:root{--bg:#16191f;--surface:#1d2129;--surface-2:#252a34;--border:#2e3440;--text:#d5dae1;--text-strong:#e8ebef;--muted:#8d96a3;--accent:#7fb5a8;--accent-soft:#7fb5a81f;--warm:#d0b07a;--danger:#d28a8a;--radius:12px;--font:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;--serif:Georgia, "Times New Roman", serif;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{background:var(--bg);color:var(--text);font:16px/1.65 var(--font);flex-direction:column;min-height:100vh;margin:0;display:flex}#app{flex-direction:column;flex:1;display:flex}main{flex:1}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}h1,h2,h3{color:var(--text-strong);line-height:1.25}h1{margin:0 0 .6rem;font-size:1.9rem}h2{margin:1.6rem 0 .7rem;font-size:1.4rem}h3{margin:1.3rem 0 .5rem;font-size:1.1rem}p{margin:.5rem 0 .9rem}em{color:var(--warm);font-style:normal}code{background:var(--surface-2);border-radius:6px;padding:.1em .4em;font-size:.92em}::selection{background:#7fb5a84d}.container{width:100%;max-width:980px;margin:0 auto;padding:0 16px}.topbar{z-index:10;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border-bottom:1px solid var(--border);background:#16191feb;position:sticky;top:0}.topbar-inner{align-items:center;gap:20px;max-width:980px;margin:0 auto;padding:10px 16px;display:flex}.logo{color:var(--text-strong);flex-shrink:0;align-items:center;gap:10px;font-size:1.1rem;font-weight:700;display:flex}.logo:hover{text-decoration:none}.logo-mark{font-family:var(--serif);color:var(--accent);background:var(--surface-2);border-radius:8px;padding:1px 7px}.nav{scrollbar-width:none;gap:4px;display:flex;overflow-x:auto}.nav::-webkit-scrollbar{display:none}.nav a{color:var(--muted);white-space:nowrap;border-radius:8px;padding:6px 12px}.nav a:hover{color:var(--text);background:var(--surface);text-decoration:none}.nav a.active{color:var(--text-strong);background:var(--surface-2)}@media (width<=640px){.topbar-inner{flex-direction:column;align-items:stretch;gap:6px;padding-bottom:6px}.nav{margin:0 -16px;padding:0 12px}}main.container{padding-top:28px;padding-bottom:48px}.footer{border-top:1px solid var(--border);color:var(--muted);padding:18px 0;font-size:.88rem}.btn{background:var(--surface-2);color:var(--text);border:1px solid var(--border);font:inherit;cursor:pointer;border-radius:10px;justify-content:center;align-items:center;gap:6px;padding:9px 16px;font-size:.95rem;transition:background .15s,border-color .15s;display:inline-flex}.btn:hover{background:#2c323d;text-decoration:none}.btn:disabled{opacity:.4;cursor:default}.btn.primary{background:var(--accent-soft);color:var(--accent);border-color:#7fb5a873}.btn.primary:hover{background:#7fb5a833}.btn.small{padding:5px 11px;font-size:.85rem}.hero{padding:24px 0 8px}.lead{color:var(--muted);max-width:680px;font-size:1.12rem}.hero-actions{flex-wrap:wrap;gap:10px;margin-top:18px;display:flex}.tiles{grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px;margin:32px 0;display:grid}.tile{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);padding:18px;transition:border-color .15s,transform .15s}.tile:hover{border-color:#7fb5a880;text-decoration:none;transform:translateY(-2px)}.tile h3{color:var(--accent);margin:0 0 6px}.tile p{color:var(--muted);margin:0;font-size:.93rem}.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:6px 22px 14px}.steps li{margin:6px 0}.page-title{margin-bottom:14px}.chips{flex-wrap:wrap;gap:8px;margin-bottom:20px;display:flex}.chip{background:var(--surface);border:1px solid var(--border);color:var(--muted);border-radius:999px;padding:5px 13px;font-size:.92rem}.chip:hover{color:var(--text);text-decoration:none}.chip.active{color:var(--accent);background:var(--accent-soft);border-color:#7fb5a880}.lesson{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:4px 26px 20px}.lesson>h2:first-child{margin-top:1.2rem}@media (width<=640px){.lesson{padding:4px 16px 16px}}.pager{flex-wrap:wrap;justify-content:space-between;gap:10px;margin-top:18px;display:flex}.ex{border-left:3px solid var(--accent);background:var(--surface-2);border-radius:0 8px 8px 0;flex-wrap:wrap;gap:4px 