:root {
  --ink: #0a0b0d;
  --ink-2: #0f1115;
  --surface: #14171d;
  --surface-2: #191d24;
  --line: #242932;
  --fg: #f4f5f7;
  --muted: #99a1ad;
  --muted-2: #6f7784;
  --brass: #dda85f;
  --brass-soft: rgba(221, 168, 95, .14);
  --radius: 8px;
  --maxw: 1160px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--fg);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "SF Pro SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }

a { color: inherit; text-decoration: none; }

h1, h2, h3 { margin: 0; line-height: 1.2; font-weight: 700; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: background .18s ease, border-color .18s ease, color .18s ease, transform .18s ease;
  white-space: nowrap;
}

.btn-solid { background: var(--fg); color: #0a0b0d; }
.btn-solid:hover { background: #ffffff; transform: translateY(-1px); }

.btn-ghost { border-color: var(--line); color: var(--fg); }
.btn-ghost:hover { border-color: #3a4150; background: rgba(255,255,255,.04); }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(10, 11, 13, .78);
  backdrop-filter: saturate(150%) blur(14px);
  -webkit-backdrop-filter: saturate(150%) blur(14px);
  border-bottom: 1px solid rgba(36, 41, 50, .7);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }

.brand-mark {
  width: 28px; height: 28px;
  display: grid; place-items: center;
  color: var(--brass);
}
.brand-mark svg { width: 22px; height: 22px; }
.brand-name { font-size: 17px; letter-spacing: .2px; }

.nav-links { display: flex; gap: 22px; margin-left: auto; }
.nav-links a { color: var(--muted); font-size: 15px; transition: color .18s ease; }
.nav-links a:hover { color: var(--fg); }

.nav-store { padding: 8px 16px; font-size: 14px; }

/* ---------- 产品下拉菜单 ---------- */
.nav-item { position: relative; }

.nav-trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--muted);
  font: inherit;
  font-size: 15px;
  cursor: pointer;
  transition: color .18s ease;
}
.nav-trigger:hover,
.nav-trigger[aria-expanded="true"] { color: var(--fg); }

.nav-trigger .caret { width: 10px; height: 6px; transition: transform .18s ease; }
.nav-trigger[aria-expanded="true"] .caret { transform: rotate(180deg); }

.nav-menu {
  position: absolute;
  top: calc(100% + 16px);
  left: -14px;
  z-index: 50;
  min-width: 264px;
  padding: 8px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 26px 54px rgba(0,0,0,.58);
}
.nav-menu[hidden] { display: none; }

.nav-menu a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 6px;
  color: var(--fg);
  transition: background .15s ease;
}
.nav-menu a:hover { background: var(--surface-2); }
.nav-menu img {
  width: 32px; height: 32px;
  flex: none;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,.08);
}
.nav-menu span { display: flex; flex-direction: column; line-height: 1.35; }
.nav-menu b { font-size: 14.5px; font-weight: 600; }
.nav-menu em { color: var(--muted-2); font-style: normal; font-size: 12.5px; }

/* 锚点跳转时避开吸顶导航 */
#depu, #fretreel, #jianqian, #lepuku,
#access, #about, #changelog, #faq { scroll-margin-top: 84px; }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; padding: 76px 24px 40px; }

.hero-glow {
  position: absolute;
  top: -320px; right: -180px;
  width: 720px; height: 720px;
  background: radial-gradient(closest-side, rgba(221,168,95,.16), rgba(221,168,95,0));
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 18px;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13px;
  color: var(--brass);
  background: var(--brass-soft);
}

.hero h1 {
  font-size: clamp(44px, 6vw, 76px);
  letter-spacing: .5px;
  margin-bottom: 18px;
}

.lead {
  margin: 0 0 14px;
  font-size: clamp(18px, 2.1vw, 24px);
  color: #dfe3e9;
  line-height: 1.5;
}

.hero-sub { margin: 0 0 32px; color: var(--muted); max-width: 30em; }

.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

.hero-devices {
  position: relative;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
  aspect-ratio: 1 / 1.18;
}

