:root {
  --wc-bg: #0f1419;
  --wc-card: #161b22;
  --wc-border: #30363d;
  --wc-text: #e6edf3;
  --wc-muted: #8b949e;
  --wc-accent: #2563eb;
  --wc-green: #10b981;
  --wc-red: #ef4444;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--wc-bg);
  color: var(--wc-text);
  line-height: 1.5;
}
.wc-wrap { max-width: 1100px; margin: 0 auto; padding: 24px; }
.wc-card {
  background: var(--wc-card);
  border: 1px solid var(--wc-border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
}
.wc-btn {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-weight: 600;
  background: var(--wc-accent);
  color: #fff;
  text-decoration: none;
}
.wc-btn.secondary { background: transparent; border: 1px solid var(--wc-border); color: var(--wc-text); }
.wc-btn.danger { background: var(--wc-red); }
input, textarea, select {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--wc-border);
  background: var(--wc-bg);
  color: var(--wc-text);
  margin-bottom: 12px;
}
.wc-grid { display: grid; grid-template-columns: 280px 1fr; gap: 16px; }
@media (max-width: 800px) { .wc-grid { grid-template-columns: 1fr; } }
.wc-student-list { list-style: none; padding: 0; margin: 0; max-height: 400px; overflow-y: auto; }
.wc-student-list li {
  padding: 8px 10px;
  border-bottom: 1px solid var(--wc-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.wc-hand { color: #f59e0b; font-weight: 700; }
.wc-lesson { min-height: 200px; }
.wc-block { margin-bottom: 16px; }
.wc-code { background: #0d1117; padding: 12px; overflow-x: auto; border-radius: 8px; }
.wc-muted { color: var(--wc-muted); font-size: 14px; }
.wc-link-box {
  background: #0d1117;
  padding: 12px;
  border-radius: 8px;
  word-break: break-all;
  font-family: monospace;
  font-size: 13px;
}