/* ──────────────────────────────────────────────────────────────────────────
   快翻官网样式  Signal & Decode  主题
   ────────────────────────────────────────────────────────────────────────── */

/* ── 1. 原始令牌 ─────────────────────────────────────────────────────────── */
:root {
  /* primitives */
  --p-black:        #060b18;
  --p-deep:         #080f20;
  --p-navy:         #0d1a35;
  --p-card:         #0f1e38;
  --p-border:       #1a2e52;
  --p-border-hi:    #223c6a;
  --p-cyan:         #3b82f6;
  --p-cyan-dim:     rgba(59, 130, 246, 0.15);
  --p-cyan-glow:    rgba(59, 130, 246, 0.08);
  --p-amber:        #ffad00;
  --p-amber-dim:    rgba(255, 173, 0, 0.15);
  --p-text:         #e8eaf2;
  --p-muted:        #6b7a99;
  --p-dim:          #3d4f70;
  --p-success:      #00c9a7;

  /* semantic */
  --color-bg:       var(--p-black);
  --color-surface:  var(--p-deep);
  --color-card:     var(--p-card);
  --color-border:   var(--p-border);
  --color-accent:   var(--p-cyan);
  --color-accent-dim: var(--p-cyan-dim);
  --color-cta:      var(--p-amber);
  --color-cta-dim:  var(--p-amber-dim);
  --color-text:     var(--p-text);
  --color-muted:    var(--p-muted);

  /* spacing */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* radius */
  --radius-sm:   6px;
  --radius-md:   12px;
  --radius-lg:   20px;
  --radius-pill: 999px;

  /* shadows */
  --shadow-card:   0 4px 24px rgba(0,0,0,0.5), 0 1px 0 rgba(255,255,255,0.03) inset;
  --shadow-cyan:   0 0 40px rgba(59, 130, 246, 0.22);
  --shadow-amber:  0 4px 24px rgba(255, 173, 0, 0.3);

  /* typography */
  --font-display: 'Syne', system-ui, sans-serif;
  --font-body:    'DM Sans', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', monospace;

  /* motion */
  --dur-fast:   120ms;
  --dur-base:   240ms;
  --dur-slow:   480ms;
  --ease-out:   cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in:    cubic-bezier(0.4, 0, 1, 1);
}

/* ── 2. 重置 & 基础 ──────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body { overflow-x: hidden; }

a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font: inherit; }
img { max-width: 100%; }

/* ── 3. 滚动条 ───────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb { background: var(--p-border-hi); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--p-muted); }

/* ── 4. 顶部横幅 ─────────────────────────────────────────────────────────── */
.site-banner {
  position: relative;
  z-index: 200;
  background: linear-gradient(90deg, rgba(59,130,246,0.12) 0%, rgba(255,173,0,0.08) 100%);
  border-bottom: 1px solid var(--color-border);
  padding: 10px var(--space-lg);
  text-align: center;
  font-size: 14px;
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}
.site-banner.hidden { display: none; }
.banner-close {
  position: absolute;
  right: var(--space-lg);
  font-size: 18px;
  color: var(--color-muted);
  line-height: 1;
  transition: color var(--dur-fast);
}
.banner-close:hover { color: var(--color-text); }

/* ── 5. 导航栏 ───────────────────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 0 var(--space-xl);
  background: rgba(6, 11, 24, 0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid rgba(26, 46, 82, 0.6);
  transition: box-shadow var(--dur-base);
}
.site-nav.scrolled {
  box-shadow: 0 8px 32px rgba(0,0,0,0.5);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  height: 60px;
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.brand-logo {
  width: 30px;
  height: 30px;
  border-radius: 7px;
  flex-shrink: 0;
}
.footer-brand-logo {
  width: 28px;
  height: 28px;
}
.brand-name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.3px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  margin-left: auto;
}
.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-muted);
  transition: color var(--dur-fast);
  white-space: nowrap;
}
.nav-links a:hover { color: var(--color-text); }
.nav-actions { margin-left: var(--space-lg); flex-shrink: 0; }
.btn-cta {
  display: inline-block;
  padding: 8px 20px;
  background: var(--color-cta);
  color: #000;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-pill);
  transition: box-shadow var(--dur-base), transform var(--dur-fast);
  white-space: nowrap;
}
.btn-cta:hover {
  box-shadow: var(--shadow-amber);
  transform: translateY(-1px);
}
.nav-mobile-toggle { display: none; font-size: 22px; color: var(--color-muted); }

