/* ===== Doubao Download Page ===== */
:root {
  --brand: #0066FF;
  --brand-hover: #005AE0;
  --accent: #007AFF;
  --text-1: rgba(0,0,0,0.95);
  --text-2: rgba(0,0,0,0.70);
  --text-3: rgba(0,0,0,0.50);
  --bg: #FFFFFF;
  --card-grad: linear-gradient(285deg, #F8F3EE -3.93%, #FFFFFF 50.17%, #EBF0F6 103.2%);
  --border: #ECECEC;
  --nav-shadow: 0 4px 7px rgba(37,50,59,0.12);
  --pill: 15px;
  --card: 12px;
  --font: -apple-system, BlinkMacSystemFont, "Inter", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; }
body {
  font-family: var(--font); background: var(--bg);
  color: var(--text-1); line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* Navbar — floating pill */
.navbar {
  position: fixed; top: 24px; left: 50%; transform: translateX(-50%);
  z-index: 1000; background: rgba(255,255,255,0.64);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border: 1px solid #FFF; border-radius: var(--pill);
  box-shadow: var(--nav-shadow); padding: 4px 6px;
  display: flex; align-items: center;
}
.nav-item {
  display: flex; align-items: center; justify-content: center;
  padding: 6px 20px; border-radius: var(--pill);
  font-size: 14px; font-weight: 500; color: #3F4A5B;
  text-decoration: none; cursor: pointer; transition: all 0.2s;
  white-space: nowrap;
}
.nav-item:hover { background: #FFF; color: var(--brand); }
.nav-item.active { background: var(--accent); color: #FAFAFA; }
.nav-item.active:hover { background: var(--brand-hover); color: #FAFAFA; }
.nav-logo-dot {
  width: 28px; height: 28px; background: var(--brand);
  border-radius: 8px; display: flex; align-items: center;
  justify-content: center; color: #FFF; font-weight: 700;
  font-size: 16px; margin-right: 8px;
}

/* Hero */
.hero { padding: 160px 0 50px; text-align: center; }
.hero-badge {
  display: inline-block;
  background: linear-gradient(135deg, rgba(0,102,255,0.08), rgba(0,122,255,0.08));
  color: var(--brand); padding: 6px 16px; border-radius: 20px;
  font-size: 13px; font-weight: 600; margin-bottom: 24px;
}
.hero h1 {
  font-size: 46px; font-weight: 700; letter-spacing: -0.92px;
  line-height: 1.1; margin-bottom: 8px;
}
.hero h1 .brand-text {
  background: linear-gradient(135deg, #0066FF, #007AFF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 20px; color: var(--text-2); max-width: 790px;
  margin: 8px auto 40px; letter-spacing: -0.4px; line-height: 1.2;
}

/* Version tabs */
.ver-tabs {
  display: inline-flex; background: rgba(0,0,0,0.04);
  border-radius: var(--pill); padding: 4px; margin-bottom: 40px;
}
.ver-tab {
  padding: 10px 28px; border-radius: var(--pill);
  font-size: 16px; font-weight: 500; color: var(--text-2);
  cursor: pointer; transition: all 0.2s; border: none;
  background: none; font-family: var(--font);
}
.ver-tab:hover { color: var(--text-1); }
.ver-tab.active {
  background: #FFF; color: var(--text-1); font-weight: 600;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

/* Download button */
.dl-btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; background: var(--accent); color: #FFF;
  padding: 14px 48px; border-radius: var(--pill);
  font-size: 17px; font-weight: 600; text-decoration: none;
  border: none; cursor: pointer; transition: all 0.2s;
  font-family: var(--font); min-width: 260px;
}
.dl-btn:hover { background: var(--brand-hover); transform: scale(1.02); }
.dl-btn:active { background: #0047B3; }
.dl-hint { margin-top: 12px; font-size: 14px; color: var(--text-3); }

/* Sections */
.section { padding: 80px 0; }
.sec-head {
  text-align: center; font-size: 46px; font-weight: 600;
  letter-spacing: -0.92px; line-height: 1.1; margin-bottom: 16px;
}
.sec-sub {
  text-align: center; color: var(--text-2); font-size: 20px;
  margin-bottom: 50px; letter-spacing: -0.4px;
}

