:root {
  --navy-deep: #021331;
  --navy: #0B1A3A;
  --cream: #F7F6F0;
  --card: #FFFFFF;
  --green: #7BE04E;
  --muted: #4A5670;
  --line: rgba(11, 26, 58, 0.08);
  --on-dark: #FFFFFF;
  --on-dark-muted: rgba(255, 255, 255, 0.72);
  --radius: 12px;
  --font-zh: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans CJK SC", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-en: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--cream);
  color: var(--navy);
  font-family: var(--font-zh);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

html[data-lang="en"] body { font-family: var(--font-en); }

/* language visibility */
html[data-lang="zh"] .en,
html[data-lang="en"] .zh { display: none; }

h1, h2, h3, p { margin: 0; }
ul, ol { list-style: none; margin: 0; padding: 0; }
a { color: inherit; }

.wrap {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 16px;
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background: var(--navy-deep);
  color: var(--on-dark);
  min-height: 88vh;
  min-height: 88svh;
  display: flex;
  flex-direction: column;
}

.hero-grain {
  position: absolute;
  inset: 0;
  background: url("images/grain.png") repeat;
  background-size: 160px 160px;
  opacity: 0.08;
  pointer-events: none;
}

.topbar {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.lang-switch {
  display: inline-flex;
  padding: 3px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.lang-switch button {
  appearance: none;
  border: 0;
  margin: 0;
  min-width: 52px;
  padding: 6px 12px;
  border-radius: 999px;
  background: transparent;
  color: var(--on-dark-muted);
  font: inherit;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.2;
  cursor: pointer;
}

.lang-switch button[aria-pressed="true"] {
  background: var(--green);
  color: var(--navy-deep);
  font-weight: 600;
}

.lang-switch button:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

.hero-body {
  position: relative;
  z-index: 1;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 24px 16px 72px;
  max-width: 760px;
  margin: 0 auto;
}

.hero-logo {
  width: 160px;
  height: 160px;
  margin-bottom: 28px;
}

.hero h1 .nw { white-space: nowrap; }

.hero h1 {
  font-size: 26px;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: 0.01em;
}

.hero-sub {
  margin-top: 16px;
  font-size: 17px;
  color: var(--on-dark-muted);
  max-width: 560px;
}

.tag {
  margin-top: 32px;
  display: inline-block;
  padding: 8px 18px;
  border-radius: 999px;
  border: 1px solid rgba(123, 224, 78, 0.55);
  color: var(--green);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  cursor: default;
  user-select: none;
}

/* ---------- sections ---------- */
.section { padding: 56px 0 0; }
main { padding-bottom: 72px; }

.section h2 {
  font-size: 22px;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 20px;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--line);
}

.card p {
  color: var(--muted);
  font-size: 15px;
}

.card-lead p {
  color: var(--navy);
  font-size: 17px;
  line-height: 1.8;
}

.card h3 {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 8px;
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--green);
  color: var(--navy-deep);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

.dot {
  display: block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--green);
  margin-bottom: 16px;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr;
  gap: 56px;
}

.two-col .card p { color: var(--navy); }

.mail {
  color: var(--navy);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-color: var(--green);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
  word-break: break-all;
}

/* ---------- footer ---------- */
.footer {
  background: var(--navy-deep);
  color: var(--on-dark-muted);
  padding: 32px 0 40px;
  font-size: 12px;
  line-height: 1.8;
}

.footer p + p { margin-top: 4px; }
.footer a { color: var(--on-dark); text-decoration: none; }
.footer a:hover { text-decoration: underline; }

/* ---------- larger screens ---------- */
@media (min-width: 720px) {
  .wrap { padding: 0 32px; }
  .topbar { padding: 20px 32px; }
  .hero-logo { width: 200px; height: 200px; }
  .hero h1 { font-size: 40px; }
  .hero-sub { font-size: 18px; }
  .section { padding-top: 80px; }
  main { padding-bottom: 96px; }
  .section h2 { font-size: 26px; margin-bottom: 24px; }
  .grid { grid-template-columns: repeat(3, 1fr); gap: 20px; }
  .card { padding: 28px; }
  .two-col { grid-template-columns: 1fr 1fr; gap: 20px; }
}