/* Research Operations Sourcebook Stylesheet */

/* Root variables following GOV.UK design principles */
:root {
  --govuk-blue: #1d70b8;
  --govuk-dark-blue: #003078;
  --govuk-black: #0b0c0c;
  --govuk-grey-1: #6f777b;
  --govuk-grey-2: #b1b4b6;
  --govuk-grey-3: #f3f2f1;
  --govuk-white: #ffffff;
  --govuk-green: #00703c;
  --govuk-orange: #f47738;
  --govuk-red: #d4351c;
  --govuk-purple: #4c2c92;
  
  --max-width: 960px;
  --spacing-unit: 8px;
}

/* Reset and base styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  line-height: 1.6;
}

body {
  font-family: "GDS Transport", Arial, sans-serif;
  color: var(--govuk-black);
  background-color: var(--govuk-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Layout */
.govuk-width-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 calc(var(--spacing-unit) * 2);
}

header {
  background-color: var(--govuk-black);
  border-bottom: 10px solid var(--govuk-blue);
  padding: calc(var(--spacing-unit) * 2) 0;
}

header h1 {
  color: var(--govuk-white);
  font-size: 2rem;
  font-weight: 700;
  margin: 0;
}

header .subtitle {
  color: var(--govuk-grey-2);
  font-size: 1.125rem;
  margin-top: calc(var(--spacing-unit) * 1);
}

main {
  padding: calc(var(--spacing-unit) * 4) 0;
  min-height: 60vh;
}

footer {
  background-color: var(--govuk-grey-3);
  border-top: 1px solid var(--govuk-grey-2);
  padding: calc(var(--spacing-unit) * 3) 0;
  margin-top: calc(var(--spacing-unit) * 6);
}

footer p {
  color: var(--govuk-grey-1);
  font-size: 0.875rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  margin-top: calc(var(--spacing-unit) * 4);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.5rem;
}

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: calc(var(--spacing-unit) * 2);
  max-width: 66ch;
}

a {
  color: var(--govuk-blue);
  text-decoration: underline;
}

a:hover {
  color: var(--govuk-dark-blue);
  text-decoration-thickness: 3px;
}

a:focus {
  outline: 3px solid var(--govuk-orange);
  outline-offset: 0;
  background-color: var(--govuk-orange);
  color: var(--govuk-black);
}

/* Breadcrumbs */
.govuk-breadcrumbs {
  margin-top: calc(var(--spacing-unit) * 2);
  margin-bottom: calc(var(--spacing-unit) * 3);
}

.govuk-breadcrumbs__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--spacing-unit) * 1);
}

.govuk-breadcrumbs__list-item {
  display: inline-block;
}

.govuk-breadcrumbs__list-item:not(:last-child)::after {
  content: "›";
  margin-left: calc(var(--spacing-unit) * 1);
  color: var(--govuk-grey-1);
}

.govuk-breadcrumbs__link {
  text-decoration: underline;
}

/* Navigation */
.pillar-nav {
  background-color: var(--govuk-grey-3);
  padding: calc(var(--spacing-unit) * 3);
  margin-bottom: calc(var(--spacing-unit) * 4);
  border-left: 5px solid var(--govuk-blue);
}

.pillar-nav h2 {
  margin-top: 0;
  font-size: 1.5rem;
}

.pillar-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: calc(var(--spacing-unit) * 2);
  margin-top: calc(var(--spacing-unit) * 3);
}

.pillar-card {
  background-color: var(--govuk-white);
  border: 2px solid var(--govuk-grey-2);
  padding: calc(var(--spacing-unit) * 3);
  transition: all 0.2s ease;
}

.pillar-card:hover {
  border-color: var(--govuk-blue);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.pillar-card h3 {
  margin-top: 0;
  margin-bottom: calc(var(--spacing-unit) * 1);
  font-size: 1.25rem;
}

.pillar-card .pillar-code {
  font-family: "Courier New", monospace;
  font-size: 0.875rem;
  color: var(--govuk-grey-1);
  display: block;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.pillar-card p {
  font-size: 0.9375rem;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* Rule/Guidance/Principle boxes */
.rule-container {
  margin: calc(var(--spacing-unit) * 3) 0;
  border-left: 5px solid;
  padding: calc(var(--spacing-unit) * 3);
  background-color: var(--govuk-grey-3);
  page-break-inside: avoid;
  break-inside: avoid;
}

/* Nested rule containers within parent guidance */
.rule-container .rule-container {
  margin: calc(var(--spacing-unit) * 2) 0;
  background-color: var(--govuk-white);
}

