/* ───────── Theme: 素雅 — ink-wash neutrals + celadon × bronze ───────── */
:root {
  --bg-start: #faf7f2;       /* warm xuan-paper */
  --bg-end:   #f1f0eb;       /* cool stone */
  --card:     #ffffff;
  --card-accent: #f5f2ec;    /* cream */
  --ink:      #2d2e33;       /* warm charcoal, not pure black */
  --ink-muted:#8b8d92;       /* warm gray */
  --border:   #e7e3da;       /* warm subtle */
  --accent:   #6b7d6e;       /* 青灰 celadon-sage */
  --accent-2: #9b8264;       /* 烟褐 muted bronze */
  --accent-soft: rgba(107, 125, 110, 0.10);
  --accent-soft-2: rgba(155, 130, 100, 0.10);
  --danger:   #a64b4b;       /* muted brick */
  --shadow-sm: 0 1px 2px rgba(45, 46, 51, 0.04), 0 1px 4px rgba(45, 46, 51, 0.05);
  --shadow-md: 0 4px 14px rgba(45, 46, 51, 0.06), 0 2px 6px rgba(45, 46, 51, 0.04);
  --radius: 14px;
  --radius-sm: 10px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "Inter", "Segoe UI", system-ui, -apple-system,
    BlinkMacSystemFont, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(1400px 700px at 12% -10%, rgba(107, 125, 110, 0.05), transparent 60%),
    radial-gradient(1200px 600px at 110% 10%, rgba(155, 130, 100, 0.05), transparent 60%),
    linear-gradient(180deg, var(--bg-start) 0%, var(--bg-end) 100%);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ───────── Top bar ───────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(160%) blur(12px);
  background: rgba(255, 255, 255, 0.78);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 40px; height: 40px;
  border-radius: 12px;
  background: var(--ink);
  color: var(--bg-start);
  display: grid; place-items: center;
  font-weight: 700; font-size: 20px;
  letter-spacing: -0.02em;
}
.brand-title {
  font-weight: 800; font-size: 18px; letter-spacing: -0.01em;
}
.brand-sub {
  font-size: 12px; color: var(--ink-muted);
}
.tabs { display: flex; gap: 4px; }
.tab {
  background: transparent;
  border: 0;
  padding: 8px 18px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 14px;
  color: var(--ink-muted);
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s, color 0.15s;
}
.tab:hover { color: var(--ink); background: var(--accent-soft); }
.tab.active {
  background: var(--ink);
  color: var(--bg-start);
}

/* ───────── Tab panes ───────── */
.tab-pane {
  display: none;
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}
.tab-pane.active { display: block; }

/* ───────── Feed (Tab 1) ───────── */
.feed-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-muted);
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s;
}
.chip:hover { color: var(--accent); border-color: var(--accent); }
.chip.active {
  background: var(--ink);
  border-color: var(--ink);
  color: white;
}
.feed-meta { font-size: 13px; color: var(--ink-muted); }

/* Xiaohongshu-style waterfall (CSS columns) */
.feed-masonry {
  column-count: 2;
  column-gap: 14px;
}
@media (min-width: 720px) { .feed-masonry { column-count: 3; column-gap: 16px; } }
@media (min-width: 1024px) { .feed-masonry { column-count: 4; column-gap: 18px; } }

.paper-card {
  break-inside: avoid;
  background: var(--card);
  border-radius: var(--radius);
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  display: block;
  width: 100%;
}
.paper-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.paper-card-img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--card-accent);
  object-fit: cover;
}
.paper-card-body { padding: 10px 12px 12px; }
.paper-card-headline {
  font-weight: 700;
  font-size: 15px;
  line-height: 1.32;
  color: var(--ink);
  margin: 0 0 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.paper-card-subtitle {
  font-size: 12px;
  line-height: 1.4;
  color: var(--ink-muted);
  margin: 0 0 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.paper-card-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  color: var(--ink-muted);
}
.paper-card-foot .venue {
  background: var(--accent-soft);
  color: var(--accent);
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 600;
}
.paper-card-foot .likes {
  display: inline-flex; align-items: center; gap: 4px;
}

.feed-empty, .ds-empty {
  text-align: center;
  padding: 60px 20px;
  color: var(--ink-muted);
  font-size: 14px;
}

/* ───────── Paper detail modal ───────── */
.paper-body { padding: 0; }
.paper-body .hero {
  width: 100%;
  max-height: 360px;
  object-fit: cover;
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--card-accent);
}
.paper-body .paper-head {
  padding: 20px 28px 0;
}
.paper-body h2.headline {
  font-size: 24px;
  margin: 0 0 4px;
  line-height: 1.25;
}
.paper-body .paper-title {
  font-size: 15px;
  color: var(--ink-muted);
  margin: 0 0 12px;
  font-style: italic;
}
.paper-body .paper-meta {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin-bottom: 16px;
}
.paper-body .pill {
  background: var(--accent-soft);
  color: var(--accent);
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 500;
}
.paper-body .pill.sky {
  background: var(--accent-soft-2);
  color: var(--accent-2);
}
.paper-body .paper-content {
  padding: 0 28px 28px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink);
}
.paper-body .paper-content h1,
.paper-body .paper-content h2,
.paper-body .paper-content h3 {
  margin-top: 1.4em;
  margin-bottom: 0.4em;
}
.paper-body .paper-content a {
  color: var(--accent);
  text-decoration: none;
}
.paper-body .paper-content a:hover { text-decoration: underline; }
.paper-body .paper-content code {
  background: var(--card-accent);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.9em;
}
.paper-body .paper-content pre {
  background: var(--card-accent);
  border: 1px solid var(--border);
  padding: 12px;
  border-radius: 10px;
  overflow-x: auto;
}
.paper-body .paper-content img {
  max-width: 100%;
  border-radius: 10px;
  margin: 12px 0;
}
.paper-body .actions-row {
  padding: 12px 28px 0;
  display: flex; gap: 8px; flex-wrap: wrap;
}

