/* ==========================================================================
   Common Styles - Base Layout
   ========================================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-base);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Links */
a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

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

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Lists */
ul,
ol {
  list-style: none;
}

/* Buttons */
button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

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

/* Inputs */
input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
}

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

/* Skip Link (Accessibility)
   ========================================================================== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: var(--z-modal);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

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

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 var(--container-padding);
  max-width: var(--container-max-width);
  margin: 0 auto;
}

/* Logo & Site Info */
.site-brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-brand a {
  color: var(--color-text-primary);
  text-decoration: none;
}

.site-name {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
}

.site-tagline {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  display: none;
}

/* Main Navigation */
.main-nav {
  display: none;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.nav-item a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-item a:hover,
.nav-item a.active {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}

/* Header Utilities */
.header-utils {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.btn-icon:hover {
  background-color: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.btn-icon svg {
  width: 20px;
  height: 20px;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: flex;
}

.mobile-menu-toggle .icon-close {
  display: none;
}

.mobile-menu-toggle.active .icon-menu {
  display: none;
}

.mobile-menu-toggle.active .icon-close {
  display: block;
}

/* Mobile Navigation */
.mobile-nav {
  display: none;
  position: absolute;
  top: var(--header-height);
  left: 0;
  right: 0;
  background-color: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-lg);
  max-height: calc(100vh - var(--header-height));
  overflow-y: auto;
}

.mobile-nav.active {
  display: block;
}

.mobile-nav-list {
  padding: var(--spacing-md);
}

.mobile-nav-item a {
  display: block;
  padding: var(--spacing-md);
  color: var(--color-text-secondary);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
}

.mobile-nav-item a:hover,
.mobile-nav-item a.active {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}

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

/* Breadcrumb */
.breadcrumb {
  margin-bottom: var(--spacing-lg);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-sm);
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-text-tertiary);
}

.breadcrumb-item:not(:last-child)::after {
  content: '/';
  color: var(--color-text-tertiary);
}

.breadcrumb-item a {
  color: var(--color-text-secondary);
}

.breadcrumb-item a:hover {
  color: var(--color-primary);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--color-text-primary);
  font-weight: var(--font-weight-medium);
}

/* Page Header */
.page-header {
  margin-bottom: var(--spacing-xl);
}

.page-title {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.page-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* Content Sections */
.content-section {
  margin-bottom: var(--spacing-2xl);
}

.section-title {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--color-border);
}

.section-content {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

.section-content p {
  margin-bottom: var(--spacing-md);
}

.section-content p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  margin-top: auto;
}

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

/* Footer Navigation */
.footer-nav {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h3 {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-links a:hover {
  color: var(--color-primary);
}

/* Footer Bottom */
.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
}

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

.footer-legal a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-legal a:hover {
  color: var(--color-primary);
}

.footer-copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

/* Visibility */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Text */
.text-center {
  text-align: center;
}

.text-primary {
  color: var(--color-primary);
}

.text-secondary {
  color: var(--color-text-secondary);
}

/* Spacing */
.mt-md {
  margin-top: var(--spacing-md);
}

.mb-md {
  margin-bottom: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

/* ==========================================================================
   Responsive - Tablet (768px+)
   ========================================================================== */
@media (min-width: 768px) {
  :root {
    --container-padding: 1.5rem;
  }

  .site-tagline {
    display: block;
  }

  .main-nav {
    display: block;
  }

  .mobile-menu-toggle {
    display: none;
  }

  .mobile-nav {
    display: none !important;
  }

  .page-title {
    font-size: var(--font-size-4xl);
  }

  .footer-nav {
    grid-template-columns: repeat(4, 1fr);
  }

  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

/* ==========================================================================
   Responsive - Desktop (1024px+)
   ========================================================================== */
@media (min-width: 1024px) {
  :root {
    --container-padding: 2rem;
  }

  .nav-item a {
    padding: var(--spacing-sm) var(--spacing-lg);
  }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
  .site-header,
  .site-footer,
  .breadcrumb,
  .btn-icon {
    display: none;
  }

  .site-main {
    padding: 0;
  }

  body {
    font-size: 12pt;
    line-height: 1.5;
    color: #000;
    background: #fff;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}