14px;margin:5px 0;padding:7px 12px;display:flex}.ex-en{color:var(--text-strong);font-weight:500}.ex-ru{color:var(--muted)}.note{color:var(--text);background:#d0b07a14;border:1px solid #d0b07a4d;border-radius:10px;margin:14px 0;padding:10px 14px}.formula{background:var(--surface-2);color:var(--accent);border-radius:8px;margin:8px 0;padding:8px 12px;font-family:ui-monospace,Menlo,Consolas,monospace;overflow-x:auto}.table-wrap{margin:10px 0 14px;overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:.95rem}th,td{border-bottom:1px solid var(--border);text-align:left;vertical-align:top;padding:7px 10px}th{color:var(--muted);background:var(--surface-2);font-weight:600}td:first-child{color:var(--text-strong)}.cards-toolbar{flex-wrap:wrap;align-items:center;gap:10px;margin-bottom:18px;display:flex}.select{background:var(--surface-2);color:var(--text);border:1px solid var(--border);font:inherit;border-radius:10px;padding:8px 12px;font-size:.95rem}.toggle{color:var(--muted);cursor:pointer;-webkit-user-select:none;user-select:none;align-items:center;gap:7px;font-size:.93rem;display:inline-flex}.toggle input{accent-color:var(--accent)}.card-stage{perspective:1200px;max-width:520px;margin:0 auto}.flashcard{aspect-ratio:3/2;cursor:pointer;width:100%;transform-style:preserve-3d;-webkit-tap-highlight-color:transparent;transition:transform .45s;position:relative}.flashcard.flipped{transform:rotateY(180deg)}.face{backface-visibility:hidden;border:1px solid var(--border);text-align:center;border-radius:18px;flex-direction:column;justify-content:center;align-items:center;padding:20px;display:flex;position:absolute;inset:0}.face.front{background:var(--surface)}.face.back{background:#1f2a2a;border-color:#7fb5a859;transform:rotateY(180deg)}.face .word{color:var(--text-strong);word-break:break-word;font-size:clamp(1.7rem,6vw,2.6rem);font-weight:600}.face.back .word{color:var(--accent)}.face .hint{color:var(--muted);font-size:.8rem;position:absolute;bottom:12px}.face .cat{color:var(--muted);font-size:.78rem;position:absolute;top:12px;left:16px}.face .known-badge{color:var(--accent);font-size:.78rem;position:absolute;top:12px;right:16px}.speak{color:var(--muted);cursor:pointer;background:0 0;border:none;border-radius:8px;padding:6px;font-size:1.2rem;position:absolute;top:8px;right:8px}.speak:hover{color:var(--accent);background:var(--surface-2)}.card-controls{flex-wrap:wrap;justify-content:center;gap:10px;margin-top:18px;display:flex}.card-meta{text-align:center;color:var(--muted);margin-top:12px;font-size:.9rem}.progress{background:var(--surface-2);border-radius:4px;max-width:520px;height:4px;margin:10px auto 0;overflow:hidden}.progress>div{background:var(--accent);height:100%;transition:width .2s}.kbd-hint{text-align:center;color:var(--muted);margin-top:10px;font-size:.8rem}@media (hover:none){.kbd-hint{display:none}}.video-layout{grid-template-columns:minmax(0,1fr) 300px;align-items:start;gap:20px;display:grid}@media (width<=820px){.video-layout{grid-template-columns:1fr}}.player{border-radius:var(--radius);border:1px solid var(--border);background:#000;overflow:hidden}.player video{background:#000;width:100%;max-height:70vh;display:block}.video-title{margin:14px 0 4px;font-size:1.3rem}.video-sub{color:var(--muted);font-size:.9rem}.video-controls{flex-wrap:wrap;align-items:center;gap:10px;margin-top:12px;display:flex}.playlist{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);max-height:70vh;overflow-y:auto}.playlist-head{border-bottom:1px solid var(--border);color:var(--muted);padding:12px 14px;font-size:.88rem}.playlist a{color:var(--text);border-bottom:1px solid var(--border);gap:10px;padding:10px 14px;display:flex}.playlist a:last-child{border-bottom:none}.playlist a:hover{background:var(--surface-2);text-decoration:none}.playlist a.active{background:var(--accent-soft);color:var(--accent)}.playlist .num{color:var(--muted);font-variant-numeric:tabular-nums;min-width:22px}.empty{text-align:center;color:var(--muted);background:var(--surface);border:1px dashed var(--border);border-radius:var(--radius);padding:40px 16px}