/* ───────── Datasets (Tab 2) ───────── */
.ds-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.ds-header h1 {
  font-size: 26px;
  letter-spacing: -0.02em;
  margin: 0 0 4px;
}
.ds-sub {
  margin: 0;
  color: var(--ink-muted);
  font-size: 14px;
  max-width: 600px;
}
.btn-primary {
  background: var(--ink);
  color: var(--bg-start);
  border: 0;
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s, transform 0.15s;
}
.btn-primary:hover { background: var(--accent); transform: translateY(-1px); }
.btn-secondary {
  background: var(--card);
  color: var(--ink);
  border: 1px solid var(--border);
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
  font-family: inherit;
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

.table-filters {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
  box-shadow: var(--shadow-sm);
}
.filters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}
.filters-grid label {
  display: flex;
  flex-direction: column;
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-muted);
  gap: 4px;
}
.filters-grid input,
.filters-grid select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: var(--card);
  color: var(--ink);
}
.filters-grid input:focus,
.filters-grid select:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}

.ds-meta { font-size: 13px; color: var(--ink-muted); margin: 4px 4px 12px; }

.ds-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
@media (min-width: 720px) { .ds-grid { grid-template-columns: 1fr 1fr; } }

.dataset-card {
  background: var(--card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 18px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.card-header {
  display: flex; justify-content: space-between; gap: 12px;
}
.card-title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.3;
}
.card-title a {
  font-size: 12px;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  margin-left: 8px;
}
.card-title a:hover { text-decoration: underline; }
.card-actions { display: flex; gap: 6px; flex-shrink: 0; }
.card-actions button {
  background: transparent;
  border: 1px solid var(--border);
  padding: 4px 10px;
  font-size: 11px;
  border-radius: 6px;
  cursor: pointer;
  color: var(--ink-muted);
  font-family: inherit;
  transition: all 0.15s;
}
.card-actions button:hover { color: var(--accent); border-color: var(--accent); }
.card-actions button.danger:hover { color: var(--danger); border-color: var(--danger); }
.card-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag-pill {
  background: var(--card-accent);
  border: 1px solid var(--border);
  color: var(--ink);
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 500;
}
.tag-pill.highlight {
  background: var(--accent-soft);
  border-color: transparent;
  color: var(--accent);
}
.tag-pill.sky {
  background: var(--accent-soft-2);
  border-color: transparent;
  color: var(--accent-2);
}
.card-description { font-size: 13.5px; line-height: 1.55; color: var(--ink); }
.card-description p { margin: 0 0 6px; }
.card-logistics {
  border-top: 1px dashed var(--border);
  padding-top: 10px;
  display: flex; flex-direction: column; gap: 8px;
}
.logistics-item { font-size: 12px; }
.logistics-label {
  display: block;
  font-weight: 700;
  color: var(--ink-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 10px;
  margin-bottom: 2px;
}
.logistics-item a {
  color: var(--accent);
  text-decoration: none;
  word-break: break-all;
}
.logistics-item a:hover { text-decoration: underline; }

/* ───────── Modals ───────── */
.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 20px;
}
.modal[hidden] { display: none; }
.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(31, 42, 55, 0.5);
  backdrop-filter: blur(4px);
}
.modal-panel {
  position: relative;
  background: var(--card);
  border-radius: 16px;
  width: 100%;
  max-width: 680px;
  max-height: 88vh;
  overflow-y: auto;
  padding: 28px;
  box-shadow: 0 30px 80px rgba(31, 42, 55, 0.25);
}
.modal-panel.paper-panel { padding: 0; max-width: 720px; }
.modal-close {
  position: absolute;
  top: 12px; right: 16px;
  background: rgba(255, 255, 255, 0.85);
  border: 0;
  font-size: 24px;
  width: 36px; height: 36px;
  border-radius: 999px;
  cursor: pointer;
  color: var(--ink);
  z-index: 2;
  box-shadow: var(--shadow-sm);
}
.modal-close:hover { color: var(--danger); }

.modal-panel h2 {
  font-size: 22px;
  margin: 0 0 16px;
  letter-spacing: -0.01em;
}

/* ───────── Form ───────── */
.ds-form fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}
.ds-form legend {
  padding: 0 8px;
  font-weight: 700;
  font-size: 13px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.ds-form label {
  display: flex;
  flex-direction: column;
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-muted);
  gap: 4px;
  margin-bottom: 12px;
}
.ds-form .field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
@media (max-width: 600px) {
  .ds-form .field-grid { grid-template-columns: 1fr; }
}
.ds-form input,
.ds-form select,
.ds-form textarea {
  padding: 9px 11px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: white;
  color: var(--ink);
  width: 100%;
  font-weight: 400;
}
.ds-form textarea {
  min-height: 70px;
  resize: vertical;
}
.ds-form input:focus,
.ds-form select:focus,
.ds-form textarea:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}
.ds-form .helper {
  font-weight: 400;
  font-size: 11px;
  color: var(--ink-muted);
}
.ds-form details.retrieval {
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 16px;
}
.ds-form details.retrieval summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 13px;
  color: var(--accent);
}
.ds-form details.retrieval[open] summary { margin-bottom: 12px; }
.ds-form .actions {
  display: flex; gap: 10px; justify-content: flex-end;
}

/* ───────── Footer ───────── */
.site-foot {
  text-align: center;
  padding: 30px 20px;
  font-size: 12px;
  color: var(--ink-muted);
  border-top: 1px solid var(--border);
}
.site-foot code {
  background: var(--card-accent);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 11px;
}