/* ========================================
   Quickq App — Aurora Gradient Theme
   极光渐变 · 简约精美 · 极致体验
   ======================================== */

/* --- Design Tokens --- */
:root {
  --primary: #6366F1;
  --primary-light: #818CF8;
  --primary-dark: #4F46E5;
  --accent: #EC4899;
  --violet: #8B5CF6;
  --gradient: linear-gradient(135deg, #6366F1 0%, #8B5CF6 50%, #EC4899 100%);
  --gradient-subtle: linear-gradient(135deg, #EEF2FF 0%, #F5F3FF 50%, #FDF2F8 100%);
  --gradient-hero: linear-gradient(135deg, #1E1B4B 0%, #312E81 30%, #4C1D95 60%, #701A75 100%);

  --bg: #FAFAFA;
  --surface: #FFFFFF;
  --surface-2: #F9FAFB;
  --text: #111827;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;
  --border: #E5E7EB;
  --border-light: #F3F4F6;

  --radius: 16px;
  --radius-sm: 10px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06);
  --shadow: 0 4px 16px rgba(0,0,0,.06);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.08);
  --shadow-glow: 0 8px 32px rgba(99,102,241,.18);

  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --max-w: 1120px;
  --header-h: 64px;
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
}
a { color: var(--primary); text-decoration: none; transition: color .2s; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

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

/* --- Header --- */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--header-h);
  background: rgba(255,255,255,.82);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  transition: box-shadow .3s;
}
.header.scrolled { box-shadow: var(--shadow-sm); }
.header-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 100%;
}
.header-brand {
  display: flex; align-items: center; gap: 8px;
  font-size: 1.25rem; font-weight: 800; color: var(--text);
  text-decoration: none;
}
.header-brand .brand-icon {
  width: 32px; height: 32px; border-radius: 8px;
  background: var(--gradient); display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: .9rem; font-weight: 700;
}
.header-brand .brand-sub { font-weight: 400; color: var(--text-secondary); font-size: .85rem; }

.header-nav { display: flex; align-items: center; gap: 4px; }
.header-nav a {
  padding: 6px 14px; border-radius: 8px; font-size: .875rem; font-weight: 500;
  color: var(--text-secondary); transition: all .2s;
}
.header-nav a:hover { color: var(--text); background: var(--surface-2); }
.nav-cta {
  background: var(--gradient) !important; color: #fff !important;
  padding: 8px 20px !important; border-radius: 10px !important; font-weight: 600 !important;
  box-shadow: var(--shadow-glow);
}
.nav-cta:hover { opacity: .92; color: #fff !important; transform: translateY(-1px); }

.menu-toggle {
  display: none; background: none; border: none; cursor: pointer;
  width: 36px; height: 36px; position: relative;
}
.menu-toggle span {
  display: block; width: 20px; height: 2px; background: var(--text);
  border-radius: 2px; position: absolute; left: 8px;
  transition: all .3s;
}
.menu-toggle span:nth-child(1) { top: 10px; }
.menu-toggle span:nth-child(2) { top: 17px; }
.menu-toggle span:nth-child(3) { top: 24px; }
.menu-toggle.active span:nth-child(1) { top: 17px; transform: rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { top: 17px; transform: rotate(-45deg); }

.mobile-nav {
  display: none; position: fixed; top: var(--header-h); left: 0; right: 0;
  background: rgba(255,255,255,.96); backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px; z-index: 999;
}
.mobile-nav.open { display: flex; flex-direction: column; gap: 4px; }
.mobile-nav a {
  padding: 12px 16px; border-radius: 10px; font-size: .95rem;
  color: var(--text-secondary); font-weight: 500;
}
.mobile-nav a:hover { background: var(--surface-2); color: var(--text); }

/* --- Hero --- */
.hero {
  position: relative; overflow: hidden;
  padding: 140px 0 80px;
  background: var(--gradient-hero);
  color: #fff;
}
.hero::before {
  content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle at 30% 40%, rgba(139,92,246,.3) 0%, transparent 50%),
              radial-gradient(circle at 70% 60%, rgba(236,72,153,.2) 0%, transparent 50%);
  animation: aurora 8s ease-in-out infinite alternate;
}
@keyframes aurora {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-3%, 2%) scale(1.05); }
}
.hero .container { position: relative; z-index: 1; }
.hero-badge {
  display: inline-block; padding: 6px 16px; border-radius: 20px;
  background: rgba(255,255,255,.12); backdrop-filter: blur(8px);
  font-size: .8rem; font-weight: 600; letter-spacing: .04em;
  margin-bottom: 20px; border: 1px solid rgba(255,255,255,.15);
}
.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 800;
  line-height: 1.15; letter-spacing: -.02em; margin-bottom: 20px;
}
.hero-title .hl {
  background: linear-gradient(90deg, #C7D2FE, #E9D5FF, #FBCFE8);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: 1.1rem; line-height: 1.7; color: rgba(255,255,255,.78);
  max-width: 520px; margin-bottom: 32px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* --- Buttons --- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 24px; border-radius: var(--radius-sm); font-size: .9rem;
  font-weight: 600; border: none; cursor: pointer; transition: all .25s;
  text-decoration: none; font-family: inherit;
}
.btn-primary {
  background: var(--gradient); color: #fff;
  box-shadow: var(--shadow-glow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 40px rgba(99,102,241,.28); color: #fff; }
.btn-outline {
  background: rgba(255,255,255,.1); color: #fff;
  border: 1px solid rgba(255,255,255,.2);
}
.btn-outline:hover { background: rgba(255,255,255,.18); color: #fff; }
.btn-lg { padding: 14px 32px; font-size: 1rem; border-radius: 12px; }
.btn-dark { background: var(--text); color: #fff; }
.btn-dark:hover { background: #1F2937; color: #fff; transform: translateY(-2px); }

