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

:root {
  --color-primary: #475569;
  --color-secondary: #1e293b;
  --color-accent: #38bdf8;
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --font-main: 'Verdana', 'Geneva', 'Tahoma', sans-serif;
  --max-width: 1100px;
  --radius: 6px;
  --shadow-sm: inset 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -1px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.1), 0 4px 6px -2px rgba(15, 23, 42, 0.05);
  --gradient-subtle: linear-gradient(135deg, #f8fafc 0%, #ffffff 100%);
  --gradient-primary: linear-gradient(135deg, #475569 0%, #1e293b 100%);
  --gradient-accent: linear-gradient(135deg, #38bdf8 0%, #0ea5e9 100%);
}

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-main);
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-secondary);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

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;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

h6 {
  font-size: 1rem;
  margin-top: 1rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

p {
  margin-bottom: 1.25rem;
  font-size: 1rem;
  line-height: 1.75;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
  border-bottom: 1px solid transparent;
}

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

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

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

em {
  font-style: italic;
  color: var(--color-primary);
}

blockquote {
  margin: 2rem 0;
  padding: 1.5rem 2rem;
  background: var(--gradient-subtle);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  font-style: italic;
  color: var(--color-primary);
  position: relative;
}

blockquote::before {
  content: '"';
  position: absolute;
  top: 0.5rem;
  left: 0.75rem;
  font-size: 3rem;
  color: var(--color-border);
  line-height: 1;
}

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

.site-header {
  background: var(--gradient-primary);
  color: var(--color-bg);
  padding: 2rem 1rem;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 3px solid var(--color-accent);
}

.site-header h1 {
  margin: 0;
  font-size: 2rem;
  color: var(--color-bg);
  background: none;
  -webkit-text-fill-color: initial;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.site-nav {
  margin-top: 1rem;
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.site-nav a {
  color: var(--color-bg);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 0.05em;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  border-bottom: none;
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.site-nav a:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-bg);
  box-shadow: var(--shadow-sm);
}

.site-main {
  flex: 1;
  padding: 3rem 1rem;
  background: var(--gradient-subtle);
}

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

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.875rem;
  margin-bottom: 2rem;
  padding: 0.75rem 1.25rem;
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.breadcrumbs a {
  color: var(--color-text-muted);
  border-bottom: none;
}

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

.breadcrumbs span {
  color: var(--color-border);
}

.card {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--color-accent);
}

.card h2 {
  margin-top: 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  background: var(--color-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

table thead {
  background: var(--gradient-primary);
  color: var(--color-bg);
}

table th {
  padding: 1rem;
  text-align: left;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 0.05em;
  border-bottom: 2px solid var(--color-accent);
}

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

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

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

table tbody tr:hover {
  background: linear-gradient(90deg, rgba(56, 189, 248, 0.08) 0%, rgba(56, 189, 248, 0.02) 100%);
}

table tbody tr:last-child td {
  border-bottom: none;
}

details {
  margin: 1.5rem 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

summary {
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  font-weight: 600;
  color: var(--color-secondary);
  background: var(--gradient-subtle);
  user-select: none;
  transition: background-color 0.2s ease, color 0.2s ease;
  list-style: none;
  position: relative;
}

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

summary::after {
  content: '+';
  position: absolute;
  right: 1.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  transition: transform 0.2s ease;
}

details[open] summary::after {
  content: '−';
  transform: rotate(90deg);
}

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

details div {
  padding: 1.5rem;
  border-top: 1px solid var(--color-border);
}

.site-footer {
  background: var(--color-secondary);
  color: var(--color-surface);
  padding: 3rem 1rem 2rem;
  margin-top: auto;
  box-shadow: 0 -4px 6px -1px rgba(15, 23, 42, 0.08);
}

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

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

.site-footer p {
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
}

ul, ol {
  margin-bottom: 1.25rem;
  padding-left: 2rem;
}

ul li, ol li {
  margin-bottom: 0.5rem;
  line-height: 1.75;
}

ul {
  list-style-type: disc;
}

ul ul {
  list-style-type: circle;
  margin-top: 0.5rem;
}

ol {
  list-style-type: decimal;
}

code {
  background: var(--color-surface);
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
  color: var(--color-secondary);
  border: 1px solid var(--color-border);
}

pre {
  background: var(--color-secondary);
  color: var(--color-surface);
  padding: 1.5rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 2rem 0;
  box-shadow: var(--shadow-md);
  border-left: 4px solid var(--color-accent);
}

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

hr {
  border: none;
  height: 2px;
  background: var(--gradient-accent);
  margin: 3rem 0;
  border-radius: 1px;
}

button, input[type="submit"], input[type="button"] {
  background: var(--gradient-accent);
  color: var(--color-bg);
  border: none;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius);
  cursor: pointer;
  transition: box-shadow 0.2s ease, background-color 0.2s ease;
  box-shadow: var(--shadow-sm);
}

button:hover, input[type="submit"]:hover, input[type="button"]:hover {
  box-shadow: var(--shadow-md);
  background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
}

button:focus-visible, input[type="submit"]:focus-visible, input[type="button"]:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

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

input[type="text"]:focus, input[type="email"]:focus, input[type="search"]:focus, input[type="url"]:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

textarea {
  resize: vertical;
  min-height: 120px;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--color-secondary);
}

form {
  margin: 2rem 0;
}

fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  background: var(--gradient-subtle);
}

legend {
  padding: 0 0.5rem;
  font-weight: 700;
  color: var(--color-secondary);
}

@media (min-width: 768px) {
  h1 {
    font-size: 3.5rem;
  }

  h2 {
    font-size: 2.5rem;
  }

  h3 {
    font-size: 1.875rem;
  }

  .site-header {
    padding: 2.5rem 2rem;
  }

  .site-header h1 {
    font-size: 2.5rem;
  }

  .site-nav {
    margin-top: 1.5rem;
  }

  .site-nav ul {
    gap: 2rem;
  }

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

  .card {
    padding: 2.5rem;
  }

  blockquote {
    padding: 2rem 3rem;
  }

  .container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .site-footer {
    padding: 4rem 2rem 2.5rem;
  }
}

@media (min-width: 1024px) {
  h1 {
    font-size: 4rem;
  }

  .site-header {
    padding: 3rem 2rem;
  }

  .site-header h1 {
    font-size: 3rem;
  }

  .site-main {
    padding: 5rem 2rem;
  }

  .card {
    padding: 3rem;
  }

  table th, table td {
    padding: 1.25rem;
  }

  .container {
    gap: 3rem;
  }
}

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

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

  .site-main {
    padding: 0;
    background: var(--color-bg);
  }

  .container {
    max-width: 100%;
  }

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

  a {
    color: var(--color-text);
    border-bottom: none;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
    color: var(--color-text-muted);
  }

  blockquote {
    page-break-inside: avoid;
  }

  h1, h2, h3, h4, h5, h6 {
    page-break-after: avoid;
  }
}