.device {
  position: absolute;
  margin: 0;
  width: 43%;
  max-width: 230px;
  border-radius: 22px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,.10);
  background: #000;
  box-shadow: 0 30px 62px rgba(0,0,0,.62);
}
.device img { width: 100%; }

.device-back { left: 0; top: 15%; transform: rotate(-6deg); opacity: .88; }
.device-mid  { right: 0; top: 9%; transform: rotate(6deg); opacity: .94; }
.device-front { left: 50%; top: 0; width: 46%; transform: translateX(-50%); z-index: 3; }

.icon-strip {
  position: relative;
  max-width: var(--maxw);
  margin: 64px auto 0;
  padding: 26px 24px;
  list-style: none;
  display: grid;
  /* 五个 App：图标条跟着改成 5 列，否则第 5 个会掉到第二行、右边空三格 */
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.icon-strip li {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--muted);
  font-size: 15px;
}

.icon-strip img {
  width: 42px; height: 42px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.08);
}

/* ---------- 产品区块 ---------- */
.apps {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 96px 24px 40px;
}

.section-head { margin-bottom: 64px; }
.section-head h2 { font-size: clamp(28px, 3.4vw, 40px); margin-bottom: 12px; }
.section-head p { margin: 0; color: var(--muted); font-size: 17px; }

.product {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr);
  gap: 60px;
  align-items: center;
  padding: 72px 0;
  border-top: 1px solid var(--line);
}

.product-reverse .product-media { order: 2; }

.product-media { min-width: 0; }

.shot-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  align-items: start;
  justify-items: center;
}

.shot-row img,
.wide-shot img {
  width: 100%;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,.08);
  background: #000;
  box-shadow: 0 18px 40px rgba(0,0,0,.45);
}

.wide-shot { margin-bottom: 20px; }
.wide-shot:last-child { margin-bottom: 0; }

.shot-row img { width: 100%; max-width: 300px; }
.shot-row img:only-child { grid-column: 1 / -1; max-width: 300px; }

.product-head { display: flex; align-items: center; gap: 16px; margin-bottom: 24px; }

.product-icon {
  width: 60px; height: 60px;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,.10);
  flex: none;
}

.product-head h3 { font-size: 25px; }
.product-tag { margin: 3px 0 0; color: var(--brass); font-size: 14px; }

.product-title {
  margin: 0 0 16px;
  font-size: clamp(21px, 2.3vw, 28px);
  font-weight: 700;
  line-height: 1.35;
}

.product-desc { margin: 0 0 22px; color: var(--muted); font-size: 16px; }

/* 支持平台 */
.platform-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 10px;
  padding: 0;
  list-style: none;
}
.platform-list li {
  padding: 4px 11px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(255,255,255,.03);
  color: #cfd5de;
  font-size: 12.5px;
  letter-spacing: .2px;
}
.platform-note { margin: 0 0 24px; color: var(--muted-2); font-size: 13px; }

.feature-list {
  margin: 0 0 30px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.feature-list li {
  position: relative;
  padding-left: 26px;
  color: #d7dbe2;
  font-size: 15.5px;
}

.feature-list li::before {
  content: "";
  position: absolute;
  left: 4px; top: 9px;
  width: 7px; height: 7px;
  border-radius: 2px;
  background: var(--brass);
}

.btn-store {
  background: var(--fg);
  color: #0a0b0d;
  padding: 13px 24px;
}
.btn-store:hover { background: #ffffff; transform: translateY(-1px); }
.btn-store svg { width: 17px; height: 17px; }

.product-note { margin: 14px 0 0; color: var(--muted-2); font-size: 13.5px; }
.product-note a { color: var(--brass); border-bottom: 1px solid rgba(221,168,95,.35); }
.product-note a:hover { border-bottom-color: var(--brass); }

/* 乐谱库版本与价格 */
.plan-block { margin: 0 0 30px; }
.plan-block:last-of-type { margin-bottom: 18px; }

.plan-label {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 12px;
  border-radius: 6px;
  background: var(--brass-soft);
  color: var(--brass);
  font-size: 13px;
  font-weight: 600;
}

