:root{--surface:#f7f7f5;--paper:#fff;--ink:#171717;--muted:#777;--soft:#626262;--line:#e5e5e0;--line-strong:#d6d6d0;color:var(--ink);background:var(--surface);font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-family:PingFang SC,Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Microsoft YaHei,Arial,sans-serif;line-height:1.5}*{box-sizing:border-box}html{background:var(--surface);min-width:320px}body{min-width:320px;min-height:100svh;margin:0}img,svg{display:block}a{color:inherit}.app-shell{background:var(--surface);min-height:100svh;color:var(--ink);padding-bottom:76px}button,input,select,textarea{font:inherit}button{cursor:pointer}.topbar{z-index:20;border-bottom:1px solid var(--line);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#f7f7f5e0;justify-content:space-between;align-items:center;gap:24px;padding:18px clamp(18px,4vw,48px);display:flex;position:sticky;top:0}.brand,.desktop-nav button,.mobile-nav button,.episode-card button,.caption-row,.result-list button{color:inherit;background:0 0;border:0}.brand{text-align:left;align-items:center;gap:12px;display:flex}.brand-mark{color:#fff;background:#141414;border-radius:14px;place-items:center;width:42px;height:42px;font-family:Georgia,serif;font-size:23px;display:grid}.brand strong{font-size:20px;line-height:1.1;display:block}.brand small{color:var(--muted);margin-top:3px;font-size:12px;display:block}.desktop-nav{align-items:center;gap:6px;display:none}.desktop-nav button{min-height:38px;color:var(--muted);border-radius:999px;align-items:center;gap:7px;padding:0 14px;display:inline-flex}.desktop-nav button.active,.desktop-nav button:hover{background:var(--ink);color:#fff}.page{width:min(1440px,100%);margin:0 auto;padding:clamp(18px,3vw,42px)}.home-layout{gap:22px;display:grid}.study-panel{gap:18px;display:grid}.hero-copy,.filter-panel,.profile-card,.upload-box,.admin-sidebar,.workflow-grid article,.method-grid article{border:1px solid var(--line);background:var(--paper);border-radius:8px;box-shadow:0 18px 48px #0000000a}.hero-copy{padding:24px}.hero-copy p,.page-heading p{color:var(--muted);margin:0 0 8px;font-weight:700}.hero-copy h1,.page-heading h1,.profile-card h1{letter-spacing:0;margin:0;font-size:clamp(30px,5vw,60px);line-height:1.02}.hero-copy span,.page-heading span{max-width:720px;color:var(--soft);margin-top:18px;display:block}.stat-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;display:grid}.metric{border:1px solid var(--line);background:#fff;border-radius:8px;grid-template-columns:auto 1fr;align-items:center;gap:9px 10px;min-width:0;padding:16px;display:grid}.metric strong{grid-column:2;font-size:25px}.metric span{color:var(--muted);font-size:13px}.metric.blue svg{color:#1777c7}.metric.green svg{color:#0d9e51}.metric.rose svg{color:#d90b52}.metric.dark svg{color:#111}.filter-panel{padding:20px}.section-title{align-items:center;gap:10px;margin-bottom:18px;display:flex}.section-title h1,.section-title h2{margin:0;font-size:22px}.field-grid{gap:14px;display:grid}label{color:var(--muted);gap:8px;font-size:14px;display:grid}input,select,textarea{box-sizing:border-box;border:1px solid var(--line-strong);width:100%;min-width:0;color:var(--ink);background:#fff;border-radius:8px;outline:none;padding:13px 14px}textarea{resize:vertical}input:focus,select:focus,textarea:focus{border-color:#111;box-shadow:0 0 0 3px #00000014}.tag-list,.pill-row{flex-wrap:wrap;gap:8px;display:flex}.tag-list{margin-top:18px}.tag-list button,.pill-row span,.mode-tabs button{border:1px solid var(--line);color:var(--muted);background:#fff;border-radius:999px;padding:7px 11px;font-size:13px}.tag-list button:first-child,.mode-tabs button.active{background:var(--ink);border-color:var(--ink);color:#fff}.episode-grid{grid-template-columns:1fr;gap:18px;display:grid}.empty-state{border:1px solid var(--line);min-height:280px;color:var(--soft);text-align:center;background:#fff;border-radius:8px;align-content:center;place-items:center;gap:10px;padding:28px;display:grid}.empty-state