/* ============================================
   德扑圈下载中心 - Premium Design System
   Inspired by Apple, OpenAI, Stripe, Linear
   ============================================ */

/* ---------- Reset ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
img, svg { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea { font-family: inherit; }

/* ---------- Design Tokens ---------- */
:root {
  /* Backgrounds */
  --bg-base: #07070d;
  --bg-elevated: #0d0d18;
  --bg-card: rgba(255, 255, 255, 0.025);
  --bg-card-hover: rgba(255, 255, 255, 0.05);
  --bg-glass: rgba(255, 255, 255, 0.04);
  --bg-glass-strong: rgba(255, 255, 255, 0.08);

  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-default: rgba(255, 255, 255, 0.1);
  --border-hover: rgba(255, 255, 255, 0.18);
  --border-glow: rgba(139, 92, 246, 0.3);

  /* Text */
  --text-primary: #f5f5f7;
  --text-secondary: rgba(245, 245, 247, 0.68);
  --text-tertiary: rgba(245, 245, 247, 0.42);
  --text-inverse: #07070d;

  /* Brand Colors */
  --indigo: #6366f1;
  --violet: #8b5cf6;
  --cyan: #06b6d4;
  --gold: #fbbf24;
  --gold-deep: #f59e0b;
  --emerald: #10b981;
  --rose: #f43f5e;

  /* Gradients */
  --grad-brand: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
  --grad-cool: linear-gradient(135deg, #06b6d4 0%, #6366f1 100%);
  --grad-gold: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
  --grad-emerald: linear-gradient(135deg, #10b981 0%, #06b6d4 100%);
  --grad-mesh: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 102, 241, 0.15), transparent),
               radial-gradient(ellipse 60% 50% at 80% 50%, rgba(139, 92, 246, 0.1), transparent),
               radial-gradient(ellipse 60% 50% at 20% 80%, rgba(6, 182, 212, 0.08), transparent);
  --grad-text: linear-gradient(135deg, #a78bfa 0%, #818cf8 50%, #06b6d4 100%);
  --grad-text-gold: linear-gradient(135deg, #fbbf24 0%, #fcd34d 50%, #fbbf24 100%);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 64px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.25);
  --shadow-glow-gold: 0 0 40px rgba(251, 191, 36, 0.2);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Cascadia Code", "Consolas", monospace;

  /* Spacing */
  --container-max: 1200px;
  --container-narrow: 860px;
  --section-pad: 100px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-full: 9999px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --dur-fast: 0.2s;
  --dur-base: 0.4s;
  --dur-slow: 0.7s;
}

/* ---------- Base ---------- */
body {
  font-family: var(--font-sans);
  background: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: var(--grad-mesh);
  pointer-events: none;
  z-index: 0;
}

::selection { background: rgba(139, 92, 246, 0.3); color: #fff; }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.2); }

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}
.container-narrow { max-width: var(--container-narrow); }

.section { padding: var(--section-pad) 0; position: relative; z-index: 1; }
.section-sm { padding: 60px 0; }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col { display: flex; flex-direction: column; }
.gap-sm { gap: 8px; }
.gap-md { gap: 16px; }
.gap-lg { gap: 32px; }

.text-center { text-align: center; }
.text-gradient {
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.text-gradient-gold {
  background: var(--grad-text-gold);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5 { line-height: 1.15; font-weight: 700; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.5rem, 6vw, 4.5rem); font-weight: 800; letter-spacing: -0.03em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.3rem, 2.5vw, 1.75rem); }
h4 { font-size: 1.15rem; }
p { color: var(--text-secondary); }
.lead { font-size: 1.15rem; color: var(--text-secondary); line-height: 1.7; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--violet);
  margin-bottom: 16px;
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--grad-brand);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--dur-base) var(--ease-out);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}
.btn-primary {
  background: var(--grad-brand);
  color: #fff;
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(99, 102, 241, 0.45);
}
.btn-gold {
  background: var(--grad-gold);
  color: #1a1a00;
  box-shadow: 0 4px 20px rgba(251, 191, 36, 0.25);
}
.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(251, 191, 36, 0.4);
}
.btn-ghost {
  background: var(--bg-glass);
  color: var(--text-primary);
  border: 1px solid var(--border-default);
  backdrop-filter: blur(12px);
}
.btn-ghost:hover {
  background: var(--bg-glass-strong);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}
.btn-lg { padding: 18px 40px; font-size: 1.1rem; }
.btn-sm { padding: 10px 20px; font-size: 0.9rem; }
.btn-block { width: 100%; }

