:root {
  color-scheme: light;
  --navy: #102231;
  --navy-2: #172e3c;
  --gold: #e5c27a;
  --paper: #f4f6f4;
  --white: #fff;
  --ink: #203543;
  --muted: #5a6c76;
  --line: #ccd5d5;
  --good: #21624b;
  --warning: #634a17;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 96px; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.7 "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", system-ui, sans-serif; }
button, input, select, textarea { font: inherit; }
a { color: #155172; text-underline-offset: 4px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid #a16c0e; outline-offset: 3px; }
h1, h2, h3, p { margin-top: 0; }
h2 { font-size: clamp(25px, 2.3vw, 32px); line-height: 1.35; letter-spacing: -.025em; }
h3 { font-size: 18px; line-height: 1.4; }
.shell { width: min(1160px, calc(100% - 48px)); margin-inline: auto; }
.skip-link { position: absolute; left: 18px; top: -90px; padding: 10px 15px; background: white; z-index: 30; }
.skip-link:focus { top: 12px; }
.preview-banner { padding: 10px 18px; background: #e5c27a; color: #102231; text-align: center; font-size: 13px; font-weight: 800; }
.site-header { position: sticky; top: 0; z-index: 20; background: rgba(16,34,49,.98); border-bottom: 1px solid #365060; }
.header-inner { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 26px; }
.brand { display: inline-flex; align-items: center; gap: 11px; flex: none; color: white; font-size: 19px; line-height: 1.1; font-weight: 800; text-decoration: none; }
.brand small { display: block; margin-top: 4px; font-size: 11px; font-weight: 500; letter-spacing: .12em; color: #c7d4d8; }
.brand-mark { display: grid; place-items: center; width: 36px; height: 36px; border: 1px solid var(--gold); color: var(--gold); font-size: 24px; font-weight: 400; }
.site-header nav { display: flex; align-items: center; justify-content: flex-end; flex-wrap: wrap; gap: 24px; }
.site-header nav a { color: #dce5e5; font-size: 14px; font-weight: 600; text-decoration: none; white-space: nowrap; }
.site-header nav a:hover { color: white; }
.site-header nav .nav-support { padding: 7px 15px; border: 1px solid var(--gold); color: var(--gold); border-radius: 4px; }
.site-header :focus-visible, .hero :focus-visible, .support :focus-visible { outline-color: var(--gold); }

.hero { overflow: hidden; background: var(--navy); color: white; border-bottom: 5px solid var(--gold); }
.hero-inner { display: grid; grid-template-columns: minmax(0,1fr) minmax(360px,.84fr); min-height: 540px; align-items: center; gap: 42px; padding-block: 58px 64px; }
.hero-copy { position: relative; z-index: 1; }
.hero-kicker { margin-bottom: 16px; color: var(--gold); font-size: 13px; font-weight: 700; letter-spacing: .035em; }
.hero h1 { max-width: 630px; margin-bottom: 23px; font-size: clamp(44px,5.3vw,70px); line-height: 1.16; letter-spacing: -.045em; font-weight: 780; }
.hero-intro { max-width: 520px; margin-bottom: 0; color: #d4dee1; font-size: 17px; line-height: 1.85; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-block: 30px 15px; }
.btn { display: inline-flex; min-height: 52px; align-items: center; justify-content: center; padding: 12px 21px; border-radius: 4px; font-size: 16px; font-weight: 750; text-decoration: none; }
.btn-primary { background: var(--gold); color: var(--navy); border: 1px solid var(--gold); }
.btn-primary:hover { background: #f3d79c; }
.btn-outline { border: 1px solid #a3b4ba; color: white; }
.btn-outline:hover { background: #253e4c; }
.btn-disabled { border: 1px solid #74858c; background: #283d47; color: #e0e8e8; cursor: not-allowed; }
.hero-help { margin-bottom: 26px; color: #d4dee1; font-size: 14px; }
.hero-help a, .hero-risk a { color: #f0d79e; }
