/* Base Styles - Luminous Minimalism */
body {
  background-color: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-sans);
  font-weight: var(--font-normal);
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  line-height: 1.6;
}

.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  background: var(--color-bg);
}

/* Header - Floating Glass Design */
.header {
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--color-border-light);
  display: flex;
  align-items: center;
  padding: 0 var(--spacing-xl);
  gap: var(--spacing-lg);
  flex-shrink: 0;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  z-index: var(--z-sticky);
  position: relative;
}

@media (prefers-color-scheme: dark) {
  .header {
    background-color: rgba(30, 41, 59, 0.85);
  }
}

.header__title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: var(--font-bold);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  letter-spacing: -0.02em;
  transition: opacity var(--transition-fast);
  cursor: pointer;
}

.header__title:hover {
  opacity: 0.8;
}

.header__logo {
  height: 36px;
  width: 36px;
  object-fit: contain;
  border-radius: var(--radius-md);
}

/* Search - Premium Input Design */
.header__search {
  flex: 1;
  max-width: 520px;
  position: relative;
}

.header__search-input {
  width: 100%;
  padding: 0.625rem 1rem;
  padding-left: 2.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background-color: var(--color-bg-secondary);
  color: var(--color-text);
  font-size: 0.9375rem;
  font-weight: var(--font-normal);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-xs);
}

.header__search-input:hover {
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-sm);
}

.header__search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  background-color: var(--color-bg-elevated);
  box-shadow: 0 0 0 3px var(--color-primary-subtle), var(--shadow-md);
  transform: translateY(-1px);
}

.header__search-input::placeholder {
  color: var(--color-text-tertiary);
}

.header__search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-tertiary);
  pointer-events: none;
  font-size: 1rem;
  transition: color var(--transition-fast);
}

.header__search-input:focus + .header__search-icon,
.header__search:focus-within .header__search-icon {
  color: var(--color-primary);
}

.header__actions {
  display: flex;
  gap: var(--spacing-sm);
  margin-left: auto;
  align-items: center;
}

/* Header Stats - Prompt Counter & Tier Badge */
.header__stats {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.5rem 0.875rem;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-base);
}

.header__stats:hover {
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.header__prompt-count {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.875rem;
  font-weight: var(--font-semibold);
  color: var(--color-text);
  font-feature-settings: 'tnum' 1;
  padding-right: var(--spacing-sm);
  border-right: 1px solid var(--color-border);
}

.header__prompt-count-icon {
  font-size: 1rem;
}

.header__prompt-count--warning {
  color: var(--color-warning);
}

.header__prompt-count--danger {
  color: var(--color-error);
}

.header__tier-badge {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.75rem;
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.625rem;
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  cursor: pointer;
}

.header__tier-badge--free {
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

.header__tier-badge--free:hover {
  background: var(--color-bg-hover);
  transform: scale(1.05);
}

.header__tier-badge--pro {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  color: white;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.header__tier-badge--pro:hover {
  opacity: 0.9;
  transform: scale(1.05);
}

/* Main Content - Spacious Grid */
.main-content {
  flex: 1;
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(420px, 1fr) minmax(560px, 1.4fr);
  overflow: hidden;
  gap: 0;
  position: relative;
}

/* Buttons - Modern & Tactile */
.btn {
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-lg);
  font-weight: var(--font-medium);
  font-size: 0.9375rem;
  transition: all var(--transition-base);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  cursor: pointer;
  border: none;
  letter-spacing: -0.01em;
  white-space: nowrap;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.15), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.btn:hover::before {
  opacity: 1;
}

.btn--primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
  box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.btn--primary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-xs), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.btn--secondary {
  background-color: var(--color-bg-elevated);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-xs);
}

.btn--secondary:hover {
  background-color: var(--color-bg-hover);
  border-color: var(--color-border-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn--secondary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-xs);
}

.btn--sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn--icon {
  padding: 0.625rem;
  border-radius: var(--radius-lg);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-base);
  color: var(--color-text-secondary);
  background: transparent;
  width: 40px;
  height: 40px;
}

.btn--icon:hover {
  background-color: var(--color-bg-secondary);
  color: var(--color-text);
  box-shadow: var(--shadow-xs);
}

.btn--full {
  width: 100%;
}

/* Empty State - Elegant & Inviting */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-4xl);
  text-align: center;
  color: var(--color-text-secondary);
}

.empty-state__icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-xl);
  opacity: 0.15;
  color: var(--color-text-tertiary);
  filter: grayscale(100%);
}

.empty-state__title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: var(--font-semibold);
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.02em;
}

.empty-state__description {
  margin-bottom: var(--spacing-xl);
  font-size: 0.9375rem;
  line-height: 1.6;
  max-width: 400px;
  color: var(--color-text-tertiary);
}

/* Loading Spinner - Smooth Animation */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2.5px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-circle);
  animation: spin 0.8s cubic-bezier(0.68, -0.55, 0.27, 1.55) infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.loading-overlay {
  position: absolute;
  inset: 0;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal-backdrop);
}

@media (prefers-color-scheme: dark) {
  .loading-overlay {
    background-color: rgba(15, 23, 42, 0.8);
  }
}

/* Scrollbar - Refined & Subtle */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-xl);
  border: 2px solid transparent;
  background-clip: padding-box;
  transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-border-hover);
  background-clip: padding-box;
}

/* Selection - Brand Highlight */
::selection {
  background-color: var(--color-primary-subtle);
  color: var(--color-text);
}

/* Focus Visible - Clear & Accessible */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

/* Utility Classes */
.hidden {
  display: none !important;
}

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

.text-small {
  font-size: 0.875rem;
}

.text-xs {
  font-size: 0.8125rem;
}

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

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

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

/* Responsive Design */
@media (max-width: 1200px) {
  .main-content {
    grid-template-columns: var(--sidebar-width) 1fr 1fr;
  }
}

@media (max-width: 1024px) {
  .main-content {
    grid-template-columns: var(--sidebar-width) 1fr;
  }

  .prompt-detail {
    position: fixed;
    top: var(--header-height);
    right: 0;
    bottom: 0;
    width: 100%;
    max-width: 640px;
    background-color: var(--color-bg);
    border-left: 1px solid var(--color-border);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    z-index: var(--z-fixed);
    box-shadow: var(--shadow-2xl);
  }

  .prompt-detail.active {
    transform: translateX(0);
  }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 72px;
    --header-height: 60px;
  }

  .header {
    padding: 0 var(--spacing-md);
    gap: var(--spacing-md);
  }

  .header__title span:last-child {
    display: none;
  }

  .header__search {
    max-width: 200px;
  }

  .header__stats {
    padding: 0.375rem 0.625rem;
    gap: 0.375rem;
  }

  .header__prompt-count {
    font-size: 0.8125rem;
    padding-right: var(--spacing-xs);
  }

  .header__prompt-count-icon {
    font-size: 0.875rem;
  }

  .header__tier-badge {
    font-size: 0.6875rem;
    padding: 0.1875rem 0.5rem;
  }

  .btn span {
    display: none;
  }

  .btn {
    padding: 0.625rem;
  }

  .main-content {
    grid-template-columns: var(--sidebar-width) 1fr;
  }
}