/* ---------- Glass Card ---------- */
.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  backdrop-filter: blur(20px);
  transition: all var(--dur-base) var(--ease-out);
  position: relative;
  overflow: hidden;
}
.glass-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
}
.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.glass-card-glow:hover {
  box-shadow: var(--shadow-glow);
  border-color: var(--border-glow);
}

/* ---------- Badge ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  backdrop-filter: blur(12px);
}
.badge-gold { background: rgba(251,191,36,0.1); border-color: rgba(251,191,36,0.25); color: var(--gold); }
.badge-violet { background: rgba(139,92,246,0.1); border-color: rgba(139,92,246,0.25); color: #a78bfa; }
.badge-emerald { background: rgba(16,185,129,0.1); border-color: rgba(16,185,129,0.25); color: var(--emerald); }
.badge-dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; }
.badge-dot-live { background: var(--emerald); box-shadow: 0 0 8px var(--emerald); animation: pulse 2s infinite; }

@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: all var(--dur-base) var(--ease-out);
}
.nav-scrolled {
  background: rgba(7, 7, 13, 0.8);
  backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 0;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.nav-logo svg { width: 36px; height: 36px; }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: all var(--dur-fast) var(--ease-out);
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-glass); }
.nav-link.active { color: var(--text-primary); background: var(--bg-glass-strong); }
.nav-cta { display: flex; align-items: center; gap: 12px; }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--dur-fast) var(--ease-out);
}
.nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.mobile-menu {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(7, 7, 13, 0.95);
  backdrop-filter: blur(24px);
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-base) var(--ease-out);
}
.mobile-menu.open { opacity: 1; pointer-events: auto; }
.mobile-menu a { font-size: 1.5rem; font-weight: 600; color: var(--text-primary); }

/* ---------- Hero ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  padding: 120px 0 80px;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
.hero-bg::before {
  content: "";
  position: absolute;
  top: 10%; left: 50%;
  width: 800px; height: 800px;
  transform: translateX(-50%);
  background: radial-gradient(circle, rgba(99,102,241,0.15) 0%, transparent 60%);
  filter: blur(60px);
}
.hero-bg::after {
  content: "";
  position: absolute;
  bottom: -20%; right: -10%;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(139,92,246,0.1) 0%, transparent 60%);
  filter: blur(60px);
}
.hero-content { position: relative; z-index: 2; }
.hero h1 { margin-bottom: 24px; }
.hero .lead { max-width: 620px; margin-bottom: 40px; font-size: 1.25rem; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: flex;
  gap: 48px;
  margin-top: 64px;
  flex-wrap: wrap;
}
.hero-stat-num { font-size: 2.5rem; font-weight: 800; letter-spacing: -0.03em; }
.hero-stat-label { font-size: 0.85rem; color: var(--text-tertiary); margin-top: 4px; }

/* Floating orbs */
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.5;
  animation: float 8s ease-in-out infinite;
}
.orb-1 { width: 300px; height: 300px; background: rgba(99,102,241,0.3); top: 20%; left: -5%; }
.orb-2 { width: 250px; height: 250px; background: rgba(139,92,246,0.2); bottom: 10%; right: 5%; animation-delay: -3s; }
.orb-3 { width: 200px; height: 200px; background: rgba(6,182,212,0.15); top: 50%; left: 40%; animation-delay: -5s; }