h1,.empty-state p{margin:0}.episode-card{border:1px solid var(--line);background:#fff;border-radius:8px;min-width:0;overflow:hidden;box-shadow:0 16px 40px #0000000f}.episode-card button{text-align:left;width:100%;display:grid}.cover-wrap{aspect-ratio:16/9;background:#ddd;position:relative;overflow:hidden}.cover-wrap img,.cover-wrap video{object-fit:cover;width:100%;height:100%;transition:transform .25s}.cover-placeholder{color:#fff;background:#171717;place-items:center;width:100%;height:100%;font-weight:800;display:grid}.episode-card:hover img,.episode-card:hover video{transform:scale(1.04)}.cover-wrap span,.cover-wrap strong{color:#fff;text-shadow:0 1px 8px #00000080;position:absolute;bottom:10px}.cover-wrap span{left:12px}.cover-wrap strong{right:12px}.episode-body{gap:10px;padding:18px;display:grid}.episode-topline,.episode-meta,.learner-top,.focus-toolbar,.caption-actions,.table-head,.table-row{justify-content:space-between;align-items:center;gap:12px;display:flex}.favorite-button,.caption-favorite{color:var(--muted);cursor:pointer;transition:color .15s}.caption-favorite{border-radius:4px;align-items:center;padding:2px;display:inline-flex}.caption-favorite:hover{background:#d9155714}.favorite-button.active,.caption-favorite.active{color:#d91557}.episode-topline h2{margin:0;font-size:22px}.rating{color:#f6b800;flex-shrink:0;gap:1px;display:inline-flex}.accent,.episode-body p,.episode-meta{color:var(--soft)}.episode-body h3{margin:0;font-size:17px}.episode-body p{-webkit-line-clamp:3;-webkit-box-orient:vertical;margin:0;display:-webkit-box;overflow:hidden}.episode-meta{flex-wrap:wrap;font-size:13px}.learner-top{margin-bottom:14px}.learner-top p{color:var(--muted);margin:0 0 2px}.learner-top h1{margin:0;font-size:clamp(20px,3vw,32px)}.icon-button{border:1px solid var(--line);width:40px;height:40px;color:var(--ink);background:#fff;border-radius:999px;flex:none;place-items:center;display:grid}.mode-tabs{gap:8px;margin-bottom:18px;padding-bottom:4px;display:flex;overflow-x:auto}.mode-tabs button{flex:none;min-width:64px}.learning-workspace{gap:22px;display:grid}.player-column{gap:14px;min-width:0;display:grid}.video-stage{aspect-ratio:16/9;background:#111;border-radius:8px;position:relative;overflow:hidden}.video-stage img,.video-stage video{object-fit:cover;width:100%;height:100%}.video-stage img{opacity:.82}.video-stage button{background:#ffffffdb;border:0;border-radius:999px;place-items:center;width:82px;height:82px;display:grid;position:absolute;inset:50% auto auto 50%;transform:translate(-50%,-50%)}.video-time{color:#fff;justify-content:space-between;font-size:13px;display:flex;position:absolute;bottom:14px;left:16px;right:16px}.control-strip{align-items:center;gap:8px;display:flex;overflow-x:auto}.control-strip button{border:1px solid var(--line);background:#fff;border-radius:999px;justify-content:center;align-items:center;min-width:38px;height:38px;display:inline-flex}.control-strip .play-button{background:var(--ink);color:#fff}.focus-card,.caption-row{border:1px solid var(--line);background:#fff;border-radius:8px}.focus-card{gap:22px;min-height:270px;padding:20px;display:grid}.focus-card>p:nth-child(2),.focus-primary{color:var(--ink);text-align:center;align-self:end;font-size:clamp(23px,4vw,34px);font-weight:700;line-height:1.38}.focus-card>p:nth-child(3),.practice-panel>p,.reading-card>p:last-child{color:var(--soft);text-align:center}.practice-panel,.reading-card,.word-card-list{align-content:center;gap:14px;display:grid}.practice-panel textarea{resize:vertical;min-height:130px}.practice-panel small{color:var(--soft);line-height:1.6}.word-card-list{grid-template-columns:1fr}.word-card{border:1px solid var(--line);text-align:center;background:#fff8fb;border-radius:8px;gap:8px;padding:16px;display:grid}.word-card