:root {
  color: #10244a;
  background: #ffffff;
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  font-synthesis: none;
  letter-spacing: 0;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; color: #10244a; background: #fff; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.site-header {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 6vw, 88px);
  border-bottom: 1px solid #dce5f1;
  background: rgba(255, 255, 255, .96);
  position: sticky;
  top: 0;
  z-index: 20;
}

.brand img { width: 158px; height: 52px; object-fit: contain; }
nav { display: flex; align-items: center; gap: 30px; font-size: 14px; font-weight: 600; }
nav a:hover { color: #0768ea; }
.admin-link { padding: 10px 15px; border: 1px solid #c7d5e8; border-radius: 6px; }

.hero {
  min-height: min(600px, calc(100vh - 110px));
  position: relative;
  display: flex;
  align-items: center;
  padding: 68px clamp(22px, 8vw, 120px);
  background-image: url('/landing-assets/main.png');
  background-size: cover;
  background-position: center;
  overflow: hidden;
}

.hero-shade { position: absolute; inset: 0; background: rgba(249, 252, 255, .78); }
.hero-content { position: relative; width: min(610px, 100%); }
.eyebrow { margin: 0 0 14px; color: #008fa7; font-size: 13px; font-weight: 800; }
h1, h2, h3, p { letter-spacing: 0; }
h1 { margin: 0; font-size: clamp(46px, 7vw, 82px); line-height: 1.05; color: #082b69; }
.hero-copy { max-width: 590px; margin: 24px 0 0; font-size: clamp(18px, 2vw, 23px); line-height: 1.75; color: #334d72; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.hero-note { margin: 17px 0 0; font-size: 13px; color: #627594; }

.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 700;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}
.button:hover { transform: translateY(-1px); box-shadow: 0 8px 22px rgba(17, 66, 133, .16); }
.button.primary { color: #fff; background: #086bea; }
.button.primary:hover { background: #005fd7; }
.button.secondary { color: #123867; background: #fff; border-color: #bdccdf; }
.button.dark { color: #fff; background: #172d4d; }
.button.full { width: 100%; }
.button.disabled { color: #8795a8; background: #edf1f5; border-color: #e0e6ed; cursor: not-allowed; }

.download-section { padding: 82px clamp(20px, 6vw, 88px); background: #f5f8fc; }
.section-heading { max-width: 700px; margin: 0 auto 38px; text-align: center; }
.section-heading h2, .feature-copy h2, .start-band h2 { margin: 0; font-size: clamp(30px, 4vw, 44px); line-height: 1.2; color: #0b2d61; }
.section-heading > p:last-child { margin: 16px 0 0; color: #60728d; line-height: 1.8; }
.download-grid { max-width: 1180px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.download-card {
  min-height: 364px;
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: 27px;
  border: 1px solid #dbe4ef;
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 7px 24px rgba(28, 54, 91, .06);
}
.download-card.recommended { border: 2px solid #2681ef; padding: 26px; }
.download-card > div:nth-child(2) { flex: 1; }
.download-card h3 { margin: 8px 0 10px; font-size: 21px; }
.download-card p { margin: 0; min-height: 68px; color: #61718a; font-size: 14px; line-height: 1.7; }
.download-card small { display: block; margin-top: 14px; color: #8090a8; }
.platform-mark { width: 48px; height: 48px; display: grid; place-items: center; border-radius: 8px; font-size: 28px; font-weight: 800; }
.platform-mark.windows { color: #086bea; background: #e8f3ff; }
.platform-mark.apple { color: #182940; background: #edf0f4; font-size: 18px; }
.platform-mark.intel { color: #007f86; background: #e2f7f5; font-family: Georgia, serif; }
.tag { display: inline-block; padding: 4px 8px; border-radius: 4px; color: #0062d9; background: #e7f2ff; font-size: 12px; font-weight: 800; }
.tag.muted { color: #75849a; background: #eef2f6; }
.mac-tip { max-width: 900px; margin: 28px auto 0; padding: 18px 20px; border-left: 4px solid #00a39a; background: #fff; color: #5d6e87; font-size: 14px; line-height: 1.7; }
.mac-tip strong { color: #16375e; }

.feature-section { max-width: 1260px; margin: 0 auto; padding: 92px 40px; display: grid; grid-template-columns: .85fr 1.15fr; gap: 62px; align-items: center; }
.feature-copy > p:not(.eyebrow) { margin: 20px 0 0; color: #64758d; line-height: 1.85; }
.feature-copy ul { list-style: none; margin: 30px 0 0; padding: 0; display: grid; gap: 19px; }
.feature-copy li { display: flex; gap: 15px; align-items: flex-start; }
.feature-copy li > span { width: 38px; height: 32px; display: grid; place-items: center; border-radius: 6px; color: #0870e9; background: #e9f3ff; font-size: 12px; font-weight: 800; flex: 0 0 auto; }
.feature-copy li div { display: grid; gap: 5px; }
.feature-copy li strong { font-size: 16px; }
.feature-copy li small { color: #718198; line-height: 1.55; }
.product-shot { margin: 0; border: 1px solid #d8e2ee; border-radius: 8px; overflow: hidden; background: #fff; box-shadow: 0 18px 46px rgba(26, 61, 106, .14); }
.product-shot img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; object-position: left top; }
.product-shot figcaption { padding: 13px 17px; color: #718097; font-size: 12px; border-top: 1px solid #e3e9f1; }

.start-band { margin: 0; padding: 52px clamp(22px, 8vw, 120px); display: flex; align-items: center; justify-content: space-between; gap: 24px; color: #fff; background: #0b315f; }
.start-band h2 { color: #fff; font-size: clamp(27px, 3vw, 38px); }
.start-band p { margin: 12px 0 0; color: #bfd0e4; }

footer { min-height: 130px; padding: 28px clamp(20px, 6vw, 88px); display: flex; align-items: center; gap: 30px; color: #738096; font-size: 13px; }
footer img { width: 130px; height: 55px; object-fit: contain; }
footer p { flex: 1; }
footer a { color: #36577f; font-weight: 700; }

@media (max-width: 900px) {
  .download-grid { grid-template-columns: 1fr; max-width: 580px; }
  .download-card { min-height: 0; }
  .download-card p { min-height: 0; }
  .feature-section { grid-template-columns: 1fr; gap: 42px; }
}

@media (max-width: 640px) {
  .site-header { height: 64px; padding: 0 16px; }
  .brand img { width: 122px; height: 44px; }
  nav a:not(.admin-link) { display: none; }
  .admin-link { padding: 8px 10px; font-size: 13px; }
  .hero { min-height: 590px; padding: 48px 22px; background-position: 36% center; }
  h1 { font-size: 52px; }
  .hero-copy { font-size: 18px; }
  .hero-actions .button { width: 100%; }
  .download-section { padding: 62px 16px; }
  .download-card { padding: 22px; }
  .download-card.recommended { padding: 21px; }
  .feature-section { padding: 66px 20px; }
  .start-band { align-items: stretch; flex-direction: column; padding: 42px 22px; }
  footer { align-items: flex-start; flex-direction: column; gap: 12px; }
  footer p { margin: 0; }
}

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