/* Feature cards with gradient */
.feat-list { display: flex; flex-direction: column; gap: 16px; max-width: 790px; margin: 0 auto; }
.feat-card {
  display: flex; align-items: center; gap: 60px;
  background: var(--card-grad); border: 1px solid var(--border);
  border-radius: var(--card); padding: 0 72px; height: 160px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.feat-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.06); }
.feat-left { flex: 1; display: flex; flex-direction: column; gap: 8px; }
.feat-left h3 { font-size: 46px; font-weight: 600; letter-spacing: -0.92px; line-height: 1.2; }
.feat-left p { font-size: 20px; color: var(--text-2); letter-spacing: -0.4px; line-height: 1.6; }
.feat-right {
  flex-shrink: 0; width: 290px; height: 82px;
  border-radius: 10px; background: rgba(0,102,255,0.06);
  display: flex; align-items: center; justify-content: center;
  font-size: 36px;
}

/* Requirements */
.req-sec { background: #F8F9FA; padding: 80px 0; }
.req-grid { display: flex; justify-content: center; gap: 24px; max-width: 800px; margin: 0 auto; }
.req-card {
  flex: 1; background: #FFF; border-radius: var(--card);
  padding: 32px; border: 1px solid var(--border);
}
.req-card h3 { font-size: 24px; font-weight: 600; margin-bottom: 20px; }
.req-row { display: flex; justify-content: space-between; padding: 10px 0; font-size: 16px; border-bottom: 1px solid #F0F0F0; }
.req-row:last-child { border-bottom: none; }
.req-label { color: var(--text-3); }
.req-value { color: var(--text-1); font-weight: 500; }

/* FAQ */
.faq-list { max-width: 790px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  padding: 20px 0; font-size: 20px; font-weight: 500;
  cursor: pointer; display: flex; justify-content: space-between;
  align-items: center; user-select: none; transition: color 0.2s;
}
.faq-q:hover { color: var(--brand); }
.faq-q::after { content: '+'; font-size: 24px; font-weight: 300; color: var(--text-3); transition: transform 0.3s; }
.faq-item.open .faq-q::after { content: '−'; transform: rotate(90deg); }
.faq-a { font-size: 16px; color: var(--text-2); line-height: 1.7; padding-bottom: 20px; display: none; }
.faq-item.open .faq-a { display: block; }

/* CTA */
.cta-sec { text-align: center; padding: 80px 0; background: linear-gradient(180deg, #F0F5FF, #FFF); }
.cta-sec h2 { font-size: 46px; font-weight: 600; letter-spacing: -0.92px; margin-bottom: 12px; }
.cta-sec p { font-size: 20px; color: var(--text-2); margin-bottom: 40px; }

/* Footer */
.footer { background: #1A1C20; color: #8E8E93; padding: 60px 0 30px; }
.footer a { color: #8E8E93; text-decoration: none; transition: color 0.2s; font-size: 14px; }
.footer a:hover { color: #FFF; }
.footer-grid { display: flex; gap: 80px; margin-bottom: 40px; flex-wrap: wrap; }
.footer-brand { max-width: 300px; }
.footer-brand h4 { color: #FFF; font-size: 16px; margin-bottom: 10px; }
.footer-brand p { font-size: 14px; line-height: 1.6; }
.footer-col h4 { color: #FFF; font-size: 13px; font-weight: 600; margin-bottom: 14px; text-transform: uppercase; letter-spacing: 0.05em; }
.footer-col a { display: block; margin-bottom: 10px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding-top: 24px; display: flex; justify-content: space-between; font-size: 13px; flex-wrap: wrap; gap: 12px; }

@media (max-width: 768px) {
  .hero h1 { font-size: 32px; } .hero-desc { font-size: 16px; }
  .sec-head { font-size: 32px; }
  .feat-card { flex-direction: column; height: auto; padding: 24px; gap: 20px; }
  .feat-left h3 { font-size: 28px; } .feat-left p { font-size: 16px; }
  .feat-right { width: 100%; height: 180px; }
  .req-grid { flex-direction: column; }
  .footer-grid { flex-direction: column; gap: 32px; }
  .navbar { top: 12px; }
  .nav-item { padding: 6px 12px; font-size: 12px; }
}
@media (max-width: 480px) {
  .hero h1 { font-size: 28px; }
  .dl-btn { padding: 12px 32px; font-size: 15px; min-width: auto; }
}