/* ===========================================================================
   Briefing — marketing site styles
   Palette derived from the app icon (upward line chart + bars)
   =========================================================================== */

:root {
  --navy: #0e2a47;
  --blue: #2f63f6;
  --blue-deep: #1f4fe0;
  --teal: #19b6bd;
  --cyan: #4fd1d6;
  --sky: #7aa5f0;
  --orange: #f5a623;
  --orange-soft: #ffb74d;

  --ink: #0e1b2e;
  --muted: #5a6b82;
  --line: rgba(14, 42, 71, 0.10);
  --line-soft: rgba(14, 42, 71, 0.06);

  --bg: #eef4fc;
  --bg-2: #e3edfa;
  --card: rgba(255, 255, 255, 0.72);
  --card-solid: #ffffff;

  --radius: 18px;
  --radius-lg: 26px;
  --shadow-sm: 0 1px 2px rgba(14, 42, 71, 0.06), 0 4px 14px rgba(14, 42, 71, 0.06);
  --shadow: 0 10px 30px rgba(14, 42, 71, 0.10), 0 2px 8px rgba(14, 42, 71, 0.06);
  --shadow-lg: 0 30px 70px rgba(14, 42, 71, 0.18), 0 8px 24px rgba(14, 42, 71, 0.08);

  --maxw: 1120px;
  --gut: 24px;

  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
    "Helvetica Neue", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  line-height: 1.65;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(79, 209, 214, 0.18), transparent 60%),
    radial-gradient(1000px 560px at -5% 0%, rgba(122, 165, 240, 0.22), transparent 55%),
    linear-gradient(180deg, var(--bg-2), var(--bg) 30%, #f4f8fd);
  background-attachment: fixed;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue-deep); text-decoration: none; }
a:hover { text-decoration: underline; }

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

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gut);
}

/* ---- Language toggle visibility ------------------------------------------ */
html.lang-zh .en { display: none !important; }
html.lang-en .zh { display: none !important; }

/* ---- Navigation ---------------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(160%) blur(18px);
  -webkit-backdrop-filter: saturate(160%) blur(18px);
  background: rgba(238, 244, 252, 0.72);
  border-bottom: 1px solid var(--line-soft);
}
.nav-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 8px; box-shadow: var(--shadow-sm); }
.nav-links {
  display: flex;
  gap: 26px;
  margin-left: 14px;
}
.nav-links a {
  color: var(--muted);
  font-size: 15px;
  font-weight: 500;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-spacer { flex: 1; }

.lang-btn {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--ink);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  padding: 7px 13px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.lang-btn:hover { background: #fff; border-color: var(--blue); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font: inherit;
  font-weight: 600;
  font-size: 15px;
  padding: 11px 20px;
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.15s, box-shadow 0.2s, background 0.2s;
  white-space: nowrap;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(135deg, var(--blue), var(--blue-deep));
  color: #fff;
  box-shadow: 0 8px 22px rgba(47, 99, 246, 0.35);
}
.btn-primary:hover { box-shadow: 0 12px 28px rgba(47, 99, 246, 0.45); }
.btn-ghost {
  background: var(--card);
  color: var(--ink);
  border-color: var(--line);
}
.btn-ghost:hover { background: #fff; border-color: var(--blue); }
.btn-sm { padding: 8px 15px; font-size: 14px; }

/* ---- Hero ---------------------------------------------------------------- */
.hero {
  padding: 76px 0 40px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
}
.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-deep);
  background: rgba(47, 99, 246, 0.10);
  border: 1px solid rgba(47, 99, 246, 0.18);
  padding: 6px 13px;
  border-radius: 999px;
  margin-bottom: 22px;
}
.pill .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--teal); }
h1.hero-title {
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  font-weight: 800;
}
.grad {
  background: linear-gradient(120deg, var(--blue) 10%, var(--teal) 60%, var(--orange));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  font-size: clamp(16px, 2vw, 19px);
  color: var(--muted);
  margin: 0 0 30px;
  max-width: 540px;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 13px; align-items: center; }
.hero-note { font-size: 13px; color: var(--muted); margin-top: 16px; }
.hero-note b { color: var(--ink); }

/* ---- App window mockup --------------------------------------------------- */
.mock {
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  overflow: hidden;
  transform: perspective(1400px) rotateY(-8deg) rotateX(3deg);
  transition: transform 0.5s ease;
}
.mock:hover { transform: perspective(1400px) rotateY(0deg) rotateX(0deg); }
.mock-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.5);
  border-bottom: 1px solid var(--line-soft);
}
.mock-bar .tl { width: 11px; height: 11px; border-radius: 50%; }
.tl.r { background: #ff6058; } .tl.y { background: #ffbd2e; } .tl.g { background: #28c940; }
.mock-bar .mock-title { margin-left: 8px; font-size: 13px; font-weight: 600; color: var(--muted); }
.mock-body { padding: 16px; display: flex; flex-direction: column; gap: 13px; }

