/* ============================================
   Global Layout Styles
   ============================================ */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-sans);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: var(--line-height-normal);
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-4);
}

h1 {
  font-size: var(--font-size-5xl);
}

h2 {
  font-size: var(--font-size-4xl);
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

h5 {
  font-size: var(--font-size-lg);
}

h6 {
  font-size: var(--font-size-base);
}

p {
  margin-bottom: var(--spacing-4);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

a {
  color: var(--color-cyan);
  text-decoration: none;
  transition: var(--transition-fast);
}

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

/* ============================================
   Layout Containers
   ============================================ */

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.container-small {
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.container-large {
  max-width: 1536px;
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

/* ============================================
   Sections & Spacing
   ============================================ */

section {
  padding: var(--spacing-20) 0;
}

section.section-compact {
  padding: var(--spacing-12) 0;
}

section.section-spacious {
  padding: var(--spacing-24) 0;
}

/* ============================================
   Grid Systems
   ============================================ */

.grid {
  display: grid;
  gap: var(--spacing-6);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-6);
}

/* ============================================
   Flexbox Utilities
   ============================================ */

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.flex-column {
  display: flex;
  flex-direction: column;
}

.flex-wrap {
  flex-wrap: wrap;
}

.gap-2 { gap: var(--spacing-2); }
.gap-3 { gap: var(--spacing-3); }
.gap-4 { gap: var(--spacing-4); }
.gap-6 { gap: var(--spacing-6); }
.gap-8 { gap: var(--spacing-8); }

/* ============================================
   Spacing Utilities
   ============================================ */

.mt-2 { margin-top: var(--spacing-2); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-6 { margin-top: var(--spacing-6); }
.mt-8 { margin-top: var(--spacing-8); }

.mb-2 { margin-bottom: var(--spacing-2); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }

.px-4 { padding-left: var(--spacing-4); padding-right: var(--spacing-4); }
.px-6 { padding-left: var(--spacing-6); padding-right: var(--spacing-6); }
.py-4 { padding-top: var(--spacing-4); padding-bottom: var(--spacing-4); }
.py-6 { padding-top: var(--spacing-6); padding-bottom: var(--spacing-6); }

/* ============================================
   Display Utilities
   ============================================ */

.inline-block {
  display: inline-block;
}

.block {
  display: block;
}

.hidden {
  display: none;
}

.invisible {
  visibility: hidden;
}

/* ============================================
   Text Utilities
   ============================================ */

.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

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

.text-sm {
  font-size: var(--font-size-sm);
}

.text-lg {
  font-size: var(--font-size-lg);
}

.font-bold {
  font-weight: var(--font-weight-bold);
}

.font-semibold {
  font-weight: var(--font-weight-semibold);
}

/* ============================================
   Top Navigation
   ============================================ */

.top-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(180deg, rgba(34, 40, 48, 0.98) 0%, rgba(24, 28, 35, 0.95) 100%);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0, 217, 255, 0.1);
  z-index: var(--z-sticky);
}

.top-nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  text-decoration: none;
}

.logo .logo-icon {
  width: 24px;
  height: 24px;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links li {
  position: relative;
}

.nav-links a {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  transition: var(--transition-base);
  position: relative;
}

.nav-links a::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-purple));
  transition: var(--transition-base);
  transform: translateX(-50%);
  border-radius: 2px;
}

.nav-links a:hover {
  color: var(--color-text-primary);
  background: rgba(0, 217, 255, 0.05);
  text-decoration: none;
}

.nav-links a:hover::before {
  width: 60%;
}

.nav-links a.active {
  color: var(--color-cyan);
  background: rgba(0, 217, 255, 0.1);
}

.nav-links a.active::before {
  width: 60%;
}

.nav-links .nav-icon {
  width: 16px;
  height: 16px;
  opacity: 0.7;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.hamburger-menu {
  display: none;
  background: transparent;
  border: none;
  color: var(--color-text-primary);
  cursor: pointer;
  padding: var(--spacing-2);
}

