/* ── kami 风格参考：纸张质感、留白、墨蓝强调色 ─────────────────── */
:root {
  /* 色 — Kami warm palette */
  --bg: #f5f4ed;                                    /* parchment */
  --surface: #faf9f5;                               /* ivory */
  --ink: #141413;                                    /* near black */
  --ink-light: #3d3d3a;                              /* dark warm */
  --ink-sub: #504e49;                                /* olive subtext */
  --ink-muted: #6b6a64;                              /* stone tertiary */
  --accent: #1B365D;                                 /* ink blue */
  --accent-hover: #142d4a;                           /* ink blue deep */
  --accent-bg: rgba(27, 54, 93, 0.06);              /* brand whisper */
  --border: #e8e6dc;                                 /* warm border */
  --border-soft: #e5e3d8;                            /* soft row separator */
  --shadow: rgba(0, 0, 0, 0.05);                     /* whisper shadow */
  --radius: 8px;

  /* 字体 — Kami serif-first */
  --font-body: "TsangerJinKai02", "Source Han Serif SC", "Noto Serif CJK SC", "Songti SC", "STSong", Georgia, serif;
  --font-sans: var(--font-body);                     /* Kami: sans = serif */
  --mono: "JetBrains Mono", "SF Mono", "Fira Code", Consolas, Monaco, monospace;

  /* 布局 */
  --max-width: 1080px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

/* ── Header ─────────────────────────────────────────────────────── */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-bar {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-brand {
  font-family: var(--font-body);
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--ink);
}

.nav-links {
  display: flex;
  gap: 16px;
  margin-left: auto;
}
.nav-links a {
  font-size: 0.9rem;
  color: var(--ink-light);
}
.nav-links a:hover {
  color: var(--accent);
}

/* ── Container ──────────────────────────────────────────────────── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px;
}

/* ── Date Navigation ────────────────────────────────────────────── */
.date-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.date-title {
  font-family: var(--font-body);
  font-size: 1.5rem;
  font-weight: 500;
}

.date-nav-btn {
  display: inline-block;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--ink-light);
  transition: all 0.2s;
}
.date-nav-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* ── Date Chips ─────────────────────────────────────────────────── */
.date-quick-nav {
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--ink-light);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.date-chip {
  padding: 4px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.8rem;
  color: var(--ink-light);
}
.date-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}
.date-chip.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ── Paper Card ─────────────────────────────────────────────────── */
.paper-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.paper-card {
  background: var(--surface);
  border: 0.5px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  transition: box-shadow 0.2s;
}
.paper-card:hover {
  box-shadow: 0 2px 12px var(--shadow);
}

.paper-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
}

.paper-title {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 500;
  line-height: 1.5;
  flex: 1;
}
.paper-title a {
  color: var(--ink);
}
.paper-title a:hover {
  color: var(--accent);
}

.paper-upvotes {
  font-size: 0.85rem;
  color: var(--ink-light);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.paper-one-line,
.paper-abstract-preview {
  margin-top: 8px;
  color: var(--ink-light);
  font-size: 0.92rem;
  line-height: 1.6;
}

.paper-meta {
  margin-top: 8px;
  font-size: 0.82rem;
  color: var(--ink-light);
}

.paper-tags {
  margin-top: 8px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 1px 5px;
  background: #EEF2F7;
  color: var(--accent);
  border-radius: 2px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

.paper-footer {
  margin-top: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.summary-badge {
  font-size: 0.8rem;
  padding: 2px 8px;
  border-radius: 2px;
}
.summary-none {
  background: var(--border);
  color: var(--ink-muted);
}
.summary-pending {
  background: rgba(27, 54, 93, 0.06);
  color: var(--ink-sub);
}
.summary-processing {
  background: rgba(27, 54, 93, 0.10);
  color: var(--accent);
}
.summary-done {
  background: rgba(27, 54, 93, 0.08);
  color: #3d6e3d;
}
.summary-failed,
.summary-permanent_failure {
  background: rgba(140, 40, 40, 0.08);
  color: #8c2828;
}

.btn-detail {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 500;
}

/* ── Empty State ────────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--ink-light);
}
.empty-state p:first-child {
  font-size: 1.2rem;
}
.hint {
  font-size: 0.85rem;
  margin-top: 8px;
}

