:root {
  --bg: #080c18;
  --bg2: #0d1230;
  --surface: #111639;
  --surface2: #1a2050;
  --border: #1e2860;
  --text: #e8ecf4;
  --text2: #8892b0;
  --accent: #00f0a0;
  --accent2: #00c080;
  --accent-dim: rgba(0,240,160,0.15);
  --blue: #4a9eff;
  --amber: #f0c040;
  --red: #ff4466;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 8px 32px rgba(0,0,0,0.4);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(8,12,24,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: 56px;
}
.nav-brand { display: flex; align-items: center; gap: 8px; cursor: pointer; }
.nav-logo { font-size: 22px; color: var(--accent); }
.nav-title { font-size: 18px; font-weight: 700; letter-spacing: -0.3px; }
.nav-badge {
  font-size: 10px; font-weight: 700; padding: 2px 6px;
  background: var(--accent); color: #000; border-radius: 4px;
  letter-spacing: 0.5px;
}
.nav-links { display: flex; gap: 4px; }
.nav-link {
  padding: 8px 16px; border-radius: 8px; font-size: 14px; font-weight: 500;
  color: var(--text2); transition: all .2s;
}
.nav-link:hover, .nav-link.active { color: var(--text); background: var(--surface); }

.page { display: none; padding: 56px 0 40px; animation: fadeIn .3s ease; }
.page.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* Home */
.hero {
  text-align: center; padding: 60px 20px 40px;
  background: linear-gradient(180deg, var(--bg2) 0%, transparent 100%);
}
.hero-title { font-size: 42px; font-weight: 800; letter-spacing: -1px; line-height: 1.2; }
.accent { color: var(--accent); }
.hero-sub { color: var(--text2); font-size: 15px; margin-top: 8px; }

.search-box {
  max-width: 640px; margin: 28px auto 0;
  display: flex; gap: 8px; background: var(--surface);
  border: 1px solid var(--border); border-radius: 50px;
  padding: 4px 4px 4px 20px; transition: border-color .2s, box-shadow .2s;
}
.search-box:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-dim); }
.search-box input {
  flex: 1; border: none; background: none; color: var(--text);
  font-size: 16px; font-family: var(--font); outline: none; height: 48px;
}
.search-box input::placeholder { color: var(--text2); }
.search-box button {
  display: flex; align-items: center; gap: 6px; padding: 0 24px;
  background: var(--accent); color: #000; border: none; border-radius: 50px;
  font-size: 15px; font-weight: 600; cursor: pointer; transition: all .2s;
  white-space: nowrap;
}
.search-box button:hover { background: var(--accent2); transform: scale(1.02); }
.search-box button svg { flex-shrink: 0; }

.source-toggles {
  display: flex; justify-content: center; gap: 8px; margin-top: 16px;
  flex-wrap: wrap;
}
.source-tag {
  display: flex; align-items: center; gap: 6px; padding: 6px 14px;
  border-radius: 20px; font-size: 13px; font-weight: 500; cursor: pointer;
  border: 1px solid var(--border); transition: all .2s; user-select: none;
}
.source-tag.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }
.source-tag:hover { border-color: var(--text2); }
.source-tag .dot { width: 8px; height: 8px; border-radius: 50%; }

.home-section { max-width: 700px; margin: 24px auto 0; padding: 0 20px; }
.section-header { font-size: 13px; font-weight: 600; color: var(--text2); margin-bottom: 12px; text-transform: uppercase; letter-spacing: 1px; display: flex; align-items: center; gap: 6px; }
.section-icon { font-size: 14px; }
.hot-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.hot-tag {
  padding: 8px 18px; border-radius: 20px; font-size: 14px; font-weight: 500;
  background: var(--surface); border: 1px solid var(--border); cursor: pointer;
  transition: all .2s;
}
.hot-tag:hover { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }

.recent-list { display: flex; flex-direction: column; gap: 4px; }
.recent-item {
  display: flex; align-items: center; gap: 8px; padding: 10px 14px;
  border-radius: var(--radius-sm); cursor: pointer; transition: background .15s; font-size: 14px;
}
.recent-item:hover { background: var(--surface); }
.recent-item .icon { color: var(--text2); }

.home-footer { text-align: center; color: var(--text2); font-size: 12px; padding: 40px 20px; opacity: 0.5; }

/* Results */
.results-header {
  position: sticky; top: 56px; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px; background: rgba(8,12,24,0.9); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border); gap: 12px;
}
.results-meta { display: flex; align-items: center; gap: 12px; flex: 1; min-width: 0; }
.results-meta #results-keyword { font-weight: 700; font-size: 16px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.results-meta #results-count { color: var(--text2); font-size: 13px; white-space: nowrap; }
.results-controls select {
  background: var(--surface); color: var(--text); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 6px 12px; font-size: 13px;
  font-family: var(--font); cursor: pointer; outline: none;
}