.hero-risk { max-width: 540px; border-top: 1px solid #4a5c65; padding-top: 14px; margin-bottom: 0; color: #bdc9ce; font-size: 12px; line-height: 1.65; }
.hero-visual { position: relative; height: 380px; display: flex; align-items: center; isolation: isolate; }
.hero-visual::before { content: ""; position: absolute; inset: 8px 0 0 0; background-image: linear-gradient(#ffffff0a 1px, transparent 1px), linear-gradient(90deg,#ffffff0a 1px,transparent 1px); background-size: 40px 40px; mask-image: linear-gradient(90deg,transparent,#000 40%); }
.staff-lines { position: absolute; inset: 42px 15px auto -15px; height: 150px; opacity: .4; background: repeating-linear-gradient(to bottom, transparent 0 23px, #8ca6af 24px 25px, transparent 26px 32px); transform: skewY(-10deg); }
.sound-line { position: absolute; top: 34px; right: 12px; display: flex; align-items: center; gap: 10px; height: 35px; }
.sound-line span { display: block; width: 3px; height: 12px; background: var(--gold); opacity: .75; }
.sound-line span:nth-child(2), .sound-line span:nth-child(8) { height: 20px; }
.sound-line span:nth-child(3), .sound-line span:nth-child(7) { height: 28px; }
.sound-line span:nth-child(4), .sound-line span:nth-child(6) { height: 35px; }
.sound-line span:nth-child(5) { height: 23px; }
.harmonica { position: relative; width: 100%; padding: 24px 24px 23px; background: linear-gradient(145deg,#d2d9d5,#85949a 12%,#e4e5d8 40%,#7d9299 92%); border: 4px solid #b7c5c5; border-radius: 19px 19px 35px 35px; box-shadow: 0 24px 55px #07151eaa, inset 0 3px 0 #fff9; transform: rotate(-5deg); }
.harmonica::before, .harmonica::after { content: ""; position: absolute; top: 28px; width: 8px; height: 8px; border-radius: 50%; background: #30434c; border: 2px solid #bfc8c7; }
.harmonica::before { left: 10px; }
.harmonica::after { right: 10px; }
.harmonica-name { margin: 0 15px 16px; color: #172f3a; font-size: 18px; font-weight: 800; letter-spacing: .17em; }
.harmonica-name span { float: right; margin-top: 7px; font-size: 9px; letter-spacing: .18em; font-weight: 700; }
.harmonica-holes { display: grid; grid-template-columns: repeat(10,minmax(0,1fr)); gap: 5px; padding: 13px 9px; border-radius: 6px; background: #d2d4cc; border: 2px solid #5f737a; box-shadow: inset 0 3px 7px #31434a99; }
.harmonica-holes i { display: block; height: 43px; border-radius: 2px; background: #122431; box-shadow: inset 2px 2px 4px #050e12; }
.harmonica-tail { display: flex; justify-content: space-between; margin: 13px 13px 0; color: #1e3843; font-size: 10px; letter-spacing: .1em; font-weight: 700; }
.visual-coordinate { position: absolute; right: 0; bottom: 0; color: #aebfc3; font-size: 11px; letter-spacing: .1em; }

main > .shell { margin-top: 70px; }
.section-lead { margin-bottom: 25px; }
.section-lead h2 { margin-bottom: 8px; }
.section-lead p { color: var(--muted); margin-bottom: 0; }
.announcements { display: grid; grid-template-columns: 180px 1fr; gap: 22px; padding: 22px 26px; background: #e6edf0; border-left: 3px solid #607f89; }
.announcements h2 { font-size: 18px; margin: 0; }
.announcement-list article + article { border-top: 1px solid #becdd0; padding-top: 14px; margin-top: 14px; }
.announcement-list h3 { font-size: 15px; margin-bottom: 4px; }
.announcement-list p { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 14px; margin-bottom: 0; }
.product-rows { border-top: 2px solid var(--navy); }
.product-row { display: flex; justify-content: space-between; gap: 26px; align-items: center; padding: 22px 0; border-bottom: 1px solid var(--line); }
.product-row h3 { display: inline; margin: 0 0 0 15px; font-size: 21px; }
.product-row p { margin: 7px 0 0; color: var(--muted); font-size: 14px; }