/* --- Sections --- */
.section { padding: 80px 0; }
.section-alt { background: var(--surface); }
.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 800;
  letter-spacing: -.02em; margin-bottom: 12px; text-align: center;
}
.section-desc {
  text-align: center; color: var(--text-secondary); font-size: .95rem;
  max-width: 560px; margin: 0 auto 48px;
}
.section-tag {
  display: inline-block; padding: 4px 12px; border-radius: 6px;
  background: var(--gradient-subtle); color: var(--primary);
  font-size: .75rem; font-weight: 700; letter-spacing: .06em;
  text-transform: uppercase; margin-bottom: 12px; text-align: center;
}

/* --- Cards --- */
.card {
  background: var(--surface); border-radius: var(--radius);
  padding: 28px; border: 1px solid var(--border-light);
  transition: all .3s;
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: transparent; }
.card-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--gradient-subtle); display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; margin-bottom: 16px;
}
.card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--text-secondary); font-size: .88rem; line-height: 1.65; }

/* --- Feature Grid --- */
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.features-grid .card { padding: 32px 28px; }

/* --- Stats --- */
.stats-row {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
  margin: 48px 0;
}
.stat-item { text-align: center; }
.stat-num {
  font-size: clamp(1.8rem, 3vw, 2.5rem); font-weight: 800;
  background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-label { color: var(--text-secondary); font-size: .85rem; margin-top: 4px; }

/* --- Steps --- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.step { text-align: center; padding: 32px 20px; }
.step-num {
  width: 48px; height: 48px; border-radius: 50%; margin: 0 auto 16px;
  background: var(--gradient); color: #fff; font-weight: 800; font-size: 1.1rem;
  display: flex; align-items: center; justify-content: center;
}
.step h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.step p { color: var(--text-secondary); font-size: .85rem; }

/* --- Platforms --- */
.platforms-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.platform-card {
  text-align: center; padding: 28px 16px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border-light);
  transition: all .3s; text-decoration: none; color: inherit;
}
.platform-card:hover { box-shadow: var(--shadow); transform: translateY(-4px); border-color: var(--primary-light); }
.platform-card .icon { font-size: 2rem; margin-bottom: 12px; }
.platform-card h4 { font-size: .95rem; font-weight: 600; margin-bottom: 4px; }
.platform-card p { font-size: .8rem; color: var(--text-muted); }

/* --- CTA Box --- */
.cta-box {
  text-align: center; padding: 56px 40px; border-radius: var(--radius-lg);
  background: var(--gradient-hero); color: #fff; position: relative; overflow: hidden;
}
.cta-box::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 20% 50%, rgba(139,92,246,.3) 0%, transparent 50%);
}
.cta-box > * { position: relative; }
.cta-box h2 { font-size: 1.6rem; font-weight: 800; margin-bottom: 12px; letter-spacing: -.01em; }
.cta-box p { color: rgba(255,255,255,.78); margin-bottom: 24px; font-size: .95rem; }

/* --- Compare Table --- */
.compare-table {
  width: 100%; border-collapse: separate; border-spacing: 0;
  font-size: .88rem; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--border);
}
.compare-table th {
  background: var(--surface-2); font-weight: 700; padding: 12px 16px;
  text-align: left; border-bottom: 2px solid var(--border);
}
.compare-table td {
  padding: 11px 16px; border-bottom: 1px solid var(--border-light);
  color: var(--text-secondary);
}
.compare-table tr:last-child td { border-bottom: none; }
.compare-table tr:hover td { background: var(--gradient-subtle); }
.compare-table .check { color: #22C55E; font-weight: 700; }
.compare-table .cross { color: #EF4444; }

/* --- FAQ --- */
.faq-item {
  border: 1px solid var(--border-light); border-radius: var(--radius-sm);
  margin-bottom: 10px; overflow: hidden; transition: all .3s;
}
.faq-item[open] { border-color: var(--primary-light); box-shadow: var(--shadow-sm); }
.faq-item summary {
  padding: 16px 20px; font-weight: 600; cursor: pointer; font-size: .92rem;
  display: flex; align-items: center; justify-content: space-between;
  list-style: none; transition: color .2s;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; font-size: 1.2rem; font-weight: 300; color: var(--primary); transition: transform .3s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item[open] summary { color: var(--primary); }
.faq-answer { padding: 0 20px 16px; color: var(--text-secondary); font-size: .88rem; line-height: 1.75; }

