:root {
  --ink: #20221f;
  --muted: #626760;
  --line: #dfe2dc;
  --surface: #ffffff;
  --soft: #f3f5f2;
  --yellow: #f4d84f;
  --yellow-dark: #d9b900;
  --green: #387b56;
  font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  color: var(--ink);
  background: var(--surface);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; background: var(--surface); }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
img { display: block; max-width: 100%; }

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  height: 64px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 28px;
  padding: 0 max(24px, calc((100vw - 1200px) / 2));
  border-bottom: 1px solid rgba(32, 34, 31, .1);
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(12px);
}

.brand { display: inline-flex; align-items: center; gap: 10px; width: fit-content; font-weight: 750; }
.brand img { width: 34px; height: 34px; border: 1px solid var(--line); border-radius: 6px; object-fit: cover; }
.site-header nav { display: flex; align-items: center; gap: 30px; color: #444842; font-size: 14px; }
.site-header nav a:hover { color: #000000; }
.header-download { justify-self: end; padding: 9px 15px; border: 1px solid #242620; border-radius: 6px; font-size: 14px; font-weight: 700; }
.header-download:hover { background: #242620; color: #ffffff; }

.hero {
  min-height: 620px;
  height: min(74vh, 760px);
  display: flex;
  align-items: center;
  padding: 42px max(24px, calc((100vw - 1200px) / 2));
  background-color: #f0f1f3;
  background-image: url('/assets/hero.jpg');
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
}

.hero-content { width: min(520px, 50%); }
.eyebrow { margin: 0 0 12px; color: #596058; font-size: 13px; font-weight: 750; letter-spacing: 0; text-transform: uppercase; }
.hero h1 { margin: 0; font-size: clamp(54px, 7vw, 92px); line-height: 1; letter-spacing: 0; }
.hero-copy { max-width: 480px; margin: 24px 0 28px; color: #41453f; font-size: 18px; line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.primary-action, .secondary-action, .disabled-action {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid #20221f;
  border-radius: 6px;
  font-weight: 750;
}
.primary-action { background: #20221f; color: #ffffff; }
.primary-action:hover { background: #000000; }
.secondary-action { background: rgba(255, 255, 255, .86); }
.secondary-action:hover { background: #ffffff; }
.test-label { margin: 14px 0 0; color: #656a64; font-size: 12px; }

.feature-band, .product-section, .download-section, .faq-section {
  padding: 92px max(24px, calc((100vw - 1200px) / 2));
}
.section-heading { max-width: 680px; }
.section-heading h2 { margin: 0; font-size: clamp(34px, 4vw, 52px); line-height: 1.18; letter-spacing: 0; }
.section-heading > p:last-child { margin: 18px 0 0; color: var(--muted); font-size: 16px; line-height: 1.8; }
.feature-list { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 58px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.feature-list article { min-height: 240px; padding: 28px 34px 32px 0; }
.feature-list article + article { padding-left: 34px; border-left: 1px solid var(--line); }
.feature-number { color: var(--green); font-size: 12px; font-weight: 800; }
.feature-list h3 { margin: 42px 0 12px; font-size: 22px; }
.feature-list p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.8; }

.product-section { padding-top: 40px; background: var(--soft); }
.product-heading { margin-bottom: 44px; }
.notes-demo { position: relative; min-height: 540px; overflow: hidden; border: 1px solid #d5d9d3; background: #e8ebe7; }
.demo-note { position: absolute; width: 290px; min-height: 270px; border: 1px solid rgba(40, 42, 37, .16); box-shadow: 0 18px 40px rgba(43, 47, 41, .18); }
.demo-note header { height: 46px; display: grid; grid-template-columns: 34px 1fr 34px 34px; align-items: center; padding: 0 6px; border-bottom: 1px solid rgba(40, 42, 37, .12); }
.demo-note header span { display: grid; place-items: center; width: 30px; height: 30px; font-size: 20px; }
.demo-note h3 { margin: 20px 20px 8px; font-size: 18px; }
.demo-note p { margin: 0 20px 24px; color: #40433e; font-size: 14px; line-height: 1.9; }
.note-yellow { z-index: 3; top: 118px; left: 12%; background: #fff3a0; transform: rotate(-2deg); }
.note-yellow header { background: #f0d45c; }
.note-pink { z-index: 2; top: 54px; left: 40%; background: #ffc6d9; transform: rotate(1.4deg); }
.note-pink header { background: #f09bb6; }
.note-blue { z-index: 1; top: 150px; right: 10%; background: #bde4ff; transform: rotate(2.2deg); }
.note-blue header { background: #7ec4ef; }
.sync-pill { position: absolute; right: 24px; bottom: 22px; display: flex; align-items: center; gap: 8px; padding: 9px 12px; border: 1px solid #cbd2ca; border-radius: 6px; background: rgba(255, 255, 255, .92); color: #435047; font-size: 12px; font-weight: 700; }
.sync-pill span { width: 8px; height: 8px; border-radius: 50%; background: #46a36c; }

