:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1e222b;
  --border: #2a2f3a;
  --text: #e7e9ee;
  --muted: #98a0b3;
  --accent: #5b8cff;
  --accent-2: #2fd08a;
  --radius: 10px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

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

.topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 14px 24px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
  flex-wrap: wrap;
}

.brand { font-weight: 700; font-size: 1.1rem; color: var(--text); }
.topnav { display: flex; gap: 16px; flex: 1; }
.topnav a { color: var(--muted); font-weight: 500; }
.topnav a.active, .topnav a:hover { color: var(--text); }

.search-form, .search-form-inline { display: flex; gap: 8px; }
.search-form input, .search-form-inline input {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  min-width: 220px;
}
.search-form button, .search-form-inline button {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
}
.search-form-inline { margin-bottom: 20px; }

.content { max-width: 980px; margin: 0 auto; padding: 28px 20px 80px; }

h1 { font-size: 1.7rem; margin-bottom: 4px; }
h2 { font-size: 1.2rem; margin-top: 36px; border-bottom: 1px solid var(--border); padding-bottom: 8px; }

.muted { color: var(--muted); }

.breadcrumb { color: var(--muted); font-size: 0.9rem; margin-bottom: 12px; }
.breadcrumb a { color: var(--muted); }

.stat-row { display: flex; flex-wrap: wrap; gap: 14px; margin: 20px 0 32px; }
.stat {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 18px;
  min-width: 100px;
  text-align: center;
}
.stat strong { display: block; font-size: 1.3rem; }
.stat span { color: var(--muted); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; margin: 14px 0 8px; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  display: block;
  color: var(--text);
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.card:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-1px); }
.card h3 { margin: 8px 0 4px; font-size: 1.02rem; }

.tag {
  display: inline-block;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--muted);
}
.tag-course { color: var(--accent-2); }
.tag-basic { color: var(--accent); }
.tag-event { color: #f0b84b; }
.tag-chat { color: #e37bd0; }

.section-block { margin-top: 28px; }
.lesson-list, .feed-list, .comment-list, .link-list, .search-results { list-style: none; padding: 0; margin: 10px 0; }
.lesson-list li {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 6px;
  background: var(--panel);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.feed-list li {
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 10px;
  background: var(--panel);
}
.feed-title { font-weight: 600; font-size: 1.02rem; display: block; margin-bottom: 4px; }
.feed-meta { color: var(--muted); font-size: 0.85rem; margin: 4px 0; }

.comment-list li {
  padding: 10px 12px;
  border-inline-start: 2px solid var(--border);
  margin-bottom: 8px;
}

.badge {
  font-size: 0.7rem;
  background: var(--panel-2);
  color: var(--muted);
  padding: 2px 8px;
  border-radius: 999px;
}
.badge-ok { color: var(--accent-2); }

.link-list a { word-break: break-all; }

.notice {
  background: #21283a;
  border: 1px solid #313e5c;
  color: #c7d2f5;
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  margin: 14px 0;
}

.prose p { margin: 0 0 14px; white-space: pre-wrap; }
.transcript { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }

.video-block { margin: 16px 0; }
.video-block video { width: 100%; max-height: 520px; border-radius: var(--radius); background: #000; }
.transcript-toggle { margin-top: 8px; }
.transcript-toggle summary { cursor: pointer; color: var(--accent); }

.video-thumb {
  background: var(--panel-2);
  border-radius: 8px 8px 0 0;
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: var(--muted);
  position: relative;
}
.video-card { padding: 0; overflow: hidden; }
.video-card-body { padding: 12px; }
.video-thumb .duration {
  position: absolute;
  bottom: 6px;
  right: 8px;
  background: rgba(0,0,0,0.65);
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 4px;
  color: #fff;
}

.pager { display: flex; gap: 16px; align-items: center; margin: 20px 0; }

.search-results li {
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 10px;
  background: var(--panel);
}
.search-results a { font-weight: 600; }
.search-results p { margin: 6px 0 0; color: var(--text); }

.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.login-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.login-card h1 { margin: 0; font-size: 1.4rem; }
.login-card label { display: flex; flex-direction: column; gap: 6px; font-size: 0.9rem; color: var(--muted); }
.login-card input {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 1rem;
}
.login-card button {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 11px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  margin-top: 6px;
}
.login-error {
  background: #3a1f24;
  border: 1px solid #5c2b33;
  color: #f5b8c0;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.9rem;
}

@media (max-width: 600px) {
  .topbar { gap: 10px; }
  .search-form input, .search-form-inline input { min-width: 140px; }
}