/* ── 6. Hero 区域 ────────────────────────────────────────────────────────── */
.hero-section {
  position: relative;
  min-height: 90vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(26, 46, 82, 0.4) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26, 46, 82, 0.4) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 0%, transparent 100%);
}
.hero-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(59,130,246,0.08) 0%, transparent 65%);
  pointer-events: none;
}
.char-field {
  position: absolute;
  inset: 0;
  overflow: hidden;
}
.char-particle {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--p-dim);
  pointer-events: none;
  animation: floatChar linear infinite;
  opacity: 0;
  user-select: none;
}
@keyframes floatChar {
  0%   { transform: translateY(0); opacity: 0; }
  10%  { opacity: 0.4; }
  80%  { opacity: 0.3; }
  100% { transform: translateY(-300px); opacity: 0; }
}

.hero-content {
  position: relative;
  z-index: 10;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-xl) var(--space-2xl);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}
.hero-text { display: flex; flex-direction: column; gap: var(--space-lg); }
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--color-accent-dim);
  border: 1px solid rgba(59, 130, 246, 0.30);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--color-accent);
  font-weight: 500;
  width: fit-content;
}
.badge-dot {
  width: 7px;
  height: 7px;
  background: var(--color-accent);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--color-accent);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.7; }
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(48px, 6vw, 76px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -2px;
  color: var(--color-text);
}
.hero-title em {
  font-style: normal;
  background: linear-gradient(120deg, var(--color-accent) 0%, #7dd3fc 50%, var(--color-cta) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-muted);
  max-width: 500px;
}
.hero-note {
  font-size: 13px;
  color: var(--p-dim);
  padding-left: var(--space-sm);
  border-left: 2px solid var(--p-border);
}
.hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}
.btn-primary-large {
  display: inline-block;
  padding: 14px 32px;
  background: linear-gradient(135deg, var(--color-cta) 0%, #ff8c00 100%);
  color: #000;
  font-size: 16px;
  font-weight: 700;
  border-radius: var(--radius-pill);
  transition: box-shadow var(--dur-base), transform var(--dur-fast);
  white-space: nowrap;
}
.btn-primary-large:hover {
  box-shadow: var(--shadow-amber);
  transform: translateY(-2px);
}
.btn-ghost-large {
  display: inline-block;
  padding: 14px 28px;
  border: 1px solid var(--color-border);
  color: var(--color-muted);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-pill);
  transition: border-color var(--dur-base), color var(--dur-fast);
  white-space: nowrap;
}
.btn-ghost-large:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* 翻译演示卡 */
.hero-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}
.translate-demo {
  width: 100%;
  max-width: 420px;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card), var(--shadow-cyan);
  overflow: hidden;
}
.demo-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--color-border);
  background: rgba(0,0,0,0.3);
}
.demo-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.demo-dot.r { background: #ff5f57; }
.demo-dot.y { background: #febc2e; }
.demo-dot.g { background: #28c840; }
.demo-lang-tag {
  margin-left: auto;
  font-size: 11px;
  color: var(--color-muted);
  font-family: var(--font-mono);
}
/* 平台标识（header 右侧） */
.demo-platform-tag {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text);
  font-family: var(--font-mono);
}
.demo-platform-icon {
  width: 16px;
  height: 16px;
  border-radius: 50%;
}
/* 聊天内容區 */
.demo-chat {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: var(--space-md) var(--space-lg);
  flex: 1;
}
/* 消息气泡 */
.demo-msg {
  padding: 10px 13px;
  border-radius: 14px;
  max-width: 90%;
}
.demo-msg-src {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.07);
  border-top-left-radius: 4px;
  align-self: flex-start;
}
.demo-msg-tgt {
  background: rgba(59,130,246,0.10);
  border: 1px solid rgba(59,130,246,0.22);
  border-bottom-right-radius: 4px;
  align-self: flex-end;
}
.demo-msg .demo-text {
  font-size: 13px;
  font-weight: 400;
  line-height: 1.55;
  min-height: unset;
  transition: opacity 0.3s;
}
.demo-msg-meta {
  display: block;
  font-size: 10px;
  color: var(--p-dim);
  margin-top: 5px;
  opacity: 0.65;
  transition: opacity 0.3s;
}
/* 引擎标识行 */
.demo-translate-row {
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
}
.demo-translate-row::before,
.demo-translate-row::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(59,130,246,0.25), transparent);
}
.demo-translate-row .demo-engine {
  font-size: 10px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  background: rgba(59,130,246,0.10);
  border: 1px solid rgba(59,130,246,0.20);
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  white-space: nowrap;
  font-weight: 600;
}
.demo-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  border-top: 1px solid var(--color-border);
  font-size: 12px;
  color: var(--color-muted);
  background: rgba(0,0,0,0.2);
}
.demo-status.done { color: var(--p-success); }