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

/* ---------- Section Header ---------- */
.section-header { text-align: center; max-width: 680px; margin: 0 auto 64px; }
.section-header h2 { margin-bottom: 16px; }
.section-header .lead { font-size: 1.1rem; }

/* ---------- Feature Grid ---------- */
.feature-icon {
  width: 56px; height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
}
.feature-icon svg { width: 28px; height: 28px; }
.feature-icon-violet { background: rgba(139,92,246,0.1); border-color: rgba(139,92,246,0.2); }
.feature-icon-gold { background: rgba(251,191,36,0.1); border-color: rgba(251,191,36,0.2); }
.feature-icon-cyan { background: rgba(6,182,212,0.1); border-color: rgba(6,182,212,0.2); }
.feature-icon-emerald { background: rgba(16,185,129,0.1); border-color: rgba(16,185,129,0.2); }

/* ---------- Download Cards ---------- */
.download-card {
  text-align: center;
  padding: 48px 32px;
}
.download-card .platform-icon {
  width: 80px; height: 80px;
  margin: 0 auto 24px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.download-card .platform-icon svg { width: 40px; height: 40px; }
.platform-android { background: rgba(16,185,129,0.1); border: 1px solid rgba(16,185,129,0.2); }
.platform-ios { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); }
.platform-windows { background: rgba(6,182,212,0.1); border: 1px solid rgba(6,182,212,0.2); }

.version-tag {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-tertiary);
  margin-top: 8px;
}

/* ---------- App Showcase ---------- */
.app-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.app-mockup {
  position: relative;
  display: flex;
  justify-content: center;
}
.phone-frame {
  width: 320px;
  height: 640px;
  border-radius: 48px;
  background: linear-gradient(145deg, #1a1a2e, #0d0d18);
  border: 2px solid var(--border-default);
  padding: 12px;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  position: relative;
  overflow: hidden;
}
.phone-screen {
  width: 100%; height: 100%;
  border-radius: 36px;
  overflow: hidden;
  background: var(--bg-elevated);
  position: relative;
}
.phone-notch {
  position: absolute;
  top: 12px; left: 50%;
  transform: translateX(-50%);
  width: 120px; height: 28px;
  background: #07070d;
  border-radius: 0 0 16px 16px;
  z-index: 10;
}

/* ---------- Changelog ---------- */
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 7px; top: 8px; bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--violet), transparent);
}
.timeline-item { position: relative; padding-bottom: 48px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute;
  left: -32px; top: 4px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--bg-base);
  border: 3px solid var(--violet);
  box-shadow: 0 0 12px rgba(139,92,246,0.4);
}
.timeline-version { font-size: 1.3rem; font-weight: 700; }
.timeline-date { font-size: 0.85rem; color: var(--text-tertiary); margin-left: 12px; }
.changelog-list { margin-top: 16px; }
.changelog-list li {
  padding: 6px 0;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.changelog-tag {
  display: inline-block;
  padding: 2px 8px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 4px;
  flex-shrink: 0;
  margin-top: 2px;
}
.tag-new { background: rgba(16,185,129,0.15); color: var(--emerald); }
.tag-fix { background: rgba(251,191,36,0.15); color: var(--gold); }
.tag-improve { background: rgba(99,102,241,0.15); color: #818cf8; }
.tag-security { background: rgba(244,63,94,0.15); color: var(--rose); }

/* ---------- FAQ ---------- */
.faq-item {
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: all var(--dur-fast) var(--ease-out);
  background: var(--bg-card);
}
.faq-item.open { border-color: var(--border-hover); background: var(--bg-card-hover); }
.faq-question {
  width: 100%;
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
  transition: color var(--dur-fast);
}
.faq-question:hover { color: var(--violet); }
.faq-icon {
  width: 24px; height: 24px;
  flex-shrink: 0;
  transition: transform var(--dur-base) var(--ease-out);
}
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--dur-base) var(--ease-out), padding var(--dur-base);
}
.faq-item.open .faq-answer { max-height: 500px; padding: 0 24px 24px; }
.faq-answer p { color: var(--text-secondary); line-height: 1.7; }