strong{color:#b5124b;font-size:24px}.word-card.new{background:#fff7e8}.word-card.new strong{color:#a45600}.word-card.common{background:#edf8f3}.word-card.common strong{color:#087348}.word-card span{color:var(--soft)}.word-sheet-backdrop{z-index:40;background:#0003;align-items:end;display:grid;position:fixed;inset:0}.word-sheet{background:#f7f7f7;border-radius:8px 8px 0 0;justify-self:center;width:min(620px,100vw);max-height:84vh;overflow:auto;box-shadow:0 -18px 50px #00000029}.word-sheet-bar{background:#d4d4d4;border-radius:999px;width:46px;height:4px;margin:12px auto 10px}.word-sheet header{border-bottom:1px solid var(--line);background:#eef1ff;grid-template-columns:1fr auto;gap:12px;padding:14px 18px;display:grid}.word-sheet header>button{background:0 0;border:0;grid-area:1/2;font-size:26px}.word-sheet header>div{grid-column:1;align-items:center;gap:12px;display:flex}.word-favorite{color:#171717;cursor:pointer;background:0 0;border:1px solid #0000;border-radius:50%;place-items:center;width:32px;height:32px;display:inline-grid}.word-favorite.active{color:#d91557;background:#ffe8ef}.word-favorite:disabled{cursor:not-allowed;opacity:.45}.word-sheet h2{margin:0;font-size:22px}.word-pronounce{color:var(--soft);justify-content:space-between;align-items:center;gap:12px;padding:16px 20px;display:flex}.word-pronounce button{min-width:0;color:inherit;font:inherit;cursor:pointer;background:0 0;border:0;align-items:center;gap:8px;display:inline-flex}.word-pronounce button strong{color:#171717;font-weight:600}.uk-phonetic{color:#555;font-weight:600}.kind-chip{border-radius:999px;padding:4px 10px}.kind-chip.key{color:#b5124b;background:#ffe8ef}.kind-chip.new{color:#a45600;background:#fff0d6}.kind-chip.common{color:#087348;background:#e4f6ee}.word-definition{background:#fff;border-radius:8px;gap:10px;margin:0 14px 18px;padding:18px;display:grid;box-shadow:0 2px 12px #00000014}.word-definition span,.word-definition p{color:var(--soft);margin:0}.word-sheet footer{border-top:1px solid var(--line);justify-content:space-between;gap:12px;padding:16px 20px;display:flex}.word-sheet footer button{font:inherit;background:0 0;border:0}.word-levels{gap:8px;display:flex}.word-levels span{color:#fff;background:#637083;border-radius:999px;place-items:center;width:20px;height:20px;font-size:12px;display:grid}.highlight-word{font:inherit;cursor:pointer;border:0;border-radius:5px;padding:1px 4px;display:inline}.highlight-word.key{color:#b5124b;background:#ffe8ef}.highlight-word.new{color:#a45600;background:#fff0d6}.highlight-word.common{color:#087348;background:#e4f6ee}.caption-list{gap:12px;min-width:0;max-height:72vh;padding-right:4px;display:grid;overflow:auto}.caption-row{text-align:left;cursor:pointer;gap:10px;padding:18px;display:grid}.caption-row.active{box-shadow:inset 4px 0 0 var(--ink)}.caption-row>p{margin:0;font-size:18px;line-height:1.5}.caption-row>p:last-child{color:var(--soft);font-size:15px}.caption-row>.caption-primary{color:var(--ink);font-size:18px}.caption-actions{color:var(--muted);justify-content:flex-start;font-size:13px}.narrow-page,.methods-page,.profile-page{max-width:1120px}.search-box{border:1px solid var(--line);background:#fff;border-radius:8px;grid-template-columns:auto 1fr auto;align-items:center;gap:12px;padding:8px 8px 8px 16px;display:grid}.search-box input{box-shadow:none;border:0;padding:13px 0}.search-box button,.upload-box button,.success-button{background:var(--ink);color:#fff;border:0;border-radius:8px;padding:13px 20px;font-weight:700}.result-count{color:var(--muted);text-align:center;margin:28px 0}.result-list{gap:22px;display:grid}.result-list button{border-bottom:1px solid var(--line);text-align:left;gap:8px;padding:0 0 22px;display:grid}.result-list p{margin:0}.result-list p:first-child{font-size:19px}.result-list p:nth-child(2),.result-list span{color:var(--soft)}.page-heading{margin-bottom:26px}.page-heading.compact