:root {
  --color-primary: #1F4E5F;
  --color-secondary: #2E6F7E;
  --color-accent: #C86B3C;
  --color-bg: #F6F7F8;
  --color-surface: #FFFFFF;
  --color-text: #0F1A1F;
  --color-muted: #4B5B63;
  --color-border: #D6DDE1;
  --radius: 14px;
  --shadow: 0 10px 28px rgba(15,26,31,0.10);
  --maxw: 1120px;
  --font-stack: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, 'Noto Sans', 'Liberation Sans', sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-stack);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  min-height: 100vh;
}

header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow);
}

header nav {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

header nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 2rem;
}

header nav a {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

header nav a:hover {
  color: var(--color-primary);
}

header nav a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.breadcrumbs {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0.75rem 1.5rem;
  max-width: var(--maxw);
  margin: 0 auto;
  font-size: 0.9rem;
  color: var(--color-muted);
}

.breadcrumbs a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumbs a:hover {
  color: var(--color-secondary);
}

.breadcrumbs a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  background-color: var(--color-surface);
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  margin-top: 2rem;
  margin-bottom: 2rem;
}

h1 {
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-primary);
  margin: 0 0 2rem 0;
  text-align: left;
}

h2 {
  font-size: 1.75rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
  margin: 2.5rem 0 1rem 0;
  text-align: left;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-secondary);
  margin: 2rem 0 0.75rem 0;
  text-align: left;
}

p {
  margin: 0 0 1.5rem 0;
  max-width: 65ch;
}

a {
  color: var(--color-primary);
  text-decoration: underline;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-secondary);
}

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

blockquote {
  border-left: 4px solid var(--color-accent);
  padding: 1.5rem 2rem;
  margin: 2rem 0;
  background-color: var(--color-bg);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--color-muted);
}

blockquote p {
  margin: 0 0 0.5rem 0;
  font-size: 1.1rem;
}

blockquote cite {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  font-style: normal;
}

aside {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin: 2rem 0;
  max-width: 400px;
}

aside h3 {
  margin-top: 0;
  color: var(--color-primary);
}

aside ul {
  margin: 0;
  padding-left: 1.25rem;
}

aside li {
  margin-bottom: 0.5rem;
  color: var(--color-muted);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  background-color: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

caption {
  font-weight: 600;
  color: var(--color-primary);
  text-align: left;
  padding: 1rem;
  background-color: var(--color-bg);
  border-bottom: 2px solid var(--color-border);
}

th {
  background-color: var(--color-primary);
  color: var(--color-surface);
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 1rem;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

tbody tr:nth-child(even) {
  background-color: var(--color-bg);
}

tbody tr:hover {
  background-color: rgba(31, 78, 95, 0.05);
}

@media (max-width: 767px) {
  table {
    font-size: 0.9rem;
  }
  
  th, td {
    padding: 0.75rem 0.5rem;
  }
  
  table {
    overflow-x: auto;
    display: block;
    white-space: nowrap;
  }
  
  thead, tbody, tr {
    display: table;
    width: 100%;
    table-layout: fixed;
  }
}

details {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin: 1.5rem 0;
  background-color: var(--color-surface);
}

summary {
  padding: 1.25rem;
  font-weight: 600;
  color: var(--color-primary);
  cursor: pointer;
  transition: background-color 0.2s ease;
  border-radius: var(--radius);
}

summary:hover {
  background-color: var(--color-bg);
}

summary:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

details[open] summary {
  border-bottom: 1px solid var(--color-border);
  border-radius: var(--radius) var(--radius) 0 0;
}

details > *:not(summary) {
  padding: 0 1.25rem 1.25rem 1.25rem;
}

details p {
  margin-bottom: 1rem;
}

details p:last-child {
  margin-bottom: 0;
}

section {
  margin: 3rem 0;
}

article {
  margin: 0;
}

footer {
  background-color: var(--color-primary);
  color: var(--color-surface);
  text-align: center;
  padding: 2rem 1.5rem;
  margin-top: auto;
}

footer p {
  margin: 0;
  max-width: none;
}

@media (min-width: 768px) {
  body {
    grid-template-columns: 1fr;
  }
  
  main {
    padding: 3rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  h1 {
    font-size: 3rem;
  }
  
  h2 {
    font-size: 2rem;
  }
  
  aside {
    max-width: 450px;
  }
  
  header nav {
    padding: 1.5rem 2rem;
  }
  
  .breadcrumbs {
    padding: 1rem 2rem;
  }
}

@media (min-width: 1024px) {
  main {
    padding: 4rem;
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 3rem;
    align-items: start;
  }
  
  article {
    grid-column: 1 / -1;
  }
  
  aside {
    grid-column: 2;
    position: sticky;
    top: 2rem;
    max-width: none;
  }
  
  h1 {
    font-size: 3.5rem;
  }
  
  section {
    margin: 4rem 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0F1A1F;
    --color-surface: #1A2B32;
    --color-text: #F6F7F8;
    --color-muted: #B0BCC3;
    --color-border: #2E3F46;
  }
}