:root{color-scheme:dark;--color-bg:#101113;--color-surface:#191b1f;--color-surface-raised:#22252a;--color-surface-hover:#292d33;--color-border:#363b43;--color-border-strong:#4c535e;--color-text:#f2f4f5;--color-text-secondary:#b8c0ca;--color-text-muted:#9aa4b0;--color-accent:#ffb547;--color-accent-hover:#ffc66d;--color-accent-deep:#d88412;--color-text-on-accent:#1b1308;--color-focus:#66d9ef;--color-success:#78c995;--color-danger:#ff9587;--bg:var(--color-bg);--panel:var(--color-surface);--panel-2:var(--color-surface-raised);--line:var(--color-border);--muted:var(--color-text-muted);--text:var(--color-text);--orange:var(--color-accent);--orange-d:var(--color-accent-deep);--teal:var(--color-focus);--shadow:0 24px 70px rgba(0,0,0,.38);--shadow-hover:0 14px 34px rgba(0,0,0,.34);--transition-fast:160ms ease;--transition-ui:220ms cubic-bezier(.2,.8,.2,1)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Manrope,"Noto Sans TC",sans-serif;font-size:16px;line-height:1.6}.wrap{width:min(1180px,calc(100% - 48px));margin:auto}a{color:inherit;text-decoration:none}button{font:inherit}.topbar{height:76px;border-bottom:1px solid var(--line);display:flex;align-items:center;padding:0 max(24px,calc((100vw - 1180px)/2));position:sticky;top:0;background:rgba(12,14,17,.92);backdrop-filter:blur(18px);z-index:20}.brand{font-size:20px;font-weight:600;display:flex;gap:11px;align-items:center;letter-spacing:-.5px}.brand b{color:var(--orange)}.brand-mark{width:27px;height:27px;border:1px solid #41464d;display:flex;align-items:center;justify-content:center;gap:2px;border-radius:4px}.brand-mark i{width:3px;background:var(--orange);display:block;border-radius:2px}.brand-mark i:nth-child(1){height:7px}.brand-mark i:nth-child(2){height:15px}.brand-mark i:nth-child(3){height:10px}.desktop-nav{margin-left:auto;display:flex;align-items:stretch;height:100%}.desktop-nav a{display:flex;align-items:center;padding:0 17px;color:#aeb5bd;font-size:14px;border-bottom:2px solid transparent;transition:.2s}.desktop-nav a:hover,.desktop-nav a.active{color:#fff;border-color:var(--orange)}.menu-btn{display:none;margin-left:auto;background:none;border:0;padding:12px}.menu-btn span{display:block;width:24px;height:1px;background:#fff;margin:6px}.mobile-nav{display:none}.page{display:none;animation:fade .35s ease}.page.active{display:block}@keyframes fade{from{opacity:.3;transform:translateY(5px)}}
.hero{min-height:620px;display:grid;grid-template-columns:1.1fr .9fr;gap:80px;align-items:center;padding-top:62px;padding-bottom:66px}.eyebrow,.index{font-family:"DM Mono",monospace;color:var(--orange);font-size:12px;letter-spacing:1.7px}.eyebrow{display:flex;align-items:center;gap:10px}.eyebrow span{height:7px;width:7px;background:var(--orange);border-radius:50%;box-shadow:0 0 0 5px rgba(232,153,75,.12)}h1,h2,p{margin-top:0}.hero h1,.page-intro h1{font-size:clamp(48px,6vw,76px);line-height:1.03;letter-spacing:-4px;margin:22px 0 26px}.hero h1 em,.page-intro h1 em{font-style:normal;color:#818994}.lead{font-size:18px;color:#aab0b8;max-width:630px}.hero-actions{display:flex;align-items:center;gap:13px;margin-top:35px;flex-wrap:wrap}.btn{min-height:48px;padding:0 19px;border-radius:5px;display:inline-flex;align-items:center;gap:24px;font-weight:700;font-size:14px;border:1px solid var(--line);cursor:pointer}.btn.primary{background:var(--orange);border-color:var(--orange);color:#18130d}.btn.primary:hover{background:#f4ad67}.btn.secondary{background:var(--panel)}.btn.secondary:hover{border-color:#59606a}.text-link{font-size:14px;color:#aeb5bd;padding:12px}.text-link span{color:var(--orange)}
