:root{--bg:#0a0c10;--surface:#12151c;--surface2:#1a1e28;--surface3:#222736;--border:#242a3a;--text:#edf0f7;--muted:#8b93a7;--dim:#5a6275;--accent:#ff6b3d;--accent-soft:#ff6b3d24;--teal:#38e1c6;--teal-soft:#38e1c61f;--purple:#8b5cf6;--gold:#ffc93d;--red:#ff4d6a;--green:#3ddc84;--blue:#4d9fff}*{box-sizing:border-box;margin:0;padding:0}html,body{height:100%}body{background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;font-family:Inter,Segoe UI,system-ui,sans-serif;display:flex;overflow:hidden}::-webkit-scrollbar{width:10px}::-webkit-scrollbar-thumb{background:var(--surface3);border-radius:5px}::-webkit-scrollbar-track{background:0 0}.sidebar{background:var(--surface);border-right:1px solid var(--border);flex-direction:column;width:250px;min-width:250px;height:100vh;padding:20px 14px;display:flex;overflow-y:auto}.logo{align-items:center;gap:10px;padding:6px 10px 20px;display:flex}.logo-mark{background:linear-gradient(135deg,var(--accent),#ff3d77);border-radius:11px;justify-content:center;align-items:center;width:36px;height:36px;font-size:17px;display:flex;box-shadow:0 4px 18px #ff6b3d59}.logo-name{letter-spacing:-.4px;font-size:18px;font-weight:800}.logo-name span{color:var(--accent)}.logo-name small{color:var(--dim);letter-spacing:1.5px;font-size:10px;font-weight:700;display:block}.tier-item{cursor:pointer;-webkit-user-select:none;user-select:none;border:1px solid #0000;border-radius:12px;align-items:center;gap:11px;margin-bottom:4px;padding:11px 12px;transition:all .18s;display:flex}.tier-item:hover{background:var(--surface2)}.tier-item.active{background:var(--accent-soft);border-color:#ff6b3d40}.tier-item.locked{opacity:.45;cursor:not-allowed}.tier-ico{background:var(--surface3);border-radius:10px;flex-shrink:0;justify-content:center;align-items:center;width:34px;height:34px;font-size:16px;display:flex}.tier-meta{flex:1;min-width:0}.tier-meta b{font-size:13px;display:block}.tier-meta .pbar{margin-top:5px}.tier-count{color:var(--dim);font-size:10.5px;font-weight:700}.sidebar-bottom{flex-direction:column;gap:10px;margin-top:auto;padding-top:16px;display:flex}.tuner-mini{background:var(--surface2);border:1px solid var(--border);border-radius:13px;padding:12px}.tuner-mini .row{justify-content:space-between;align-items:baseline;margin-bottom:7px;display:flex}.tuner-mini b{font-size:20px}.tuner-mini small{color:var(--muted);font-size:10.5px}.reset-link{color:var(--dim);text-align:center;cursor:pointer;font-size:10.5px}.reset-link:hover{color:var(--red)}.tool-row{gap:6px;display:flex}.lang-btn{white-space:nowrap;border:1px solid var(--border);min-width:0;color:var(--muted);cursor:pointer;background:0 0;border-radius:10px;flex:1;padding:8px 2px;font-family:inherit;font-size:11.5px;font-weight:700}.lang-btn:hover{color:var(--text);border-color:var(--dim)}.stats{background:var(--surface2);border:1px solid var(--border);border-radius:13px;margin-bottom:12px;padding:11px 12px}.stats-row{justify-content:space-between;align-items:baseline;margin-bottom:8px;font-size:12.5px;font-weight:700;display:flex}.stats-row b{font-size:15px}#statLevel{color:var(--gold)}.stats-xp{color:var(--dim);margin-top:6px;font-size:10.5px;font-weight:700}.toast{left:50%;bottom:calc(26px + env(safe-area-inset-bottom));z-index:80;opacity:0;pointer-events:none;background:var(--surface3);border:1px solid var(--gold);color:var(--gold);white-space:nowrap;border-radius:99px;padding:10px 20px;font-size:14px;font-weight:800;transition:all .25s;position:fixed;transform:translate(-50%,20px);box-shadow:0 8px 30px #00000080}.toast.show{opacity:1;transform:translate(-50%)}.update-bar{left:50%;top:calc(12px + env(safe-area-inset-top));z-index:90;background:var(--teal);color:#06231e;cursor:pointer;border:none;border-radius:99px;max-width:calc(100vw - 24px);padding:11px 