/* ── Paper Detail ───────────────────────────────────────────────── */
.paper-detail {
  max-width: 780px;
  margin: 0 auto;
}

.back-link {
  display: inline-block;
  margin-bottom: 16px;
  font-size: 0.85rem;
  color: var(--ink-light);
}

.detail-title {
  font-family: var(--font-body);
  font-size: 1.6rem;
  font-weight: 500;
  line-height: 1.4;
  margin-bottom: 12px;
}
.detail-title .title-en {
  display: block;
  font-size: 1rem;
  font-weight: 400;
  color: var(--ink-light);
  margin-top: 4px;
}

.detail-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.88rem;
  color: var(--ink-light);
  margin-bottom: 12px;
}

.detail-tags {
  margin-bottom: 12px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.detail-links {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}
.ext-link {
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--ink-light);
}
.ext-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* ── Summary Sections ───────────────────────────────────────────── */
.summary-section {
  margin-bottom: 24px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.summary-section h2 {
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: 8px;
  color: var(--accent);
}

.summary-section p {
  font-size: 0.92rem;
  line-height: 1.8;
}

.one-line {
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.6;
}

.abstract-section {
  background: #faf8f5;
}
.abstract-en {
  font-size: 0.9rem;
  color: var(--ink-light);
  font-style: italic;
}

/* ── Summary Placeholders ───────────────────────────────────────── */
.summary-placeholder {
  padding: 24px;
  text-align: center;
  border-radius: var(--radius);
  margin-bottom: 24px;
}
.summary-placeholder.processing {
  background: rgba(27, 54, 93, 0.06);
}
.summary-placeholder.failed {
  background: rgba(140, 40, 40, 0.06);
}
.summary-placeholder.none {
  background: var(--border);
}
.error-detail {
  font-size: 0.85rem;
  color: #8c2828;
  margin-top: 8px;
}

.quality-warning {
  padding: 10px 16px;
  background: rgba(27, 54, 93, 0.06);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--ink-sub);
  margin-bottom: 16px;
}

/* ── Footer ─────────────────────────────────────────────────────── */
.site-footer {
  margin-top: 48px;
  padding: 20px;
  text-align: center;
  font-size: 0.8rem;
  color: var(--ink-light);
  border-top: 1px solid var(--border);
}

/* ── Responsive ─────────────────────────────────────────────────── */
/* ── Nav Search ──────────────────────────────────────────────────── */
.nav-search {
  display: flex;
  align-items: center;
  margin-right: auto;
}

.nav-search-input {
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  background: var(--bg);
  color: var(--ink);
  width: 180px;
  transition: border-color 0.2s;
  font-family: var(--font-sans);
}
.nav-search-input:focus {
  outline: none;
  border-color: var(--accent);
}

/* ── Search Page ────────────────────────────────────────────────── */
.search-form {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.search-input {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: var(--font-sans);
  background: var(--surface);
  color: var(--ink);
}
.search-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(45, 95, 138, 0.1);
}

.search-btn {
  padding: 10px 24px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
}
.search-btn:hover {
  background: var(--accent-hover);
}

/* ── Tag Filter ─────────────────────────────────────────────────── */
.tag-filter {
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}
.tag-filter-label {
  font-size: 0.85rem;
  color: var(--ink-light);
}
.tag-chip {
  display: inline-block;
  padding: 4px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.8rem;
  color: var(--ink-light);
}
.tag-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}
.tag-chip.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ── Search Meta & Sort ─────────────────────────────────────────── */
.search-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  font-size: 0.9rem;
  color: var(--ink-light);
}
.sort-toggle a {
  color: var(--ink-light);
  font-size: 0.85rem;
}
.sort-toggle a.active {
  color: var(--accent);
  font-weight: 500;
}
.sort-toggle a:hover {
  color: var(--accent);
  text-decoration: none;
}
.sort-divider {
  color: var(--border);
  margin: 0 4px;
}

/* ── Search Highlight ───────────────────────────────────────────── */
mark {
  background: rgba(27, 54, 93, 0.10);
  color: var(--ink);
  padding: 1px 2px;
  border-radius: 2px;
}