h1{font-size:clamp(28px,4vw,44px)}.method-grid{gap:16px;display:grid}.method-grid article{padding:22px}.method-grid h2{margin:0 0 10px;font-size:24px}.method-grid p,.method-grid span,.method-grid li{color:var(--soft)}.method-grid ol{margin:16px 0 0;padding-left:22px}.profile-page{gap:20px;display:grid}.profile-card{gap:18px;padding:24px;display:grid}.danger-button{color:#fff;background:#e90917;border:0;border-radius:8px;padding:14px 20px;font-weight:700}.success-button{background:#09a844}.success-button:disabled{cursor:not-allowed;opacity:.58}.form-notice{color:var(--soft);margin:0}.admin-layout{gap:22px;display:grid}.admin-sidebar{align-content:start;gap:10px;padding:18px;display:grid}.admin-brand{align-items:center;gap:12px;margin-bottom:14px;display:flex}.admin-brand span{color:var(--muted);font-size:13px;display:block}.admin-sidebar button{color:var(--soft);background:0 0;border:0;border-radius:8px;align-items:center;gap:10px;padding:12px;display:flex}.admin-sidebar button:first-of-type,.admin-sidebar button:hover{background:var(--ink);color:#fff}.admin-main{min-width:0}.workflow-grid{gap:12px;margin-bottom:22px;display:grid}.workflow-grid article{gap:6px;padding:18px;display:grid;position:relative}.workflow-grid article>span{color:#1769c2;background:#eff6ff;border-radius:999px;place-items:center;width:32px;height:32px;font-weight:700;display:grid}.workflow-grid p{color:var(--soft);margin:0}.workflow-grid em{color:var(--muted);font-size:13px;font-style:normal;position:absolute;top:18px;right:18px}.admin-editor{gap:18px;display:grid}.upload-box{text-align:center;place-items:center;padding:34px 20px;display:grid}.upload-box p{max-width:440px;color:var(--soft)}.review-table{border:1px solid var(--line);background:#fff;border-radius:8px;overflow:auto}.table-head,.table-row{grid-template-columns:90px 1.4fr 1.2fr 1fr;min-width:780px;display:grid}.table-head{color:var(--muted);background:#f1f1ef;font-weight:700}.table-head span,.table-row span{border-bottom:1px solid var(--line);padding:14px}.table-row span{color:var(--soft)}.mobile-nav{z-index:30;border:1px solid var(--line);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#ffffffe6;border-radius:8px;grid-template-columns:repeat(4,1fr);display:grid;position:fixed;bottom:12px;left:12px;right:12px;box-shadow:0 18px 45px #00000024}.mobile-nav button{min-height:58px;color:var(--muted);place-items:center;gap:3px;font-size:12px;display:grid}.mobile-nav button.active{color:var(--ink);font-weight:700}@media (width>=680px){.episode-grid,.field-grid,.workflow-grid,.method-grid,.profile-page{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (width>=980px){.app-shell{padding-bottom:0}.desktop-nav{display:flex}.mobile-nav{display:none}.home-layout{grid-template-columns:minmax(300px,390px) 1fr;align-items:start}.study-panel{max-height:calc(100svh - 110px);padding-right:4px;position:sticky;top:94px;overflow:auto}.episode-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.learning-workspace{grid-template-columns:minmax(360px,.92fr) minmax(420px,1.08fr);align-items:start}.player-column{position:sticky;top:108px}.admin-layout{grid-template-columns:250px 1fr}.admin-sidebar{position:sticky;top:96px}}@media (width>=1240px){.episode-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.workflow-grid{grid-template-columns:repeat(5,minmax(0,1fr))}}@media (width<=480px){.topbar{padding:14px}.brand-mark{width:38px;height:38px}.brand strong{font-size:18px}.brand small{white-space:nowrap;text-overflow:ellipsis;max-width:180px;overflow:hidden}.page{padding:14px}.stat-grid{grid-template-columns:1fr}.hero-copy,.filter-panel,.profile-card{padding:18px}.search-box{grid-template-columns:auto 1fr}.search-box button{grid-column:1/-1}}.back-link{color:var(--muted);cursor:pointer;background:0 0;border:0;padding:8px 0;font-size:14px}.back-link:hover{color:var(--ink)}.auth-page{flex-direction:column;align-items:center;padding-top:40px;display:flex}.auth-card{border:1px