:root {
  --bg: #ffffff;
  --bg-alt: #f6f8fc;
  --text: #1f2433;
  --text-soft: #5b6172;
  --primary: #4f46e5;
  --primary-2: #06b6d4;
  --border: #e6e9f2;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(31, 36, 51, 0.08);
  --max: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  /* 全部是系統字型 —— 這個站刻意不載入任何外部資源(見 README)。
     不要在這裡加 Noto Sans TC 之類的網路字型名稱:沒有對應的 @font-face
     或 <link> 的話它永遠不會生效,只會讓人誤以為有。 */
  font-family: "PingFang TC", "Microsoft JhengHei", "Heiti TC",
    -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}
.brand:hover { text-decoration: none; }
.nav-links { display: flex; flex-wrap: wrap; gap: 22px; }
.nav-links a { color: var(--text-soft); font-size: 0.95rem; }
.nav-links a:hover { color: var(--primary); text-decoration: none; }

/* Hero */
.hero {
  background: linear-gradient(180deg, var(--bg-alt), #ffffff);
  padding: 72px 0 64px;
}
.hero-inner {
  display: flex;
  align-items: center;
  gap: 48px;
}
.hero-text { flex: 1; }
.eyebrow {
  color: var(--primary);
  font-weight: 600;
  letter-spacing: 0.06em;
  margin: 0 0 12px;
  font-size: 0.9rem;
}
.hero h1 {
  font-size: 2.6rem;
  line-height: 1.25;
  margin: 0 0 18px;
  letter-spacing: -0.01em;
}
.lead {
  color: var(--text-soft);
  font-size: 1.1rem;
  max-width: 30em;
  margin: 0 0 28px;
}
.hero-art {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
}
.hero-art img {
  filter: drop-shadow(0 20px 40px rgba(79, 70, 229, 0.25));
}

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.98rem;
  transition: transform .12s ease, box-shadow .12s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-ghost {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}

/* Sections */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-alt); }
.section-title {
  font-size: 1.9rem;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}
.section-sub {
  color: var(--text-soft);
  margin: 0 0 36px;
}

/* App card */
.app-card {
  display: flex;
  gap: 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}
.app-icon {
  border-radius: 22px;
  flex: 0 0 auto;
  box-shadow: 0 8px 20px rgba(14, 165, 233, 0.25);
}
.app-info h3 {
  margin: 0 0 4px;
  font-size: 1.4rem;
}
.app-en {
  color: var(--text-soft);
  font-weight: 500;
  font-size: 1rem;
  margin-left: 6px;
}
.app-tagline {
  color: var(--primary);
  font-weight: 600;
  margin: 0 0 12px;
}
.app-desc { color: var(--text-soft); margin: 0 0 16px; }
.feature-list {
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 24px;
}
.feature-list li {
  position: relative;
  padding-left: 24px;
  color: var(--text);
}
.feature-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--primary-2);
  font-weight: 700;
}
.badge {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
}
.badge-soon {
  background: #eef2ff;
  color: var(--primary);
  border: 1px solid #dfe3ff;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-grid p { color: var(--text-soft); }
.values { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.values li {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
}
.values strong { color: var(--text); }
.values span { color: var(--text-soft); font-size: 0.95rem; }

/* Contact */
.contact-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 28px;
  box-shadow: var(--shadow);
  max-width: 560px;
}
.contact-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
}
.contact-row:last-child { border-bottom: none; }
.contact-label { color: var(--text-soft); font-weight: 600; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  background: #fff;
  padding: 36px 0;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}
.footer-links { display: flex; gap: 20px; }
.footer-links a { color: var(--text-soft); font-size: 0.92rem; }
.copyright { color: var(--text-soft); font-size: 0.9rem; margin: 0; width: 100%; }

/* Legal page */
.legal { padding: 56px 0 72px; }
.legal h1 { font-size: 2rem; margin: 0 0 6px; }
.legal .updated { color: var(--text-soft); margin: 0 0 32px; }
.legal h2 { font-size: 1.25rem; margin: 32px 0 10px; }
.legal p, .legal li { color: var(--text-soft); }
.legal ul { padding-left: 22px; }
.back-link { display: inline-block; margin-bottom: 24px; }

/* Responsive */
@media (max-width: 820px) {
  .hero-inner { flex-direction: column-reverse; text-align: center; }
  .hero-actions { justify-content: center; }
  .lead { margin-left: auto; margin-right: auto; }
  .hero-art img { width: 180px; height: 180px; }
  .hero h1 { font-size: 2.1rem; }
  .about-grid { grid-template-columns: 1fr; }

  /* 導覽列換到第二行,不要隱藏。只有 4 個連結,不值得為它加漢堡選單的 JS ——
     而藏起來的代價是手機上首頁完全找不到「隱私權政策」(只剩捲到頁尾),
     那正是 Google Play 審核人員最常用的裝置。 */
  .nav {
    height: auto;
    flex-wrap: wrap;
    padding-top: 12px;
    padding-bottom: 12px;
  }
  .nav-links {
    width: 100%;
    justify-content: center;
    gap: 16px;
    margin-top: 4px;
  }
  .nav-links a { font-size: 0.85rem; }
  .app-card { flex-direction: column; }
  .feature-list { grid-template-columns: 1fr; }
}