.paper-snippet {
  margin-top: 8px;
  color: var(--ink-light);
  font-size: 0.92rem;
  line-height: 1.6;
}
.paper-date {
  margin-left: 12px;
  font-size: 0.82rem;
  color: var(--ink-light);
}

/* ── Pagination ─────────────────────────────────────────────────── */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-top: 32px;
  padding-top: 16px;
}
.page-btn {
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--ink-light);
}
.page-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}
.page-info {
  font-size: 0.85rem;
  color: var(--ink-light);
}

/* ── Reading List ───────────────────────────────────────────────── */
.page-heading {
  font-family: var(--font-body);
  font-size: 1.5rem;
  font-weight: 500;
  margin-bottom: 20px;
}

.reading-list-filters {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.filter-chip {
  display: inline-block;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--ink-light);
}
.filter-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}
.filter-chip.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ── Paper Card Footer (enhanced) ──────────────────────────────── */
.paper-footer {
  margin-top: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.paper-footer-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.paper-footer-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ── Bookmark Button ────────────────────────────────────────────── */
.btn-bookmark {
  background: none;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  color: var(--ink-light);
  padding: 2px 4px;
  transition: color 0.2s;
  line-height: 1;
}
.btn-bookmark:hover {
  color: var(--accent);
}
.btn-bookmark.active {
  color: var(--accent);
}

/* ── Reading Badge ──────────────────────────────────────────────── */
.reading-badge {
  font-size: 0.75rem;
  padding: 2px 6px;
  border-radius: 2px;
}
.reading-unread {
  background: var(--border);
  color: var(--ink-muted);
}
.reading-skimmed {
  background: rgba(27, 54, 93, 0.08);
  color: var(--accent);
}
.reading-read_summary {
  background: rgba(27, 54, 93, 0.06);
  color: #3d6e3d;
}
.reading-read_full {
  background: rgba(27, 54, 93, 0.10);
  color: #3d6e3d;
  font-weight: 500;
}

/* ── Responsive ─────────────────────────────────────────────────── */
@media (max-width: 880px) {
  .container {
    padding: 20px 32px;
  }
  .charts-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 16px;
  }
  .nav-bar {
    padding: 10px 16px;
    flex-wrap: wrap;
  }
  .nav-search-input {
    width: 120px;
  }
  .nav-links {
    gap: 12px;
    margin-left: 0;
    width: 100%;
    justify-content: center;
  }
  .date-nav {
    gap: 8px;
  }
  .date-title {
    font-size: 1.2rem;
  }
  .paper-card {
    padding: 14px 16px;
  }
  .detail-title {
    font-size: 1.3rem;
  }
  .detail-meta {
    flex-direction: column;
    gap: 4px;
  }
  .search-form {
    flex-direction: column;
  }
  .reading-list-filters {
    gap: 4px;
  }
  .filter-chip {
    padding: 4px 10px;
    font-size: 0.8rem;
  }
}

/* ── Search Mode Toggle ───────────────────────────────────────── */
.search-mode-toggle {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.mode-option {
  padding: 8px 14px;
  font-size: 0.85rem;
  color: var(--ink-light);
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 4px;
}
.mode-option input[type="radio"] {
  display: none;
}
.mode-option:hover {
  background: var(--bg);
}
.mode-option.active {
  background: var(--accent);
  color: #fff;
}

/* ── Similarity Score ──────────────────────────────────────────── */
.similarity-score {
  font-size: 0.8rem;
  color: var(--accent);
  white-space: nowrap;
  padding: 2px 8px;
  background: #EEF2F7;
  border-radius: 4px;
  font-variant-numeric: tabular-nums;
}

/* ── Similar Papers ────────────────────────────────────────────── */
.similar-papers {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.similar-papers h2 {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 500;
  margin-bottom: 12px;
  color: var(--accent);
}
.similar-paper-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.similar-paper-item:last-child {
  border-bottom: none;
}
.similar-paper-title a {
  font-size: 0.92rem;
  color: var(--ink);
}
.similar-paper-title a:hover {
  color: var(--accent);
}
.similar-paper-dist {
  font-size: 0.8rem;
  color: var(--ink-light);
}

