:root {
  /* Surface hierarchy — tonal layering, no borders */
  --surface:                 #f7fafc;
  --surface-container-lowest:#ffffff;
  --surface-container-low:   #eff4f7;
  --surface-container:       #e7eff3;
  --primary:                 #455f88;
  --primary-dim:             #39537c;
  --primary-container:       #d6e3ff;
  --on-surface:              #283439;
  --on-surface-variant:      #546166;
  --outline-variant:         #a7b4ba;
  --error:                   #9f403d;

  /* Type stacks */
  --serif: "Newsreader", Georgia, "Songti SC", "Noto Serif SC", serif;
  --sans:  "Public Sans", -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --label: "Inter", -apple-system, "Segoe UI", sans-serif;

  /* Scale */
  --radius-sm: 0.125rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --max-read: 720px;
}

* { box-sizing: border-box; }

html { background: var(--surface); }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  background: var(--surface);
  color: var(--on-surface);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  max-width: var(--max-read);
  margin: 0 auto;
  padding: 0 28px;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color .15s ease;
}
a:hover { color: var(--primary-dim); text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }

em { font-style: italic; }

/* ----- Header ----- */
.site-header {
  padding: 40px 0 24px;
}
.header-inner {
  display: flex;
  align-items: baseline;
  gap: 18px;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  color: var(--on-surface);
}
.brand:hover { color: var(--on-surface); text-decoration: none; }
.brand-mark {
  font-family: var(--serif);
  font-style: italic;
  font-size: 28px;
  color: var(--primary);
  line-height: 1;
  transform: translateY(2px);
}
.brand-text {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 20px;
  letter-spacing: -0.01em;
}
.brand-subtitle {
  font-family: var(--label);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  padding-left: 16px;
  margin-left: auto;
}

/* ----- Main ----- */
.main { padding: 32px 28px 80px; }

/* ----- Masthead / Hero ----- */
.masthead {
  padding: 40px 0 48px;
}
.eyebrow {
  font-family: var(--label);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  margin: 0 0 18px;
}
.display {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(40px, 6vw, 60px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--on-surface);
  margin: 0 0 20px;
}
.display em {
  font-style: italic;
  font-weight: 500;
  color: var(--primary);
}
.lede {
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.55;
  color: var(--on-surface-variant);
  margin: 0 0 32px;
  max-width: 600px;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 36px;
  margin: 0;
  padding: 20px 0 0;
}
.meta-row > div { margin: 0; }
.meta-row dt {
  font-family: var(--label);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  margin-bottom: 4px;
}
.meta-row dd {
  margin: 0;
  font-family: var(--sans);
  font-size: 14px;
  color: var(--on-surface);
}

/* ----- Sections ----- */
.section { margin-top: 16px; }
.section-title {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 500;
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--on-surface);
  margin: 0 0 24px;
}

/* Generic label */
.label {
  font-family: var(--label);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
}

/* ----- Issue list (homepage) ----- */
.issue-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.issue {
  margin: 0;
}
.issue-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 20px;
  color: var(--on-surface);
  border-left: 2px solid transparent;
  transition: background-color .18s ease, border-color .18s ease, padding-left .18s ease;
}
.issue-link:hover {
  background: var(--surface-container-low);
  border-left-color: var(--primary);
  padding-left: 24px;
  color: var(--on-surface);
  text-decoration: none;
}
.issue + .issue .issue-link {
  /* Separate issues with a near-invisible ghost rule (15% outline) */
  box-shadow: inset 0 1px 0 rgba(167, 180, 186, 0.28);
}
.issue-day { display: flex; flex-direction: column; gap: 4px; }
.issue-date { font-size: 10px; }
.issue-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 20px;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.issue-count {
  display: flex;
  align-items: baseline;
  gap: 8px;
  text-align: right;
  flex-shrink: 0;
}
.count-num {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 28px;
  color: var(--primary);
  line-height: 1;
  font-feature-settings: "lnum";
}

/* ----- Paper list (daily) ----- */
.breadcrumb {
  margin: 0 0 24px;
  font-family: var(--label);
  font-size: 12px;
  letter-spacing: 0.08em;
}
.breadcrumb a { color: var(--on-surface-variant); }
.breadcrumb a:hover { color: var(--primary); }

.paper-list {
  list-style: none;
  counter-reset: none;
  padding: 0;
  margin: 0;
}
.paper {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 20px;
  padding: 28px 20px;
  border-left: 2px solid transparent;
  transition: background-color .18s ease, border-color .18s ease;
}
.paper:hover {
  background: var(--surface-container-low);
  border-left-color: var(--primary);
}
.paper + .paper {
  box-shadow: inset 0 1px 0 rgba(167, 180, 186, 0.28);
}
.paper-index {
  font-size: 11px;
  color: var(--on-surface-variant);
  padding-top: 6px;
  font-feature-settings: "lnum", "tnum";
}
.paper-body { min-width: 0; }
.paper-title {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 22px;
  line-height: 1.25;
  letter-spacing: -0.005em;
}
.paper-title a { color: var(--on-surface); }
.paper-title a:hover { color: var(--primary); text-decoration: none; }
.paper-authors {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-size: 14px;
  color: var(--on-surface-variant);
  font-style: italic;
}
.paper-venue {
  margin: 0 0 14px;
  display: block;
}
.paper-abstract {
  margin: 0;
  font-family: var(--serif);
  font-size: 16px;
  line-height: 1.6;
  color: var(--on-surface);
}

/* ----- Empty / Footer ----- */
.empty {
  font-family: var(--serif);
  font-style: italic;
  font-size: 17px;
  color: var(--on-surface-variant);
  padding: 24px 20px;
}

.site-footer {
  margin-top: 80px;
  padding: 32px 0 48px;
  background: var(--surface-container-low);
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: baseline;
  font-size: 12px;
  color: var(--on-surface-variant);
}
.footer-value {
  font-family: var(--label);
  font-size: 12px;
  color: var(--on-surface);
}
.footer-sep { color: var(--outline-variant); padding: 0 6px; }

/* ----- Responsive ----- */
@media (max-width: 640px) {
  .wrap { padding: 0 20px; }
  .site-header { padding: 28px 0 16px; }
  .brand-subtitle { margin-left: 0; padding-left: 0; }
  .masthead { padding: 24px 0 32px; }
  .display { font-size: 36px; }
  .lede { font-size: 17px; }
  .paper { grid-template-columns: 1fr; gap: 8px; padding: 24px 16px; }
  .paper-index { padding-top: 0; }
  .issue-link { padding: 18px 16px; gap: 16px; }
  .count-num { font-size: 22px; }
  .issue-title { font-size: 17px; }
}