.product-index { display: inline-block; min-width: 54px; padding: 2px 8px; background: #dfe8e8; color: #254b58; border-radius: 2px; text-align: center; font-size: 12px; font-weight: 700; }
.product-end { display: flex; min-width: 225px; align-items: center; justify-content: space-between; gap: 18px; }
.product-end strong { font-size: 22px; white-space: nowrap; color: var(--navy); }
.product-end a { font-size: 14px; white-space: nowrap; font-weight: 700; }
.guide-steps { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 22px; padding: 0; margin: 0; list-style: none; }
.guide-steps li { display: flex; gap: 12px; border-top: 1px solid #78909a; padding-top: 17px; }
.guide-steps li > span { flex: none; color: #607984; font-size: 13px; font-weight: 800; }
.guide-steps h3 { margin-bottom: 8px; font-size: 17px; }
.guide-steps p { margin-bottom: 0; color: var(--muted); font-size: 14px; }
.guide-detail { margin-top: 22px; }
details summary { cursor: pointer; font-weight: 700; }
.guide-detail summary { color: #155172; font-size: 14px; }
.guide-detail > div { max-width: 780px; margin-top: 12px; color: var(--muted); font-size: 14px; }
.guide-detail p:last-child { margin-bottom: 0; }
.library-lead { display: flex; align-items: end; justify-content: space-between; gap: 28px; }
.song-search { display: grid; gap: 5px; min-width: 275px; font-size: 13px; font-weight: 700; }
.song-search input { padding: 10px 13px; border: 1px solid #8097a1; border-radius: 4px; background: white; }
.library-count { margin: -7px 0 9px; font-size: 13px; color: var(--muted); }
.songs { border-top: 2px solid var(--navy); }
.song { display: grid; grid-template-columns: minmax(210px,1fr) minmax(220px,320px) 142px; align-items: center; gap: 25px; padding: 18px 3px; border-bottom: 1px solid var(--line); }
.song-identity { display: flex; align-items: baseline; justify-content: space-between; gap: 14px; min-width: 0; }
.song-identity h3 { overflow-wrap: anywhere; margin: 0; font-size: 18px; }
.song-status { flex: none; font-size: 14px; white-space: nowrap; font-weight: 750; }
.song-status.is-free { color: var(--good); }
.song-status.is-paused { color: #775d22; }
.song-status.is-paid { color: var(--navy); }
.song-listen audio { display: block; width: 100%; height: 40px; }
.audio-error { margin: 5px 0 0; color: #8a381e; font-size: 12px; }
.song-action { text-align: right; white-space: nowrap; font-size: 13px; color: var(--muted); }
.song-action a { display: inline-flex; min-height: 36px; align-items: center; padding: 5px 12px; border: 1px solid #47687a; border-radius: 4px; color: #17415a; text-decoration: none; font-weight: 750; }
.song-action a:hover { background: #e2e9e9; }
.empty-state { padding: 22px 0; margin: 0; color: var(--muted); }
.song-toggle { display: block; min-height: 44px; margin: 20px auto 0; padding: 8px 22px; border: 1px solid #47687a; border-radius: 4px; background: transparent; color: #17415a; font-weight: 750; cursor: pointer; }
.song-toggle:hover { background: #e2e9e9; }
.library-note { color: var(--muted); font-size: 13px; margin: 12px 0 0; }
.risk { border-left: 4px solid #a87a2a; background: #f1e9d6; padding: 22px 27px; }
.risk h2 { font-size: 21px; color: #513c18; }
.risk p { color: #4e431f; font-size: 14px; margin-bottom: 8px; }
.risk details { font-size: 13px; color: #4e431f; }
.risk details p { margin-top: 10px; }
.purchase { display: grid; grid-template-columns: minmax(0,.85fr) minmax(0,1fr); gap: 54px; padding: 45px; background: #e6ecea; border-radius: 8px; }
.section-tag { color: #3e6672; font-size: 13px; font-weight: 800; margin-bottom: 12px; }
.purchase-info h2 { max-width: 470px; margin-bottom: 20px; font-size: clamp(27px,2.5vw,35px); }
.purchase-info > p { max-width: 490px; }
.purchase-info strong { color: var(--navy); white-space: nowrap; }
