:root {
  color-scheme: light;
  --ink: #14161a;
  --muted: #5d6675;
  --line: #d9dee7;
  --panel: #f5f7fb;
  --accent: #e62117;
  --accent-dark: #b91c14;
  --blue: #1f6feb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: #ffffff;
  font: 16px/1.55 Arial, "Microsoft YaHei", sans-serif;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1120px;
  margin: 0 auto;
  padding: 22px 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
}

.mark {
  display: block;
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--accent);
  overflow: hidden;
}

.mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 11px;
  background: var(--accent-dark);
}

.play {
  position: absolute;
  left: 13px;
  top: 9px;
  z-index: 1;
  width: 0;
  height: 0;
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 8px solid #ffffff;
}

.line {
  position: absolute;
  z-index: 1;
  left: 8px;
  height: 3px;
  border-radius: 999px;
}

.line-one {
  right: 8px;
  bottom: 10px;
  background: #ffffff;
}

.line-two {
  left: 11px;
  right: 11px;
  bottom: 5px;
  background: #60a5fa;
}

.nav-download {
  color: var(--accent-dark);
  font-weight: 700;
  text-decoration: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: 42px;
  max-width: 1120px;
  min-height: 640px;
  margin: 0 auto;
  padding: 72px 24px 56px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent-dark);
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: 68px;
  line-height: 1.02;
  letter-spacing: 0;
}

.lead {
  max-width: 620px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 20px;
}

.actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 34px;
  flex-wrap: wrap;
}

.primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 8px;
  color: #ffffff;
  background: var(--accent);
  font-weight: 800;
  text-decoration: none;
}

.primary:hover {
  background: var(--accent-dark);
}

.meta {
  color: var(--muted);
  font-size: 14px;
}

.player-demo {
  min-height: 360px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(31, 111, 235, 0.12), rgba(230, 33, 23, 0.12)),
    #111827;
  position: relative;
  overflow: hidden;
}

.player-bar {
  display: flex;
  gap: 7px;
  padding: 16px;
}

.player-bar span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.45);
}

.caption-card {
  position: absolute;
  left: 50%;
  bottom: 38px;
  transform: translateX(-50%);
  width: min(86%, 520px);
  padding: 13px 16px;
  border-radius: 8px;
  color: #ffffff;
  background: rgba(0, 0, 0, 0.68);
  text-align: center;
}

.caption-card p {
  margin: 0;
}

.caption-card .target {
  margin-top: 6px;
  color: #dbeafe;
}

.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 46px 24px;
}

h2 {
  margin: 0 0 22px;
  font-size: 30px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

article {
  min-height: 154px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

article p,
.notice p {
  margin: 0;
  color: var(--muted);
}

.install,
.notice {
  border-top: 1px solid var(--line);
}

ol {
  margin: 0;
  padding-left: 22px;
  color: var(--muted);
}

li + li {
  margin-top: 8px;
}

code {
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--panel);
  color: var(--blue);
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  max-width: 1120px;
  margin: 30px auto 0;
  padding: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

footer a {
  color: var(--accent-dark);
  font-weight: 700;
  text-decoration: none;
}

.policy {
  max-width: 860px;
}

.policy h1 {
  font-size: 46px;
}

.policy h2 {
  margin-top: 44px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.policy h3 {
  margin-top: 24px;
}

.policy p {
  color: var(--muted);
}

@media (max-width: 820px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 42px;
  }

  h1 {
    font-size: 46px;
  }

  .feature-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 560px) {
  .topbar,
  footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }
}