/* PCV Site — Shared Stylesheet */

:root {
  --red: #CC0000;
  --red-dark: #990000;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-400: #9ca3af;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--gray-900);
  background: #fff;
  margin: 0;
  padding: 0;
  line-height: 1.65;
}

/* Layout */
.wrap {
  max-width: 740px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header */
header {
  border-bottom: 3px solid var(--red);
  padding: 2rem 0 1.25rem;
  margin-bottom: 2rem;
}
header h1 {
  font-size: 1.75rem;
  margin: 0 0 0.25rem;
  letter-spacing: -0.02em;
}
header h1 span { color: var(--red); }
header .subtitle {
  color: var(--gray-600);
  font-size: 0.95rem;
  margin: 0;
}
header .affiliation {
  color: var(--gray-400);
  font-size: 0.8rem;
  margin: 0.25rem 0 0;
}

/* Navigation */
nav {
  display: flex;
  gap: 1.5rem;
  margin-top: 0.75rem;
}
nav a {
  color: var(--red);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}
nav a:hover { text-decoration: underline; }
nav a.active {
  color: var(--gray-900);
  font-weight: 600;
}

/* Headings */
h2 {
  font-size: 1.35rem;
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--gray-200);
  letter-spacing: -0.01em;
}
h3 {
  font-size: 1.1rem;
  margin: 1.75rem 0 0.5rem;
  color: var(--gray-800);
}
h4 {
  font-size: 0.95rem;
  margin: 1.25rem 0 0.4rem;
  color: var(--gray-700);
}

/* Paragraphs and lists */
p { margin: 0 0 1rem; }
ul, ol { margin: 0 0 1rem; padding-left: 1.5rem; }
li { margin-bottom: 0.3rem; }

/* Links */
a { color: var(--red); }
a:hover { color: var(--red-dark); }

/* Code */
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--gray-100);
  padding: 0.15em 0.35em;
  border-radius: 3px;
}
pre {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: 4px;
  padding: 1rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
  margin: 0 0 1.25rem;
}
pre code {
  background: none;
  padding: 0;
  border-radius: 0;
}

/* Phase diagram */
.phases {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin: 1.75rem 0;
  flex-wrap: wrap;
}
.phase-box {
  text-align: center;
  padding: 0.75rem 1.5rem;
  border: 2px solid var(--red);
  border-radius: 6px;
  font-weight: 600;
  font-size: 1rem;
  background: #fff;
  min-width: 120px;
}
.phase-box small {
  display: block;
  font-weight: 400;
  font-size: 0.78rem;
  color: var(--gray-600);
  margin-top: 0.2rem;
}
.phase-arrow {
  font-size: 1.5rem;
  color: var(--red);
  padding: 0 0.5rem;
  line-height: 1;
}

/* Steps */
.steps {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}
.steps li {
  counter-increment: step;
  padding-left: 2.25rem;
  position: relative;
  margin-bottom: 0.75rem;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.05em;
  width: 1.5rem;
  height: 1.5rem;
  background: var(--red);
  color: #fff;
  border-radius: 50%;
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Two-column lists (when/when not) */
.cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin: 1rem 0 1.5rem;
}
.col h4 { margin-top: 0; }

/* Callout boxes */
.callout {
  border-left: 3px solid var(--red);
  background: var(--gray-50);
  padding: 0.75rem 1rem;
  margin: 1rem 0 1.25rem;
  border-radius: 0 4px 4px 0;
  font-size: 0.92rem;
}
.callout p:last-child { margin-bottom: 0; }

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.9rem;
}
th, td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--gray-200);
}
th {
  font-weight: 600;
  border-bottom: 2px solid var(--gray-200);
  white-space: nowrap;
}

/* Button */
.btn {
  display: inline-block;
  background: var(--red);
  color: #fff;
  padding: 0.6rem 1.25rem;
  border-radius: 4px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  transition: background 0.15s;
}
.btn:hover {
  background: var(--red-dark);
  color: #fff;
}

/* Footer */
footer {
  margin-top: 3rem;
  padding: 1.25rem 0;
  border-top: 1px solid var(--gray-200);
  color: var(--gray-400);
  font-size: 0.8rem;
}
footer a { color: var(--gray-600); }

/* Mobile */
@media (max-width: 600px) {
  header h1 { font-size: 1.4rem; }
  h2 { font-size: 1.15rem; }
  .phases { flex-direction: column; gap: 0; }
  .phase-arrow { transform: rotate(90deg); padding: 0.25rem 0; }
  .cols { grid-template-columns: 1fr; gap: 0.75rem; }
  .phase-box { min-width: unset; width: 100%; }
}