.engine-pills {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  justify-content: center;
}
.engine-pill {
  padding: 5px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-size: 12px;
  color: var(--color-muted);
  cursor: pointer;
  transition: all var(--dur-fast);
}
.engine-pill.active {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-dim);
}

/* 统计数字栏 */
.stats-bar {
  position: relative;
  z-index: 10;
  width: 100%;
  max-width: 800px;
  margin: 0 auto var(--space-2xl);
  padding: var(--space-lg) var(--space-xl);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}
.stat-item strong {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
  color: var(--color-accent);
}
.stat-item span {
  font-size: 13px;
  color: var(--color-muted);
}
.stat-sep {
  width: 1px;
  height: 36px;
  background: var(--color-border);
}

/* ── 7. 功能区 ───────────────────────────────────────────────────────────── */
.section-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-xl);
}
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}
.section-kicker {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  letter-spacing: -1px;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}
.section-desc {
  font-size: 16px;
  color: var(--color-muted);
  max-width: 520px;
  margin: 0 auto;
}
.features-section {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}
.feature-card {
  padding: var(--space-xl) var(--space-lg);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--dur-base), transform var(--dur-base);
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
  opacity: 0;
  transition: opacity var(--dur-base);
}
.feature-card:hover {
  border-color: var(--p-border-hi);
  transform: translateY(-4px);
}
.feature-card:hover::before { opacity: 1; }
.feature-icon {
  font-size: 32px;
  margin-bottom: var(--space-md);
  display: block;
}
.feature-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}
.feature-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ── 8. 定价区 ───────────────────────────────────────────────────────────── */
.pricing-section { background: var(--color-bg); }
.pricing-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-lg);
  justify-content: center;
  margin-bottom: var(--space-lg);
}
.pricing-skeleton {
  text-align: center;
  color: var(--color-muted);
  padding: var(--space-3xl);
  font-size: 14px;
}
.pricing-card {
  flex: 1;
  min-width: 240px;
  max-width: 320px;
  padding: var(--space-xl);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  transition: border-color var(--dur-base), box-shadow var(--dur-base), transform var(--dur-base);
  position: relative;
}
.pricing-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-cyan);
  transform: translateY(-6px);
}
.pricing-card.featured {
  border-color: var(--color-accent);
  background: linear-gradient(180deg, rgba(59,130,246,0.08) 0%, var(--color-card) 40%);
}
.pricing-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  padding: 4px 16px;
  background: var(--color-accent);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  border-radius: var(--radius-pill);
  white-space: nowrap;
}
.pricing-name {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
}
.pricing-desc {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.6;
  min-height: 40px;
}
.pricing-price {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.price-currency-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-cta);
  opacity: 0.7;
  text-transform: uppercase;
}
.price-amount {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 700;
  color: var(--color-cta);
  line-height: 1;
  letter-spacing: -0.5px;
}
.price-currency {
  font-size: 16px;
  color: var(--color-muted);
  margin-bottom: 2px;
  display: none;  /* 已改用 .price-currency-label */
}
.feature-icon-img {
  width: 40px;
  height: 40px;
  margin-bottom: var(--space-sm);
}
.price-period {
  font-size: 13px;
  color: var(--p-dim);
}
.pricing-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  flex: 1;
}
.pricing-features li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 14px;
  color: var(--color-muted);
}
.pricing-features li::before {
  content: '✓';
  color: var(--p-success);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}
.pricing-cta {
  display: block;
  text-align: center;
  padding: 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  transition: all var(--dur-base);
  margin-top: auto;
}
.pricing-card.featured .pricing-cta {
  background: var(--color-cta);
  color: #000;
  border-color: var(--color-cta);
}
.pricing-card:not(.featured) .pricing-cta:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.pricing-note {
  text-align: center;
  font-size: 13px;
  color: var(--p-dim);
}

