:root {
  --paper: #EEF0F3;
  --ink: #1A1F2B;
  --muted: #5E6577;
  --rule: #CDD2DB;
  --accent: #3346C8;
  --accent-soft: #DDE1F7;
  --bar-low: #B6BCC9;
  --focus: #3346C8;

  --serif: "Literata", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "Instrument Sans", "Segoe UI", system-ui, -apple-system, sans-serif;

  --step--1: 0.8125rem;
  --step-0: 1rem;
  --step-1: 1.1875rem;
  --step-2: 1.5rem;
  --step-4: 2.375rem;

  color-scheme: light;
  box-sizing: border-box;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #12151C;
    --ink: #E4E7EE;
    --muted: #9298A8;
    --rule: #2A303C;
    --accent: #8C9BFF;
    --accent-soft: #262D4A;
    --bar-low: #4A5366;
    --focus: #8C9BFF;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: inherit; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--step-0);
  line-height: 1.6;
  font-optical-sizing: auto;
}

.wrap {
  max-width: 46rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}

a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { color: var(--accent); }

:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 2px; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

.skip {
  position: absolute; left: 1rem; top: -3rem;
  background: var(--ink); color: var(--paper);
  padding: 0.5rem 0.75rem; font-family: var(--sans);
}
.skip:focus { top: 1rem; }

/* Masthead ------------------------------------------------------------- */

.masthead { border-bottom: 1px solid var(--rule); }
.masthead .wrap {
  display: flex; flex-wrap: wrap; gap: 0.75rem 1.5rem;
  align-items: center; justify-content: space-between;
  padding-top: 0.9rem; padding-bottom: 0.9rem;
}
.site-name {
  margin: 0; font-family: var(--sans); font-weight: 600;
  font-size: var(--step-0); letter-spacing: -0.01em;
}
.day-nav { display: flex; gap: 0.4rem; align-items: center; font-family: var(--sans); }
.day-nav button { white-space: nowrap; }
.day-nav button, .day-nav select {
  font: inherit; font-size: var(--step--1); color: var(--ink);
  background: transparent; border: 1px solid var(--rule);
  border-radius: 6px; padding: 0.35rem 0.6rem; cursor: pointer;
}
.day-nav button:hover:not(:disabled), .day-nav select:hover { border-color: var(--muted); }
.day-nav button:disabled { color: var(--muted); opacity: 0.5; cursor: default; }

/* Day header and scite strip ------------------------------------------ */

.day-head { padding: 2.75rem 0 1.25rem; }
.day-head h1 {
  margin: 0; font-weight: 500;
  font-size: var(--step-4); line-height: 1.15; letter-spacing: -0.015em;
}
.day-summary {
  margin: 0.6rem 0 1.75rem; color: var(--muted);
  font-family: var(--sans); font-size: var(--step--1);
}

.strip {
  display: flex; align-items: flex-end; gap: 2px;
  height: 84px; border-bottom: 1px solid var(--ink);
}
.strip a {
  flex: 1 1 0; min-width: 2px; min-height: 2px;
  background: var(--bar-low); border-radius: 1px 1px 0 0;
}
.strip a.above { background: var(--accent); }
.strip a.dim { opacity: 0.3; }
.strip a:hover { background: var(--ink); }

/* Controls -------------------------------------------------------------- */

.controls {
  display: flex; flex-wrap: wrap; gap: 0.75rem 1rem; align-items: center;
  padding: 1rem 0 0.5rem; font-family: var(--sans); font-size: var(--step--1);
}
.threshold { display: flex; border: 0; margin: 0; padding: 0; }
.threshold label { cursor: pointer; }
.threshold input { position: absolute; opacity: 0; pointer-events: none; }
.threshold span {
  display: block; padding: 0.4rem 0.75rem;
  border: 1px solid var(--rule); margin-left: -1px;
}
.threshold label:first-of-type span { border-radius: 6px 0 0 6px; margin-left: 0; }
.threshold label:last-of-type span { border-radius: 0 6px 6px 0; }
.threshold input:checked + span {
  background: var(--accent-soft); border-color: var(--accent);
  color: var(--ink); position: relative;
}
.threshold input:focus-visible + span { outline: 2px solid var(--focus); outline-offset: 2px; }

