* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #0f4c75;
  --color-secondary: #1b262c;
  --color-accent: #bbe1fa;
  --color-bg: #ffffff;
  --color-surface: #f0f7ff;
  --color-text: #1b262c;
  --color-text-muted: #6b7b8d;
  --color-border: #d1dce6;
  --font-main: 'Verdana', 'Geneva', 'Tahoma', sans-serif;
  --max-width: 1100px;
  --radius: 6px;
}

body {
  font-family: var(--font-main);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image: linear-gradient(180deg, var(--color-bg) 0%, var(--color-surface) 100%);
  background-attachment: fixed;
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  color: var(--color-secondary);
  letter-spacing: -0.02em;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: -0.03em;
}

h2 {
  font-size: 2rem;
  margin-top: 2rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--color-primary);
}

h3 {
  font-size: 1.5rem;
  margin-top: 1.5rem;
  color: var(--color-primary);
}

h4 {
  font-size: 1.25rem;
  margin-top: 1.25rem;
}

h5 {
  font-size: 1.125rem;
  margin-top: 1rem;
}

h6 {
  font-size: 1rem;
  margin-top: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

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

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

strong {
  font-weight: 700;
  color: var(--color-secondary);
}

em {
  font-style: italic;
}

blockquote {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  border-left: 5px solid var(--color-primary);
  background: linear-gradient(135deg, var(--color-surface) 0%, var(--color-accent) 100%);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: 0 2px 8px rgba(15, 76, 117, 0.1), 0 4px 16px rgba(15, 76, 117, 0.05);
  font-style: italic;
  color: var(--color-text);
}

::selection {
  background-color: var(--color-accent);
  color: var(--color-secondary);
}

.site-header {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: var(--color-bg);
  padding: 1.5rem 1rem;
  box-shadow: 0 4px 12px rgba(27, 38, 44, 0.15), 0 8px 24px rgba(27, 38, 44, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 4px solid var(--color-accent);
}

.site-header .container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: center;
}

.site-header h1 {
  color: var(--color-bg);
  margin: 0;
  font-size: 1.75rem;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.site-nav {
  background-color: var(--color-surface);
  border-bottom: 2px solid var(--color-border);
  box-shadow: 0 2px 6px rgba(27, 38, 44, 0.08);
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
}

.site-nav li {
  margin: 0;
}

.site-nav a {
  display: block;
  padding: 0.625rem 1.25rem;
  color: var(--color-text);
  border: 2px solid transparent;
  border-radius: var(--radius);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 0.05em;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.site-nav a:hover {
  background-color: var(--color-primary);
  color: var(--color-bg);
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(15, 76, 117, 0.2);
  border-bottom-color: var(--color-primary);
}

.site-main {
  padding: 2rem 1rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
}

.breadcrumbs {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
  padding: 0.75rem 1rem;
  background-color: var(--color-surface);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  box-shadow: 0 1px 3px rgba(27, 38, 44, 0.05);
}

.breadcrumbs a {
  color: var(--color-primary);
  border-bottom: 1px solid transparent;
}

.breadcrumbs a:hover {
  border-bottom-color: var(--color-primary);
}

.card {
  background-color: var(--color-bg);
  border: 2px solid var(--color-border);
  border-radius: calc(var(--radius) * 2);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 8px rgba(27, 38, 44, 0.08), 0 4px 16px rgba(27, 38, 44, 0.04);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.card:hover {
  box-shadow: 0 4px 16px rgba(15, 76, 117, 0.12), 0 8px 32px rgba(15, 76, 117, 0.08);
  border-color: var(--color-accent);
}

.card h2 {
  margin-top: 0;
}

.card h3 {
  margin-top: 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  background-color: var(--color-bg);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(27, 38, 44, 0.08);
}

thead {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: var(--color-bg);
}

th {
  padding: 1rem;
  text-align: left;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 0.05em;
  border-bottom: 3px solid var(--color-accent);
}

td {
  padding: 0.875rem 1rem;
  border-bottom: 1px solid var(--color-border);
}

tbody tr {
  transition: background-color 0.2s ease;
}

tbody tr:nth-child(odd) {
  background-color: var(--color-surface);
}

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

tbody tr:hover {
  background-color: var(--color-accent);
  box-shadow: inset 0 0 0 2px var(--color-primary);
}

details {
  margin: 1.5rem 0;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-bg);
  box-shadow: 0 2px 6px rgba(27, 38, 44, 0.06);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

details:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(15, 76, 117, 0.1);
}

