:root {
  --ink: #10162a;
  --ink-soft: #4a5268;
  --ink-faint: #8a91a5;
  --paper: #ffffff;
  --paper-warm: #f7f8fb;
  --line: #e4e7ef;
  --brand: #1b3fd8;
  --brand-dark: #142fa6;
  --accent: #e8571f;
  --ok: #0f9d58;
  --warn-bg: #fff8ec;
  --warn-line: #f0d9a8;
  --radius: 12px;
  --wrap: 720px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
  font-size: 16.5px;
  letter-spacing: .01em;
}

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }

/* ---------- site header ---------- */
/* Solid background rather than a translucent one with backdrop-filter:
   this header has to render predictably inside in-app WebViews. */
.site-head {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky; top: 0; z-index: 50;
}
.head-row {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 13px 0;
}
.logo { display: flex; align-items: center; gap: 9px; text-decoration: none; color: var(--ink); }
.logo-mark {
  width: 32px; height: 32px; border-radius: 8px;
  background: linear-gradient(135deg, var(--brand), #4a6bf5);
  color: #fff; font-weight: 800; font-size: 13px;
  display: flex; align-items: center; justify-content: center;
  letter-spacing: -.02em; flex: 0 0 32px;
}
.logo-text { font-weight: 800; font-size: 17px; letter-spacing: .02em; }
.logo-text small { display: block; font-size: 10.5px; font-weight: 500; color: var(--ink-faint); letter-spacing: .06em; }

.nav { display: flex; gap: 4px; flex-wrap: wrap; }
.nav a {
  color: var(--ink-soft); text-decoration: none;
  font-size: 14px; padding: 6px 9px; border-radius: 7px;
  white-space: nowrap;
}
.nav a:hover { background: var(--paper-warm); color: var(--brand); }
.nav a[aria-current="page"] { color: var(--brand); font-weight: 700; }

/* ---------- typography ---------- */
h1 { font-size: 29px; line-height: 1.35; font-weight: 900; letter-spacing: -.01em; margin-bottom: 14px; }
h2 { font-size: 21px; line-height: 1.45; font-weight: 800; margin: 38px 0 12px; letter-spacing: -.005em; }
h3 { font-size: 17.5px; font-weight: 700; margin: 26px 0 8px; }
p { margin-bottom: 16px; color: var(--ink-soft); }
p strong, li strong { color: var(--ink); font-weight: 700; }
a { color: var(--brand); }

.lede { font-size: 18px; color: var(--ink-soft); margin-bottom: 26px; }
.meta { font-size: 13px; color: var(--ink-faint); margin-bottom: 26px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }

main { padding: 30px 0 10px; }

ul, ol { margin: 0 0 18px 0; padding-left: 22px; color: var(--ink-soft); }
li { margin-bottom: 9px; }

/* ---------- components ---------- */
.hero-img {
  width: 100%; border-radius: var(--radius);
  display: block; margin: 0 0 26px; border: 1px solid var(--line);
}

.card {
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; margin: 0 0 18px; background: var(--paper);
}
.card h3 { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }

.grid { display: grid; gap: 14px; margin-bottom: 22px; }
@media (min-width: 620px) { .grid.cols-2 { grid-template-columns: 1fr 1fr; } }

.spec {
  width: 100%; border-collapse: collapse; font-size: 15px;
  margin: 0 0 22px; display: block; overflow-x: auto;
}
.spec table { width: 100%; border-collapse: collapse; min-width: 420px; }
.spec th, .spec td { padding: 11px 13px; text-align: left; border-bottom: 1px solid var(--line); }
.spec th { background: var(--paper-warm); font-weight: 700; font-size: 14px; color: var(--ink); }
.spec td { color: var(--ink-soft); }

.note {
  background: var(--warn-bg); border: 1px solid var(--warn-line);
  border-radius: var(--radius); padding: 15px 17px; margin: 0 0 22px;
  font-size: 14.5px; color: #6b5320;
}
.note strong { color: #4a3810; }
.note p:last-child { margin-bottom: 0; color: inherit; }

.steps { counter-reset: s; list-style: none; padding: 0; }
.steps > li {
  counter-increment: s; position: relative;
  padding: 0 0 4px 40px; margin-bottom: 20px;
}
.steps > li::before {
  content: counter(s); position: absolute; left: 0; top: 1px;
  width: 27px; height: 27px; border-radius: 50%;
  background: var(--brand); color: #fff;
  font-size: 13.5px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.steps h3 { margin: 0 0 5px; }

/* ---------- CTA ---------- */
.cta-box {
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--paper-warm); padding: 22px; margin: 30px 0;
  text-align: center;
}
.cta-box h3 { margin: 0 0 6px; font-size: 18px; }
.cta-box p { font-size: 14.5px; margin-bottom: 16px; }
.btn {
  display: inline-block; background: var(--brand); color: #fff;
  text-decoration: none; font-weight: 700; font-size: 16.5px;
  padding: 14px 30px; border-radius: 10px;
  transition: background .15s ease, transform .1s ease;
  border: none; cursor: pointer;
}
.btn:hover { background: var(--brand-dark); }
.btn:active { transform: scale(.985); }
.btn-sub { display: block; font-size: 12.5px; color: var(--ink-faint); margin-top: 11px; }

/* ---------- FAQ ---------- */
details {
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 0; margin-bottom: 10px; overflow: hidden;
}
details summary {
  cursor: pointer; padding: 15px 17px; font-weight: 700;
  font-size: 16px; list-style: none; position: relative;
  padding-right: 44px;
}
details summary::-webkit-details-marker { display: none; }
details summary::after {
  content: "+"; position: absolute; right: 17px; top: 13px;
  font-size: 20px; font-weight: 400; color: var(--ink-faint);
}
details[open] summary::after { content: "\2212"; }
details[open] summary { border-bottom: 1px solid var(--line); }
.details-body { padding: 15px 17px; }
.details-body p:last-child { margin-bottom: 0; }

/* ---------- footer ---------- */
.site-foot {
  border-top: 1px solid var(--line); margin-top: 46px;
  padding: 28px 0 40px; background: var(--paper-warm);
  font-size: 13.5px; color: var(--ink-faint);
}
.foot-nav { display: flex; flex-wrap: wrap; gap: 6px 18px; margin-bottom: 16px; }
.foot-nav a { color: var(--ink-soft); text-decoration: none; }
.foot-nav a:hover { color: var(--brand); text-decoration: underline; }
.disclosure {
  border-top: 1px solid var(--line); padding-top: 15px; margin-top: 15px;
  line-height: 1.7; font-size: 12.5px;
}
.disclosure p { color: var(--ink-faint); font-size: 12.5px; margin-bottom: 9px; }
.disclosure p:last-child { margin-bottom: 0; }

@media (max-width: 560px) {
  body { font-size: 16px; }
  h1 { font-size: 25px; }
  h2 { font-size: 19.5px; }
  .lede { font-size: 17px; }
  .nav a { font-size: 13px; padding: 5px 7px; }
  .logo-text { font-size: 16px; }
}