/* public/css/main.css
   AI 编程教学 - 前后台样式
   简洁现代风,响应式
*/

* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #d97706;
  --bg: #f8fafc;
  --bg-card: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --text-light: #64748b;
  --text-muted: #94a3b8;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,.05), 0 2px 4px rgba(0,0,0,.04);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 14px;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  background: #f1f5f9;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
}

/* ===== 顶栏 ===== */
.topbar {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.topbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.logo {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}
.logo:hover { text-decoration: none; }
.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.user-info {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-light);
}
.user-info strong { color: var(--text); }

/* ===== 徽章 ===== */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
}
.badge-trial { background: #fef3c7; color: #92400e; }
.badge-active { background: #d1fae5; color: #065f46; }
.badge-none { background: #f1f5f9; color: var(--text-muted); }

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 8px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  text-align: center;
  transition: all .15s;
  text-decoration: none;
}
.btn:hover { background: #f1f5f9; text-decoration: none; }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-sm { padding: 4px 10px; font-size: 13px; }
.btn-block { width: 100%; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-danger { background: var(--danger); border-color: var(--danger); color: #fff; }
.btn-danger:hover { opacity: .9; }

/* ===== 容器 ===== */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 24px;
}

/* ===== 首页 ===== */
.hero {
  text-align: center;
  padding: 32px 0 24px;
}
.hero h1 { font-size: 32px; margin-bottom: 8px; }
.hero .subtitle { color: var(--text-light); font-size: 16px; }

.lesson-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 16px;
}
.lesson-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  box-shadow: var(--shadow);
  transition: box-shadow .15s, transform .15s;
}
.lesson-card:hover { box-shadow: var(--shadow-md); }
.lesson-index {
  flex: 0 0 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 600;
}
.lesson-body { flex: 1; min-width: 0; }
.lesson-title { font-size: 17px; margin-bottom: 6px; }
.lesson-title a { color: var(--text); }
.lesson-title a:hover { color: var(--primary); text-decoration: none; }
.lesson-desc {
  color: var(--text-light);
  font-size: 13px;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.lesson-meta {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--text-muted);
}
.lesson-action { flex: 0 0 auto; align-self: center; }

.empty {
  text-align: center;
  padding: 64px 24px;
  color: var(--text-muted);
}

/* ===== 课时详情 ===== */
.lesson-page { padding-top: 16px; }
.back-link {
  display: inline-block;
  margin-bottom: 16px;
  color: var(--text-light);
  font-size: 13px;
}
.video-section { margin-bottom: 24px; }
.video-wrap {
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 16/9;
  position: relative;
}
.video-wrap video { width: 100%; height: 100%; display: block; }
.video-locked {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  display: flex;
  align-items: center;
  justify-content: center;
}
.lock-overlay {
  text-align: center;
  color: #fff;
}
.lock-icon { font-size: 48px; margin-bottom: 12px; }
.lock-overlay p { margin-bottom: 16px; color: #cbd5e1; }

.lesson-info { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.lesson-info .lesson-title { font-size: 22px; margin-bottom: 8px; }
.lesson-info .lesson-meta { margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
.lesson-section { margin-top: 16px; }
.section-title {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}
.lesson-description {
  white-space: pre-wrap;
  color: var(--text);
  line-height: 1.7;
}
.lesson-actions { margin-top: 24px; }
.view-badge.hidden { display: none; }
.view-badge {
  display: inline-block;
  background: #d1fae5;
  color: #065f46;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 12px;
}

/* ===== 错误页 ===== */
.error-page {
  text-align: center;
  padding: 96px 24px;
}
.error-page h1 { font-size: 56px; color: var(--text-muted); margin-bottom: 8px; }
.error-page p { color: var(--text-light); margin-bottom: 24px; }

/* ===== 后台 ===== */
.admin-body { background: #f1f5f9; }
.admin-layout {
  display: flex;
  min-height: 100vh;
}
.admin-sidebar {
  flex: 0 0 220px;
  background: #1e293b;
  color: #cbd5e1;
  padding: 24px 0;
  min-height: 100vh;
}
.admin-brand {
  padding: 0 24px 20px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  border-bottom: 1px solid #334155;
  margin-bottom: 12px;
}
.admin-nav a {
  display: block;
  padding: 10px 24px;
  color: #cbd5e1;
  font-size: 14px;
}
.admin-nav a:hover, .admin-nav a.active {
  background: #334155;
  color: #fff;
  text-decoration: none;
}
.admin-main {
  flex: 1;
  padding: 24px 32px;
  overflow-x: auto;
}
.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}
.admin-header h1 { font-size: 22px; }

.admin-table {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  border-collapse: collapse;
  overflow: hidden;
}
.admin-table th, .admin-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.admin-table th {
  background: #f8fafc;
  font-weight: 600;
  font-size: 13px;
  color: var(--text-light);
}
.admin-table tbody tr:last-child td { border-bottom: none; }
.admin-table tbody tr:hover { background: #f8fafc; }

.admin-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  max-width: 720px;
  margin-bottom: 24px;
}
.form-group { margin-bottom: 16px; }
.form-group label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
  font-size: 13px;
}
.required { color: var(--danger); }
.form-group input[type=text],
.form-group input[type=password],
.form-group textarea {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,.1);
}
.form-group textarea { resize: vertical; }
.hint { color: var(--text-muted); font-size: 12px; }

.video-status {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
  max-width: 720px;
}
.video-status p { margin-bottom: 8px; font-size: 13px; }
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 24px 0;
}

.alert {
  padding: 10px 14px;
  border-radius: var(--radius);
  margin-bottom: 16px;
  font-size: 13px;
}
.alert-error { background: #fee2e2; color: #991b1b; }

/* ===== 后台登录 ===== */
.admin-login-body {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.admin-login-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 40px;
  width: 100%;
  max-width: 360px;
  box-shadow: 0 10px 40px rgba(0,0,0,.2);
}
.admin-login-card h1 {
  font-size: 22px;
  text-align: center;
  margin-bottom: 24px;
}
.admin-login-card .form-group input { width: 100%; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .topbar-inner { padding: 10px 16px; gap: 8px; }
  .user-info { gap: 10px; font-size: 12px; }
  .container { padding: 20px 16px; }
  .lesson-card { padding: 14px; gap: 12px; }
  .lesson-index { flex-basis: 36px; height: 36px; font-size: 14px; }
  .lesson-action { width: 100%; margin-top: 8px; }
  .lesson-action .btn { width: 100%; }
  .admin-layout { flex-direction: column; }
  .admin-sidebar { flex: none; min-height: auto; }
  .admin-nav { display: flex; flex-wrap: wrap; padding: 0 12px 12px; }
  .admin-nav a { padding: 6px 12px; }
  .admin-main { padding: 16px; }
  .admin-table { font-size: 12px; }
  .admin-table th, .admin-table td { padding: 8px; }
}