex}.tabs a{color:var(--fg-soft);border-bottom:2px solid #0000;padding:10px 16px;font-size:14px;font-weight:500}.tabs a.active{color:var(--primary);border-bottom-color:var(--primary)}.auth-card{background:var(--bg-card);border:1px solid var(--border);border-radius:14px;max-width:420px;margin:80px auto;padding:36px 32px}.auth-card h1{margin:0 0 8px;font-size:22px}.auth-card p{color:var(--fg-soft);margin:0 0 24px;font-size:14px}.auth-card label{margin-bottom:6px;font-size:13px;font-weight:500;display:block}.auth-card input{border:1px solid var(--border);border-radius:8px;width:100%;margin-bottom:16px;padding:10px 12px;font-family:inherit;font-size:15px}.auth-card input:focus{border-color:var(--primary);outline:none}.auth-card button{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;width:100%;padding:12px;font-size:15px;font-weight:600}.auth-card button:hover{background:var(--primary-hover)}.auth-card .error{color:#991b1b;background:#fef2f2;border:1px solid #fca5a5;border-radius:6px;margin-bottom:16px;padding:10px 12px;font-size:13px}.auth-card .success{color:#065f46;background:#ecfdf5;border:1px solid #6ee7b7;border-radius:6px;margin-bottom:16px;padding:10px 12px;font-size:13px}.user-bar{color:var(--fg-soft);align-items:center;gap:12px;margin-left:auto;font-size:13px;display:flex}.user-bar form{display:inline}.user-bar button{color:var(--fg-soft);cursor:pointer;font:inherit;background:0 0;border:none;padding:0;text-decoration:underline}.theme-toggle{border:1px solid var(--border);background:var(--bg-card);width:32px;height:32px;color:var(--fg-soft);cursor:pointer;border-radius:8px;justify-content:center;align-items:center;padding:0;transition:border-color .15s,color .15s,background .15s;display:inline-flex;text-decoration:none!important}.theme-toggle:hover{border-color:var(--primary);color:var(--primary)}.theme-toggle-placeholder{pointer-events:none;background:0 0;border-color:#0000}.lesson-card mark,.markdown mark{background:var(--mark-bg);color:inherit;border-radius:3px;padding:0 2px}.help-empty{text-align:center;background:var(--bg-card);border:1px dashed var(--border);color:var(--fg-soft);border-radius:14px;flex-direction:column;justify-content:center;align-items:center;padding:60px 20px;display:flex}.help-empty svg{color:var(--fg-soft);opacity:.6;margin-bottom:12px}.help-empty h3{color:var(--fg);margin:0 0 6px;font-size:16px}.help-empty p{margin:0 0 16px;font-size:14px}.help-empty button{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;padding:8px 16px;font-size:13px;font-weight:600}.help-empty button:hover{background:var(--primary-hover)}.lesson-card.is-read .num{background:var(--primary-soft)}.lesson-card .read-tick{background:var(--primary);color:#fff;border-radius:50%;flex:none;justify-content:center;align-items:center;width:22px;height:22px;display:flex}.help-progress{color:var(--fg-soft);align-items:center;gap:12px;margin:0 10px 12px;padding:0 2px;font-size:12px;display:flex}.help-progress-bar{background:var(--bg);border:1px solid var(--border);border-radius:999px;flex:1;height:4px;overflow:hidden}.help-progress-bar>span{background:var(--primary);border-radius:999px;height:100%;transition:width .3s;display:block}.help-progress-reset{color:var(--fg-soft);cursor:pointer;font:inherit;background:0 0;border:none;padding:0;font-size:11px;text-decoration:underline}.lesson-page-layout{grid-template-columns:1fr 220px;align-items:start;gap:48px;display:grid}.lesson-page-main{min-width:0}.lesson-toc{font-size:13px;position:sticky;top:24px}.lesson-toc h4{text-transform:uppercase;letter-spacing:.06em;color:var(--fg-soft);margin:0 0 10px;font-size:11px;font-weight:600}.lesson-toc ul{border-left:1px solid var(--border);margin:0;padding:0;list-style:none}.lesson-toc li a{color:var(--fg-soft);border-left:2px solid #0000;margin-left:-1px;padding:6px 12px;transition:color .12s,border-color .12s;display:block}.lesson-toc li a:hover{color:var(--fg);text-decoration:none}.lesson-toc li a.active{color:var(--primary);border-left-color:var(--primary);font-weight:500}.lesson-toc li.h3 a{padding-left:24px;font-size:12px}@media (max-width:980px){.lesson-page-layout{grid-template-columns:1fr}.lesson-toc{display:none}}.lesson-nav-cards{border-top:1px solid var(--border);grid-template-columns:1fr 1fr;gap:16px;margin-top:48px;padding-top:24px;display:grid}.lesson-nav-card{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;flex-direction:column;gap:4px;padding:16px 20px;transition:border-color .15s,box-shadow .15s;display:flex}.lesson-nav-card:hover{border-color:var(--primary);box-shadow:var(--shadow-hover);text-decoration:none}.lesson-nav-card.next{text-align:right}.lesson-nav-card .lnc-label{text-transform:uppercase;letter-spacing:.06em;color:var(--fg-soft);font-size:11px}.lesson-nav-card .lnc-title{color:var(--fg);font-size:15px;font-weight:600}@media (max-width:600px){.lesson-nav-cards{grid-template-columns:1fr}.lesson-nav-card.next{text-align:left}}.title-row{align-items:center;gap:12px;display:flex}.copy-link-btn{border:1px solid var(--border);color:var(--fg-soft);font:inherit;cursor:pointer;background:0 0;border-radius:8px;flex:none;align-items:center;gap:6px;padding:6px 10px;font-size:12px;transition:border-color .15s,color .15s;display:inline-flex}.copy-link-btn:hover{border-color:var(--primary);color:var(--primary)}.help-toast{background:var(--fg);color:var(--bg);z-index:50;pointer-events:none;border-radius:999px;padding:10px 18px;font-size:13px;font-weight:500;animation:.2s ease-out helpToastIn;position:fixed;bottom:24px;left:50%;transform:translate(-50%)translateY(0);box-shadow:0 6px 24px #0000002e}@keyframes helpToastIn{0%{opacity:0;transform:translate(-50%)translateY(8px)}to{opacity:1;transform:translate(-50%)translateY(0)}}@media print{body{color:#000;background:#fff}.brand .user-bar,.help-sidebar,.help-search,.help-search-meta,.help-progress,.lesson-toc,.lesson-nav-cards,.copy-link-btn,.help-toast,.pending-pill,.video-frame{display:none!important}.help-layout,.lesson-page-layout{display:block!important}.container,.container-wide{max-width:100%!important;padding:0!important}.lesson-card,.help-sidebar,.lesson-nav-card{box-shadow:none!important;border-color:#ccc!important}.shot{page-break-inside:avoid}.markdown a[href^=http]:after{content:" (" attr(href) ")";color:#555;font-size:.85em}h1,h2,h3{page-break-after:avoid}}