#results-list { max-width: 800px; margin: 0 auto; padding: 16px; display: flex; flex-direction: column; gap: 12px; }
.article-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; cursor: pointer; transition: all .2s;
}
.article-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.article-card .source-badge {
  display: inline-flex; align-items: center; gap: 4px; padding: 2px 10px;
  border-radius: 12px; font-size: 11px; font-weight: 600; margin-bottom: 8px;
  background: var(--bg2);
}
.article-card .title { font-size: 16px; font-weight: 600; line-height: 1.4; margin-bottom: 8px; color: var(--text); }
.article-card .title:hover { color: var(--accent); }
.article-card .authors { font-size: 13px; color: var(--text2); margin-bottom: 8px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.article-card .abstract { font-size: 14px; color: var(--text2); line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.article-card .meta { display: flex; align-items: center; gap: 16px; margin-top: 12px; font-size: 12px; color: var(--text2); }
.article-card .meta .stat { display: flex; align-items: center; gap: 4px; }

.loader { text-align: center; padding: 40px; color: var(--text2); display: flex; align-items: center; justify-content: center; gap: 12px; }
.spinner { width: 20px; height: 20px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.empty-state { text-align: center; padding: 60px 20px; }
.empty-icon { font-size: 48px; display: block; margin-bottom: 16px; }
.empty-state p { color: var(--text2); font-size: 15px; }
.empty-hint { font-size: 13px; margin-top: 4px; opacity: 0.6; }

/* Detail */
.detail-container { max-width: 800px; margin: 0 auto; padding: 24px; }
.detail-header { margin-bottom: 24px; }
.detail-header .source-badge { display: inline-flex; align-items: center; gap: 4px; padding: 4px 12px; border-radius: 12px; font-size: 12px; font-weight: 600; background: var(--bg2); margin-bottom: 12px; }
.detail-header h1 { font-size: 24px; font-weight: 700; line-height: 1.35; margin-bottom: 12px; }
.detail-header .meta-row { display: flex; flex-wrap: wrap; gap: 16px; font-size: 13px; color: var(--text2); }
.detail-header .meta-row span { display: flex; align-items: center; gap: 4px; }
.detail-section { margin-bottom: 24px; }
.detail-section h3 { font-size: 14px; font-weight: 600; color: var(--accent); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.5px; }
.detail-section .abstract-text { font-size: 15px; line-height: 1.8; color: var(--text2); }
.detail-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 20px; }
.detail-actions button {
  display: flex; align-items: center; gap: 6px; padding: 10px 20px;
  border-radius: var(--radius-sm); border: 1px solid var(--border);
  background: var(--surface); color: var(--text); font-size: 14px; font-weight: 500;
  cursor: pointer; transition: all .2s; font-family: var(--font);
}
.detail-actions button:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-dim); }
.detail-actions button.primary { background: var(--accent); color: #000; border-color: var(--accent); }
.detail-actions button.primary:hover { background: var(--accent2); }

.ai-summary-box { background: var(--surface2); border: 1px solid var(--accent); border-radius: var(--radius); padding: 16px; margin-top: 16px; }
.ai-summary-box .label { font-size: 11px; font-weight: 600; color: var(--accent); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; }
.ai-summary-box .content { font-size: 14px; line-height: 1.7; color: var(--text2); white-space: pre-wrap; }

/* AI Page */
.ai-header { text-align: center; padding: 40px 20px 24px; }
.ai-title { font-size: 28px; font-weight: 700; }
.ai-sub { color: var(--text2); font-size: 14px; margin-top: 4px; }
.ai-tabs { display: flex; justify-content: center; gap: 8px; margin-top: 20px; }
.ai-tab {
  padding: 10px 22px; border-radius: 50px; font-size: 14px; font-weight: 500;
  border: 1px solid var(--border); background: var(--surface); color: var(--text2);
  cursor: pointer; transition: all .2s; font-family: var(--font);
}
.ai-tab.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }
.ai-tab:hover { border-color: var(--text2); }
.ai-body { max-width: 700px; margin: 0 auto; padding: 0 20px 40px; }
.ai-input-area { display: flex; flex-direction: column; gap: 12px; }
.ai-input-area textarea {
  width: 100%; padding: 16px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border); color: var(--text);
  font-size: 15px; font-family: var(--font); line-height: 1.6; resize: vertical;
  outline: none; transition: border-color .2s;
}
.ai-input-area textarea:focus { border-color: var(--accent); }
.ai-submit-btn {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 32px; background: var(--accent); color: #000; border: none;
  border-radius: var(--radius-sm); font-size: 15px; font-weight: 600;
  cursor: pointer; transition: all .2s; font-family: var(--font);
  align-self: flex-end;
}
.ai-submit-btn:hover { background: var(--accent2); }
.ai-submit-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.ai-result-text { font-size: 15px; line-height: 1.8; color: var(--text2); white-space: pre-wrap; word-break: break-word; }
.ai-result-header { font-size: 13px; font-weight: 600; color: var(--accent); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 12px; padding-top: 24px; }

/* Responsive */
@media (max-width: 600px) {
  .hero-title { font-size: 28px; }
  .search-box { border-radius: 24px; padding-left: 14px; }
  .search-box input { font-size: 15px; height: 44px; }
  .search-box button { padding: 0 16px; font-size: 14px; }
  .results-header { flex-direction: column; align-items: flex-start; }
  .nav-links .nav-link { padding: 6px 12px; font-size: 13px; }
  .detail-header h1 { font-size: 20px; }
}