:root {
  color-scheme: dark;
  --page: #070b0f;
  --surface: #0d171d;
  --surface-strong: #12252e;
  --line: #24434f;
  --text: #f4f8fa;
  --muted: #9db0ba;
  --cyan: #59d5ff;
  --mint: #78e0bd;
  --danger: #ff8c94;
  --content: 1120px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--page);
}

body {
  margin: 0;
  min-width: 0;
  background: var(--page);
  color: var(--text);
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  line-height: 1.65;
}

button, a { font: inherit; }

button:focus-visible, a:focus-visible {
  outline: 3px solid var(--mint);
  outline-offset: 3px;
}

.browser-notice {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 12px 20px;
  background: #fff4dc;
  color: #402d00;
  text-align: center;
  font-size: 14px;
}

.site-header {
  position: absolute;
  inset: 0 0 auto;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(calc(100% - 40px), var(--content));
  margin: 0 auto;
  padding: 24px 0;
}

.brand {
  color: var(--text);
  font-size: 26px;
  font-weight: 800;
  text-decoration: none;
}

.header-download {
  padding: 9px 15px;
  border: 1px solid rgba(255, 255, 255, .48);
  border-radius: 6px;
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
}

.hero {
  position: relative;
  min-height: min(780px, 88vh);
  overflow: hidden;
  background: #080d12;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(2, 6, 9, .34);
  pointer-events: none;
}

.hero-image {
  width: 100%;
  height: min(780px, 88vh);
  min-height: 600px;
  object-fit: cover;
  object-position: center;
  filter: brightness(.86) contrast(1.05);
}

.hero-copy {
  position: absolute;
  z-index: 2;
  left: max(20px, calc((100% - var(--content)) / 2));
  bottom: 64px;
  width: min(600px, calc(100% - 40px));
  padding: 28px 30px;
  border-left: 4px solid var(--cyan);
  background: rgba(5, 12, 17, .84);
  backdrop-filter: blur(12px);
}

.eyebrow, .section-kicker {
  margin: 0 0 8px;
  color: var(--mint);
  font-size: 14px;
  font-weight: 700;
}

.hero h1 {
  margin: 0;
  font-size: clamp(48px, 8vw, 88px);
  line-height: 1.05;
  letter-spacing: 0;
}

.hero-summary {
  max-width: 520px;
  margin: 18px 0 24px;
  color: #d3dfe4;
  font-size: 18px;
}

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

.primary-button, .secondary-button {
  min-height: 48px;
  padding: 12px 20px;
  border-radius: 6px;
  cursor: pointer;
  text-decoration: none;
  font-weight: 700;
}

.primary-button {
  border: 1px solid var(--cyan);
  background: var(--cyan);
  color: #03202b;
}

.secondary-button {
  border: 1px solid #8399a3;
  background: transparent;
  color: var(--text);
}

.primary-button:hover { background: #85e2ff; }
.secondary-button:hover { border-color: var(--cyan); color: var(--cyan); }

.release-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.download-band, .install-section, .trust-section, .privacy-section, footer {
  width: min(calc(100% - 40px), var(--content));
  margin-inline: auto;
}

.download-band {
  display: grid;
  grid-template-columns: 1fr 270px;
  gap: 64px;
  align-items: center;
  padding: 88px 0;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.2;
  letter-spacing: 0;
}

.download-copy > p:last-of-type, .trust-section > div > p:last-child, .privacy-section > p {
  max-width: 700px;
  color: var(--muted);
  font-size: 17px;
}

.release-badge {
  display: inline-block;
  margin-top: 14px;
  padding: 7px 11px;
  border: 1px solid #7b6641;
  border-radius: 4px;
  color: #ffd991;
  font-size: 13px;
}

.qr-panel {
  display: grid;
  justify-items: center;
  gap: 14px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  text-align: center;
}

.qr-box {
  display: none;
  width: 184px;
  height: 184px;
  padding: 10px;
  background: #fff;
}

.qr-box img, .qr-box canvas { width: 164px; height: 164px; }

.qr-placeholder {
  display: grid;
  place-content: center;
  gap: 8px;
  width: 184px;
  height: 184px;
  padding: 18px;
  border: 1px dashed #58717c;
  color: var(--text);
}

.qr-placeholder span, .qr-panel p { color: var(--muted); font-size: 13px; }
.qr-panel p { margin: 0; }

.install-section {
  padding: 82px 0;
  border-top: 1px solid #16272f;
}

.section-heading { margin-bottom: 38px; }

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps li {
  min-height: 205px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.step-number { color: var(--cyan); font: 700 13px ui-monospace, monospace; }
.steps h3 { margin: 26px 0 8px; font-size: 21px; }
.steps p { margin: 0; color: var(--muted); }

.trust-section {
  display: grid;
  grid-template-columns: .9fr 1.1fr;
  gap: 60px;
  padding: 80px 0;
  border-top: 1px solid #16272f;
}

.file-details {
  margin: 0;
  border-top: 1px solid var(--line);
}

.file-details > div {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.file-details dt { color: var(--muted); }
.file-details dd { margin: 0; overflow-wrap: anywhere; }
.file-details code { color: #bdd0d9; font-size: 12px; }

.checksum-row button {
  grid-column: 2;
  width: max-content;
  padding: 7px 11px;
  border: 1px solid #657d88;
  border-radius: 4px;
  background: transparent;
  color: var(--cyan);
  cursor: pointer;
}

.privacy-section {
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 60px;
  padding: 62px 0;
  border-top: 1px solid #16272f;
}

footer {
  display: flex;
  justify-content: space-between;
  padding: 32px 0 48px;
  border-top: 1px solid #16272f;
  color: var(--muted);
  font-size: 14px;
}

.toast {
  position: fixed;
  z-index: 30;
  left: 50%;
  bottom: 24px;
  max-width: calc(100% - 32px);
  padding: 11px 16px;
  border: 1px solid #55717d;
  border-radius: 6px;
  background: #14242c;
  color: var(--text);
  opacity: 0;
  transform: translate(-50%, 12px);
  transition: opacity .2s ease, transform .2s ease;
  pointer-events: none;
}

.toast.visible { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 760px) {
  .site-header { width: calc(100% - 28px); padding-top: 18px; }
  .header-download { display: none; }
  .hero { min-height: 680px; }
  .hero-image { min-height: 680px; object-position: 53% center; }
  .hero-copy { left: 14px; bottom: 24px; width: calc(100% - 28px); padding: 22px 20px; }
  .hero-summary { font-size: 16px; }
  .hero-actions { display: grid; }
  .primary-button, .secondary-button { width: 100%; text-align: center; }
  .download-band, .trust-section, .privacy-section { grid-template-columns: 1fr; gap: 34px; }
  .download-band, .install-section, .trust-section, .privacy-section { padding-block: 56px; }
  .qr-panel { width: min(100%, 270px); }
  .steps { grid-template-columns: 1fr; }
  .steps li { min-height: 0; }
  .file-details > div { grid-template-columns: 72px minmax(0, 1fr); }
  footer { gap: 20px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}