:root{--bg:#191a17;--panel:#22231f;--panel2:#292a25;--ink:#f5f2e9;--muted:#9b9b93;--line:rgba(255,255,255,.1);--orange:#ff673b;--orange2:#ff8b4d;--blue:#5c8dff;--violet:#9b74ff;--shadow:0 24px 70px rgba(0,0,0,.28);font-family:Inter,"PingFang SC","Microsoft YaHei",sans-serif;color-scheme:dark}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:radial-gradient(circle at 80% 0,rgba(255,103,59,.08),transparent 28%),var(--bg);min-height:100vh}.hidden{display:none!important}button,input{font:inherit}.topbar{position:sticky;z-index:20;top:0;height:88px;display:flex;align-items:center;gap:26px;padding:0 5.2vw;background:rgba(25,26,23,.9);border-bottom:1px solid var(--line);backdrop-filter:blur(18px)}.brand{display:flex;align-items:center;gap:12px;color:var(--ink);font-size:16px;font-weight:850;text-decoration:none;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:36px;height:36px;color:#191a17;background:var(--orange);border-radius:10px;font-size:19px}.brand em{display:block;margin-top:2px;color:var(--orange);font-size:10px;font-style:normal;letter-spacing:1.6px}.product-nav{display:flex;align-items:center;gap:4px;margin:auto;padding:4px;background:rgba(10,10,9,.42);border:1px solid var(--line);border-radius:12px}.product-nav a{padding:9px 13px;color:#9e9e97;border-radius:8px;font-size:12px;font-weight:760;text-decoration:none;white-space:nowrap}.product-nav a:hover{color:var(--ink);background:rgba(255,255,255,.05)}.product-nav a.active{color:#181815;background:var(--orange)}.nav-mobile{display:none}.account{display:flex;align-items:center;gap:12px;color:var(--muted);font-size:12px}.account button{padding:8px 12px;color:#b9b8b1;background:transparent;border:1px solid var(--line);border-radius:9px;cursor:pointer}.account button:hover{color:var(--ink);border-color:rgba(255,103,59,.6)}main{width:min(1440px,90vw);margin:0 auto 80px}.hero{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(380px,.8fr);align-items:end;gap:70px;padding:78px 0 62px}.eyebrow{margin:0 0 12px;color:var(--orange);font-size:11px;font-weight:850;letter-spacing:2.2px;text-transform:uppercase}.hero h1{max-width:760px;margin:0;font-size:clamp(44px,5.2vw,78px);line-height:1.04;letter-spacing:-3px}.hero h1 span{color:var(--orange)}.hero-copy>p:last-child{max-width:680px;margin:24px 0 0;color:#bbb9b1;font-size:17px;line-height:1.85}.hero-stats{display:grid;grid-template-columns:repeat(3,1fr);overflow:hidden;background:rgba(34,35,31,.8);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}.hero-stats div{padding:28px 18px;border-right:1px solid var(--line)}.hero-stats div:last-child{border:0}.hero-stats strong{display:block;color:var(--ink);font-size:32px}.hero-stats span{display:block;margin-top:7px;color:var(--muted);font-size:11px}.catalog-section{padding:34px 0 80px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:40px;margin-bottom:30px}.section-heading h2{margin:0;font-size:32px}.section-heading>p{max-width:520px;margin:0;color:var(--muted);line-height:1.75}.course-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.course-card{position:relative;display:flex;min-height:430px;overflow:hidden;flex-direction:column;padding:26px;color:var(--ink);background:linear-gradient(155deg,rgba(43,44,39,.98),rgba(30,31,27,.98));border:1px solid var(--line);border-radius:20px;box-shadow:0 18px 50px rgba(0,0,0,.17);cursor:pointer;transition:transform .25s,border-color .25s}.course-card:hover{transform:translateY(-6px);border-color:rgba(255,103,59,.52)}.course-card::before{content:"";position:absolute;right:-50px;top:-70px;width:220px;height:220px;border-radius:50%;background:var(--card-accent);opacity:.14;filter:blur(1px)}.course-card.basic{--card-accent:var(--blue)}.course-card.advanced{--card-accent:var(--orange)}.course-card.speech{--card-accent:var(--violet)}.course-index{display:flex;align-items:center;justify-content:space-between;color:#aaa9a2;font-size:11px;font-weight:800;letter-spacing:1px}.course-index em{padding:6px 9px;color:var(--card-accent);background:color-mix(in srgb,var(--card-accent) 11%,transparent);border-radius:999px;font-style:normal}.course-visual{display:grid;place-items:center;width:92px;height:92px;margin:45px 0 28px;background:color-mix(in srgb,var(--card-accent) 12%,#20211d);border:1px solid color-mix(in srgb,var(--card-accent) 34%,transparent);border-radius:24px;color:var(--card-accent);font-size:34px;font-weight:950;transform:rotate(-4deg)}.course-card h3{margin:0;font-size:25px;line-height:1.3}.course-card p{margin:14px 0 24px;color:#aaa9a2;line-height:1.7}.course-meta{display:flex;gap:18px;margin-top:auto;padding-top:20px;border-top:1px solid var(--line);color:#c2c0b9;font-size:12px}.course-action{display:flex;justify-content:space-between;align-items:center;margin-top:20px;color:var(--card-accent);font-size:13px;font-weight:850}.course-action b{font-size:19px}.learning-workspace{padding:42px 0}.workspace-heading{display:grid;grid-template-columns:auto minmax(0,1fr) 220px;align-items:center;gap:26px;margin-bottom:24px}.back-button{align-self:start;padding:10px 13px;color:#c7c5be;background:transparent;border:1px solid var(--line);border-radius:10px;cursor:pointer}.workspace-heading