:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #eef3f9;
  --ink: #111827;
  --muted: #5d6878;
  --faint: #8792a2;
  --line: #dce3ed;
  --accent: #0b63ce;
  --accent-dark: #084b9d;
  --warn-bg: #fff1f1;
  --warn: #a13b3b;
  --radius: 18px;
  --shadow: 0 24px 80px rgba(41, 59, 88, 0.14);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { background: #f9fbff; }

body {
  min-height: 100dvh;
  background:
    radial-gradient(circle at 20% 0%, rgba(11, 99, 206, 0.10), transparent 32rem),
    linear-gradient(180deg, #f9fbff 0%, var(--bg) 44%, #eef3f9 100%);
  color: var(--ink);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.5;
}

a { color: inherit; text-decoration: none; }
a, button {
  -webkit-tap-highlight-color: transparent;
}
a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
  outline: none;
}

.page {
  width: min(100%, 1040px);
  margin: 0 auto;
  padding: 0 clamp(18px, 4vw, 56px);
  overflow-x: hidden;
}

.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 750;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 9px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 28px);
  color: var(--muted);
  font-size: 0.94rem;
  white-space: nowrap;
}

.nav-links a,
footer a {
  transition: color 0.2s ease;
}

.nav-links a:hover,
footer a:hover {
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 440px);
  align-items: center;
  gap: clamp(28px, 6vw, 76px);
  padding: clamp(34px, 6vw, 76px) 0 clamp(42px, 7vw, 86px);
}

.hero > * { min-width: 0; }

.hero-copy {
  max-width: 640px;
  min-width: 0;
}

.kicker {
  color: var(--accent);
  font-size: 0.92rem;
  font-weight: 750;
  margin-bottom: 16px;
}

h1 {
  font-size: clamp(2.55rem, 5vw, 4.4rem);
  line-height: 1.04;
  letter-spacing: 0;
  font-weight: 820;
  white-space: nowrap;
}

.hero-copy p:not(.kicker) {
  max-width: 540px;
  margin-top: 22px;
  color: var(--muted);
  font-size: clamp(1rem, 1.35vw, 1.12rem);
  line-height: 1.68;
  overflow-wrap: anywhere;
}

.hero-card,
.steps,
.flash-area,
.notes {
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid rgba(220, 227, 237, 0.92);
  border-radius: var(--radius);
}

.hero-card {
  min-width: 0;
  overflow: hidden;
  padding: clamp(24px, 4vw, 34px);
  box-shadow: var(--shadow);
}

.firmware-meta {
  display: grid;
  gap: 6px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.meta-label,
.updated {
  display: block;
  max-width: 100%;
  color: var(--muted);
  padding: 0;
  border-radius: 0;
  font-size: 0.9rem;
  line-height: 1.5;
}

.version {
  display: block;
  min-width: 0;
  color: var(--ink);
  font-family: "SF Mono", "Fira Code", ui-monospace, monospace;
  font-size: 1rem;
  line-height: 1.45;
  white-space: nowrap;
}

.browser-note {
  display: grid;
  gap: 6px;
  color: var(--muted);
  line-height: 1.7;
  margin-top: 18px;
  overflow-wrap: anywhere;
}

.browser-note span {
  color: var(--muted);
  font-size: 0.9rem;
}

.browser-note strong {
  color: var(--ink);
  font-size: 1.08rem;
}

strong { color: var(--ink); }

h2 {
  color: var(--ink);
  font-size: clamp(1.35rem, 2.4vw, 2.25rem);
  line-height: 1.14;
  letter-spacing: 0;
  font-weight: 820;
  margin-bottom: 18px;
}

.steps,
.notes {
  min-width: 0;
  padding: clamp(22px, 4vw, 34px);
  margin-bottom: 18px;
}

.steps ol,
.notes ul {
  padding-left: 1.3rem;
  color: var(--muted);
  line-height: 1.85;
  overflow-wrap: anywhere;
}

.steps li,
.notes li {
  padding-left: 0.2rem;
}

.flash-area {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 24px;
  margin: 22px 0;
  padding: clamp(22px, 4vw, 34px);
  background: rgba(255, 255, 255, 0.76);
  box-shadow: 0 18px 48px rgba(41, 59, 88, 0.10);
}

.flash-copy {
  display: grid;
  gap: 6px;
}

.flash-copy strong {
  color: var(--ink);
  font-size: clamp(1.2rem, 2vw, 1.65rem);
}

.flash-copy span {
  color: var(--muted);
  line-height: 1.65;
}

.flash-control {
  display: block;
  min-width: 0;
}

.flash-btn {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: #fff;
  border: 0;
  border-radius: 999px;
  padding: 0 28px;
  font: inherit;
  font-size: 1rem;
  font-weight: 760;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.2s ease, background 0.2s ease;
}

.flash-btn:hover { background: var(--accent-dark); }
.flash-btn:active { transform: translateY(1px) scale(0.99); }

.unsupported {
  background: var(--warn-bg);
  color: var(--warn);
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid rgba(161, 59, 59, 0.25);
  line-height: 1.65;
  text-align: left;
}

footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 24px 0 42px;
  color: var(--faint);
  font-size: 0.92rem;
  border-top: 1px solid rgba(17, 24, 39, 0.08);
}

footer a { color: var(--muted); }
.sep { margin: 0 0.5rem; color: var(--line); }
.beian { text-align: right; }

@media (max-width: 760px) {
  .page {
    width: calc(100vw - 36px);
    padding: 0;
  }
  .nav { min-height: 64px; }
  .brand span { max-width: 52vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .nav-links { display: none; }
  .hero {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 28px 0 48px;
  }
  .hero-copy p:not(.kicker) { max-width: 100%; }
  .firmware-meta {
    padding-bottom: 16px;
  }
  .version {
    font-size: 0.86rem;
  }
  .flash-area {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .flash-control {
    width: 100%;
  }
  .flash-btn,
  .unsupported {
    width: 100%;
  }
  .unsupported {
    overflow-wrap: anywhere;
  }
  h1 {
    font-size: clamp(2rem, 9vw, 2.7rem);
    white-space: normal;
  }
  footer {
    align-items: center;
    flex-direction: column;
    justify-content: center;
    text-align: center;
  }
  .beian { text-align: center; }
}