.purchase-notice { border-left: 3px solid #688b83; padding: 11px 15px; background: #d6e5df; font-size: 14px; }
.purchase-help { font-size: 14px; }
.purchase-form-panel { min-width: 0; padding: 28px; background: white; border: 1px solid #c4d0cf; border-radius: 5px; box-shadow: 0 10px 22px #2035430d; }
.purchase-form-panel h3 { margin-bottom: 22px; font-size: 21px; }
form { display: grid; gap: 15px; }
form label { display: grid; gap: 5px; font-size: 14px; font-weight: 650; }
form input:not([type="radio"]):not([type="checkbox"]), form select, form textarea { width: 100%; min-width: 0; border: 1px solid #82969d; border-radius: 4px; padding: 10px 11px; color: var(--ink); background: white; }
form textarea { min-height: 80px; resize: vertical; }
form small { color: var(--muted); font-size: 12px; font-weight: 400; }
.choice { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; padding: 0; margin: 0; border: 0; }
.choice legend { padding: 0 0 7px; font-size: 14px; font-weight: 650; }
.choice label { display: flex; align-items: center; gap: 8px; min-height: 62px; padding: 10px; border: 1px solid #bdcacb; border-radius: 4px; cursor: pointer; line-height: 1.4; }
.choice input, .check input { flex: none; accent-color: #174f68; }
.choice strong { white-space: nowrap; }
.check { display: flex; align-items: flex-start; gap: 8px; font-size: 12px; font-weight: 400; line-height: 1.6; color: var(--muted); }
.check input { margin-top: 4px; }
.trap { position: absolute; left: -10000px; }
#purchase-submit { min-height: 47px; border: 1px solid var(--navy); border-radius: 4px; color: white; background: var(--navy); font-weight: 750; cursor: pointer; }
#purchase-submit:hover { background: #284555; }
#purchase-submit:disabled { opacity: .6; cursor: progress; }
.form-safety { margin: 0; font-size: 12px; color: var(--muted); }
.referral { padding: 22px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.referral summary { display: flex; justify-content: space-between; gap: 20px; font-size: 18px; color: var(--navy); }
.referral summary span { font-size: 13px; color: var(--muted); }
.referral-body { max-width: 910px; margin-top: 22px; color: var(--muted); font-size: 14px; }
.referral-body h2 { color: var(--ink); font-size: 22px; }
.referral-body li { margin-bottom: 12px; }
.referral-body strong { color: var(--ink); }
.support { margin-top: 70px; background: var(--navy-2); color: white; }
.support-inner { display: grid; grid-template-columns: minmax(0,.85fr) minmax(0,1fr); gap: 78px; padding-block: 60px 66px; }
.support .section-tag { color: var(--gold); }
.support h2 { font-size: 36px; margin-bottom: 15px; }
.support-lead { max-width: 390px; font-size: 19px; line-height: 1.65; margin-bottom: 30px; }
.support-channel { margin-bottom: 12px; color: var(--gold); font-size: 14px; font-weight: 750; }
.support-primary label { display: block; color: #d4e2e3; font-size: 13px; font-weight: 700; }
.copy-row { display: flex; gap: 9px; margin-top: 8px; }
.copy-row input { min-width: 0; width: 210px; padding: 8px 12px; border: 1px solid #9cb1b5; border-radius: 4px; background: #eff3f0; color: #152b39; font-size: 24px; font-weight: 800; letter-spacing: .04em; }
.copy-row button { padding: 7px 15px; border: 1px solid var(--gold); border-radius: 4px; color: var(--navy); background: var(--gold); cursor: pointer; font-weight: 750; white-space: nowrap; }
#copy-status { min-height: 28px; margin: 9px 0 0; font-size: 13px; color: #cbd9da; }
.support-steps h3 { font-size: 19px; }
.support-steps details { padding: 13px 0; border-bottom: 1px solid #4c6672; }
.support-steps summary { font-size: 15px; }
.support-steps ol { padding-left: 23px; color: #d0dfe1; font-size: 14px; }
.support-steps li { margin-bottom: 7px; }
