/* ============ PaperScout 主题变量 ============ */
:root {
  --bg: #f6f7fb;
  --bg-soft: #eef0f7;
  --card: #ffffff;
  --text: #1a2130;
  --muted: #66718c;
  --primary: #4056d6;
  --primary-2: #6d4fd8;
  --accent: #0ca678;
  --border: #e4e8f1;
  --shadow: 0 2px 14px rgba(26, 33, 48, 0.07);
  --shadow-lg: 0 10px 32px rgba(26, 33, 48, 0.12);
  --hero-text: #ffffff;
  --chip-bg: #f1f3fa;
  --radius: 14px;
}

html[data-theme="dark"] {
  --bg: #0f1320;
  --bg-soft: #161b2c;
  --card: #1a2036;
  --text: #e8ebf5;
  --muted: #929cb8;
  --primary: #7b8cff;
  --primary-2: #a17bff;
  --accent: #2ec99a;
  --border: #2a3150;
  --shadow: 0 2px 14px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 10px 32px rgba(0, 0, 0, 0.45);
  --hero-text: #f0f2ff;
  --chip-bg: #222942;
}

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

/* BUG 修复：hidden 属性必须优先于任何 display 设置（否则弹窗/对比栏加载即显示） */
[hidden] { display: none !important; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  transition: background 0.25s, color 0.25s;
}

.container { max-width: 960px; margin: 0 auto; padding: 0 20px; }

/* ============ 顶部导航 ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 58px;
}
.logo {
  font-size: 1.2rem;
  font-weight: 800;
  text-decoration: none;
  color: var(--text);
  letter-spacing: 0.3px;
}
.logo span {
  background: linear-gradient(120deg, var(--primary), var(--primary-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-stat { font-size: 0.8rem; color: var(--muted); }
.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--card);
  cursor: pointer;
  font-size: 1rem;
  transition: transform 0.15s;
}
.icon-btn:hover { transform: rotate(20deg) scale(1.08); }

/* ============ Hero ============ */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(130deg, #31449e 0%, #5636b8 55%, #7c3fd1 100%);
  padding: 72px 0 88px;
  text-align: center;
}
html[data-theme="dark"] .hero {
  background: linear-gradient(130deg, #17204a 0%, #2c1d63 55%, #40206b 100%);
}
.hero-inner { position: relative; z-index: 2; }
.hero h1 {
  color: var(--hero-text);
  font-size: clamp(1.7rem, 4.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: 1px;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(90deg, #ffd43b, #ff922b, #ff6b9d);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.tagline { color: rgba(255, 255, 255, 0.82); margin-top: 10px; font-size: 1rem; }

.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.45;
  animation: float 9s ease-in-out infinite;
}
.blob-1 { width: 320px; height: 320px; background: #64a6ff; top: -80px; left: -60px; }
.blob-2 { width: 280px; height: 280px; background: #c174ff; bottom: -100px; right: -40px; animation-delay: -4s; }
@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(24px) scale(1.06); }
}

/* ============ 检索面板（上浮卡片） ============ */
.search-panel {
  margin-top: -52px;
  position: relative;
  z-index: 5;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 22px;
}

.search-row { display: flex; align-items: center; gap: 10px; }
.search-icon { font-size: 1.1rem; opacity: 0.6; }
#q {
  flex: 1;
  padding: 14px 16px 14px 4px;
  font-size: 1.02rem;
  border: none;
  background: transparent;
  color: var(--text);
}
#q:focus { outline: none; }
#q::placeholder { color: var(--muted); }

#search-btn {
  padding: 12px 34px;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(120deg, var(--primary), var(--primary-2));
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.12s, box-shadow 0.12s;
}
#search-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 18px color-mix(in srgb, var(--primary) 40%, transparent); }
#search-btn:disabled { opacity: 0.6; cursor: wait; transform: none; }