/* ============================================
   Sidebar Navigation
   ============================================ */

.sidebar {
  position: fixed;
  top: 80px;
  left: 0;
  width: 240px;
  height: calc(100vh - 80px);
  background: linear-gradient(180deg, rgba(22, 27, 34, 0.98) 0%, rgba(13, 17, 23, 0.95) 100%);
  border-right: 1px solid rgba(0, 217, 255, 0.1);
  padding: var(--spacing-4);
  overflow-y: auto;
  z-index: var(--z-fixed);
  display: none;
}

.sidebar.dashboard-sidebar {
  display: block;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-1);
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  text-decoration: none;
  transition: var(--transition-fast);
}

.sidebar-item:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  text-decoration: none;
}

.sidebar-item.active {
  background: rgba(0, 217, 255, 0.1);
  color: var(--color-cyan);
}

.sidebar-divider {
  height: 1px;
  background: var(--color-border-default);
  margin: var(--spacing-4) 0;
}

.sidebar-section-title {
  padding: var(--spacing-2) var(--spacing-3);
  color: var(--color-text-tertiary);
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
}

/* ============================================
   Toggle Switch
   ============================================ */

.toggle {
  position: relative;
  display: inline-block;
  width: 48px;
  height: 24px;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-full);
  transition: var(--transition-base);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  left: 2px;
  bottom: 2px;
  background: var(--color-text-secondary);
  border-radius: 50%;
  transition: var(--transition-base);
}

.toggle input:checked + .toggle-slider {
  background: var(--color-cyan);
  border-color: var(--color-cyan);
}

.toggle input:checked + .toggle-slider::before {
  transform: translateX(24px);
  background: var(--color-bg-primary);
}

/* ============================================
   Button Sizes
   ============================================ */

.btn-sm {
  padding: var(--spacing-1) var(--spacing-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--spacing-3) var(--spacing-6);
  font-size: var(--font-size-base);
}

/* ============================================
   Page Layout (Top Nav + Sidebar)
   ============================================ */

/* Mobile-First: 預設單欄 */
.page-layout {
  display: block;
  min-height: 100vh;
  margin-top: 64px;
}

.page-layout main {
  width: 100%;
  padding: var(--spacing-4);
  overflow-y: auto;
}

/* ============================================
   Main Content Area
   ============================================ */

main {
  flex: 1;
}

/* ============================================
   Footer
   ============================================ */

footer {
  background: linear-gradient(180deg, var(--color-bg-secondary) 0%, var(--color-bg-primary) 100%);
  border-top: 1px solid rgba(0, 217, 255, 0.1);
  padding: var(--spacing-12) 0;
  margin-top: var(--spacing-20);
  position: relative;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-cyan), var(--color-purple), transparent);
}

footer .container {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-6);
  margin-bottom: var(--spacing-8);
}

footer h4 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-4);
  color: var(--color-text-primary);
}

footer ul {
  list-style: none;
}

footer li {
  margin-bottom: var(--spacing-2);
}

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

footer a:hover {
  color: var(--color-cyan);
}

.footer-bottom {
  border-top: 1px solid var(--color-border-default);
  padding-top: var(--spacing-6);
  text-align: center;
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

/* ============================================
   Gradients
   ============================================ */

.gradient-cyan {
  background: linear-gradient(135deg, var(--color-cyan) 0%, var(--color-cyan-dark) 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-purple {
  background: linear-gradient(135deg, var(--color-purple) 0%, var(--color-purple-dark) 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ============================================
   Scrollbar Styling
   ============================================ */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--color-bg-tertiary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-border-emphasis);
}

/* ============================================
   Selection
   ============================================ */

::selection {
  background-color: rgba(0, 217, 255, 0.3);
  color: var(--color-text-primary);
}