.appcard {
  background: var(--card-solid);
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 14px;
  box-shadow: var(--shadow-sm);
}
.appcard-head { display: flex; align-items: center; gap: 12px; }
.appcard-ico {
  width: 44px; height: 44px; border-radius: 11px; flex: none;
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  box-shadow: var(--shadow-sm);
}
.appcard-ico.alt { background: linear-gradient(135deg, var(--orange-soft), var(--orange)); }
.appcard-name { font-weight: 700; font-size: 15px; }
.appcard-meta { font-size: 12.5px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
.stars { color: var(--orange); letter-spacing: 1px; font-size: 12px; }
.reddot { width: 7px; height: 7px; border-radius: 50%; background: #ff5a52; display: inline-block; }

.badges { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.badge {
  font-size: 12px; font-weight: 600;
  padding: 5px 10px; border-radius: 9px;
  display: inline-flex; align-items: center; gap: 6px;
}
.badge .k { color: var(--muted); font-weight: 500; }
.badge.b1 { background: rgba(25, 182, 189, 0.12); color: #0d7e83; }
.badge.b2 { background: rgba(47, 99, 246, 0.10); color: var(--blue-deep); }
.badge.b3 { background: rgba(245, 166, 35, 0.14); color: #b9740a; }

/* mini chart */
.spark { margin-top: 14px; display: flex; align-items: flex-end; gap: 5px; height: 46px; }
.spark span {
  flex: 1; border-radius: 4px 4px 2px 2px;
  background: linear-gradient(180deg, var(--sky), var(--blue));
  opacity: 0.85;
}
.spark span:nth-child(4) { background: linear-gradient(180deg, var(--orange-soft), var(--orange)); }

/* ---- Section scaffolding ------------------------------------------------- */
section { padding: 56px 0; }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 44px; }
.kicker {
  font-size: 13px; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--teal); margin-bottom: 12px;
}
h2.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  font-weight: 800;
}
.section-sub { color: var(--muted); font-size: 17px; margin: 0; }

/* ---- Feature grid -------------------------------------------------------- */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature {
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.feature:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: rgba(47,99,246,0.2); }
.feature .ico {
  width: 46px; height: 46px; border-radius: 13px;
  display: grid; place-items: center; margin-bottom: 16px;
  font-size: 22px;
  background: linear-gradient(135deg, rgba(79,209,214,0.18), rgba(47,99,246,0.18));
}
.feature h3 { margin: 0 0 8px; font-size: 18px; font-weight: 700; }
.feature p { margin: 0; color: var(--muted); font-size: 15px; }

/* ---- Split detail rows --------------------------------------------------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 46px;
  align-items: center;
}
.split.rev .split-media { order: -1; }
.split + .split { margin-top: 40px; }
.split-text h3 { font-size: clamp(22px, 2.6vw, 28px); margin: 0 0 14px; font-weight: 800; letter-spacing: -0.01em; }
.split-text p { color: var(--muted); font-size: 16px; margin: 0 0 16px; }
.ticks { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.ticks li { display: flex; gap: 10px; align-items: flex-start; font-size: 15px; }
.ticks .ck {
  flex: none; width: 22px; height: 22px; border-radius: 50%;
  background: rgba(25,182,189,0.16); color: #0d7e83;
  display: grid; place-items: center; font-size: 13px; font-weight: 800; margin-top: 1px;
}

.media-card {
  background: var(--card);
  border: 1px solid rgba(255,255,255,0.7);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 22px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

/* big chart illustration */
.chart {
  height: 180px; display: flex; align-items: flex-end; gap: 10px; padding: 8px 4px 0;
  border-bottom: 1px solid var(--line); position: relative;
}
.chart .bar { flex: 1; border-radius: 6px 6px 3px 3px; background: linear-gradient(180deg, var(--sky), var(--blue)); position: relative; }
.chart .bar.o { background: linear-gradient(180deg, var(--orange-soft), var(--orange)); }
.chart-legend { display: flex; gap: 18px; margin-top: 14px; font-size: 13px; color: var(--muted); }
.chart-legend i { width: 10px; height: 10px; border-radius: 3px; display: inline-block; margin-right: 6px; vertical-align: middle; }

/* rating bars */
.ratingrow { display: flex; align-items: center; gap: 10px; margin: 9px 0; font-size: 13px; }
.ratingrow .lbl { width: 38px; color: var(--muted); }
.ratingrow .track { flex: 1; height: 8px; border-radius: 999px; background: rgba(14,42,71,0.08); overflow: hidden; }
.ratingrow .fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--teal), var(--blue)); }

