:root {
  --bg: #22262e;
  --bg-alt: #1d2127;
  --surface: #2a303a;
  --surface-2: #333a46;
  --border: #3b4351;
  --text: #e9ecef;
  --muted: #a5aeba;
  --green: #4db478;
  --green-strong: #3f9d66;
  --green-bright: #35d46b;
  --blue: #5b9bd9;
  --orange: #e08a4a;
  --radius: 14px;
  --maxw: 1080px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, "Noto Sans", "PingFang TC", "Microsoft JhengHei", sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

img, svg { max-width: 100%; }

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--green);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: 0 0 8px 0;
  z-index: 100;
}
.skip-link:focus { left: 0; }

/* ---------- Work-in-progress banner ---------- */

.wip-banner {
  background: var(--green-bright);
  color: #10281a;
  text-align: center;
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.4;
  padding: 0.65rem 1.25rem;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.2px;
}
.brand:hover { text-decoration: none; }
.brand svg { display: block; }

.main-nav {
  display: flex;
  gap: 1.4rem;
  margin-left: auto;
  align-items: center;
}
.main-nav a {
  color: var(--muted);
  font-weight: 500;
  font-size: 0.98rem;
}
.main-nav a:hover { color: var(--text); text-decoration: none; }

/* Language dropdown + mobile menu (pure CSS via <details>) */

details.dropdown { position: relative; }
details.dropdown > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--muted);
  font-size: 0.95rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  user-select: none;
}
details.dropdown > summary::-webkit-details-marker { display: none; }
details.dropdown > summary:hover { color: var(--text); border-color: var(--muted); }
details.dropdown[open] > summary { color: var(--text); }

details.dropdown .menu-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.5rem;
  min-width: 180px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  z-index: 60;
}
details.dropdown .menu-panel a {
  display: block;
  padding: 0.45rem 0.75rem;
  color: var(--text);
  border-radius: 8px;
  font-size: 0.95rem;
}
details.dropdown .menu-panel a:hover {
  background: var(--surface-2);
  text-decoration: none;
}
details.dropdown .menu-panel a[aria-current="true"] {
  color: var(--green);
  font-weight: 600;
}

.mobile-menu { display: none; }

/* ---------- Hero ---------- */

.hero {
  background: var(--bg-alt);
  padding: 4.5rem 0 3.5rem;
  border-bottom: 1px solid var(--border);
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  letter-spacing: -0.5px;
}
.hero h1 .accent { color: var(--green); }
.hero .sub {
  font-size: 1.15rem;
  color: var(--muted);
  max-width: 640px;
  margin: 0 0 2rem;
}
.cta-row { display: flex; gap: 0.9rem; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.8rem 1.5rem;
  border-radius: 12px;
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--green-strong); color: #fff; }
.btn-primary:hover { background: var(--green); }
.btn-secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-secondary:hover { border-color: var(--muted); }

/* Trust strip */
.trust-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 3rem;
}
.trust-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
}
.trust-item .icon { color: var(--green); margin-bottom: 0.5rem; }
.trust-item h3 { margin: 0 0 0.3rem; font-size: 1.02rem; }
.trust-item p { margin: 0; color: var(--muted); font-size: 0.92rem; }

/* ---------- Sections ---------- */

section { padding: 4.5rem 0; scroll-margin-top: 76px; }
section.alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 0.7rem;
}
.eyebrow.green { color: var(--green); }
.eyebrow.blue { color: var(--blue); }
.eyebrow.orange { color: var(--orange); }

section h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
  margin: 0 0 0.8rem;
  line-height: 1.2;
  letter-spacing: -0.3px;
}
.section-intro {
  color: var(--muted);
  max-width: 680px;
  margin: 0 0 2.2rem;
  font-size: 1.05rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 1.1rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.3rem;
}
.card .icon {
  display: inline-flex;
  padding: 0.55rem;
  border-radius: 10px;
  background: var(--bg-alt);
  margin-bottom: 0.9rem;
}
.card .icon.green { color: var(--green); }
.card .icon.blue { color: var(--blue); }
.card .icon.orange { color: var(--orange); }
.card h3 { margin: 0 0 0.45rem; font-size: 1.1rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* Security section */
.security-cols {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2.5rem;
  align-items: start;
}
.security-cols p { color: var(--muted); }
.point-list { list-style: none; margin: 0; padding: 0; }
.point-list li {
  display: flex;
  gap: 0.7rem;
  align-items: flex-start;
  padding: 0.55rem 0;
  color: var(--text);
}
.point-list .icon { color: var(--green); flex-shrink: 0; margin-top: 2px; }

/* Roadmap note */
.roadmap-note {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.1rem 1.3rem;
  color: var(--muted);
  margin-top: 2.4rem;
  font-size: 0.97rem;
}
.roadmap-note strong { color: var(--text); }

/* ---------- FAQ ---------- */

.faq-list { max-width: 800px; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  margin-bottom: 0.8rem;
}
.faq-item summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.2rem;
  font-weight: 600;
  font-size: 1.02rem;
  user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary .chevron {
  flex-shrink: 0;
  color: var(--muted);
  transition: transform 0.2s ease;
}
.faq-item[open] summary .chevron { transform: rotate(180deg); }
.faq-item .answer {
  padding: 0 1.2rem 1.1rem;
  color: var(--muted);
  font-size: 0.97rem;
}
.faq-item .answer p { margin: 0; }

/* ---------- Download ---------- */

.download-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}
.download-panel h2 { margin-top: 0; }
.download-panel .sub { color: var(--muted); max-width: 520px; margin: 0 auto 1.8rem; }
.download-panel .cta-row { justify-content: center; }
.download-notes {
  margin-top: 1.6rem;
  color: var(--muted);
  font-size: 0.88rem;
}
.download-notes p { margin: 0.25rem 0; }

/* ---------- Footer ---------- */

.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
  font-size: 0.93rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.4fr;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-grid h4 {
  margin: 0 0 0.7rem;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--muted);
}
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 0.4rem; }
.footer-grid a { color: var(--text); }
.footer-grid a:hover { color: var(--green); text-decoration: none; }
.footer-tagline { color: var(--muted); margin: 0.8rem 0 0; max-width: 340px; }
.lang-links { display: flex; flex-wrap: wrap; gap: 0.35rem 1rem; }
.lang-links li { margin: 0; }
.lang-links a[aria-current="true"] { color: var(--green); font-weight: 600; }
.footer-legal {
  border-top: 1px solid var(--border);
  padding-top: 1.4rem;
  color: var(--muted);
  font-size: 0.85rem;
}
.footer-legal p { margin: 0.3rem 0; }

/* ---------- Responsive ---------- */

@media (max-width: 880px) {
  .main-nav { display: none; }
  .mobile-menu { display: block; margin-left: auto; }
  .header-inner { gap: 0.8rem; }
  .security-cols { grid-template-columns: 1fr; gap: 1.5rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.6rem; }
  section { padding: 3.2rem 0; }
  .hero { padding: 3.2rem 0 2.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .faq-item summary .chevron { transition: none; }
}