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

: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: 'Georgia', 'Times New Roman', 'Palatino', serif;
  --max-width: 1100px;
  --radius: 6px;
  --shadow-sm: inset 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 2px 8px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 4px 16px rgba(15, 23, 42, 0.12);
  --transition: 0.2s ease;
}

body {
  font-family: var(--font-main);
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-text);
  background: linear-gradient(to bottom, var(--color-bg) 0%, var(--color-surface) 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-main);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-secondary);
  margin-bottom: 0.75em;
}

h1 {
  font-size: 2.5rem;
  letter-spacing: -0.02em;
  border-bottom: 3px solid var(--color-accent);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 2rem;
  border-bottom: 2px solid var(--color-border);
  padding-bottom: 0.4rem;
}

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

h4 {
  font-size: 1.25rem;
  color: var(--color-primary);
}

h5 {
  font-size: 1.1rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1.25rem;
}

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

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

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  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: linear-gradient(to right, var(--color-surface) 0%, var(--color-bg) 100%);
  border-left: 4px solid var(--color-accent);
  box-shadow: var(--shadow-sm);
  font-style: italic;
  color: var(--color-primary);
  border-radius: var(--radius);
}

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

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

.site-header {
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-primary) 100%);
  color: var(--color-bg);
  padding: 2rem 1.5rem;
  box-shadow: var(--shadow-lg);
  border-bottom: 3px solid var(--color-accent);
}

.site-header h1 {
  color: var(--color-bg);
  border-bottom: none;
  margin: 0;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.site-nav {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0;
  box-shadow: var(--shadow-sm);
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0;
}

.site-nav li {
  flex: 1 1 auto;
  min-width: 120px;
}

.site-nav a {
  display: block;
  padding: 1rem 1.5rem;
  color: var(--color-primary);
  font-weight: 600;
  border-bottom: none;
  border-right: 1px solid var(--color-border);
  text-align: center;
  transition: background-color var(--transition), color var(--transition), box-shadow var(--transition);
  position: relative;
}

.site-nav li:last-child a {
  border-right: none;
}

.site-nav a:hover {
  background: var(--color-bg);
  color: var(--color-accent);
  box-shadow: var(--shadow-sm);
}

.site-nav a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
  z-index: 1;
}

.site-main {
  flex: 1;
  padding: 2rem 1.5rem;
}

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

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 1rem 0;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 2rem;
}

.breadcrumbs a {
  color: var(--color-text-muted);
  border-bottom: 1px dotted var(--color-border);
}

.breadcrumbs a:hover {
  color: var(--color-accent);
  border-bottom-style: solid;
}

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

.site-footer {
  background: linear-gradient(to top, var(--color-secondary) 0%, var(--color-primary) 100%);
  color: var(--color-surface);
  padding: 3rem 1.5rem 2rem;
  margin-top: 4rem;
  border-top: 3px solid var(--color-accent);
  box-shadow: 0 -4px 16px rgba(15, 23, 42, 0.1);
}

.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: 0.75rem;
  color: var(--color-surface);
}

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

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.card h2,
.card h3,
.card h4 {
  margin-top: 0;
}

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

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

thead th {
  font-weight: 700;
  text-align: left;
  padding: 1rem 1.25rem;
  border-bottom: 2px solid var(--color-accent);
}

tbody tr {
  transition: background-color var(--transition);
}

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

tbody tr:hover {
  background: linear-gradient(to right, #e0f2fe 0%, var(--color-surface) 100%);
}

td {
  padding: 0.875rem 1.25rem;
  border-bottom: 1px solid var(--color-border);
}

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

th {
  font-weight: 600;
}

details {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition);
}

details[open] {
  box-shadow: var(--shadow-md);
}

summary {
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  font-weight: 600;
  color: var(--color-primary);
  background: linear-gradient(to right, var(--color-surface) 0%, var(--color-bg) 100%);
  border-bottom: 1px solid transparent;
  transition: background-color var(--transition), color var(--transition), border-color var(--transition);
  user-select: none;
  list-style-position: inside;
}

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

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

details[open] summary {
  border-bottom-color: var(--color-border);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: var(--color-bg);
}

details[open] summary:hover {
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-primary) 100%);
}

details > *:not(summary) {
  padding: 1.5rem;
  animation: slideDown 0.2s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

ul li, ol li {
  margin-bottom: 0.5rem;
  padding-left: 0.5rem;
}

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

button, .button {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-bg);
  background: linear-gradient(135deg, var(--color-accent) 0%, #0ea5e9 100%);
  border: 2px solid var(--color-accent);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color var(--transition), box-shadow var(--transition), transform var(--transition);
  box-shadow: var(--shadow-sm);
}

button:hover, .button:hover {
  background: linear-gradient(135deg, #0ea5e9 0%, var(--color-accent) 100%);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
  border-bottom-color: var(--color-accent);
}

button:focus-visible, .button:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}

button:active, .button:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

input, textarea, select {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-main);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition), box-shadow var(--transition);
}

input:hover, textarea:hover, select:hover {
  border-color: var(--color-primary);
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

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

form {
  background: var(--color-surface);
  padding: 2rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

fieldset {
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

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

hr {
  border: none;
  border-top: 2px solid var(--color-border);
  margin: 2rem 0;
  box-shadow: 0 1px 0 var(--color-bg);
}

@media (min-width: 768px) {
  body {
    font-size: 19px;
  }

  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2.25rem;
  }

  h3 {
    font-size: 1.75rem;
  }

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

  .site-nav ul {
    flex-wrap: nowrap;
  }

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

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

  .card {
    padding: 2.5rem;
  }

  table {
    font-size: 1rem;
  }

  form {
    padding: 2.5rem;
  }
}

@media (min-width: 1024px) {
  h1 {
    font-size: 3.5rem;
  }

  h2 {
    font-size: 2.5rem;
  }

  .site-header {
    padding: 3.5rem 2rem;
  }

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

  blockquote {
    padding: 2rem 3rem;
  }

  .card {
    padding: 3rem;
  }
}

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

  details > *:not(summary) {
    animation: none;
  }

  .card:hover {
    transform: none;
  }

  button:hover, .button:hover {
    transform: none;
  }
}

@media print {
  body {
    background: white;
  }

  .site-header {
    background: white;
    color: black;
    box-shadow: none;
    border-bottom: 2px solid black;
  }

  .site-nav {
    display: none;
  }

  .site-footer {
    background: white;
    color: black;
    border-top: 2px solid black;
    box-shadow: none;
  }

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

  .container {
    max-width: 100%;
  }

  a {
    color: black;
    border-bottom: 1px solid black;
  }

  .card {
    box-shadow: none;
    page-break-inside: avoid;
  }

  button, .button {
    display: none;
  }

  details summary {
    display: none;
  }

  details[open] > *:not(summary) {
    padding: 0;
  }
}