/* ============================================================
   Driving CivicSense Research, paper site stylesheet
   ============================================================ */
:root {
  --ink: #1a1a1a;
  --muted: #5f6368;
  --accent: #1565c0;
  --accent-dark: #0d47a1;
  --green: #2e7d32;
  --red: #c62828;
  --orange: #e65100;
  --rule: #d0d7de;
  --bg: #ffffff;
  --panel: #f6f8fa;
  --code-bg: #0f172a;
  --code-ink: #e2e8f0;
  --serif: Georgia, "Times New Roman", "Songti SC", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial,
          "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.62;
}

/* ---------- top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 14px;
}
.topbar-inner {
  max-width: 940px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}
.topbar .brand {
  font-weight: 700;
  color: var(--accent-dark);
  letter-spacing: 0.2px;
}
.topbar nav { display: flex; gap: 16px; margin-left: auto; flex-wrap: wrap; }
.topbar a {
  color: var(--muted);
  text-decoration: none;
  padding: 3px 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.topbar a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.topbar a.active { color: var(--accent-dark); border-bottom-color: var(--accent-dark); font-weight: 600; }

/* ---------- layout ---------- */
.container { max-width: 940px; margin: 0 auto; padding: 32px 20px 80px; }

/* ---------- header ---------- */
.paper-header { text-align: center; margin: 18px 0 30px; }
.paper-header .kicker {
  font-family: var(--sans);
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 14px;
}
.paper-header h1 {
  font-size: 30px;
  line-height: 1.25;
  margin: 0 0 12px;
  font-weight: 700;
  letter-spacing: -0.2px;
}
.paper-header .authors { font-size: 16px; color: var(--muted); margin-bottom: 6px; }
.paper-header .affil { font-size: 13.5px; color: var(--muted); margin-bottom: 16px; }
.paper-header .links { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.paper-header .links a {
  font-family: var(--sans);
  font-size: 13px;
  text-decoration: none;
  color: var(--accent-dark);
  border: 1px solid #bcd3f0;
  background: #eef4fc;
  padding: 6px 14px;
  border-radius: 999px;
  transition: background 0.15s, transform 0.1s;
}
.paper-header .links a:hover { background: #ddeaf9; transform: translateY(-1px); }

/* ---------- abstract ---------- */
.abstract {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-left: 4px solid var(--accent);
  border-radius: 4px;
  padding: 18px 22px;
  margin: 26px 0 10px;
  font-size: 15.5px;
}
.abstract .label {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent-dark);
  display: block;
  margin-bottom: 8px;
}
.keywords { font-size: 13.5px; color: var(--muted); margin: 8px 0 4px; }
.keywords b { color: var(--ink); font-family: var(--sans); font-size: 12px; letter-spacing: 1px; text-transform: uppercase; }

/* ---------- sections ---------- */
section { margin: 40px 0; }
h2.sec {
  font-family: var(--sans);
  font-size: 21px;
  font-weight: 700;
  margin: 0 0 14px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--rule);
  display: flex;
  align-items: baseline;
  gap: 10px;
}
h2.sec .no { color: var(--accent); font-size: 15px; letter-spacing: 0.5px; }
h3.sub {
  font-family: var(--sans);
  font-size: 16.5px;
  font-weight: 600;
  margin: 26px 0 10px;
  color: #20303f;
}
p { margin: 12px 0; }
ul, ol { margin: 10px 0 12px; padding-left: 26px; }
li { margin: 5px 0; }
b, strong { font-weight: 700; }

/* ---------- theorem / proof boxes ---------- */
.thm {
  margin: 16px 0;
  padding: 12px 16px 12px 14px;
  border-radius: 4px;
  border-left: 4px solid var(--accent);
  background: #f3f7fc;
}
.thm .head { font-weight: 700; font-family: var(--sans); font-size: 14px; color: var(--accent-dark); }
.thm.theorem { border-left-color: var(--accent); background: #f3f7fc; }
.thm.lemma   { border-left-color: var(--green);  background: #f2f8f3; }
.thm.corollary { border-left-color: var(--orange); background: #fdf6ee; }
.thm.definition { border-left-color: #7b1fa2; background: #f8f2fb; }
.thm.assumption { border-left-color: #00695c; background: #eef7f5; }
.thm.remark   { border-left-color: var(--muted); background: #f6f6f6; }
.thm p { margin: 8px 0 0; }

