:root{--surface-000:#0e0e10;--surface-100:#151517;--surface-200:#1c1c1f;--surface-300:#252528;--surface-400:#2f2f33;--line-subtle:#2a2a2e;--line:#3b3b40;--ink:#f3f1ee;--ink-muted:#b4b1ac;--ink-subtle:#8f8c87;--ink-disabled:#5c5a57;--brand:#ff7a50;--brand-hover:#ff8f6b;--brand-pressed:#f0663c;--brand-soft:#3a1f17;--brand-text:#ff9474;--on-brand:#1f0e07;--warning:#f5c451;--radius-md:8px;--radius-lg:12px;--font-sans:"Segoe UI", "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;--font-mono:"Cascadia Mono", Consolas, "Microsoft YaHei UI", monospace}*,:before,:after{box-sizing:border-box}html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;scroll-padding-top:72px}body{background:var(--surface-100);color:var(--ink);font-family:var(--font-sans);margin:0;font-size:16px;line-height:1.7}h1,h2,h3,p{margin:0}a{color:inherit;text-decoration:none}:focus-visible{outline:2px solid var(--ink);outline-offset:2px;border-radius:4px}.wrap{width:min(1120px,100% - 48px);margin-inline:auto}.wrap--narrow{width:min(760px,100% - 48px)}.topbar{z-index:10;backdrop-filter:blur(12px);border-bottom:1px solid var(--line-subtle);background:#0e0e10db;position:sticky;top:0}.topbar__inner{align-items:center;gap:32px;height:60px;display:flex}.logo{letter-spacing:.04em;align-items:center;gap:10px;font-size:20px;font-weight:700;display:flex}.nav{color:var(--ink-muted);gap:28px;margin-right:auto;font-size:15px;display:flex}.nav a:hover{color:var(--ink)}.btn{border-radius:var(--radius-md);height:44px;font:inherit;cursor:pointer;border:1px solid #0000;justify-content:center;align-items:center;padding:0 22px;font-size:15px;font-weight:600;transition:background-color .15s,border-color .15s;display:inline-flex}.btn--sm{height:34px;padding:0 16px;font-size:14px}.btn--primary{background:var(--brand);color:var(--on-brand)}.btn--primary:hover{background:var(--brand-hover)}.btn--primary:active{background:var(--brand-pressed)}.btn--primary:disabled{background:var(--surface-300);color:var(--ink-disabled);cursor:not-allowed}.btn--ghost{border-color:var(--line);color:var(--ink)}.btn--ghost:hover{background:var(--surface-300)}.hero{background:radial-gradient(60% 80% at 85% 20%, #ff7a5029, transparent 70%), var(--surface-000);padding:96px 0 104px;position:relative;overflow:hidden}.hero__inner{grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);align-items:center;gap:56px;display:grid}.eyebrow{color:var(--brand-text);margin-bottom:16px;font-size:15px;font-weight:600}.keep{display:inline-block}.hero h1{letter-spacing:.01em;font-size:clamp(34px,4.6vw,52px);font-weight:700;line-height:1.25}.lead{max-width:34em;color:var(--ink-muted);margin-top:24px;font-size:18px}.hero__actions{flex-wrap:wrap;align-items:center;gap:16px;margin-top:36px;display:flex}.status-pill{background:var(--surface-300);height:34px;color:var(--ink-muted);border-radius:999px;align-items:center;gap:8px;padding:0 14px;font-size:14px;display:inline-flex}.status-pill .dot{background:var(--warning);border-radius:50%;width:8px;height:8px}.mock{border:1px solid var(--line);background:var(--surface-200);border-radius:16px;padding:22px;box-shadow:0 24px 60px #00000073}.mock__bar{border-radius:var(--radius-lg);background:var(--surface-000);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;padding:10px;display:flex}.mock__modes{flex-wrap:wrap;gap:4px;display:flex}.mode{color:var(--ink-muted);white-space:nowrap;border-radius:6px;padding:5px 