:root {
  --bg: #fafaf8;
  --fg: #1c1c1c;
  --muted: #6b6b6b;
  --accent: #0a5d9c;
  --accent-hover: #084777;
  --card-bg: #ffffff;
  --border: #e3e3e0;
  --error: #b3261e;
  --success: #1f6b3a;
  --warning-bg: #fff7e0;
}

* { box-sizing: border-box; }

html { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
  width: 100%;
  flex: 1;
}
.container.narrow { max-width: 480px; }

h1, h2, h3 { line-height: 1.25; }
h1 { margin-top: 0; }

a { color: var(--accent); }
a:hover { color: var(--accent-hover); }

.muted { color: var(--muted); font-size: 0.9rem; }
.lead { font-size: 1.1rem; color: var(--muted); }
.hint { font-size: 0.8rem; color: var(--muted); font-weight: normal; }

.breadcrumb {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }

/* Cards */
.card-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: transform 0.1s, box-shadow 0.1s;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}
.card a {
  display: block;
  padding: 1.25rem;
  text-decoration: none;
  color: var(--fg);
}
.card h2 { margin: 0 0 0.25rem; font-size: 1.1rem; text-transform: capitalize; }
.card p { margin: 0; color: var(--muted); font-size: 0.9rem; }

/* Lesson page */
.lesson-page section {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  margin: 1.25rem 0;
}
.lesson-page section h2 { margin-top: 0; font-size: 1.15rem; }

.copy-box { background: #f0f6fb !important; border-color: #c8dff0 !important; }
.copy-box .url-row {
  display: flex;
  gap: 0.5rem;
  margin: 0.75rem 0;
}
.copy-box input[type="text"] {
  flex: 1;
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.95rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: white;
}
.copy-box button {
  padding: 0.65rem 1.25rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 0.95rem;
  cursor: pointer;
  font-weight: 500;
}
.copy-box button:hover { background: var(--accent-hover); }
.copy-box .copy-option { margin: 1rem 0; }
.copy-box .option-label { margin: 0 0 0.5rem; font-size: 0.95rem; color: var(--fg); }
.copy-box .option-label strong { color: var(--accent); }
.copy-box button.full-width {
  width: 100%;
  padding: 0.9rem 1.25rem;
  font-size: 1rem;
  font-weight: 600;
}
.ai-tips { margin-top: 1rem; }
.ai-tips summary { cursor: pointer; color: var(--muted); }
.ai-tips ul { margin: 0.5rem 0 0 1.25rem; padding: 0; list-style: none; }
.ai-tips li { margin: 0.25rem 0; }

.markdown ul, .markdown ol { padding-left: 1.5rem; }
.markdown p { margin: 0.5rem 0; }
.markdown code { background: #f0f0eb; padding: 0.1rem 0.35rem; border-radius: 3px; font-size: 0.9em; }

.prompt-block details summary {
  cursor: pointer;
  color: var(--muted);
  padding: 0.5rem 0;
}
.prompt-block pre {
  background: #1c1c1c;
  color: #f0f0eb;
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.85rem;
  margin: 0.5rem 0;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.prompt-block button {
  margin-top: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

/* Admin */
.admin-bar {
  background: #1c1c1c;
  color: white;
  padding: 0.75rem 0;
}
.admin-bar .row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.admin-bar h1 { margin: 0; font-size: 1.15rem; }
.admin-bar a { color: #cfe5f7; }
.admin-bar nav { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; }
.admin-bar a.primary {
  background: var(--accent);
  color: white;
  padding: 0.4rem 0.9rem;
  border-radius: 5px;
  text-decoration: none;
}
.admin-bar a.primary:hover { background: var(--accent-hover); }

.admin .subject-group { margin-top: 2rem; }
.admin .subject-group h2 {
  text-transform: capitalize;
  border-bottom: 2px solid var(--border);
  padding-bottom: 0.25rem;
}
.admin .subject-group h3 {
  color: var(--muted);
  font-weight: 600;
  text-transform: capitalize;
  font-size: 1rem;
  margin: 1.25rem 0 0.5rem;
}

.lesson-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card-bg);
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--border);
  font-size: 0.92rem;
}
.lesson-table th, .lesson-table td {
  padding: 0.6rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.lesson-table th {
  background: #f0f0eb;
  font-weight: 600;
}
.lesson-table tbody tr:last-child td { border-bottom: none; }
.lesson-table .actions { white-space: nowrap; }
.lesson-table .actions > * { margin-right: 0.6rem; }

.badge {
  display: inline-block;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}
.badge.published { background: #d6f0df; color: var(--success); }
.badge.draft { background: #f0e6c8; color: #7a5b00; }

/* Form */
.lesson-form { background: var(--card-bg); padding: 1.5rem; border-radius: 8px; border: 1px solid var(--border); }
.lesson-form label {
  display: block;
  margin: 1rem 0;
  font-weight: 600;
  font-size: 0.95rem;
}
.lesson-form label.checkbox {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
}
.lesson-form input[type="text"],
.lesson-form input[type="number"],
.lesson-form input[type="password"],
.lesson-form textarea {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  font-size: 0.95rem;
  font-family: inherit;
  margin-top: 0.3rem;
  font-weight: normal;
}
.lesson-form textarea { resize: vertical; font-family: 'SFMono-Regular', Consolas, monospace; font-size: 0.9rem; }
.lesson-form .grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
}
.lesson-form .grid label { margin: 0; }

.actions {
  display: flex;
  gap: 1rem;
  align-items: center;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}
button.primary, .button.primary {
  background: var(--accent);
  color: white;
  border: none;
  padding: 0.65rem 1.4rem;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  font-weight: 600;
}
button.primary:hover { background: var(--accent-hover); }
button.link {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  padding: 0;
  font: inherit;
  text-decoration: underline;
}
button.link.danger { color: var(--error); }
form.inline { display: inline; }
.cancel { color: var(--muted); }

/* Stack form for login */
.stack { display: flex; flex-direction: column; gap: 1rem; }
.stack label { display: flex; flex-direction: column; font-weight: 600; gap: 0.3rem; }
.stack input { padding: 0.6rem; border: 1px solid var(--border); border-radius: 5px; }

.error {
  background: #fde8e6;
  color: var(--error);
  padding: 0.75rem 1rem;
  border-radius: 6px;
  margin-bottom: 1rem;
  border: 1px solid #f5c1bc;
}
.success {
  background: #e3f5e9;
  color: var(--success);
  padding: 0.75rem 1rem;
  border-radius: 6px;
  margin-bottom: 1rem;
  border: 1px solid #b3ddc1;
}

.site-footer {
  text-align: center;
  padding: 1.5rem 1rem;
  font-size: 0.85rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

@media (max-width: 600px) {
  .container { padding: 1.25rem 1rem; }
  .lesson-table { font-size: 0.85rem; }
  .lesson-table th:nth-child(3), .lesson-table td:nth-child(3) { display: none; }
  .copy-box .url-row { flex-direction: column; }
  .copy-box button { width: 100%; }
}