.download-section { background: #ffffff; }
.download-heading { margin-bottom: 44px; }
.download-list { border-top: 1px solid var(--line); }
.download-item { min-height: 170px; display: grid; grid-template-columns: 78px 1fr auto; align-items: center; gap: 28px; padding: 28px 0; border-bottom: 1px solid var(--line); }
.platform-mark { width: 62px; height: 62px; display: grid; place-items: center; border: 1px solid #d7dbd5; border-radius: 8px; background: var(--soft); font-size: 13px; font-weight: 800; }
.windows-mark { grid-template-columns: repeat(2, 14px); grid-template-rows: repeat(2, 14px); gap: 3px; }
.windows-mark span { width: 14px; height: 14px; background: #2777c7; }
.android-mark { background: #dff1e4; color: #32704c; font-size: 22px; }
.ios-mark { background: #eff0ef; color: #444744; }
.platform-status { margin: 0 0 5px; color: var(--green); font-size: 12px; font-weight: 800; }
.download-info h3 { margin: 0; font-size: 24px; }
.download-info > p:last-child { margin: 7px 0 0; color: var(--muted); font-size: 13px; }
.download-actions { display: flex; flex-direction: column; align-items: flex-end; gap: 11px; }
.primary-action.compact { min-height: 42px; min-width: 190px; justify-content: space-between; gap: 18px; font-size: 14px; }
.primary-action.compact span { color: #cbd0ca; font-size: 11px; font-weight: 500; }
.text-link { color: #454a44; font-size: 12px; text-decoration: underline; text-underline-offset: 3px; }
.is-pending { opacity: .7; }
.disabled-action { min-width: 190px; border-color: #c7cbc5; background: #eceeeb; color: #777c76; cursor: not-allowed; }
.test-notice { display: grid; grid-template-columns: 160px 1fr; gap: 24px; margin-top: 34px; padding: 20px 22px; border-left: 4px solid var(--yellow-dark); background: #fff9d9; }
.test-notice strong { font-size: 14px; }
.test-notice p { margin: 0; color: #55594f; font-size: 13px; line-height: 1.7; }
.test-notice a { text-decoration: underline; text-underline-offset: 3px; }

.faq-section { padding-top: 42px; background: var(--soft); }
.faq-list { margin-top: 42px; border-top: 1px solid #d8dcd6; }
.faq-list details { border-bottom: 1px solid #d8dcd6; }
.faq-list summary { padding: 24px 4px; cursor: pointer; font-size: 17px; font-weight: 700; }
.faq-list details p { max-width: 760px; margin: -8px 0 24px; color: var(--muted); line-height: 1.8; }

footer { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 16px; padding: 42px max(24px, calc((100vw - 1200px) / 2)); border-top: 1px solid var(--line); background: #20221f; color: #ffffff; }
.footer-brand { grid-row: span 2; }
.footer-brand img { border-color: #555950; }
footer > p { justify-self: end; margin: 0; color: #d1d4ce; font-size: 13px; }
.copyright { color: #8f948d; }

@media (max-width: 820px) {
  .site-header { grid-template-columns: 1fr auto; gap: 14px; padding-inline: 18px; }
  .site-header nav { display: none; }
  .hero { min-height: 580px; height: 72svh; padding: 36px 22px; background-position: 58% center; }
  .hero-content { width: min(470px, 82%); }
  .hero h1 { font-size: 56px; }
  .hero-copy { font-size: 16px; }
  .feature-band, .product-section, .download-section, .faq-section { padding: 70px 22px; }
  .feature-list { grid-template-columns: 1fr; }
  .feature-list article { min-height: 0; padding: 26px 0; }
  .feature-list article + article { padding-left: 0; border-top: 1px solid var(--line); border-left: 0; }
  .feature-list h3 { margin-top: 20px; }
  .notes-demo { min-height: 650px; }
  .note-yellow { top: 54px; left: 7%; }
  .note-pink { top: 210px; left: auto; right: 7%; }
  .note-blue { top: 365px; right: auto; left: 16%; }
  .download-item { grid-template-columns: 62px 1fr; gap: 18px; }
  .download-actions { grid-column: 1 / -1; align-items: stretch; }
  .primary-action.compact, .disabled-action { width: 100%; }
}

@media (max-width: 520px) {
  .site-header { height: 58px; }
  .brand img { width: 30px; height: 30px; }
  .header-download { display: none; }
  .hero { min-height: 570px; height: 76svh; align-items: flex-start; padding-top: 64px; background-position: 62% center; }
  .hero-content { width: 100%; }
  .hero h1 { font-size: 48px; }
  .hero-copy { max-width: 330px; margin-block: 18px 22px; }
  .hero-actions { align-items: stretch; flex-direction: column; width: min(270px, 100%); }
  .section-heading h2 { font-size: 34px; }
  .feature-band, .product-section, .download-section, .faq-section { padding: 58px 18px; }
  .notes-demo { min-height: 590px; margin-inline: -18px; border-inline: 0; }
  .demo-note { width: 245px; min-height: 230px; }
  .note-yellow { left: 4%; }
  .note-pink { top: 190px; right: 4%; }
  .note-blue { top: 330px; left: 9%; }
  .sync-pill { right: 12px; bottom: 12px; }
  .download-item { grid-template-columns: 52px 1fr; }
  .platform-mark { width: 50px; height: 50px; }
  .test-notice { grid-template-columns: 1fr; gap: 8px; }
  footer { grid-template-columns: 1fr; }
  .footer-brand { grid-row: auto; }
  footer > p { justify-self: start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}