20px;font-family:inherit;font-size:13px;font-weight:800;position:fixed;transform:translate(-50%);box-shadow:0 8px 30px #00000080}.main{flex:1;height:100vh;overflow-y:auto}.view{max-width:980px;margin:0 auto;padding:34px 40px 80px;animation:.3s fadeUp;display:none}.view.active{display:block}@keyframes fadeUp{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}.eyebrow{letter-spacing:2px;color:var(--accent);text-transform:uppercase;margin-bottom:8px;font-size:11px;font-weight:800}h1{letter-spacing:-.5px;font-size:25px;font-weight:800}.sub{color:var(--muted);margin-top:6px;font-size:14px;line-height:1.55}.card{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:22px}.btn{cursor:pointer;-webkit-user-select:none;user-select:none;border:1px solid #0000;border-radius:12px;justify-content:center;align-items:center;gap:8px;padding:11px 20px;font-family:inherit;font-size:13.5px;font-weight:700;transition:all .18s;display:inline-flex}.btn-primary{background:linear-gradient(135deg,var(--accent),#ff4e5e);color:#fff;box-shadow:0 4px 16px #ff6b3d4d}.btn-primary:hover{transform:translateY(-1px)}.btn-ghost{background:var(--surface2);border-color:var(--border);color:var(--text)}.btn-ghost:hover{background:var(--surface3)}.btn-teal{background:var(--teal-soft);color:var(--teal);border-color:#38e1c64d}.btn:disabled{opacity:.4;cursor:not-allowed;transform:none}.pbar{background:var(--surface3);border-radius:99px;height:6px;overflow:hidden}.pbar>i{background:linear-gradient(90deg,var(--accent),var(--gold));border-radius:99px;height:100%;transition:width .4s;display:block}.pbar.teal>i{background:linear-gradient(90deg,var(--teal),var(--blue))}.lesson-grid{grid-template-columns:1fr 1fr;gap:14px;margin-top:22px;display:grid}.lesson-card{background:var(--surface);border:1px solid var(--border);cursor:pointer;border-radius:16px;padding:20px;transition:all .18s;position:relative}.lesson-card:hover{border-color:var(--dim);transform:translateY(-2px)}.lesson-card.done{border-color:#3ddc8459}.lesson-card.locked{opacity:.45;cursor:not-allowed}.lesson-card.locked:hover{border-color:var(--border);transform:none}.lesson-num{letter-spacing:1.5px;color:var(--dim);margin-bottom:7px;font-size:10.5px;font-weight:800}.lesson-card b{margin-bottom:5px;font-size:15px;display:block}.lesson-card p{color:var(--muted);font-size:12.5px;line-height:1.5}.lesson-badge{font-size:14px;position:absolute;top:16px;right:16px}.lesson-tags{flex-wrap:wrap;gap:6px;margin-top:12px;display:flex}.tag{background:var(--surface2);border:1px solid var(--border);color:var(--muted);border-radius:8px;padding:4px 10px;font-size:10.5px;font-weight:700}.lesson-top{align-items:center;gap:14px;margin-bottom:20px;display:flex}.back-btn{background:var(--surface2);border:1px solid 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p{color:#c9cee0;font-size:13px;line-height:1.55}.coach-box b{color:var(--text)}.ex-live{background:var(--surface2);border:1px solid var(--border);text-align:center;border-radius:14px;flex-direction:column;justify-content:center;gap:6px;min-height:96px;margin:16px 0;padding:20px;display:flex}.ex-live .big{letter-spacing:-.5px;font-size:34px;font-weight:800}.ex-live .small{color:var(--muted);font-size:12px;font-weight:600}.beat-dots{justify-content:center;gap:9px;margin-top:8px;display:flex}.beat-dot{background:var(--surface3);border-radius:50%;width:11px;height:11px;transition:all .1s}.beat-dot.hit{background:var(--accent);box-shadow:0 0 12px var(--accent);transform:scale(1.25)}.ctl-row{flex-wrap:wrap;align-items:center;gap:18px;margin-top:14px;display:flex}.ctl{flex:1;min-width:170px}.ctl 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.15s;display:block}.quiz-opt:hover{border-color:var(--dim)}.quiz-opt.right{border-color:var(--green);color:var(--green);background:#3ddc841a}.quiz-opt.wrong{border-color:var(--red);color:var(--red);background:#ff4d6a14}.chal-pair{justify-content:center;align-items:center;gap:30px;padding:6px 