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-tertiary);
  padding: 100px 0 0;
}
.breadcrumb a:hover { color: var(--violet); }
.breadcrumb-sep { opacity: 0.5; }
.breadcrumb-current { color: var(--text-secondary); }

/* ---------- Page Hero (subpages) ---------- */
.page-hero {
  padding: 60px 0 80px;
  text-align: center;
  position: relative;
}
.page-hero h1 { margin-bottom: 20px; }
.page-hero .lead { max-width: 620px; margin: 0 auto; }

/* ---------- Step Cards ---------- */
.step-card {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  padding: 32px;
}
.step-num {
  width: 48px; height: 48px;
  border-radius: 50%;
  background: var(--grad-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
  box-shadow: var(--shadow-glow);
}

/* ---------- Security Shield ---------- */
.shield-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

/* ---------- Stats Bar ---------- */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  padding: 48px;
  border-radius: var(--radius-lg);
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  backdrop-filter: blur(20px);
}
.stat-item { text-align: center; }
.stat-num {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-label { font-size: 0.9rem; color: var(--text-tertiary); margin-top: 4px; }

/* ---------- CTA Section ---------- */
.cta-section {
  text-align: center;
  padding: 80px 48px;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, rgba(99,102,241,0.08), rgba(139,92,246,0.05));
  border: 1px solid var(--border-default);
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: "";
  position: absolute;
  top: -50%; left: 50%;
  width: 600px; height: 600px;
  transform: translateX(-50%);
  background: radial-gradient(circle, rgba(139,92,246,0.1), transparent 60%);
  filter: blur(40px);
}
.cta-section h2 { position: relative; z-index: 1; }
.cta-section .lead { position: relative; z-index: 1; max-width: 500px; margin: 16px auto 32px; }
.cta-section .hero-actions { position: relative; z-index: 1; justify-content: center; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 32px;
  position: relative;
  z-index: 1;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand p { margin-top: 16px; font-size: 0.9rem; max-width: 280px; }
.footer-col h4 { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-tertiary); margin-bottom: 16px; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color var(--dur-fast);
}
.footer-col ul li a:hover { color: var(--violet); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.85rem;
  color: var(--text-tertiary);
}
.footer-social { display: flex; gap: 12px; }
.footer-social a {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--dur-fast);
}
.footer-social a:hover { background: var(--bg-glass-strong); border-color: var(--border-hover); transform: translateY(-2px); }
.footer-social svg { width: 18px; height: 18px; }

/* ---------- Floating Contact ---------- */
.floating-contact {
  position: fixed;
  right: 24px; bottom: 24px;
  z-index: 900;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.floating-btn {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: var(--grad-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md), var(--shadow-glow);
  transition: all var(--dur-base) var(--ease-spring);
  cursor: pointer;
}
.floating-btn:hover { transform: scale(1.1); }
.floating-btn svg { width: 24px; height: 24px; color: #fff; }
.floating-panel {
  position: absolute;
  bottom: 72px; right: 0;
  width: 300px;
  padding: 24px;
  border-radius: var(--radius-lg);
  background: rgba(13, 13, 24, 0.95);
  backdrop-filter: blur(24px);
  border: 1px solid var(--border-default);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(10px) scale(0.95);
  pointer-events: none;
  transition: all var(--dur-base) var(--ease-out);
}
.floating-panel.open { opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }
.floating-panel h4 { margin-bottom: 12px; }
.floating-panel .contact-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.9rem;
}
.floating-panel .contact-row:first-of-type { border-top: none; }
.floating-panel .copy-wechat-btn {
  margin-left: auto;
  background: rgba(139,92,246,0.12);
  border: 1px solid rgba(139,92,246,0.25);
  color: #a78bfa;
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  transition: all 0.2s;
  line-height: 1;
  white-space: nowrap;
}
.floating-panel .copy-wechat-btn:hover {
  background: rgba(139,92,246,0.25);
  border-color: rgba(139,92,246,0.5);
  color: #c4b5fd;
}
.floating-panel .copy-wechat-btn svg { flex-shrink: 0; }