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 18px;
  margin-top: 12px;
  padding-top: 14px;
  border-top: 1px dashed var(--border);
}
/* 筛选条件分组：标签在上，控件在下，排版更清晰 */
.f-group { display: flex; flex-direction: column; gap: 4px; }
.f-label {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 1px;
  padding-left: 2px;
}
.filters input, .filters select {
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: 9px;
  font-size: 0.9rem;
  background: var(--bg-soft);
  color: var(--text);
  transition: border-color 0.15s;
}
.filters input:focus, .filters select:focus { outline: none; border-color: var(--primary); }
#author { min-width: 170px; flex: 1; }
.year-range { display: flex; align-items: center; gap: 6px; color: var(--muted); }
.year-range input { width: 92px; }
.quick-years { display: flex; gap: 5px; }
.qy {
  padding: 8px 11px;
  font-size: 0.8rem;
  color: var(--muted);
  background: var(--chip-bg);
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.15s;
}
.qy:hover { color: var(--primary); border-color: var(--primary); }
.qy.active { background: color-mix(in srgb, var(--primary) 14%, var(--card)); color: var(--primary); font-weight: 600; }

.btn-translate {
  margin-top: 6px;
  background: none;
  border: none;
  color: var(--primary-2);
  font-size: 0.82rem;
  cursor: pointer;
  padding: 2px 0;
  margin-left: 10px;
}
.btn-translate:hover { text-decoration: underline; }
.btn-translate:disabled { opacity: 0.5; cursor: wait; }

/* 来源标签 */
.sources {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--chip-bg);
  border: 1px solid transparent;
  font-size: 0.86rem;
  cursor: pointer;
  user-select: none;
  transition: all 0.15s;
  color: var(--muted);
}
.chip:hover { border-color: var(--primary); color: var(--text); }
.chip:has(input:checked) {
  background: color-mix(in srgb, var(--primary) 12%, var(--card));
  border-color: var(--primary);
  color: var(--text);
  font-weight: 600;
}
.chip input { position: absolute; opacity: 0; pointer-events: none; }
.dot { width: 8px; height: 8px; border-radius: 50%; }
.dot-arxiv { background: #b197fc; }
.dot-openalex { background: #74c0fc; }
.dot-crossref { background: #63e6be; }
.dot-semanticscholar { background: #ffa8a8; }
.dot-pubmed { background: #a9e34b; }
.dot-dblp { background: #ffd43b; }
.dot-doaj { background: #ff922b; }
.dot-europepmc { background: #f783ac; }
.dot-openaire { background: #4dd0e1; }
.dot-baiduxueshu { background: #4263eb; }
.dot-zenodo { background: #20c997; }

/* ============ 状态提示 ============ */
.status {
  margin: 20px 0 6px;
  padding: 11px 16px;
  border-radius: 10px;
  font-size: 0.92rem;
  background: color-mix(in srgb, var(--primary) 9%, var(--card));
  color: var(--primary);
  border: 1px solid color-mix(in srgb, var(--primary) 25%, transparent);
}
.status.error {
  background: color-mix(in srgb, #e03131 9%, var(--card));
  color: #e03131;
  border-color: color-mix(in srgb, #e03131 30%, transparent);
}

/* ============ 结果列表 ============ */
.results { margin-top: 14px; display: grid; gap: 14px; }

.paper-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px 22px;
  transition: transform 0.14s, box-shadow 0.14s;
  animation: rise 0.3s ease both;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.paper-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }

.paper-title { font-size: 1.08rem; font-weight: 700; line-height: 1.45; }
.paper-title a { color: var(--text); text-decoration: none; }
.paper-title a:hover { color: var(--primary); }

.paper-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 9px 0 4px;
  font-size: 0.85rem;
  color: var(--muted);
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 600;
  background: var(--chip-bg);
  color: var(--muted);
}
.badge .dot { width: 7px; height: 7px; }
.badge.oa { background: color-mix(in srgb, var(--accent) 14%, transparent); color: var(--accent); }
.badge.cite { background: color-mix(in srgb, #e8590c 12%, transparent); color: #e8590c; }