/* ── Trends Dashboard ──────────────────────────────────────────── */
.trends-page h1 {
  font-family: var(--font-body);
  font-size: 1.5rem;
  font-weight: 500;
  margin-bottom: 24px;
}
.charts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 32px;
}
.chart-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.chart-card h2 {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: 12px;
  color: var(--accent);
}
.chart-card canvas {
  width: 100% !important;
  max-height: 300px;
}

/* ── Compare Page ──────────────────────────────────────────────── */
.compare-page h1 {
  font-family: var(--font-body);
  font-size: 1.5rem;
  font-weight: 500;
  margin-bottom: 24px;
}
.compare-table-wrapper {
  overflow-x: auto;
  margin-bottom: 24px;
}
.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.88rem;
}
.compare-table th,
.compare-table td {
  padding: 12px 16px;
  border: 1px solid var(--border);
  vertical-align: top;
  text-align: left;
}
.compare-table th {
  background: var(--bg);
  font-weight: 500;
  color: var(--ink-light);
  white-space: nowrap;
  min-width: 100px;
}
.compare-table td.field-label {
  background: var(--bg);
  font-weight: 500;
  color: var(--ink);
  white-space: nowrap;
  min-width: 90px;
}
.compare-table td.paper-col {
  min-width: 200px;
}
.compare-table td .no-summary {
  color: var(--ink-light);
  font-style: italic;
}

/* ── Image Gallery ─────────────────────────────────────────────── */
.image-gallery {
  margin-top: 24px;
}
.image-gallery h2 {
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: 12px;
  color: var(--accent);
}
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.gallery-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
}
.gallery-item .gallery-caption {
  padding: 8px 12px;
  font-size: 0.8rem;
  color: var(--ink-light);
  text-align: center;
}

/* ── 前置知识卡片 ── */
.prerequisites-list {
  display: grid;
  gap: 1rem;
}
.concept-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.2rem;
}
.concept-card h3 {
  margin: 0 0 0.4rem 0;
  font-size: 1rem;
  color: var(--accent);
}
.concept-card p {
  margin: 0.3rem 0 0 0;
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--ink);
}
.concept-why {
  font-style: italic;
  color: var(--ink-light) !important;
  border-left: 3px solid var(--accent);
  padding-left: 0.8rem;
  margin-top: 0.5rem !important;
}

/* ── 核心创新点 ── */
.key-idea {
  background: linear-gradient(135deg, var(--accent-bg), var(--surface));
  border-left: 4px solid var(--accent);
  padding: 1rem 1.2rem;
  border-radius: 0 8px 8px 0;
  margin: 1rem 0;
}

/* ── 可折叠详情 ── */
.summary-section details {
  margin: 0.8rem 0;
}
.summary-section details summary {
  cursor: pointer;
  font-weight: 500;
  color: var(--accent);
  padding: 0.4rem 0;
  user-select: none;
}
.summary-section details summary:hover {
  text-decoration: underline;
}
.summary-section details[open] summary {
  margin-bottom: 0.5rem;
}

/* ── 内联图片 ── */
.inline-figure {
  margin: 1.2rem 0;
  text-align: center;
}
.inline-figure img {
  max-width: 100%;
  border-radius: 6px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  cursor: zoom-in;
  transition: box-shadow 0.2s;
}
.inline-figure img:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.14);
}
.inline-figure figcaption {
  margin-top: 0.4rem;
  font-size: 0.85rem;
  color: var(--ink-light);
}

/* ── 图片灯箱 ── */
.lightbox-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s;
}
.lightbox-overlay.active {
  opacity: 1;
  visibility: visible;
}
.lightbox-overlay img {
  max-width: 95vw;
  max-height: 95vh;
  object-fit: contain;
  border-radius: 4px;
  box-shadow: 0 0 40px rgba(0, 0, 0, 0.4);
}

/* ── Benchmark 表格 ── */
.benchmarks-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.9rem;
}
.benchmarks-table th {
  background: var(--bg);
  font-weight: 500;
  padding: 0.5rem 0.8rem;
  text-align: left;
  border-bottom: 2px solid var(--border);
}
.benchmarks-table td {
  padding: 0.5rem 0.8rem;
  border-bottom: 1px solid var(--border);
}
.benchmarks-table .improvement {
  color: #3d6e3d;
  font-weight: 500;
}

/* ── 研究动机 ── */
.motivation-block p {
  margin-bottom: 0.8rem;
}