/* ---------- Code Block ---------- */
.code-block {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  overflow-x: auto;
  color: var(--text-secondary);
}
.code-block .token-keyword { color: #c084fc; }
.code-block .token-string { color: #fbbf24; }
.code-block .token-comment { color: var(--text-tertiary); }

/* ---------- Table ---------- */
.table-wrap { overflow-x: auto; border-radius: var(--radius-lg); border: 1px solid var(--border-subtle); }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 16px 24px; text-align: left; }
th { background: var(--bg-glass); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-tertiary); font-weight: 600; }
td { border-top: 1px solid var(--border-subtle); color: var(--text-secondary); font-size: 0.95rem; }
tr:hover td { background: var(--bg-card); }

/* ---------- Scroll Reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ---------- 404 ---------- */
.error-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 24px;
}
.error-code {
  font-size: clamp(6rem, 20vw, 12rem);
  font-weight: 900;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
  letter-spacing: -0.05em;
}

/* ---------- Sitemap ---------- */
.sitemap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.sitemap-col h3 { margin-bottom: 16px; color: var(--violet); }
.sitemap-col ul li { margin-bottom: 8px; }
.sitemap-col ul li a { color: var(--text-secondary); transition: color var(--dur-fast); }
.sitemap-col ul li a:hover { color: var(--text-primary); }

/* ---------- Contact Form ---------- */
.form-group { margin-bottom: 20px; }
.form-label { display: block; font-size: 0.9rem; font-weight: 500; margin-bottom: 8px; color: var(--text-secondary); }
.form-input, .form-textarea {
  width: 100%;
  padding: 14px 18px;
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 1rem;
  transition: all var(--dur-fast);
  backdrop-filter: blur(12px);
}
.form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--violet);
  background: var(--bg-glass-strong);
  box-shadow: 0 0 0 3px rgba(139,92,246,0.1);
}
.form-textarea { min-height: 140px; resize: vertical; }

/* ---------- Tabs ---------- */
.tabs { display: flex; gap: 8px; margin-bottom: 32px; flex-wrap: wrap; }
.tab {
  padding: 10px 24px;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  transition: all var(--dur-fast);
  cursor: pointer;
}
.tab.active { background: var(--grad-brand); color: #fff; border-color: transparent; }
.tab:hover:not(.active) { color: var(--text-primary); border-color: var(--border-hover); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: 32px; left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 14px 28px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  color: var(--text-primary);
  box-shadow: var(--shadow-lg);
  z-index: 2000;
  opacity: 0;
  transition: all var(--dur-base) var(--ease-spring);
}
.toast.show { transform: translateX(-50%) translateY(0); opacity: 1; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  :root { --section-pad: 70px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .app-showcase { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .sitemap-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --section-pad: 50px; }
  .nav-links, .nav-cta .btn { display: none; }
  .nav-toggle { display: flex; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .shield-grid { grid-template-columns: 1fr; }
  .hero { min-height: auto; padding: 100px 0 60px; }
  .hero-stats { gap: 24px; }
  .hero-stat-num { font-size: 1.8rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
  .cta-section { padding: 48px 24px; }
  .step-card { flex-direction: column; gap: 16px; }
  .timeline { padding-left: 28px; }
  .sitemap-grid { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: 1fr 1fr; padding: 32px; }
  .glass-card { padding: 24px; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
  .footer-grid { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: 1fr; }
  .nav-inner { padding: 0 16px; }
}