0;display:flex}.chal-arrow{color:var(--dim);font-size:26px}.chal-hit{width:100%;margin-top:14px;padding:26px;font-size:18px}.chal-timer{font-variant-numeric:tabular-nums}.result-pass{color:var(--green);font-weight:800}.result-fail{color:var(--gold);font-weight:800}.congrats{text-align:center;padding:40px 20px}.congrats .emoji{margin-bottom:14px;font-size:52px}.locked-view{text-align:center;padding:60px 30px}.locked-view .emoji{margin-bottom:16px;font-size:46px}.demo-note{color:var(--dim);background:var(--surface);border:1px solid var(--border);z-index:50;border-radius:99px;padding:6px 12px;font-size:10.5px;position:fixed;bottom:14px;right:16px}@media (width<=900px){.lesson-grid{grid-template-columns:1fr}}.topbar,.nav-backdrop{display:none}@supports (height:100dvh){.sidebar,.main{height:100dvh}}@supports (padding:env(safe-area-inset-top)){.sidebar{padding-top:calc(20px + env(safe-area-inset-top))}.main{padding-top:env(safe-area-inset-top)}}@media (width<=760px){body{flex-direction:column}@supports (height:100dvh){body{height:100dvh}}.topbar{box-sizing:content-box;height:54px;min-height:54px;padding:env(safe-area-inset-top) 10px 0;background:var(--surface);border-bottom:1px solid var(--border);align-items:center;gap:12px;display:flex}.menu-btn{background:var(--surface2);border:1px solid var(--border);width:44px;height:44px;color:var(--text);cursor:pointer;border-radius:11px;flex-shrink:0;justify-content:center;align-items:center;font-family:inherit;font-size:18px;display:flex}.topbar-title{letter-spacing:-.4px;font-size:17px;font-weight:800}.topbar-title span{color:var(--accent)}.topbar-stats{color:var(--gold);white-space:nowrap;margin-left:auto;font-size:12px;font-weight:800}.topbar-tier{min-width:0;color:var(--muted);white-space:nowrap;text-overflow:ellipsis;padding-right:6px;font-size:12px;font-weight:700;overflow:hidden}.sidebar{z-index:60;width:min(290px,86vw);min-width:0;height:auto;padding-top:calc(20px + env(safe-area-inset-top));padding-bottom:calc(20px + env(safe-area-inset-bottom));visibility:hidden;transition:transform .22s,visibility 0s .22s;position:fixed;top:0;bottom:0;left:0;transform:translate(-100%);box-shadow:0 0 40px #00000080}body.nav-open .sidebar{visibility:visible;transition:transform .22s;transform:none}.nav-backdrop{z-index:55;opacity:0;pointer-events:none;background:#0000008c;transition:opacity .22s;display:block;position:fixed;inset:0}body.nav-open .nav-backdrop{opacity:1;pointer-events:auto}.tier-item{padding:12px}.reset-link{padding:10px 0}@media (height<=640px){.sidebar .logo{display:none}.sidebar{padding-top:calc(12px + env(safe-area-inset-top));padding-bottom:calc(10px + env(safe-area-inset-bottom))}.stats{margin-bottom:8px;padding:8px 12px}.tier-item{margin-bottom:2px;padding:5px 12px}.sidebar-bottom{gap:4px;padding-top:8px}.tuner-mini{padding:9px 12px}.reset-link{padding:6px 0}}.main{scrollbar-width:none;width:100%;height:auto;min-height:0;padding-top:0}.main::-webkit-scrollbar{width:0;height:0}.view{padding:20px 16px calc(60px + env(safe-area-inset-bottom))}h1{font-size:22px}.card{padding:16px}.demo-note{display:none}.lesson-top{gap:12px}.back-btn{flex-shrink:0;width:44px;height:44px}.diagram-center svg{max-width:100%;height:auto}.chal-pair{gap:8px}.chal-pair svg{width:42%;max-width:170px;height:auto}.prose pre{overflow-x:auto}.prose ul{margin-left:18px}#hearBtn,#hearSlow{margin:4px 2px}.ex-live .big{font-size:28px}.ctl-row{gap:14px}.ctl-row .ctl:last-child{flex:100%!important}.ctl-row .btn{padding:14px 20px}input[type=range]{height:8px}input[type=range]::-webkit-slider-thumb{width:24px;height:24px}.quiz-opt{padding:15px 16px}.chal-hit{padding:22px 12px;font-size:16px}.step-nav .btn{flex:1;padding:13px 10px}}