:root {
  color-scheme: light dark;
  --canvas: #f4f7fb;
  --surface: rgba(255, 255, 255, 0.9);
  --text: #172033;
  --muted: #5f6b7f;
  --line: rgba(52, 72, 104, 0.16);
  --accent: #1769e0;
  --accent-soft: rgba(23, 105, 224, 0.11);
  --shadow: 0 18px 54px rgba(31, 55, 91, 0.1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --canvas: #0c111b;
    --surface: rgba(23, 31, 46, 0.92);
    --text: #f2f6ff;
    --muted: #a8b3c6;
    --line: rgba(180, 198, 230, 0.18);
    --accent: #73a9ff;
    --accent-soft: rgba(115, 169, 255, 0.14);
    --shadow: 0 20px 60px rgba(0, 0, 0, 0.28);
  }
}

* { box-sizing: border-box; }

html {
  background: var(--canvas);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "PingFang TC", sans-serif;
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 0%, rgba(68, 137, 255, 0.12), transparent 34rem),
    var(--canvas);
}

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

.shell {
  width: min(880px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 64px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 30px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 760;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 11px;
  color: white;
  background: linear-gradient(145deg, #2f7df5, #144fbf);
  box-shadow: 0 8px 24px rgba(29, 100, 220, 0.28);
}

.language-switcher {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}

.language-switcher button {
  appearance: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 11px;
  color: var(--muted);
  background: var(--surface);
  font: inherit;
  font-size: 0.82rem;
  cursor: pointer;
}

.language-switcher button[aria-pressed="true"] {
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
  color: var(--accent);
  background: var(--accent-soft);
}

.card {
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: clamp(24px, 5vw, 48px);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1, h2, h3 {
  line-height: 1.2;
  letter-spacing: -0.025em;
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(2rem, 7vw, 3.35rem);
}

h2 {
  margin: 36px 0 12px;
  padding-top: 4px;
  font-size: 1.35rem;
}

h3 { margin: 26px 0 8px; font-size: 1.05rem; }
p { margin: 10px 0; }
ul { padding-left: 1.35rem; }
li + li { margin-top: 7px; }

.lede {
  max-width: 690px;
  color: var(--muted);
  font-size: 1.08rem;
}

.meta {
  margin: 22px 0 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--muted);
  background: var(--accent-soft);
  font-size: 0.9rem;
}

.actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.action {
  display: block;
  border: 1px solid var(--line);
  border-radius: 17px;
  padding: 18px;
  color: var(--text);
  background: var(--surface);
  text-decoration: none;
}

.action strong { display: block; margin-bottom: 4px; }
.action span { color: var(--muted); font-size: 0.9rem; }
.action:hover { border-color: var(--accent); }

.notice {
  margin: 22px 0;
  padding: 16px 18px;
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  background: var(--accent-soft);
}

.contact {
  display: inline-flex;
  align-items: center;
  margin-top: 10px;
  border-radius: 12px;
  padding: 11px 15px;
  color: white;
  background: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

footer {
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.82rem;
  text-align: center;
}

[data-lang-panel][hidden] { display: none !important; }

@media (max-width: 620px) {
  .topbar { align-items: flex-start; flex-direction: column; }
  .language-switcher { justify-content: flex-start; }
  .actions { grid-template-columns: 1fr; }
  .card { border-radius: 20px; }
}

@media (prefers-reduced-motion: no-preference) {
  .action, .language-switcher button { transition: border-color 160ms ease, background-color 160ms ease, transform 160ms ease; }
  .action:hover { transform: translateY(-1px); }
}