.hero-instrument{background:linear-gradient(145deg,#1b1f24,#111418);border:1px solid #31363d;border-radius:10px;padding:21px;box-shadow:var(--shadow);position:relative}.hero-instrument:before{content:"";position:absolute;inset:7px;border:1px solid rgba(255,255,255,.03);border-radius:6px;pointer-events:none}.device-head{display:flex;justify-content:space-between;font-family:"DM Mono",monospace;font-size:12px;color:#9fa6ae}.status{display:flex;align-items:center;gap:7px}.status i{width:6px;height:6px;border-radius:50%;background:#79a887;box-shadow:0 0 8px #79a887}.waveform{height:80px;margin:28px 0 17px;background:#101216;border:1px solid #272c32;display:flex;align-items:center;gap:5px;padding:13px}.waveform span{height:var(--h);flex:1;background:linear-gradient(var(--orange),var(--orange-d));opacity:.85}.chord-display{background:#c6d3bf;color:#1b251d;padding:18px 20px;box-shadow:inset 0 0 22px rgba(42,70,50,.25);display:grid;grid-template-columns:1fr auto;align-items:end}.chord-display small{grid-column:1/-1;font-family:"DM Mono";font-size:10px;letter-spacing:1.2px;opacity:.62}.chord-display strong{font-size:40px;line-height:1;margin-top:9px}.chord-display span{font-family:"DM Mono";font-size:13px}.steps{display:grid;grid-template-columns:repeat(8,1fr);gap:6px;margin:20px 0}.steps i{height:26px;border:1px solid #333840;border-radius:2px}.steps i.on{background:var(--orange);border-color:var(--orange)}.mini-keys,.piano{height:90px;display:flex;gap:3px;align-items:stretch}.mini-keys i,.piano button{flex:1;background:#e9e7df;border:0;border-radius:0 0 3px 3px;position:relative;cursor:pointer}.mini-keys i.active,.piano button.active{background:var(--orange)}.mini-keys i.black:after,.piano button.black:after{content:"";position:absolute;right:-38%;top:0;width:70%;height:58%;background:#26292d;border-radius:0 0 3px 3px;z-index:2}.signal-strip{border-block:1px solid var(--line);background:#111317}.signal-strip .wrap{height:46px;display:flex;align-items:center;justify-content:space-between;color:#727b85;font-family:"DM Mono";font-size:11px}.signal-strip i{width:3px;height:3px;border-radius:50%;background:#424850}
.content-section{padding-top:96px}.section-head{display:flex;justify-content:space-between;align-items:end;margin-bottom:31px}.section-head h2,.quiz-banner h2{font-size:38px;letter-spacing:-1.5px;margin:5px 0}.section-head p:not(.index),.quiz-banner p:not(.index){color:var(--muted);margin:0}.section-head>a{font-size:13px;color:var(--orange);border-bottom:1px solid #704a27;padding-bottom:4px}.card-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:12px}.chord-card,.tool-card,.news-card{background:var(--panel);border:1px solid var(--line);border-radius:6px;transition:.22s}.chord-card{padding:20px;text-align:left;color:white;cursor:pointer;min-height:148px;position:relative}.chord-card:hover,.tool-card:hover,.news-card:hover{transform:translateY(-3px);border-color:#484f58}.chord-card small{font-family:"DM Mono";font-size:11px;color:var(--muted)}.chord-card strong{display:block;font-size:27px;margin-top:20px}.chord-card span{position:absolute;right:17px;bottom:15px;width:29px;height:29px;border-radius:50%;border:1px solid #454b54;display:grid;place-items:center;color:var(--orange)}.scale-list{border-top:1px solid var(--line)}.scale-row{display:grid;grid-template-columns:50px 1fr 1.4fr auto;align-items:center;gap:20px;border-bottom:1px solid var(--line);padding:22px 12px;transition:.2s;cursor:pointer}.scale-row:hover{background:#121519;padding-left:20px}.scale-row b{font-family:"DM Mono";color:#5f6771;font-size:12px}.scale-row strong{font-size:20px}.scale-row span{color:var(--muted);font-size:14px}.scale-row i{font-style:normal;color:var(--orange)}.quiz-banner{margin-top:96px;background:linear-gradient(100deg,#171a1e,#131518);border:1px solid var(--line);padding:55px;display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:center}.quiz-banner .btn{margin-top:28px}.quiz-types>div{display:grid;grid-template-columns:44px 1fr;align-items:center;border-bottom:1px solid var(--line);padding:17px 0}.quiz-types b{font-family:"DM Mono";color:var(--orange);font-size:12px;grid-row:1/3}.quiz-types span{font-weight:600}.quiz-types small{color:var(--muted)}.tool-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:12px}.tool-card{padding:24px;min-height:190px;cursor:pointer}.tool-icon{width:43px;height:43px;border:1px