details[open] {
  border-color: var(--color-primary);
}

summary {
  padding: 1rem 1.25rem;
  background: linear-gradient(90deg, var(--color-surface) 0%, var(--color-accent) 100%);
  cursor: pointer;
  font-weight: 700;
  color: var(--color-secondary);
  list-style: none;
  display: flex;
  align-items: center;
  transition: background-color 0.2s ease, color 0.2s ease;
  border-bottom: 2px solid transparent;
}

summary::-webkit-details-marker {
  display: none;
}

summary::before {
  content: '▶';
  margin-right: 0.75rem;
  transition: transform 0.2s ease;
  color: var(--color-primary);
  font-size: 0.875rem;
}

details[open] summary::before {
  transform: rotate(90deg);
}

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

summary:hover::before {
  color: var(--color-accent);
}

details[open] summary {
  border-bottom-color: var(--color-border);
}

details div {
  padding: 1.25rem;
  background-color: var(--color-bg);
}

.site-footer {
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-primary) 100%);
  color: var(--color-bg);
  padding: 2rem 1rem;
  margin-top: 3rem;
  border-top: 4px solid var(--color-accent);
  box-shadow: 0 -4px 12px rgba(27, 38, 44, 0.15);
}

.site-footer a {
  color: var(--color-accent);
  border-bottom-color: transparent;
}

.site-footer a:hover {
  color: var(--color-bg);
  border-bottom-color: var(--color-bg);
}

.site-footer p {
  margin-bottom: 0.5rem;
}

ul, ol {
  margin: 1rem 0 1rem 2rem;
}

li {
  margin-bottom: 0.5rem;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
  box-shadow: 0 2px 8px rgba(27, 38, 44, 0.1);
}

hr {
  border: none;
  border-top: 2px solid var(--color-border);
  margin: 2rem 0;
  background: linear-gradient(90deg, transparent 0%, var(--color-border) 50%, transparent 100%);
}

code {
  background-color: var(--color-surface);
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  border: 1px solid var(--color-border);
  color: var(--color-primary);
}

pre {
  background-color: var(--color-secondary);
  color: var(--color-accent);
  padding: 1.25rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 2px solid var(--color-border);
  box-shadow: 0 2px 8px rgba(27, 38, 44, 0.15);
}

pre code {
  background-color: transparent;
  border: none;
  padding: 0;
  color: var(--color-accent);
}

button, input[type="submit"] {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: var(--color-bg);
  border: 2px solid transparent;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  box-shadow: 0 2px 8px rgba(15, 76, 117, 0.2);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

button:hover, input[type="submit"]:hover {
  box-shadow: 0 4px 16px rgba(15, 76, 117, 0.3), 0 8px 32px rgba(15, 76, 117, 0.15);
  border-color: var(--color-accent);
}

button:focus-visible, input[type="submit"]:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}

input[type="text"], input[type="email"], input[type="search"], textarea, select {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  font-family: var(--font-main);
  font-size: 1rem;
  background-color: var(--color-bg);
  color: var(--color-text);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: inset 0 1px 3px rgba(27, 38, 44, 0.05);
}

input[type="text"]:focus, input[type="email"]:focus, input[type="search"]:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(15, 76, 117, 0.1), inset 0 1px 3px rgba(27, 38, 44, 0.05);
}

@media (min-width: 768px) {
  body {
    font-size: 17px;
  }

  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2.25rem;
  }

  h3 {
    font-size: 1.75rem;
  }

  .site-header .container {
    grid-template-columns: auto 1fr;
    gap: 2rem;
  }

  .site-header h1 {
    font-size: 2rem;
  }

  .site-nav ul {
    gap: 1rem;
    justify-content: center;
  }

  .site-main {
    padding: 3rem 1.5rem;
  }

  .card {
    padding: 2rem;
  }

  table {
    font-size: 1rem;
  }
}

@media (min-width: 1024px) {
  body {
    font-size: 18px;
  }

  h1 {
    font-size: 3.5rem;
  }

  h2 {
    font-size: 2.5rem;
  }

  h3 {
    font-size: 2rem;
  }

  .site-header .container {
    grid-template-columns: auto 1fr;
  }

  .site-nav ul {
    justify-content: flex-start;
  }

  .site-main {
    padding: 4rem 2rem;
  }

  .card {
    padding: 2.5rem;
  }

  blockquote {
    padding: 1.5rem 2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  summary::before {
    transition: none;
  }
}

@media print {
  .site-nav, .site-footer {
    display: none;
  }

  .site-header {
    position: static;
    box-shadow: none;
    border-bottom: 2px solid var(--color-text);
  }

  .site-main {
    max-width: 100%;
    padding: 1rem;
  }

  .card {
    border: 1px solid var(--color-text);
    box-shadow: none;
    page-break-inside: avoid;
  }

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

  details {
    border: 1px solid var(--color-text);
  }

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