.rule-container.rule {
  border-left-color: var(--govuk-blue);
}

.rule-container.guidance {
  border-left-color: var(--govuk-green);
}

.rule-container.principle {
  border-left-color: var(--govuk-orange);
}

.rule-container.conduct {
  border-left-color: var(--govuk-purple);
}

.rule-container.external {
  border-left-color: var(--govuk-grey-1);
}

.rule-header {
  display: flex;
  align-items: center;
  gap: calc(var(--spacing-unit) * 2);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.rule-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--govuk-white);
  flex-shrink: 0;
}

.rule-badge.rule {
  background-color: var(--govuk-blue);
}

.rule-badge.guidance {
  background-color: var(--govuk-green);
}

.rule-badge.principle {
  background-color: var(--govuk-orange);
}

.rule-badge.conduct {
  background-color: var(--govuk-purple);
}

.rule-badge.external {
  background-color: var(--govuk-grey-1);
}

.rule-identifier {
  font-family: "Courier New", monospace;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--govuk-grey-1);
}

.rule-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin: calc(var(--spacing-unit) * 1) 0;
}

.rule-content p {
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.rule-content p:last-child {
  margin-bottom: 0;
}

/* Lists */
ul, ol {
  margin-left: calc(var(--spacing-unit) * 3);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

li {
  margin-bottom: calc(var(--spacing-unit) * 1);
}

.rule-content ul {
  list-style-type: disc;
}

/* Nested sections within guidance containers */
.rule-content > section {
  margin-top: calc(var(--spacing-unit) * 3);
}

.rule-content > section > h5 {
  font-size: 1.125rem;
  margin-top: calc(var(--spacing-unit) * 3);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* Section navigation */
.section-nav {
  background-color: var(--govuk-grey-3);
  padding: calc(var(--spacing-unit) * 3);
  margin: calc(var(--spacing-unit) * 4) 0;
}

.section-nav h3 {
  margin-top: 0;
  font-size: 1.125rem;
}

.section-nav ul {
  list-style: none;
  margin-left: 0;
}

.section-nav li {
  margin-bottom: calc(var(--spacing-unit) * 1);
}

/* Key/Legend */
.key-container {
  background-color: var(--govuk-grey-3);
  border: 2px solid var(--govuk-grey-2);
  padding: calc(var(--spacing-unit) * 3);
  margin-bottom: calc(var(--spacing-unit) * 4);
}

.key-container h2 {
  margin-top: 0;
  font-size: 1.5rem;
}

.key-list {
  list-style: none;
  margin-left: 0;
}

.key-item {
  display: flex;
  align-items: flex-start;
  gap: calc(var(--spacing-unit) * 2);
  margin-bottom: calc(var(--spacing-unit) * 3);
}

.key-item:last-child {
  margin-bottom: 0;
}

.key-badge {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--govuk-white);
  font-weight: 700;
  flex-shrink: 0;
}

.key-description h3 {
  margin-top: 0;
  margin-bottom: calc(var(--spacing-unit) * 1);
  font-size: 1rem;
}

.key-description p {
  margin-bottom: 0;
  font-size: 0.9375rem;
}

/* Metadata */
.metadata {
  font-size: 0.875rem;
  color: var(--govuk-grey-1);
  border-top: 1px solid var(--govuk-grey-2);
  padding-top: calc(var(--spacing-unit) * 2);
  margin-top: calc(var(--spacing-unit) * 4);
}

/* Print styles */
@media print {
  header {
    border-bottom-width: 2px;
  }
  
  .pillar-nav,
  .govuk-breadcrumbs {
    display: none;
  }
  
  .rule-container {
    border-left-width: 3px;
  }
  
  a {
    color: var(--govuk-black);
    text-decoration: none;
  }
  
  a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 0.875rem;
    color: var(--govuk-grey-1);
  }
}

/* Responsive */
@media (max-width: 640px) {
  html {
    font-size: 14px;
  }
  
  .govuk-width-container {
    padding: 0 calc(var(--spacing-unit) * 1.5);
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .pillar-list {
    grid-template-columns: 1fr;
  }
  
  .rule-header {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* Accessibility enhancements */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

:focus-visible {
  outline: 3px solid var(--govuk-orange);
  outline-offset: 0;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: 0;
  left: 0;
  padding: calc(var(--spacing-unit) * 2);
  background-color: var(--govuk-orange);
  color: var(--govuk-black);
  text-decoration: none;
  z-index: 9999;
  transform: translateY(-100%);
}

.skip-link:focus {
  transform: translateY(0);
}