/* --- Friend Links (SEO) --- */
.friend-links { padding: 40px 0; border-top: 1px solid var(--border-light); }
.friend-links h3 { font-size: .85rem; font-weight: 600; color: var(--text-muted); margin-bottom: 12px; }
.friend-links-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.friend-link {
  padding: 5px 14px; border-radius: 6px; font-size: .8rem;
  background: var(--surface-2); color: var(--text-secondary); border: 1px solid var(--border-light);
  transition: all .2s;
}
.friend-link:hover { color: var(--primary); border-color: var(--primary-light); background: var(--gradient-subtle); }

/* --- Footer --- */
.footer {
  background: var(--gradient-hero); color: rgba(255,255,255,.7);
  padding: 56px 0 24px; margin-top: 0;
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
  margin-bottom: 40px;
}
.footer-brand h3 { font-size: 1.2rem; font-weight: 800; color: #fff; margin-bottom: 8px; }
.footer-brand p { font-size: .85rem; line-height: 1.6; }
.footer-col h4 { font-size: .85rem; font-weight: 700; color: #fff; margin-bottom: 14px; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul a { color: rgba(255,255,255,.6); font-size: .85rem; transition: color .2s; }
.footer-col ul a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: 20px;
  font-size: .8rem; color: rgba(255,255,255,.4); text-align: center;
}

/* --- Download Modal --- */
.modal-overlay {
  display: none; position: fixed; inset: 0; z-index: 2000;
  background: rgba(0,0,0,.45); backdrop-filter: blur(4px);
  align-items: center; justify-content: center;
}
.modal-overlay.active { display: flex; }
.modal {
  background: var(--surface); border-radius: var(--radius-lg);
  padding: 40px; max-width: 420px; width: 90%; text-align: center;
  box-shadow: var(--shadow-lg); animation: modalIn .3s ease;
}
@keyframes modalIn { from { opacity: 0; transform: scale(.92); } to { opacity: 1; transform: scale(1); } }
.modal-icon { font-size: 3rem; margin-bottom: 16px; }
.modal h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 8px; }
.modal p { color: var(--text-secondary); font-size: .88rem; margin-bottom: 24px; line-height: 1.6; }
.modal-actions { display: flex; gap: 10px; justify-content: center; }
.modal-actions .btn { min-width: 120px; }

/* --- Scroll Top --- */
#scrollTop {
  position: fixed; bottom: 24px; right: 24px; z-index: 900;
  width: 44px; height: 44px; border-radius: 12px;
  background: var(--gradient); color: #fff; border: none;
  font-size: 1rem; cursor: pointer; opacity: 0; transform: translateY(10px);
  transition: all .3s; box-shadow: var(--shadow-glow);
}
#scrollTop.visible { opacity: 1; transform: translateY(0); }
#scrollTop:hover { transform: translateY(-2px); }

/* --- Fade In --- */
.fade-in { opacity: 0; transform: translateY(24px); transition: all .6s cubic-bezier(.22,1,.36,1); }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* --- Info Box --- */
.info-box {
  padding: 16px 20px; border-radius: var(--radius-sm);
  background: var(--gradient-subtle); border-left: 3px solid var(--primary);
  font-size: .88rem; color: var(--text-secondary); line-height: 1.7;
}

/* --- Inner Page Hero --- */
.page-hero {
  padding: 120px 0 48px;
  background: var(--gradient-hero); color: #fff; position: relative; overflow: hidden;
}
.page-hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 60% 30%, rgba(139,92,246,.25) 0%, transparent 50%);
}
.page-hero .container { position: relative; }
.page-hero .hero-badge { margin-bottom: 12px; }
.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem); font-weight: 800;
  letter-spacing: -.02em; margin-bottom: 12px;
}
.page-hero h1 .hl {
  background: linear-gradient(90deg, #C7D2FE, #E9D5FF, #FBCFE8);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.page-hero p { color: rgba(255,255,255,.7); font-size: .95rem; max-width: 540px; }

/* --- Responsive --- */
@media (max-width: 900px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-row { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .platforms-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
}
@media (max-width: 640px) {
  .header-nav { display: none; }
  .menu-toggle { display: block; }
  .features-grid { grid-template-columns: 1fr; }
  .stats-row { grid-template-columns: 1fr 1fr; }
  .platforms-grid { grid-template-columns: 1fr 1fr; }
  .hero { padding: 120px 0 60px; }
  .hero-title { font-size: 2rem; }
  .section { padding: 56px 0; }
  .footer-grid { grid-template-columns: 1fr; gap: 20px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}