solid #454b52;border-radius:6px;display:grid;place-items:center;color:var(--orange);font-family:"DM Mono"}.tool-card h3{font-size:17px;margin:30px 0 5px}.tool-card p{font-size:13px;color:var(--muted)}.news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.news-card{overflow:hidden;cursor:pointer}.news-visual{height:155px;background:linear-gradient(135deg,#20252b,#121418);display:grid;place-items:center;position:relative}.news-visual:before,.news-visual:after{content:"";position:absolute;border:1px solid #343a42;border-radius:50%}.news-visual:before{width:85px;height:85px}.news-visual:after{width:45px;height:45px;background:#1a1e23}.news-visual span{font-family:"DM Mono";font-size:28px;color:var(--orange);z-index:1}.news-body{padding:21px}.tag{font-family:"DM Mono";font-size:10px;color:var(--orange);letter-spacing:1px}.news-body h3{font-size:17px;line-height:1.45;margin:9px 0}.news-body p{color:var(--muted);font-size:13px;margin:0}.news-body time{display:block;color:#69717b;font-size:11px;margin-top:18px}.content-section:last-child{padding-bottom:120px}
.inner-page{min-height:calc(100vh - 76px);padding-bottom:110px}.page-intro{padding-top:80px;padding-bottom:52px;border-bottom:1px solid var(--line)}.page-intro h1{font-size:58px;margin:13px 0 17px}.page-intro>p:last-child{color:var(--muted);font-size:17px}.explorer-layout{display:grid;grid-template-columns:290px 1fr;gap:25px;margin-top:40px}.control-panel,.result-panel,.quiz-stage{background:var(--panel);border:1px solid var(--line);border-radius:7px}.control-panel{padding:24px}.control-panel label{font-family:"DM Mono";font-size:11px;color:var(--muted);letter-spacing:1px;display:block;margin:4px 0 12px}.control-panel label:nth-of-type(2){margin-top:30px}.root-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:5px}.root-grid button,.type-list button,.quiz-tabs button,.filters button{background:#1b1f24;border:1px solid #30353c;color:#c5cbd1;cursor:pointer;border-radius:4px}.root-grid button{height:38px}.root-grid button.active,.type-list button.active,.quiz-tabs button.active,.filters button.active{background:var(--orange);border-color:var(--orange);color:#18130d;font-weight:700}.type-list{display:flex;flex-direction:column;gap:6px}.type-list button{text-align:left;padding:10px 12px}.result-panel{padding:40px}.result-top{display:flex;justify-content:space-between;align-items:start}.result-top small{font-family:"DM Mono";color:var(--muted);font-size:11px}.result-top h2{font-size:45px;letter-spacing:-1.5px;margin:7px 0}.play-btn{background:var(--orange);border:0;padding:13px 18px;border-radius:4px;font-weight:800;cursor:pointer;color:#1b140d}.play-btn span{margin-left:8px;font-family:"DM Mono";font-size:11px}.formula{display:flex;gap:8px;margin:25px 0 42px}.formula span{border:1px solid #383e46;border-radius:4px;padding:7px 12px;font-family:"DM Mono";color:#c7ccd1}.piano{height:210px;gap:4px}.piano button{font-family:"DM Mono";padding-top:165px;color:#333;font-weight:500}.piano button.active{color:#38210d}.piano button.black:after{right:-35%;width:65%}.hint,.scale-mood{font-size:13px;color:var(--muted);margin:18px 0 0}.scale-mood{border-left:2px solid var(--orange);padding-left:13px}.quiz-app{margin-top:40px}.quiz-tabs{display:flex;gap:7px;margin-bottom:14px}.quiz-tabs button{padding:11px 18px}.quiz-stage{padding:42px;max-width:850px}.quiz-meta{display:flex;justify-content:space-between;font-family:"DM Mono";font-size:11px;color:var(--muted)}.quiz-meta b{color:var(--orange)}.progress{height:3px;background:#272c32;margin:14px 0 44px}.progress i{display:block;height:100%;width:20%;background:var(--orange);transition:.25s}.quiz-question{font-size:28px;font-weight:700;max-width:680px}.answers{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:28px}.answers button{background:#191d22;border:1px solid #343a42;border-radius:5px;padding:17px;text-align:left;color:#e6e8e4;cursor:pointer}.answers button:hover{border-color:#68717b}.answers