solid var(--line);background:#fff;border-radius:12px;width:min(400px,100%);padding:32px}.auth-card h1{margin:0 0 24px;font-size:24px}.auth-card label{color:var(--muted);margin-bottom:16px;font-size:13px;display:block}.auth-card input{border:1px solid var(--line);background:#fafaf8;border-radius:8px;width:100%;margin-top:6px;padding:10px 12px;font-size:15px;display:block}.auth-card>button[type=button]{color:#fff;cursor:pointer;background:#171717;border:0;border-radius:8px;width:100%;margin-top:8px;padding:12px;font-size:15px;font-weight:600}.auth-card>button:disabled{opacity:.6;cursor:not-allowed}.auth-error{color:#d91557;margin:8px 0;font-size:13px}.auth-switch{text-align:center;color:var(--muted);margin-top:16px;font-size:13px}.auth-switch button{color:#171717;cursor:pointer;background:0 0;border:0;font-weight:600;text-decoration:underline}.subscription-page h1{margin-bottom:8px;font-size:28px}.sub-desc{color:var(--muted);margin-bottom:24px}.plan-grid{grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px;margin-bottom:40px;display:grid}.plan-card{border:2px solid var(--line);text-align:center;background:#fff;border-radius:12px;padding:24px;transition:border-color .15s}.plan-card:hover{border-color:#171717}.plan-card h2{margin:0 0 12px;font-size:18px}.plan-price{margin-bottom:12px}.plan-price strong{font-size:32px}.plan-price span{color:var(--muted);font-size:14px}.plan-card p{color:var(--muted);font-size:13px}.plan-pay-btn{color:#fff;cursor:pointer;background:#171717;border:0;border-radius:8px;width:100%;margin-top:12px;padding:10px;font-size:14px;font-weight:600;transition:background .15s}.plan-pay-btn:hover{background:#333}.plan-pay-btn:disabled{opacity:.6;cursor:not-allowed}.redeem-section{border:1px solid var(--line);background:#fff;border-radius:12px;padding:24px}.redeem-section h2{margin:0 0 8px;font-size:18px}.redeem-section>p{color:var(--muted);margin-bottom:16px;font-size:13px}.redeem-input{gap:8px;display:flex}.redeem-input input{border:1px solid var(--line);background:#fafaf8;border-radius:8px;flex:1;padding:10px 12px;font-size:15px}.redeem-input button{color:#fff;cursor:pointer;background:#171717;border:0;border-radius:8px;padding:10px 20px;font-size:15px;font-weight:600}.redeem-input button:disabled{opacity:.6;cursor:not-allowed}.redeem-message{margin-top:12px;font-size:14px}.subscribe-banner{color:#fff;background:linear-gradient(135deg,#171717,#333);border-radius:12px;margin-top:16px;padding:20px}.subscribe-banner strong{margin-bottom:4px;font-size:18px;display:block}.subscribe-banner p{color:#ffffffb3;margin-bottom:12px;font-size:13px}.subscribe-banner button{color:#171717;cursor:pointer;background:#fff;border:0;border-radius:8px;padding:10px 20px;font-size:14px;font-weight:600}.favorites-page h1{margin-bottom:16px;font-size:28px}.empty-hint{color:var(--muted);text-align:center;padding:40px 0}.favorites-list{flex-direction:column;gap:8px;display:flex}.favorite-item{text-align:left;border:1px solid var(--line);cursor:pointer;background:#fff;border-radius:10px;width:100%;padding:14px 16px;transition:border-color .15s;display:block}.favorite-item:hover{border-color:#171717}.favorite-item strong{margin-bottom:4px;font-size:15px;display:block}.favorite-item p{color:var(--muted);margin:0 0 4px;font-size:13px}.favorite-item span{color:#999;font-size:12px}.redeem-page h1{margin-bottom:8px;font-size:28px}.redeem-page>p{color:var(--muted);margin-bottom:20px}.profile-actions{flex-direction:column;gap:8px;margin-top:16px;display:flex}.profile-actions button{border:1px solid var(--line);cursor:pointer;text-align:left;background:#fff;border-radius:8px;padding:10px 16px;font-size:14px}.profile-actions button:hover{border-color:#171717}.profile-actions .danger-button{color:#d91557;border-color:#f3c0c9}.metric.clickable{cursor:pointer;transition:transform .1s}.metric.clickable:hover{transform:translateY(-1px)}