:root {
  --bg: #f6f8f5;
  --card: #ffffff;
  --ink: #1a2e1a;
  --muted: #5a6b5a;
  --line: #d5e0d5;
  --brand: #1f7a4c;
  --brand-dark: #155a38;
  --accent: #e8f5ee;
  --warn: #b42318;
  --ok: #067647;
  --radius: 12px;
  --shadow: 0 8px 24px rgba(26, 46, 26, 0.06);
  font-family: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: min(960px, calc(100% - 2rem)); margin: 0 auto; }
.main { flex: 1; padding: 2rem 0 3rem; }
.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}
.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--brand);
  text-decoration: none;
}
.nav { display: flex; align-items: center; gap: 0.85rem; flex-wrap: wrap; }
.nav a { color: var(--ink); font-size: 0.95rem; }
.inline { display: inline; margin: 0; }
.linkish {
  background: none; border: none; color: var(--ink); cursor: pointer;
  font: inherit; padding: 0; text-decoration: underline;
}
.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.25rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}
.hero {
  background: linear-gradient(160deg, #e8f5ee, #fff 55%);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 2.25rem 1.75rem;
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
}
.eyebrow { color: var(--brand); font-weight: 600; margin: 0 0 0.5rem; }
.hero h1 { margin: 0 0 0.75rem; font-size: clamp(1.6rem, 4vw, 2.2rem); line-height: 1.25; }
.lead { color: var(--muted); max-width: 40rem; }
.cta-row { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1.25rem; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--line); background: var(--card); color: var(--ink);
  border-radius: 999px; padding: 0.55rem 1.1rem; font: inherit; cursor: pointer;
  text-decoration: none;
}
.btn:hover { text-decoration: none; border-color: var(--brand); }
.btn-primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); border-color: var(--brand-dark); color: #fff; }
.btn-ghost { background: transparent; }
.btn-sm { padding: 0.35rem 0.8rem; font-size: 0.9rem; }
.steps, .highlights { margin-top: 2rem; }
.step-list { padding-left: 1.2rem; }
.step-list li { margin-bottom: 0.6rem; }
.hint, .muted, .meta { color: var(--muted); font-size: 0.92rem; }
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.25rem;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.card h2 { margin: 0; font-size: 1.1rem; }
.card-top { display: flex; justify-content: space-between; gap: 0.5rem; align-items: flex-start; }
.card-actions { margin-top: auto; padding-top: 0.75rem; }
.badge {
  font-size: 0.75rem;
  border-radius: 999px;
  padding: 0.15rem 0.55rem;
  background: #eef1ee;
  color: var(--muted);
  white-space: nowrap;
}
.badge-ok { background: var(--accent); color: var(--ok); }
.form {
  max-width: 420px;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  margin-top: 1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}
.form label { display: flex; flex-direction: column; gap: 0.35rem; font-weight: 600; font-size: 0.95rem; }
.form input {
  font: inherit; padding: 0.6rem 0.7rem; border-radius: 8px;
  border: 1px solid var(--line); background: #fff;
}
.form input:focus { outline: 2px solid #b7dfc8; border-color: var(--brand); }
.alert {
  border-radius: 10px; padding: 0.75rem 1rem; margin: 1rem 0;
}
.alert-error { background: #fef3f2; color: var(--warn); border: 1px solid #fecdca; }
.alert-ok { background: var(--accent); color: var(--ok); border: 1px solid #abe0c4; }
.course-list { list-style: none; padding: 0; margin: 1rem 0 0; }
.course-list li {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1rem; margin-bottom: 0.75rem;
}
.placeholder-box {
  margin: 1.25rem 0;
  padding: 2rem 1.25rem;
  text-align: center;
  background: repeating-linear-gradient(-45deg, #fff, #fff 12px, #f0f5f1 12px, #f0f5f1 24px);
  border: 2px dashed var(--line);
  border-radius: 16px;
}
.placeholder-box .big { font-size: 1.6rem; font-weight: 700; margin: 0 0 0.5rem; color: var(--brand); }
.mt { margin-top: 1.5rem; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.85em; }
@media (max-width: 560px) {
  .course-list li { flex-direction: column; align-items: flex-start; }
}

.otp-row {
  display: flex;
  gap: 0.5rem;
  align-items: stretch;
}
.otp-row input { flex: 1; min-width: 0; }
.otp-row .btn { white-space: nowrap; flex-shrink: 0; }
.otp-row .btn:disabled { opacity: 0.6; cursor: not-allowed; }