/* ---- Privacy banner ------------------------------------------------------ */
.privacy-banner {
  background: linear-gradient(135deg, var(--navy), #14385e);
  border-radius: var(--radius-lg);
  padding: 48px;
  color: #eaf2ff;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}
.privacy-banner::after {
  content: "";
  position: absolute; right: -60px; top: -60px; width: 260px; height: 260px;
  background: radial-gradient(circle, rgba(79,209,214,0.35), transparent 70%);
}
.privacy-banner .kicker { color: var(--cyan); }
.privacy-banner h2 { color: #fff; font-size: clamp(24px, 3vw, 34px); margin: 0 0 14px; font-weight: 800; }
.privacy-banner p { color: rgba(234,242,255,0.78); font-size: 16px; max-width: 620px; margin: 0 0 26px; }
.privacy-points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; position: relative; }
.pp {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 14px; padding: 18px;
}
.pp .n { font-size: 22px; margin-bottom: 8px; }
.pp h4 { margin: 0 0 5px; font-size: 16px; color: #fff; }
.pp p { font-size: 13.5px; color: rgba(234,242,255,0.72); margin: 0; }

/* ---- FAQ ----------------------------------------------------------------- */
.faq { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq details {
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 4px 20px;
  box-shadow: var(--shadow-sm);
}
.faq summary {
  cursor: pointer; list-style: none; padding: 16px 0;
  font-weight: 600; font-size: 16px; display: flex; justify-content: space-between; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--blue); font-size: 22px; font-weight: 400; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin: 0 0 16px; color: var(--muted); font-size: 15px; }

/* ---- CTA ----------------------------------------------------------------- */
.cta-final { text-align: center; }
.cta-final h2 { font-size: clamp(26px, 3.4vw, 38px); margin: 0 0 14px; font-weight: 800; letter-spacing: -0.02em; }
.cta-final p { color: var(--muted); font-size: 17px; margin: 0 0 26px; }
.cta-final .hero-cta { justify-content: center; }

/* ---- Footer -------------------------------------------------------------- */
.footer {
  border-top: 1px solid var(--line);
  margin-top: 24px;
  padding: 40px 0 50px;
}
.footer-inner { display: flex; flex-wrap: wrap; gap: 24px; justify-content: space-between; align-items: flex-start; }
.footer .brand { font-size: 16px; }
.footer-tag { color: var(--muted); font-size: 14px; margin: 12px 0 0; max-width: 320px; }
.footer-cols { display: flex; gap: 56px; flex-wrap: wrap; }
.footer-col h5 { margin: 0 0 12px; font-size: 13px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
.footer-col a { display: block; color: var(--ink); font-size: 14.5px; margin-bottom: 9px; }
.footer-col a:hover { color: var(--blue-deep); }
.footer-bottom {
  margin-top: 34px; padding-top: 20px; border-top: 1px solid var(--line-soft);
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: space-between;
  color: var(--muted); font-size: 13px;
}

/* ---- Legal (privacy / terms) pages --------------------------------------- */
.legal { padding: 56px 0 30px; }
.legal-card {
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: clamp(28px, 5vw, 56px);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  max-width: 860px;
  margin: 0 auto;
}
.legal-card h1 { font-size: clamp(28px, 4vw, 40px); margin: 0 0 8px; font-weight: 800; letter-spacing: -0.02em; }
.legal-meta { color: var(--muted); font-size: 14px; margin: 0 0 28px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.legal-card h2 {
  font-size: 21px; font-weight: 700; margin: 34px 0 12px;
  scroll-margin-top: 80px;
}
.legal-card h2 .num { color: var(--blue); margin-right: 8px; }
.legal-card h3 { font-size: 17px; font-weight: 700; margin: 22px 0 8px; }
.legal-card p { color: #2a3a52; font-size: 15.5px; margin: 0 0 14px; }
.legal-card ul { margin: 0 0 16px; padding-left: 22px; }
.legal-card li { color: #2a3a52; font-size: 15.5px; margin-bottom: 8px; }
.legal-card strong { color: var(--ink); }
.legal-card a { font-weight: 500; }
.callout {
  background: rgba(47, 99, 246, 0.06);
  border: 1px solid rgba(47, 99, 246, 0.16);
  border-left: 4px solid var(--blue);
  border-radius: 12px;
  padding: 16px 18px;
  margin: 0 0 22px;
}
.callout p { margin: 0; font-size: 15px; }
.back-link { display: inline-flex; align-items: center; gap: 7px; font-size: 14px; margin-bottom: 22px; color: var(--muted); }
.back-link:hover { color: var(--blue-deep); text-decoration: none; }

/* ---- Responsive ---------------------------------------------------------- */
@media (max-width: 920px) {
  .hero { grid-template-columns: 1fr; gap: 36px; padding-top: 52px; }
  .mock { transform: none; max-width: 460px; }
  .mock:hover { transform: none; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .split, .split.rev { grid-template-columns: 1fr; gap: 26px; }
  .split.rev .split-media { order: 0; }
  .privacy-points { grid-template-columns: 1fr; }
  .nav-links { display: none; }
}
@media (max-width: 560px) {
  .features { grid-template-columns: 1fr; }
  .privacy-banner { padding: 30px 22px; }
  section { padding: 44px 0; }
  .footer-cols { gap: 30px; }
  .hero-cta { width: 100%; }
  .hero-cta .btn { flex: 1; justify-content: center; }
}

/* reduce motion */
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
  .mock { transform: none; }
}