/* Reset and Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1f2937;
  --color-text-muted: #6b7280;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-border: #e5e7eb;
  --color-bg-alt: #f9fafb;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, monospace;
  --max-width: 48rem;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
}

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

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

/* Container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: 2.25rem;
  margin-bottom: var(--spacing-md);
}

h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-lg);
}

h3 {
  font-size: 1.25rem;
  margin-top: var(--spacing-md);
}

p {
  margin-bottom: var(--spacing-sm);
}

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

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

ul, ol {
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-md);
}

li {
  margin-bottom: var(--spacing-xs);
}

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--spacing-lg) 0;
}

strong {
  font-weight: 600;
}

code {
  font-family: var(--font-mono);
  background-color: var(--color-bg-alt);
  padding: 0.125rem 0.25rem;
  border-radius: 0.25rem;
  font-size: 0.875rem;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-sm) 0;
  background-color: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
}

.site-logo:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 1.5rem;
  height: 1.5rem;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: all 0.2s ease;
}

.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--spacing-md);
}

.nav-menu a {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  padding: var(--spacing-xs) 0;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--color-accent);
  text-decoration: none;
}

/* Main Content */
main {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

.content {
  max-width: 100%;
}

.content.home h1 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
}

.content.home p:first-of-type {
  font-size: 1.125rem;
  color: var(--color-text-muted);
}

/* Buttons */
.btn {
  display: inline-block;
  background-color: var(--color-accent);
  color: #ffffff;
  padding: 0.625rem 1.25rem;
  border-radius: 0.375rem;
  font-weight: 500;
  text-decoration: none;
  transition: background-color 0.2s ease;
}

.btn:hover {
  background-color: var(--color-accent-hover);
  color: #ffffff;
  text-decoration: none;
}

/* App Card */
.app-card {
  background-color: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  padding: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

.app-card h3 {
  margin-top: 0;
  margin-bottom: var(--spacing-xs);
}

.app-card h3 a {
  color: var(--color-text);
}

.app-card h3 a:hover {
  color: var(--color-accent);
}

.app-card p {
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

/* Page List */
.page-list {
  list-style: none;
  padding: 0;
  margin-top: var(--spacing-lg);
}

.page-list li {
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
}

.page-list li:last-child {
  border-bottom: none;
}

.page-list a {
  font-weight: 500;
}

.page-list p {
  margin: var(--spacing-xs) 0 0;
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-lg) 0;
  margin-top: auto;
  background-color: var(--color-bg-alt);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.footer-section p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.footer-nav {
  display: flex;
  gap: var(--spacing-md);
}

.footer-nav a {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

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

/* Mobile Responsive */
@media (max-width: 640px) {
  :root {
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
  }

  h1 {
    font-size: 1.875rem;
  }

  h2 {
    font-size: 1.375rem;
  }

  .content.home h1 {
    font-size: 2rem;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-md);
    gap: 0;
  }

  .nav-menu.nav-open {
    display: flex;
  }

  .nav-menu li {
    margin: 0;
  }

  .nav-menu a {
    display: block;
    padding: var(--spacing-xs) 0;
  }

  .site-header {
    position: relative;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-nav {
    flex-wrap: wrap;
    justify-content: center;
  }
}