.price-grid { display: grid; gap: 14px; }

.price-card {
  position: relative;
  padding: 20px 22px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}
.price-card-hot { border-color: rgba(221,168,95,.42); background: #1a1d24; }
.price-badge {
  position: absolute;
  top: -11px; left: 22px;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--brass);
  color: #17120a;
  font-size: 11.5px;
  font-weight: 700;
}
.price-top h4 { margin: 0 0 8px; font-size: 17px; }
.price { display: flex; align-items: baseline; gap: 5px; margin: 0; }
.price .amount { color: var(--fg); font-size: 29px; font-weight: 700; letter-spacing: .5px; }
.price .unit { color: var(--muted-2); font-size: 13px; }
.price-desc { margin: 10px 0 0; color: var(--brass); font-size: 13.5px; }
.price-card ul { margin: 14px 0 0; padding-left: 18px; }
.price-card li { color: var(--muted); font-size: 13.5px; margin-bottom: 5px; }
.price-foot { margin: 16px 0 0; color: var(--muted-2); font-size: 13px; }
.price-foot b { color: #d7dbe2; }

/* Windows / macOS 安装包下载 */
.download-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  margin: 0 0 6px;
}
.btn-download svg { width: 17px; height: 17px; }
.download-meta { color: var(--muted-2); font-size: 13px; }
.download-note { margin: 10px 0 4px; color: var(--muted-2); font-size: 13px; }

/* ---------- 关于 ---------- */
.about { border-top: 1px solid var(--line); margin-top: 40px; }

.about-inner {
  max-width: 780px;
  margin: 0 auto;
  padding: 88px 24px 96px;
}

.about h2 { font-size: clamp(26px, 3vw, 34px); margin-bottom: 22px; }
.about p { color: var(--muted); margin: 0 0 16px; font-size: 16.5px; }
.about-mail { color: #d7dbe2; }
.about-mail a { color: var(--brass); border-bottom: 1px solid rgba(221,168,95,.35); }
.about-mail a:hover { border-bottom-color: var(--brass); }

/* ---------- 更新日志 / 常见问题 ---------- */
.changelog, .faq, .access { border-top: 1px solid var(--line); }
.changelog { margin-top: 40px; }

.section-narrow {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 88px 24px 0;
}
.faq .section-narrow { padding-bottom: 96px; }
.access .section-narrow { padding-bottom: 88px; }

/* ---------- 购买与开通 ---------- */
.steps {
  list-style: none;
  margin: 0 0 52px;
  padding: 0;
  display: grid;
  gap: 14px;
}
.steps li {
  display: flex;
  gap: 18px;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}
.step-no {
  flex: none;
  width: 30px; height: 30px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--brass-soft);
  color: var(--brass);
  font-size: 14px;
  font-weight: 700;
}
.steps h3 { margin: 3px 0 5px; font-size: 16px; }
.steps p { margin: 0; color: var(--muted); font-size: 14.5px; }

.qr-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  max-width: 640px;
}
.qr-card {
  margin: 0;
  padding: 24px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  text-align: center;
}
.qr-card img {
  width: 100%;
  max-width: 220px;
  margin: 0 auto 16px;
  border-radius: 8px;
  background: #fff;
}
.qr-card figcaption { font-size: 16px; font-weight: 600; }
.qr-card p { margin: 4px 0 0; color: var(--muted-2); font-size: 13.5px; }

.access-note {
  max-width: 48em;
  margin: 28px 0 0;
  color: var(--muted-2);
  font-size: 13.5px;
}

.log-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}
.log-list > li {
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}
.log-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 14px;
}
.log-head img {
  width: 40px; height: 40px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.08);
}
.log-head h3 { font-size: 17px; }
.log-ver {
  padding: 2px 9px;
  border-radius: 5px;
  background: var(--brass-soft);
  color: var(--brass);
  font-size: 12.5px;
  font-weight: 600;
}
.log-head time { margin-left: auto; color: var(--muted-2); font-size: 13px; }
.log-list > li > ul { margin: 0; padding-left: 18px; }
.log-list > li > ul > li { color: var(--muted); font-size: 14.5px; margin-bottom: 5px; }