button.correct{border-color:#6e9f7a;background:#18231c}.answers button.wrong{border-color:#a66557;background:#261a18}.feedback{min-height:31px;margin-top:18px;color:#aeb5bd}.next-btn{border:0;margin-top:8px}.tools-page{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin-top:40px}.tools-page .tool-card{min-height:230px}.tools-page .tool-card h3{font-size:22px}.tool-demo{border-top:1px solid var(--line);margin-top:20px;padding-top:16px;display:flex;gap:8px;align-items:center}.tool-demo select,.tool-demo input{background:#101317;border:1px solid #353b43;color:white;border-radius:4px;padding:9px;min-width:0}.tool-demo output{color:var(--orange);font-family:"DM Mono"}.news-page{margin-top:35px}.filters{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:25px}.filters button{padding:9px 15px}.news-grid.full{grid-template-columns:repeat(3,1fr)}
.play-btn,.piano button,.chord-card{touch-action:manipulation;will-change:transform}.play-btn.is-playing,.chord-card.is-playing,.piano button.is-playing{animation:note-press .2s ease-out;box-shadow:0 0 0 2px rgba(240,139,50,.36),0 0 24px rgba(240,139,50,.62);z-index:5}.piano button.black.is-playing:after{background:#f08b32;box-shadow:0 0 18px rgba(240,139,50,.75)}@keyframes note-press{0%{transform:translateY(0) scale(1)}45%{transform:translateY(5px) scale(.985)}100%{transform:translateY(0) scale(1)}}@media(prefers-reduced-motion:reduce){.play-btn.is-playing,.chord-card.is-playing,.piano button.is-playing{animation:none}}
footer{border-top:1px solid var(--line);padding:34px 0;color:var(--muted)}footer .wrap{display:flex;justify-content:space-between;align-items:center}footer p{margin:0;font-size:13px}footer>div>span{font-family:"DM Mono";font-size:11px}
@media(max-width:900px){.desktop-nav{display:none}.menu-btn{display:block}.mobile-nav{display:none;position:fixed;z-index:19;top:76px;inset-inline:0;background:#111418;border-bottom:1px solid var(--line);padding:14px 24px}.mobile-nav.open{display:grid}.mobile-nav a{display:flex;justify-content:space-between;padding:13px 0;border-bottom:1px solid #252a30}.mobile-nav span{color:var(--muted)}.hero{grid-template-columns:1fr;gap:45px;padding-top:60px}.hero-instrument{max-width:600px}.card-grid,.tool-grid{grid-template-columns:repeat(2,1fr)}.quiz-banner{grid-template-columns:1fr}.explorer-layout{grid-template-columns:1fr}.control-panel{display:grid;grid-template-columns:1fr 1fr;gap:25px}.control-panel label:nth-of-type(2){margin-top:4px}.news-grid,.news-grid.full{grid-template-columns:repeat(2,1fr)}}
@media(max-width:620px){.wrap{width:min(100% - 30px,1180px)}.topbar{padding:0 15px}.hero{min-height:auto;padding-top:52px}.hero h1{font-size:47px;letter-spacing:-2.8px}.lead{font-size:16px}.hero-actions{align-items:stretch}.text-link{width:100%;padding-left:0}.hero-instrument{padding:14px}.signal-strip .wrap span:nth-of-type(n+3),.signal-strip .wrap i:nth-of-type(n+2){display:none}.content-section{padding-top:72px}.section-head{align-items:start}.section-head>a{display:none}.section-head h2,.quiz-banner h2{font-size:31px}.card-grid{grid-template-columns:repeat(2,1fr)}.chord-card{min-height:130px}.scale-row{grid-template-columns:35px 1fr auto}.scale-row span{display:none}.quiz-banner{margin-top:72px;padding:30px 22px;gap:35px}.tool-grid,.tools-page{grid-template-columns:1fr}.news-grid,.news-grid.full{grid-template-columns:1fr}.page-intro{padding-top:52px}.page-intro h1{font-size:43px;letter-spacing:-2px}.explorer-layout{margin-top:20px}.control-panel{display:block}.control-panel label:nth-of-type(2){margin-top:25px}.result-panel{padding:24px}.result-top h2{font-size:34px}.play-btn span{display:none}.piano{height:145px}.piano button{font-size:11px;padding-top:112px}.quiz-tabs{overflow:auto}.quiz-tabs button{white-space:nowrap}.quiz-stage{padding:26px 20px}.quiz-question{font-size:23px}.answers{grid-template-columns:1fr}.scale-list{overflow:hidden}footer .wrap{flex-wrap:wrap;gap:20px}footer p{order:3;width:100%}}