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

:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --border-color: #a2a9b1;
  --text-primary: #202122;
  --text-secondary: #54595d;
  --link-color: #3366cc;
  --link-visited: #795cb2;
  --header-bg: #ffffff;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --filter-bg: #e8f0fe;
  --filter-border: #c6d9f1;
  --filter-active-bg: #1a73e8;
  --filter-active-text: #ffffff;
}

[data-theme="dark"] {
  --bg-primary: #202122;
  --bg-secondary: #27272a;
  --bg-card: #2d2d30;
  --border-color: #44464c;
  --text-primary: #f0f0f0;
  --text-secondary: #b0b0b0;
  --link-color: #6ca0dc;
  --link-visited: #9a7fc4;
  --header-bg: #2d2d30;
  --shadow: 0 2px 8px rgba(0,0,0,0.4);
  --filter-bg: #2a2a3a;
  --filter-border: #444466;
  --filter-active-bg: #4da3ff;
  --filter-active-text: #000000;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
}

a {
  color: var(--link-color);
  text-decoration: none;
}

a:visited {
  color: var(--link-visited);
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3em;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 0.9em;
  transition: background 0.2s;
}

.btn:hover {
  background: var(--bg-card);
}

.lang-select {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 6px 10px;
  color: var(--text-primary);
  font-size: 0.9em;
  cursor: pointer;
}

main {
  padding: 30px 0;
}

.page-header {
  margin-bottom: 30px;
}

.page-header h1 {
  font-size: 1.8em;
  font-weight: 400;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
}

.search-box {
  margin: 20px 0;
}

.search-box input {
  width: 100%;
  max-width: 400px;
  padding: 10px 15px;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1em;
}

.section {
  margin: 30px 0;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.section-header h2 {
  font-size: 1.4em;
  font-weight: 400;
  color: var(--text-secondary);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
  text-decoration: none;
  color: var(--text-primary);
  transition: box-shadow 0.2s, transform 0.2s;
  display: block;
}

.card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
  text-decoration: none;
}

.card h3 {
  color: var(--link-color);
  margin-bottom: 8px;
  font-size: 1.1em;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95em;
}

.tags {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 2px 10px;
  font-size: 0.8em;
  color: var(--text-secondary);
}

.ootq-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.85em;
}

.ootq-low { background: #e8f5e9; color: #2e7d32; border: 1px solid #a5d6a7; }
.ootq-mid { background: #fff3e0; color: #ef6c00; border: 1px solid #ffcc80; }
.ootq-high { background: #fce4ec; color: #c62828; border: 1px solid #f48fb1; }
.ootq-top { background: #f3e5f5; color: #7b1fa2; border: 1px solid #ce93d8; }

[data-theme="dark"] .ootq-low { background: #1b3320; color: #81c784; border-color: #2e7d32; }
[data-theme="dark"] .ootq-mid { background: #3d2a1a; color: #ffb74d; border-color: #ef6c00; }
[data-theme="dark"] .ootq-high { background: #3d1a24; color: #ef5350; border-color: #c62828; }
[data-theme="dark"] .ootq-top { background: #2d1b3d; color: #ba68c8; border-color: #7b1fa2; }

.content-page {
  max-width: 900px;
}

.content-page h1 {
  font-size: 1.8em;
  font-weight: 400;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
  margin-bottom: 20px;
}

.content-body {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 25px;
  margin: 20px 0;
}

.content-body p {
  margin-bottom: 15px;
}

.content-body ul, .content-body ol {
  margin: 15px 0;
  padding-left: 25px;
}

.content-body li {
  margin-bottom: 8px;
}

.content-body img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  margin: 15px 0;
}

.breadcrumb {
  color: var(--text-secondary);
  font-size: 0.9em;
  margin-bottom: 15px;
}

.breadcrumb a {
  color: var(--text-secondary);
}

.breadcrumb span {
  margin: 0 8px;
}

.info-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 15px;
  margin: 20px 0;
}

footer {
  border-top: 1px solid var(--border-color);
  padding: 20px 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9em;
  margin-top: 40px;
}

.empty-state {
  text-align: center;
  padding: 40px;
  color: var(--text-secondary);
}

@media (max-width: 600px) {
  .card-grid {
    grid-template-columns: 1fr;
  }

  .header-inner {
    flex-wrap: wrap;
  }

  .page-header h1 {
    font-size: 1.5em;
  }
}