.proof {
  margin: 10px 0 18px;
  padding-left: 16px;
  border-left: 3px solid #d5dce3;
  color: #3c4651;
  font-size: 15px;
}
.proof .head { font-style: italic; font-weight: 600; color: var(--muted); font-family: var(--sans); font-size: 13px; }
.proof p { margin: 8px 0; }
.qed { float: right; }

/* ---------- math ---------- */
mjx-container { overflow-x: auto; padding: 2px 0; }
.eq { text-align: center; margin: 18px 0; font-size: 16.5px; }
.eqno { float: right; color: var(--muted); font-size: 13px; }

/* ---------- figures ---------- */
figure {
  margin: 26px 0;
  text-align: center;
}
figure svg, figure img {
  max-width: 100%;
  height: auto;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: white;
}
figcaption {
  font-size: 13.5px;
  color: var(--muted);
  margin-top: 10px;
  line-height: 1.5;
  text-align: left;
  font-family: var(--sans);
}
figcaption b { color: var(--ink); }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; margin: 18px 0; }
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 14.5px;
  font-family: var(--sans);
}
caption {
  caption-side: top;
  text-align: left;
  font-size: 13.5px;
  color: var(--muted);
  margin-bottom: 8px;
  font-family: var(--sans);
}
caption b { color: var(--ink); }
th, td { padding: 8px 12px; text-align: left; }
thead th {
  border-top: 2px solid #303030;
  border-bottom: 1px solid #9aa2ab;
  font-weight: 600;
}
tbody tr:last-child td { border-bottom: 2px solid #303030; }
tbody td { border-bottom: 1px solid var(--rule); vertical-align: top; }
.tag {
  font-family: var(--sans);
  font-size: 11.5px;
  font-weight: 700;
  padding: 2px 9px;
  border-radius: 999px;
  white-space: nowrap;
}
.tag.critical { background: #fdecea; color: #c62828; }
.tag.warning { background: #fff3e0; color: #e65100; }
.tag.caution { background: #fff8e1; color: #8a6d00; }
.tag.safe { background: #e8f5e9; color: #2e7d32; }

/* ---------- code ---------- */
pre.code {
  background: var(--code-bg);
  color: var(--code-ink);
  border-radius: 8px;
  padding: 16px 18px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 12.8px;
  line-height: 1.55;
  margin: 14px 0;
  tab-size: 4;
}
pre.code .cmt { color: #7ee787; }
pre.code .kw  { color: #79c0ff; font-weight: 600; }
pre.code .ty  { color: #d2a8ff; }
pre.code .st  { color: #ffa657; }
pre.code .num { color: #a5d6ff; }
.code-cap {
  font-family: var(--sans);
  font-size: 12px;
  color: var(--muted);
  margin: 4px 0 2px;
}
.code-cap b { color: var(--ink); }

/* ---------- TOC ---------- */
.toc {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 14px 22px;
  margin: 26px 0;
  font-family: var(--sans);
  font-size: 14px;
  columns: 2;
  column-gap: 30px;
}
.toc .toc-title {
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 8px;
  column-span: all;
}
.toc a { color: var(--accent-dark); text-decoration: none; }
.toc a:hover { text-decoration: underline; }
.toc li { margin: 3px 0; }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--rule);
  margin-top: 60px;
  padding-top: 18px;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}
footer a { color: var(--accent-dark); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ---------- references ---------- */
ol.refs { font-size: 14px; color: #2b2f33; }
ol.refs li { margin: 8px 0; }
ol.refs .cite { font-family: var(--mono); font-size: 12px; color: var(--accent); }

/* ---------- responsive ---------- */
@media (max-width: 640px) {
  body { font-size: 16px; }
  .paper-header h1 { font-size: 23px; }
  .toc { columns: 1; }
  .topbar nav { margin-left: 0; }
}

/* ---------- vulnerability warning blocks ---------- */
.vuln-item {
  border-left: 4px solid #f9a825;
  background: #fffbe6;
}
.vuln-item .head { color: #8a6d00; font-weight: 700; font-family: var(--sans); font-size: 14px; }

/* Reviewer concerns and responses (Discussion) */
ol.reviewer-response {
  margin: 0.6rem 0 1.2rem 1.4rem;
  padding-left: 0.4rem;
}
ol.reviewer-response li {
  margin-bottom: 0.75rem;
  line-height: 1.65;
}

/* Project tagline (paper header) */
.paper-header .tagline {
  margin: 10px 0 14px;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

/* clickable reference links */
ol.refs .ref-link {
  font-family: var(--mono);
  font-size: 11px;
  margin-left: 4px;
  white-space: nowrap;
}