.support-fallback, .support-privacy { color: #cbd9da; font-size: 13px; line-height: 1.75; }
.support-fallback { margin-top: 20px; }
.support-privacy { padding-left: 13px; border-left: 2px solid var(--gold); }
.site-footer { padding: 24px 0; background: #0a1b27; color: #b2c1c5; font-size: 12px; }
.mobile-support { display: none; }

@media (max-width: 980px) {
  .hero-inner { grid-template-columns: minmax(0,1fr) minmax(300px,.8fr); gap: 24px; }
  .hero h1 { font-size: clamp(42px,5.5vw,58px); }
  .harmonica { padding: 19px 16px; }
  .harmonica-holes { gap: 3px; }
  .song { grid-template-columns: minmax(180px,1fr) minmax(200px,260px) 116px; gap: 14px; }
  .song-identity { display: block; }
  .song-status { display: block; }
  .purchase { gap: 28px; padding: 30px; }
  .support-inner { gap: 40px; }
}
@media (max-width: 720px) {
  .site-header { position: static; }
  .header-inner { display: block; padding-block: 13px; }
  .site-header nav { justify-content: flex-start; gap: 7px 18px; margin-top: 12px; }
  .site-header nav a { font-size: 13px; }
  .site-header nav .nav-support { padding: 3px 8px; }
  html { scroll-padding-top: 20px; }
  .hero-inner { grid-template-columns: 1fr; padding-block: 41px 35px; }
  .hero-visual { height: 220px; max-width: 510px; width: 100%; margin: 0 auto; }
  .hero h1 { font-size: clamp(42px,8vw,60px); }
  .harmonica { padding: 16px 19px; }
  .harmonica-holes i { height: 29px; }
  .staff-lines { top: 8px; }
  .visual-coordinate { bottom: -6px; }
  main > .shell { margin-top: 52px; }
  .announcements { grid-template-columns: 1fr; gap: 8px; }
  .guide-steps { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .song { grid-template-columns: 1fr 130px; gap: 10px 15px; }
  .song-identity { display: flex; grid-column: 1 / -1; }
  .song-listen { min-width: 0; }
  .song-action { align-self: center; }
  .purchase, .support-inner { grid-template-columns: 1fr; }
  .support-inner { padding-block: 45px; }
  .mobile-support { position: fixed; right: 14px; bottom: 14px; z-index: 18; display: inline-flex; min-height: 44px; align-items: center; padding: 8px 15px; border: 1px solid var(--gold); border-radius: 4px; background: var(--navy); color: var(--gold); box-shadow: 0 5px 14px #07151e55; font-size: 14px; font-weight: 750; text-decoration: none; }
  .site-footer { padding-bottom: 68px; }
}
@media (max-width: 520px) {
  .shell { width: calc(100% - 32px); }
  .hero-kicker { font-size: 12px; }
  .hero h1 { font-size: 45px; }
  .hero-intro { font-size: 15px; }
  .hero-actions { display: grid; }
  .btn { width: 100%; }
  .hero-visual { height: 182px; }
  .harmonica-name { margin-bottom: 8px; font-size: 14px; }
  .harmonica-name span { font-size: 7px; }
  .harmonica-holes { padding: 9px 6px; }
  .harmonica-holes i { height: 24px; }
  .product-row { display: block; }
  .product-end { min-width: 0; margin-top: 12px; justify-content: flex-start; gap: 25px; }
  .guide-steps { grid-template-columns: 1fr; gap: 15px; }
  .library-lead { display: block; }
  .song-search { margin-top: 20px; min-width: 0; }
  .song { grid-template-columns: 1fr; gap: 10px; }
  .song-identity { grid-column: 1; }
  .song-action { text-align: left; }
  .risk { padding: 19px; }
  .purchase { padding: 21px 16px; }
  .purchase-form-panel { padding: 20px 16px; }
  .choice { grid-template-columns: 1fr; }
  .referral summary { display: block; }
  .referral summary span { display: block; }
  .copy-row { flex-wrap: wrap; }
  .copy-row input { width: 100%; }
}
@media (max-width: 350px) {
  .hero h1 { font-size: 40px; }
  .site-header nav { gap: 7px 13px; }
  .harmonica-name span { display: none; }
  .harmonica-holes i { height: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}