/* Firefox 官网 — 桌面端样式 */
:root {
  --fx-orange: #ff7139;
  --fx-orange-deep: #e66000;
  --fx-amber: #ffa012;
  --fx-ink: #1a1b26;
  --fx-navy: #20123a;
  --fx-slate: #2b2a33;
  --fx-mist: #f9f9fb;
  --fx-cloud: #e0e0e6;
  --fx-text: #15141a;
  --fx-muted: #5b5b66;
  --fx-white: #ffffff;
  --fx-line: rgba(21, 20, 26, 0.08);
  --font-display: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-body: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --max: 1180px;
  --nav-h: 72px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 1280px;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--fx-text);
  background: var(--fx-mist);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.container {
  width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

/* —— Header —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(249, 249, 251, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--fx-line);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--fx-ink);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a {
  padding: 8px 14px;
  font-size: 15px;
  font-weight: 600;
  color: var(--fx-slate);
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}

.site-nav a:hover {
  color: var(--fx-orange-deep);
  background: rgba(255, 113, 57, 0.08);
}

.site-nav a.is-active {
  color: var(--fx-orange-deep);
  background: rgba(255, 113, 57, 0.12);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 20px;
  font-size: 14px;
  font-weight: 700;
  color: var(--fx-white);
  background: linear-gradient(135deg, var(--fx-orange) 0%, var(--fx-orange-deep) 100%);
  border-radius: 8px;
  box-shadow: 0 4px 14px rgba(230, 96, 0, 0.28);
  transition: transform 0.2s, box-shadow 0.2s;
}

.header-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(230, 96, 0, 0.36);
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 52px;
  padding: 0 28px;
  font-size: 16px;
  font-weight: 700;
  border-radius: 10px;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.btn-primary {
  color: var(--fx-white);
  background: linear-gradient(135deg, var(--fx-orange) 0%, var(--fx-orange-deep) 100%);
  box-shadow: 0 8px 24px rgba(230, 96, 0, 0.32);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(230, 96, 0, 0.4);
}

.btn-ghost {
  color: var(--fx-ink);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--fx-cloud);
}

.btn-ghost:hover {
  background: var(--fx-white);
  transform: translateY(-1px);
}

.btn-outline {
  color: var(--fx-orange-deep);
  background: transparent;
  border: 2px solid var(--fx-orange);
}

.btn-outline:hover {
  background: rgba(255, 113, 57, 0.08);
}

.btn-block {
  width: 100%;
}

/* —— Hero —— */
.hero {
  position: relative;
  overflow: hidden;
  min-height: calc(100vh - var(--nav-h));
  display: flex;
  align-items: center;
  background:
    radial-gradient(ellipse 80% 60% at 70% 40%, rgba(255, 160, 18, 0.22) 0%, transparent 55%),
    radial-gradient(ellipse 50% 70% at 15% 80%, rgba(255, 113, 57, 0.18) 0%, transparent 50%),
    linear-gradient(160deg, #fff8f3 0%, #f3f0ff 45%, #eef2ff 100%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 113, 57, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 113, 57, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 20%, transparent 75%);
  pointer-events: none;
}

.hero .container {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
  padding-top: 48px;
  padding-bottom: 64px;
}

.hero-copy {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.hero.is-ready .hero-copy {
  opacity: 1;
  transform: translateY(0);
}

.hero-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fx-orange-deep);
}

.hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--fx-ink);
}

.hero-lead {
  margin: 0 0 32px;
  max-width: 520px;
  font-size: 19px;
  line-height: 1.65;
  color: var(--fx-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 18px;
}

.hero-note {
  margin: 0;
  font-size: 13px;
  color: var(--fx-muted);
}

.hero-visual {
  position: relative;
  opacity: 0;
  transform: translateX(36px) scale(0.98);
  transition: opacity 0.85s ease 0.12s, transform 0.85s ease 0.12s;
}

.hero.is-ready .hero-visual {
  opacity: 1;
  transform: translateX(0) scale(1);
}

.browser-frame {
  position: relative;
  border-radius: 16px 16px 12px 12px;
  overflow: hidden;
  background: var(--fx-ink);
  box-shadow:
    0 40px 80px rgba(32, 18, 58, 0.28),
    0 0 0 1px rgba(255, 255, 255, 0.08);
  animation: floatY 6s ease-in-out infinite;
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.browser-chrome {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 16px;
  background: #2b2a33;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #5b5b66;
}

.dot:nth-child(1) { background: #ff5f57; }
.dot:nth-child(2) { background: #febc2e; }
.dot:nth-child(3) { background: #28c840; }

.browser-url {
  flex: 1;
  margin-left: 8px;
  padding: 6px 12px;
  font-size: 12px;
  color: #cfcfd8;
  background: #1a1b26;
  border-radius: 6px;
}

.browser-body {
  display: grid;
  grid-template-columns: 72px 1fr;
  min-height: 320px;
  background: linear-gradient(145deg, #2a1f3d 0%, #1a1b26 55%, #251a14 100%);
}

.browser-side {
  padding: 16px 10px;
  border-right: 1px solid rgba(255, 255, 255, 0.06);
}

.side-pill {
  height: 36px;
  margin-bottom: 10px;
  border-radius: 8px;
  background: rgba(255, 113, 57, 0.15);
}

.side-pill:nth-child(2) { background: rgba(255, 255, 255, 0.06); }
.side-pill:nth-child(3) { background: rgba(255, 255, 255, 0.04); }

.browser-main {
  padding: 24px;
}

.fake-line {
  height: 12px;
  margin-bottom: 14px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.1);
}

.fake-line.w60 { width: 60%; }
.fake-line.w80 { width: 80%; }
.fake-line.w40 { width: 40%; background: rgba(255, 113, 57, 0.35); }