.faq-list { display: grid; gap: 10px; }
.faq-list details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}
.faq-list summary {
  position: relative;
  padding: 17px 52px 17px 20px;
  cursor: pointer;
  font-size: 15.5px;
  font-weight: 600;
  list-style: none;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 20px; top: 50%;
  transform: translateY(-50%);
  color: var(--muted-2);
  font-size: 19px;
  line-height: 1;
}
.faq-list details[open] summary::after { content: "\2212"; }
.faq-list details p {
  margin: 0;
  padding: 0 20px 18px;
  color: var(--muted);
  font-size: 14.5px;
}
.faq-list details p b { color: #d7dbe2; }
.faq-list details a { color: var(--brass); }

/* ---------- 页脚 ---------- */
.nf {
  max-width: 560px;
  margin: 0 auto;
  padding: 22vh 24px 96px;
  text-align: center;
}
.nf-code {
  margin: 0 0 10px;
  color: var(--brass);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 3px;
}
.nf h1 { font-size: clamp(26px, 4vw, 36px); margin-bottom: 12px; }
.nf-sub { margin: 0 0 32px; color: var(--muted); }
.nf-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

.footer { border-top: 1px solid var(--line); background: var(--ink-2); }

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px 24px 56px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px 28px;
  align-items: center;
  color: var(--muted-2);
  font-size: 13.5px;
}

.footer-brand { display: flex; align-items: center; gap: 8px; color: var(--muted); }
.footer-brand .brand-name { font-size: 15px; color: var(--fg); }
.footer-dot { color: var(--muted-2); }

.footer-nav { display: flex; gap: 20px; margin-left: auto; flex-wrap: wrap; }
.footer-nav a { color: var(--muted); }
.footer-nav a:hover { color: var(--fg); }

.footer-links { display: flex; gap: 20px; flex-wrap: wrap; flex-basis: 100%; }
.footer-links a { display: inline-flex; align-items: center; gap: 6px; color: var(--muted-2); }
.footer-links a:hover { color: var(--muted); }
.footer-links img { width: 15px; height: 15px; }

.footer-copy { margin: 0; width: 100%; color: var(--muted-2); }

/* ---------- 滚动出现 ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 36px; }
  .hero-devices { order: 2; max-width: 420px; }
  .product { grid-template-columns: 1fr; gap: 34px; padding: 56px 0; }
  .product-reverse .product-media { order: 0; }
  .icon-strip { grid-template-columns: repeat(2, 1fr); gap: 18px; }
}

@media (max-width: 620px) {
  .nav-inner { padding: 12px 18px; gap: 14px; }
  .nav-links { margin-left: auto; gap: 0; }
  .nav-links > a { display: none; }
  .nav-store { display: none; }
  .nav-menu { left: auto; right: -12px; min-width: 252px; }

  .hero { padding: 48px 18px 28px; }
  .hero-devices { aspect-ratio: auto; max-width: 250px; }
  .device-back, .device-mid { display: none; }
  .device-front { position: static; width: 100%; max-width: 250px; transform: none; }

  .apps { padding: 64px 18px 20px; }
  .section-head { margin-bottom: 40px; }
  .shot-row { gap: 12px; }
  .product .shot-row img { max-width: none; }
  .price-foot { font-size: 12.5px; }
  .section-narrow { padding: 64px 18px 0; }
  .faq .section-narrow { padding-bottom: 72px; }
  .access .section-narrow { padding-bottom: 64px; }
  .qr-row { grid-template-columns: 1fr; max-width: 320px; }
  .steps li { padding: 18px; gap: 14px; }
  .log-head time { margin-left: 0; flex-basis: 100%; }
  .log-list > li { padding: 18px; }
  .about-inner { padding: 64px 18px 72px; }
  .footer-inner { padding: 32px 18px 44px; }
  .footer-links { margin-left: 0; }
  .icon-strip li { justify-content: flex-start; }
}