.paper-authors { font-size: 0.88rem; color: var(--muted); }
.author-link:hover { color: var(--primary); text-decoration: underline !important; }

.paper-abstract {
  margin-top: 8px;
  font-size: 0.9rem;
  color: var(--muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: none;
}
.paper-abstract.expanded { -webkit-line-clamp: unset; }

.abs-toggle, .copy-btn {
  margin-top: 6px;
  background: none;
  border: none;
  color: var(--primary);
  font-size: 0.82rem;
  cursor: pointer;
  padding: 2px 0;
}
.abs-toggle:hover, .copy-btn:hover { text-decoration: underline; }

.paper-actions {
  margin-top: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.btn-open {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  font-size: 0.88rem;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(120deg, var(--accent), #0b9e8a);
  border: none;
  border-radius: 9px;
  text-decoration: none;
  transition: transform 0.12s, box-shadow 0.12s;
}
.btn-open:hover { transform: translateY(-1px); box-shadow: 0 5px 16px color-mix(in srgb, var(--accent) 45%, transparent); }

.btn-pdf {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--primary);
  background: color-mix(in srgb, var(--primary) 10%, var(--card));
  border: 1px solid color-mix(in srgb, var(--primary) 35%, transparent);
  border-radius: 9px;
  text-decoration: none;
  transition: all 0.12s;
}
.btn-pdf:hover { background: color-mix(in srgb, var(--primary) 20%, var(--card)); }

/* ============ 关键词高亮 ============ */
mark {
  background: color-mix(in srgb, #ffd43b 50%, transparent);
  color: inherit;
  border-radius: 3px;
  padding: 0 1px;
}
html[data-theme="dark"] mark { background: color-mix(in srgb, #ffd43b 30%, transparent); }

/* ============ 骨架屏 / 空状态 ============ */
.skeleton {
  height: 116px;
  border-radius: var(--radius);
  background: linear-gradient(90deg, var(--bg-soft) 25%, var(--card) 50%, var(--bg-soft) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.2s infinite;
  border: 1px solid var(--border);
}
@keyframes shimmer { from { background-position: 200% 0; } to { background-position: -200% 0; } }

.empty { text-align: center; color: var(--muted); padding: 48px 0; }
.empty .big { font-size: 2.4rem; display: block; margin-bottom: 10px; }

/* ============ 最新论文雷达（爬虫） ============ */
.trending { margin-top: 36px; }
.trending-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.trending-head h2 { font-size: 1.15rem; }
.trending-meta { font-size: 0.8rem; color: var(--muted); }
.trending-note { font-size: 0.82rem; color: var(--muted); margin: 4px 0 14px; }
.trending-list { display: grid; gap: 10px; }
.trend-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 13px 16px;
  transition: transform 0.12s;
}
.trend-item:hover { transform: translateX(4px); }
.trend-no {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-size: 0.78rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(120deg, var(--primary), var(--primary-2));
}
.trend-title { font-size: 0.93rem; font-weight: 600; }
.trend-title a { color: var(--text); text-decoration: none; }
.trend-title a:hover { color: var(--primary); }
.trend-authors { font-size: 0.8rem; color: var(--muted); margin-top: 2px; }

/* ============ 分页 ============ */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 22px;
}
.page-btn {
  padding: 9px 22px;
  font-size: 0.9rem;
  color: var(--text);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.15s;
}
.page-btn:hover:not(:disabled) { border-color: var(--primary); color: var(--primary); }
.page-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.page-info { font-size: 0.9rem; color: var(--muted); font-weight: 600; }

/* ============ 刷新按钮 ============ */
.refresh-btn {
  margin-left: auto;
  padding: 5px 14px;
  font-size: 0.8rem;
  color: var(--primary);
  background: color-mix(in srgb, var(--primary) 10%, var(--card));
  border: 1px solid color-mix(in srgb, var(--primary) 30%, transparent);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
}
.refresh-btn:hover { background: color-mix(in srgb, var(--primary) 20%, var(--card)); }
.refresh-btn:disabled { opacity: 0.5; cursor: wait; }