10px;font-size:13px;font-weight:500}.mode--on{background:var(--brand);color:var(--on-brand)}.mock__song{color:var(--ink-muted);align-items:center;gap:10px;font-size:13px;display:flex}.mock__play{background:var(--brand);border-radius:50%;width:22px;height:22px;position:relative}.mock__play:before,.mock__play:after{content:"";background:var(--on-brand);width:2px;height:8px;position:absolute;top:7px}.mock__play:before{left:8px}.mock__play:after{left:12px}.mock__time{font-variant-numeric:tabular-nums;color:var(--ink-subtle)}.mock__lyrics{text-align:center;padding:36px 8px 28px}.lyric{color:var(--ink-subtle);font-size:16px;font-weight:500}.lyric--current{color:var(--ink);margin-bottom:10px;font-size:24px;font-weight:700}.lyric__sung{color:var(--brand-text)}.mock__wave{align-items:center;gap:4px;height:56px;padding:0 8px;display:flex}.mock__wave span{height:var(--h);background:var(--surface-400);border-radius:2px;flex:1}.mock__wave span.is-played{background:var(--brand)}.section{padding:88px 0}.section--alt{background:var(--surface-000)}.section h2{margin-bottom:36px;font-size:clamp(26px,3vw,34px);font-weight:700;line-height:1.35}.section__lead{max-width:44em;color:var(--ink-muted);margin:-20px 0 36px}.grid{gap:20px;display:grid}.grid--2{grid-template-columns:repeat(2,1fr)}.grid--3{grid-template-columns:repeat(3,1fr)}.grid--4{grid-template-columns:repeat(4,1fr)}.card{border:1px solid var(--line);border-radius:var(--radius-lg);background:var(--surface-200);padding:28px}.card h3{margin-bottom:10px;font-size:19px;line-height:1.4}.card p{color:var(--ink-muted);font-size:15px}.card--big h2{margin-bottom:12px;font-size:24px}.card--big .btn{margin-top:24px}.hint{margin-top:12px;color:var(--ink-subtle)!important;font-size:14px!important}.mode-card kbd{border:1px solid var(--line);background:var(--surface-300);color:var(--ink-muted);font-family:var(--font-mono);border-radius:6px;margin-bottom:16px;padding:2px 8px;font-size:13px;display:inline-block}.mode-card--ai{background:linear-gradient(180deg, var(--brand-soft), var(--surface-200) 70%);border-color:#ff7a5073}.mode-card--ai h3{color:var(--brand-text)}.note{color:var(--ink-subtle);margin-top:20px;font-size:14px}.steps{grid-template-columns:repeat(3,1fr);gap:36px 28px;margin:0;padding:0;list-style:none;display:grid}.step{flex-direction:column;gap:16px;display:flex}.step__num{background:var(--brand-soft);width:40px;height:40px;color:var(--brand-text);border-radius:50%;place-items:center;font-weight:700;display:grid}.step h3{margin-bottom:8px;font-size:18px}.step p{color:var(--ink-muted);font-size:15px}.faq{flex-direction:column;gap:12px;display:flex}.faq details{border:1px solid var(--line);border-radius:var(--radius-lg);background:var(--surface-200)}.faq summary{cursor:pointer;justify-content:space-between;align-items:center;gap:16px;padding:18px 22px;font-size:17px;font-weight:600;list-style:none;display:flex}.faq summary::-webkit-details-marker{display:none}.faq summary:after{content:"+";color:var(--ink-subtle);font-size:22px;font-weight:400;line-height:1}.faq details[open] summary:after{content:"−"}.faq details p{color:var(--ink-muted);padding:0 22px 20px}.footer{border-top:1px solid var(--line-subtle);background:var(--surface-000);color:var(--ink-subtle);font-size:14px}.footer__inner{justify-content:space-between;padding:28px 0;display:flex}@media (width<=960px){.hero__inner{grid-template-columns:minmax(0,1fr)}.grid--4{grid-template-columns:repeat(2,1fr)}.steps{grid-template-columns:1fr}.step{flex-direction:row}.step__num{flex:none}}@media (width<=720px){.nav{display:none}.topbar__inner{justify-content:space-between}.hero{padding:56px 0 64px}.lead{font-size:16px}.section{padding:64px 0}.grid--2,.grid--3,.grid--4{grid-template-columns:1fr}.card{padding:22px}.mock{padding:14px}.mock__lyrics{padding:24px 4px 20px}.lyric--current{font-size:19px}.lyric{font-size:14px}}