/* ── 9. FAQ 区 ───────────────────────────────────────────────────────────── */
.faq-section { background: var(--color-surface); border-top: 1px solid var(--color-border); }
.faq-inner { max-width: 720px; margin: 0 auto; padding: var(--space-3xl) var(--space-xl); }
.faq-list { display: flex; flex-direction: column; gap: 4px; }
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-card);
  transition: border-color var(--dur-base);
}
.faq-item:hover { border-color: var(--p-border-hi); }
.faq-question {
  width: 100%;
  text-align: left;
  padding: var(--space-md) var(--space-lg);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  transition: color var(--dur-fast);
}
.faq-item.open .faq-question { color: var(--color-accent); }
.faq-icon {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  font-size: 14px;
  color: var(--color-muted);
  transition: transform var(--dur-base), border-color var(--dur-base), color var(--dur-base);
}
.faq-item.open .faq-icon {
  transform: rotate(45deg);
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--dur-slow) var(--ease-out), padding var(--dur-base);
  padding: 0 var(--space-lg);
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}
.faq-item.open .faq-answer {
  max-height: 300px;
  padding: 0 var(--space-lg) var(--space-md);
}

/* ── 10. 底部 CTA 区 ─────────────────────────────────────────────────────── */
.cta-section {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
}
.cta-inner {
  position: relative;
  text-align: center;
  max-width: 700px;
}
.cta-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 500px;
  height: 300px;
  background: radial-gradient(ellipse, rgba(59,130,246,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.cta-title {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  letter-spacing: -1.5px;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  position: relative;
}
.cta-desc {
  font-size: 17px;
  color: var(--color-muted);
  margin-bottom: var(--space-xl);
  position: relative;
}
.cta-btns {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
  position: relative;
}

/* ── 11. 页脚 ────────────────────────────────────────────────────────────── */
.site-footer {
  background: #040810;
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) var(--space-xl);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: var(--space-xl);
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.footer-brand > div:first-child {
  display: flex;
  align-items: center;
  gap: 8px;
}
.footer-brand-name {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
}
.footer-slogan {
  font-size: 13px;
  color: var(--p-dim);
}
.footer-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}
.footer-social-link {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--color-muted);
  transition: color var(--dur-fast);
}
.footer-social-link:hover { color: var(--color-accent); }
.footer-social-link.hidden { display: none; }
.footer-copy {
  font-size: 12px;
  color: var(--p-dim);
  white-space: nowrap;
}

/* ── 12. 响应式 ──────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .hero-content { grid-template-columns: 1fr; gap: var(--space-xl); }
  .hero-visual { display: none; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: var(--space-lg); }
  .footer-links { justify-content: flex-start; }
}
@media (max-width: 640px) {
  .nav-inner { padding: 0 var(--space-md); gap: var(--space-md); }
  .nav-links { display: none; position: absolute; top: 60px; left: 0; right: 0; flex-direction: column; background: rgba(8,11,24,0.98); border-bottom: 1px solid var(--color-border); padding: var(--space-md); gap: 0; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px var(--space-md); border-bottom: 1px solid var(--color-border); }
  .nav-mobile-toggle { display: block; margin-left: auto; }
  .stats-bar { flex-direction: column; gap: var(--space-md); }
  .stat-sep { width: 40px; height: 1px; }
  .features-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 42px; }
  .section-inner { padding: var(--space-2xl) var(--space-md); }
  .faq-inner { padding: var(--space-2xl) var(--space-md); }
}

/* ── 13. 页面加载动画 ─────────────────────────────────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
.anim-in {
  animation: fadeInUp 0.6s var(--ease-out) both;
}
.anim-in:nth-child(1) { animation-delay: 0.05s; }
.anim-in:nth-child(2) { animation-delay: 0.12s; }
.anim-in:nth-child(3) { animation-delay: 0.19s; }
.anim-in:nth-child(4) { animation-delay: 0.26s; }
.anim-in:nth-child(5) { animation-delay: 0.33s; }
.anim-in:nth-child(6) { animation-delay: 0.40s; }

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

/* ── 下载区 ─────────────────────────────────────────────────────────────── */
.download-section {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: var(--space-3xl) 0;
}
.download-btns {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
  margin-top: var(--space-xl);
}
.download-btn-win,
.download-btn-mac {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 600;
  transition: transform var(--dur-fast), box-shadow var(--dur-base);
  white-space: nowrap;
}
.download-btn-win {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 0 0 rgba(59,130,246,0);
}
.download-btn-win:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(59,130,246,0.35);
}
.download-btn-mac {
  background: transparent;
  border: 1.5px solid var(--color-border);
  color: var(--color-text);
}
.download-btn-mac:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}