/* ============ 最近检索 / 热词 ============ */
.history {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}
.history-chips { display: flex; flex-wrap: wrap; gap: 6px; flex: 1; }
.h-chip {
  padding: 4px 12px;
  font-size: 0.8rem;
  color: var(--muted);
  background: var(--chip-bg);
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
}
.h-chip:hover { color: var(--primary); border-color: var(--primary); }
.link-btn {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 0.78rem;
  cursor: pointer;
}
.link-btn:hover { color: #e03131; }

/* ============ AI 工具栏 / 面板 ============ */
.ai-toolbar { display: flex; gap: 10px; margin-top: 16px; }
.ai-btn {
  padding: 9px 18px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.15s;
}
.ai-btn:hover:not(:disabled) { border-color: var(--primary-2); color: var(--primary-2); }
.ai-btn:disabled { opacity: 0.5; cursor: wait; }
.ai-panel {
  margin-top: 12px;
  padding: 18px 20px;
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary-2) 8%, var(--card)), var(--card));
  border: 1px solid color-mix(in srgb, var(--primary-2) 30%, transparent);
  border-radius: var(--radius);
  font-size: 0.92rem;
  line-height: 1.8;
  white-space: pre-wrap;
  animation: rise 0.3s ease both;
}
.ai-panel .ai-src {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
  font-size: 0.82rem;
  color: var(--muted);
}
.ai-panel .ai-src a { color: var(--primary); text-decoration: none; }

/* ============ 收藏星标 ============ */
.fav-btn {
  background: none;
  border: none;
  font-size: 1.05rem;
  cursor: pointer;
  padding: 2px 4px;
  opacity: 0.45;
  transition: transform 0.15s, opacity 0.15s;
}
.fav-btn:hover { transform: scale(1.2); opacity: 1; }
.fav-btn.active { opacity: 1; }

.title-tr {
  background: none;
  border: none;
  color: var(--primary-2);
  font-size: 0.78rem;
  cursor: pointer;
  margin-left: 8px;
  vertical-align: middle;
}
.title-tr:hover { text-decoration: underline; }

/* ============ 对比栏 / 弹窗 ============ */
.compare-bar {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  z-index: 90;
  font-size: 0.88rem;
}
.cmp-check { accent-color: var(--primary); cursor: pointer; }

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 14, 25, 0.55);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.modal-card {
  position: relative;
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-width: 720px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 24px;
  animation: rise 0.25s ease both;
}
.modal-close {
  position: absolute;
  top: 12px;
  right: 14px;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  cursor: pointer;
  color: var(--muted);
}
.modal-close:hover { color: var(--text); }
.modal-card h3 { margin-bottom: 14px; font-size: 1.05rem; }
.modal-card table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
.modal-card th, .modal-card td { padding: 8px 10px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
.modal-card th { color: var(--muted); font-weight: 600; white-space: nowrap; }
.export-row { display: flex; gap: 10px; margin-top: 14px; }
.export-row .page-btn { font-size: 0.82rem; padding: 7px 14px; }

/* ============ Toast / Footer ============ */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 0.88rem;
  box-shadow: var(--shadow-lg);
  z-index: 100;
  animation: rise 0.25s ease both;
}

.footer { margin: 44px 0 30px; text-align: center; font-size: 0.8rem; color: var(--muted); line-height: 1.9; }

/* ============ 响应式 ============ */
@media (max-width: 640px) {
  .hero { padding: 52px 0 72px; }
  .search-row { flex-wrap: wrap; padding: 12px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg-soft); }
  .search-row #q { flex: 1 1 100%; padding: 10px 4px; border-bottom: 1px solid var(--border); }
  .search-row .search-icon { display: none; }
  #search-btn { flex: 1; margin-top: 4px; }
  .year-range { display: none; }
  #author { min-width: 100%; }
  .nav-stat { display: none; }
}