h2{margin:0 0 8px;font-size:30px}.workspace-heading>div>p:last-child{margin:0;color:var(--muted);line-height:1.6}.course-progress span{display:flex;justify-content:space-between;margin-bottom:9px;color:var(--muted);font-size:12px}.course-progress b{color:var(--orange)}.course-progress>div{height:7px;overflow:hidden;background:rgba(255,255,255,.08);border-radius:99px}.course-progress i{display:block;width:0;height:100%;background:linear-gradient(90deg,var(--orange),var(--orange2));border-radius:inherit;transition:width .3s}.workspace-grid{display:grid;grid-template-columns:minmax(0,1fr) 390px;gap:18px;align-items:start}.player-column,.lesson-panel{background:var(--panel);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}.player-column{overflow:hidden}.video-shell{position:relative;aspect-ratio:16/9;background:#080908}.video-shell video{display:block;width:100%;height:100%;background:#000}.video-placeholder{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column;color:#d9d7d0;background:radial-gradient(circle at center,rgba(255,103,59,.1),transparent 35%)}.play-mark{display:grid;place-items:center;width:66px;height:66px;margin-bottom:18px;padding-left:4px;color:#191a17;background:var(--orange);border-radius:50%;font-size:24px}.video-placeholder small{margin-top:8px;color:#777871}.lesson-detail{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:22px 24px}.lesson-detail h3{margin:0;font-size:22px}.complete-button{padding:10px 14px;color:#d5d2ca;background:transparent;border:1px solid var(--line);border-radius:10px;white-space:nowrap;cursor:pointer}.complete-button.completed{color:#20211d;background:#7ed79b;border-color:#7ed79b}.complete-button:disabled{opacity:.4;cursor:not-allowed}.player-message{min-height:22px;margin:0;padding:0 24px 18px;color:#f3a38b;font-size:12px}.lesson-panel{max-height:calc(100vh - 140px);overflow:hidden}.lesson-panel-head{display:flex;justify-content:space-between;padding:20px 20px 14px}.lesson-panel-head span{color:var(--muted);font-size:12px}.lesson-search{display:flex;align-items:center;gap:8px;margin:0 16px 12px;padding:10px 12px;color:var(--muted);background:rgba(0,0,0,.16);border:1px solid var(--line);border-radius:10px}.lesson-search input{width:100%;color:var(--ink);background:transparent;border:0;outline:0}.lesson-list{max-height:calc(100vh - 260px);overflow-y:auto;padding:0 10px 16px}.chapter-title{position:sticky;z-index:2;top:0;margin:0;padding:15px 10px 8px;color:#777871;background:var(--panel);font-size:10px;font-weight:850;letter-spacing:1.4px}.lesson-item{display:grid;grid-template-columns:34px minmax(0,1fr) auto;align-items:center;gap:8px;width:100%;padding:11px 10px;color:#bbb9b2;text-align:left;background:transparent;border:0;border-radius:10px;cursor:pointer}.lesson-item:hover{color:var(--ink);background:rgba(255,255,255,.04)}.lesson-item.active{color:var(--ink);background:rgba(255,103,59,.11)}.lesson-number{display:grid;place-items:center;width:28px;height:28px;color:#85857e;background:rgba(255,255,255,.05);border-radius:8px;font-size:10px}.lesson-item.active .lesson-number{color:#1b1c18;background:var(--orange)}.lesson-title{overflow:hidden;font-size:12px;line-height:1.45;text-overflow:ellipsis;white-space:nowrap}.lesson-state{color:#6f7069;font-size:12px}.lesson-state.done{color:#7ed79b}.loading-state{position:fixed;z-index:50;inset:0;display:grid;place-items:center;align-content:center;gap:15px;background:var(--bg)}.loading-state span{width:34px;height:34px;border:3px solid rgba(255,255,255,.1);border-top-color:var(--orange);border-radius:50%;animation:spin .8s linear infinite}.loading-state p{color:var(--muted)}@keyframes spin{to{transform:rotate(360deg)}}
@media(max-width:1080px){.topbar{padding-inline:24px;gap:14px}.brand>span:last-child{display:none}.product-nav a{padding-inline:10px}.account span{display:none}.hero{grid-template-columns:1fr;gap:34px}.hero-stats{max-width:600px}.course-grid{grid-template-columns:repeat(2,1fr)}.workspace-grid{grid-template-columns:1fr}.lesson-panel{max-height:none}.lesson-list{max-height:540px}.workspace-heading{grid-template-columns:auto 1fr}.course-progress{grid-column:2}}
@media(max-width:720px){.topbar{height:auto;min-height:70px;padding:10px 12px;gap:8px}.brand-mark{width:34px;height:34px}.product-nav{flex:1}.product-nav a{flex:1;padding:8px 5px;text-align:center}.nav-desktop{display:none}.nav-mobile{display:inline}.account{display:none}main{width:min(100% - 28px,680px)}.hero{padding:48px 0 34px}.hero h1{font-size:42px;letter-spacing:-2px}.hero-copy>p:last-child{font-size:15px}.hero-stats div{padding:20px 10px}.hero-stats strong{font-size:25px}.section-heading{display:block}.section-heading>p{margin-top:12px}.course-grid{grid-template-columns:1fr}.course-card{min-height:350px}.course-visual{margin:28px 0 22px}.workspace-heading{display:block}.back-button{margin-bottom:20px}.course-progress{margin-top:18px}.workspace-grid{margin-inline:-14px}.player-column,.lesson-panel{border-radius:0}.lesson-detail{align-items:flex-start;padding:17px;flex-direction:column}.lesson-detail h3{font-size:18px}.lesson-panel{border-top:0}.lesson-list{max-height:55vh}}