.fake-panel {
  margin-top: 24px;
  height: 140px;
  border-radius: 12px;
  background:
    linear-gradient(135deg, rgba(255, 113, 57, 0.35), rgba(255, 160, 18, 0.15)),
    rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.glow-orb {
  position: absolute;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 113, 57, 0.45) 0%, transparent 70%);
  filter: blur(20px);
  z-index: -1;
  right: -40px;
  top: -30px;
  animation: pulseOrb 4s ease-in-out infinite;
}

@keyframes pulseOrb {
  0%, 100% { opacity: 0.7; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.08); }
}

/* —— Sections —— */
.section {
  padding: 96px 0;
}

.section-alt {
  background: var(--fx-white);
}

.section-head {
  max-width: 640px;
  margin: 0 auto 56px;
  text-align: center;
}

.section-head h2 {
  margin: 0 0 14px;
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--fx-ink);
}

.section-head p {
  margin: 0;
  font-size: 18px;
  color: var(--fx-muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-item {
  padding: 8px 4px;
}

.feature-icon {
  width: 52px;
  height: 52px;
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: linear-gradient(145deg, rgba(255, 113, 57, 0.16), rgba(255, 160, 18, 0.08));
  color: var(--fx-orange-deep);
  font-size: 22px;
  font-weight: 800;
}

.feature-item h3 {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--fx-ink);
}

.feature-item p {
  margin: 0;
  font-size: 15px;
  color: var(--fx-muted);
  line-height: 1.7;
}

/* —— Split —— */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.split-media {
  position: relative;
  min-height: 360px;
  border-radius: 20px;
  overflow: hidden;
  background:
    linear-gradient(145deg, #2a1f3d 0%, #1a1b26 50%, #3a2210 100%);
}

.split-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 30% 30%, rgba(255, 113, 57, 0.4), transparent 45%),
    radial-gradient(circle at 75% 70%, rgba(255, 160, 18, 0.25), transparent 40%);
}

.split-copy h2 {
  margin: 0 0 16px;
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.split-copy p {
  margin: 0 0 28px;
  font-size: 17px;
  color: var(--fx-muted);
  line-height: 1.7;
}

.check-list {
  margin-bottom: 28px;
}

.check-list li {
  position: relative;
  padding: 8px 0 8px 28px;
  font-size: 15px;
  font-weight: 600;
  color: var(--fx-slate);
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--fx-orange);
  box-shadow: inset 0 0 0 3px rgba(255, 255, 255, 0.45);
}

/* —— Download platforms —— */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.platform-item {
  padding: 28px 22px;
  text-align: center;
  background: var(--fx-white);
  border: 1px solid var(--fx-line);
  border-radius: 14px;
  transition: border-color 0.2s, transform 0.2s;
}

.platform-item:hover {
  border-color: rgba(255, 113, 57, 0.45);
  transform: translateY(-3px);
}

.platform-item .os-label {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--fx-ink);
}

.platform-item .os-desc {
  display: block;
  margin-bottom: 18px;
  font-size: 13px;
  color: var(--fx-muted);
}

/* —— CTA band —— */
.cta-band {
  padding: 80px 0;
  background:
    linear-gradient(120deg, #20123a 0%, #3a2218 50%, #e66000 100%);
  color: var(--fx-white);
  text-align: center;
}

.cta-band h2 {
  margin: 0 0 12px;
  font-size: 36px;
  font-weight: 800;
}

.cta-band p {
  margin: 0 0 28px;
  font-size: 17px;
  opacity: 0.88;
}

.cta-band .btn-primary {
  background: var(--fx-white);
  color: var(--fx-orange-deep);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

/* —— Page hero (inner pages) —— */
.page-hero {
  padding: 72px 0 48px;
  background:
    radial-gradient(ellipse 60% 80% at 90% 0%, rgba(255, 113, 57, 0.18), transparent 55%),
    linear-gradient(180deg, #fff8f3 0%, var(--fx-mist) 100%);
  border-bottom: 1px solid var(--fx-line);
}

.page-hero h1 {
  margin: 0 0 14px;
  font-size: 44px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.page-hero p {
  margin: 0;
  max-width: 620px;
  font-size: 18px;
  color: var(--fx-muted);
}

.content-block {
  max-width: 820px;
}

.content-block h2 {
  margin: 40px 0 12px;
  font-size: 26px;
  font-weight: 750;
}

.content-block p {
  margin: 0 0 16px;
  color: var(--fx-muted);
  line-height: 1.75;
}

.content-block ul {
  margin: 0 0 16px;
  padding-left: 20px;
  list-style: disc;
  color: var(--fx-muted);
}

.content-block li {
  margin-bottom: 8px;
}

.download-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 32px;
}

.download-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 22px;
  background: var(--fx-white);
  border: 1px solid var(--fx-line);
  border-radius: 12px;
}

.download-row strong {
  display: block;
  font-size: 16px;
  color: var(--fx-ink);
}

.download-row span {
  font-size: 13px;
  color: var(--fx-muted);
}

/* —— Footer —— */
.site-footer {
  padding: 56px 0 28px;
  background: var(--fx-ink);
  color: rgba(255, 255, 255, 0.72);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand .brand-name {
  color: var(--fx-white);
  margin-bottom: 12px;
}

.footer-brand p {
  margin: 0;
  max-width: 280px;
  font-size: 14px;
  line-height: 1.7;
}

.footer-col h4 {
  margin: 0 0 16px;
  font-size: 14px;
  font-weight: 700;
  color: var(--fx-white);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.footer-col a {
  display: block;
  margin-bottom: 10px;
  font-size: 14px;
  transition: color 0.2s;
}

.footer-col a:hover {
  color: var(--fx-orange);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 13px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}