.search { flex: 1 1 14rem; }
.search input {
  width: 100%; font: inherit; color: var(--ink); background: transparent;
  border: 1px solid var(--rule); border-radius: 6px; padding: 0.4rem 0.65rem;
}
.search input::placeholder { color: var(--muted); }
.showing { margin: 0; color: var(--muted); flex-basis: 100%; }

/* Papers --------------------------------------------------------------- */

.papers { list-style: none; margin: 0; padding: 0; }

.paper {
  display: grid; grid-template-columns: 4.75rem 1fr; gap: 0 1.25rem;
  padding: 1.75rem 0; border-top: 1px solid var(--rule);
  scroll-margin-top: 1rem;
}
.paper:first-child { border-top: 0; }

.score { text-align: right; padding-top: 0.1rem; }
.score .n {
  display: block; font-size: var(--step-4); line-height: 1; font-weight: 500;
  color: var(--accent); font-variant-numeric: lining-nums tabular-nums;
  letter-spacing: -0.02em;
}
.score .unit { display: block; margin-top: 0.3rem; font-family: var(--sans);
  font-size: var(--step--1); color: var(--muted); }

.paper h2 {
  margin: 0; font-size: var(--step-1); line-height: 1.35; font-weight: 600;
  letter-spacing: -0.005em;
}
.paper h2 a { text-decoration: none; }
.paper h2 a:hover { text-decoration: underline; }

.meta {
  margin: 0.35rem 0 0; font-family: var(--sans); font-size: var(--step--1);
  color: var(--muted); line-height: 1.5;
}
.meta .cats { display: inline-flex; flex-wrap: wrap; gap: 0.3rem; margin-left: 0.4rem; vertical-align: 1px; }
.meta .cat {
  border: 1px solid var(--rule); border-radius: 4px; padding: 0 0.35rem;
  font-size: 0.75rem;
}

.explain { margin-top: 1rem; max-width: 38rem; }
.explain h3 {
  margin: 1rem 0 0.2rem; font-family: var(--sans); font-weight: 600;
  font-size: var(--step--1); color: var(--muted);
}
.explain h3:first-child { margin-top: 0; }
.explain p { margin: 0; line-height: 1.68; }
.explain .context { color: var(--ink); }
.pending { color: var(--muted); font-style: italic; }

details.abstract { margin-top: 1rem; max-width: 38rem; }
details.abstract summary {
  cursor: pointer; font-family: var(--sans); font-size: var(--step--1);
  color: var(--muted); width: fit-content;
}
details.abstract summary:hover { color: var(--ink); }
details.abstract p { margin: 0.5rem 0 0; font-size: 0.9375rem; line-height: 1.65; }
details.abstract .comment { color: var(--muted); font-size: var(--step--1); font-family: var(--sans); }

.links {
  display: flex; gap: 1.1rem; margin: 1rem 0 0;
  font-family: var(--sans); font-size: var(--step--1);
}

.empty { padding: 3rem 0; color: var(--muted); font-family: var(--sans); }

.footer {
  border-top: 1px solid var(--rule); margin-top: 2rem;
  padding-top: 1.25rem; padding-bottom: 3rem;
  color: var(--muted); font-family: var(--sans); font-size: var(--step--1);
}
.footer p { max-width: 38rem; }

.katex { font-size: 1.02em; }

/* Small screens ---------------------------------------------------------- */

@media (max-width: 34rem) {
  :root { --step-4: 1.875rem; }
  .day-nav { width: 100%; }
  .day-nav select { flex: 1 1 auto; min-width: 0; text-overflow: ellipsis; }
  .day-head { padding-top: 1.75rem; }
  .paper { grid-template-columns: 1fr; }
  .score { text-align: left; display: flex; align-items: baseline; gap: 0.4rem; margin-bottom: 0.4rem; }
  .score .n { display: inline; font-size: var(--step-2); }
  .score .unit { display: inline; margin: 0; }
  .strip { height: 64px; gap: 1px; }
}

@media (prefers-reduced-motion: no-preference) {
  .strip a { transition: opacity 120ms ease; }
}