/* ==========================================================================
   SkyLogs Design System
   
   A calm, premium, web-first design system.
   ========================================================================== */

/* ==========================================================================
   1. CSS Custom Properties (Design Tokens)
   ========================================================================== */

:root {
  /* ---- Colors: Primary ---- */
  --color-primary-50: #eff6ff;
  --color-primary-100: #dbeafe;
  --color-primary-200: #bfdbfe;
  --color-primary-300: #93c5fd;
  --color-primary-400: #60a5fa;
  --color-primary-500: #3b82f6;
  --color-primary-600: #2563eb;
  --color-primary-700: #1d4ed8;
  --color-primary-800: #1e40af;
  --color-primary-900: #1e3a8a;
  
  /* ---- Colors: Accent (Teal) ---- */
  --color-accent-400: #2dd4bf;
  --color-accent-500: #14b8a6;
  --color-accent-600: #0d9488;
  
  /* ---- Colors: Semantic ---- */
  --color-success-50: #f0fdf4;
  --color-success-100: #dcfce7;
  --color-success-500: #22c55e;
  --color-success-600: #16a34a;
  --color-success-700: #166534;
  
  --color-warning-50: #fffbeb;
  --color-warning-100: #fef3c7;
  --color-warning-500: #f59e0b;
  --color-warning-600: #d97706;
  --color-warning-700: #92400e;
  
  --color-danger-50: #fef2f2;
  --color-danger-100: #fee2e2;
  --color-danger-500: #ef4444;
  --color-danger-600: #dc2626;
  --color-danger-700: #991b1b;
  
  /* ---- Colors: Neutral (Calm archive palette) ---- */
  --color-white: #ffffff;
  --color-gray-50: #f8fafc;
  --color-gray-100: #f1f5f9;
  --color-gray-200: #e2e8f0;
  --color-gray-300: #cbd5e1;
  --color-gray-400: #94a3b8;
  --color-gray-500: #64748b;
  --color-gray-600: #475569;
  --color-gray-700: #334155;
  --color-gray-800: #1e293b;
  --color-gray-900: #0f172a;
  --color-gray-950: #020617;
  
  /* ---- Semantic Aliases ---- */
  --color-bg-body: var(--color-gray-50);
  --color-bg-surface: var(--color-white);
  --color-bg-surface-raised: var(--color-white);
  --color-bg-muted: var(--color-gray-100);
  --color-bg-subtle: var(--color-gray-200);
  
  --color-text-primary: var(--color-gray-900);
  --color-text-secondary: var(--color-gray-600);
  --color-text-muted: var(--color-gray-400);
  --color-text-inverse: var(--color-white);
  
  --color-border: var(--color-gray-200);
  --color-border-muted: var(--color-gray-100);
  --color-border-strong: var(--color-gray-300);
  
  --color-link: var(--color-primary-600);
  --color-link-hover: var(--color-primary-700);

  /* ---- Shorthand Aliases (used by inline view styles) ---- */
  --primary: var(--color-primary-500);
  --primary-dark: var(--color-primary-700);
  --primary-light: var(--color-primary-300);
  --primary-50: var(--color-primary-50);
  --primary-100: var(--color-primary-100);
  --primary-600: var(--color-primary-600);
  --primary-700: var(--color-primary-700);
  --primary-color: var(--color-primary-500);
  --primary-hover: var(--color-primary-600);
  --secondary: var(--color-accent-500);
  --accent-50: #f0fdfa;
  --accent-700: #0f766e;
  --surface: var(--color-bg-surface);
  --surface-hover: var(--color-gray-50);
  --border: var(--color-border);
  --border-color: var(--color-border);
  --text-primary: var(--color-text-primary);
  --text-secondary: var(--color-text-secondary);
  --text-muted: var(--color-text-muted);
  --text-xs: var(--font-size-xs);
  --text-sm: var(--font-size-sm);
  --text-lg: var(--font-size-lg);
  --text-xl: var(--font-size-xl);
  --text-2xl: var(--font-size-2xl);
  --error: var(--color-danger-500);
  --error-50: var(--color-danger-50);
  --error-100: var(--color-danger-100);
  --error-200: #fecaca;
  --error-700: var(--color-danger-700);
  --error-800: #991b1b;
  --success: var(--color-success-500);
  --success-50: var(--color-success-50);
  --success-100: var(--color-success-100);
  --success-200: #bbf7d0;
  --success-700: var(--color-success-700);
  --success-800: #166534;
  --warning: var(--color-warning-500);
  --warning-50: var(--color-warning-50);
  --warning-100: var(--color-warning-100);
  --warning-700: var(--color-warning-700);
  --warning-800: #92400e;
  
  /* ---- Typography ---- */
  --font-family-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'SF Mono', SFMono-Regular, ui-monospace, Menlo, Monaco, Consolas, monospace;
  
  --font-size-xs: 0.75rem;     /* 12px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;    /* 18px */
  --font-size-xl: 1.25rem;     /* 20px */
  --font-size-2xl: 1.5rem;     /* 24px */
  --font-size-3xl: 1.875rem;   /* 30px */
  --font-size-4xl: 2.25rem;    /* 36px */
  --font-size-5xl: 3rem;       /* 48px */
  --font-size-6xl: 3.75rem;    /* 60px */
  
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  
  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  
  /* ---- Spacing ---- */
  --space-0: 0;
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  
  /* Section spacing */
  --section-spacing-sm: var(--space-12);
  --section-spacing: var(--space-20);
  --section-spacing-lg: var(--space-24);
  
  /* ---- Layout ---- */
  --container-max-width: 1280px;
  --container-padding: var(--space-6);
  --navbar-height: 64px;
  
  /* ---- Borders ---- */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-full: 9999px;
  
  --border-width: 1px;
  --border-width-2: 2px;
  
  /* ---- Shadows ---- */
  --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* ---- Transitions ---- */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  
  /* ---- Focus Ring ---- */
  --focus-ring-color: var(--color-primary-500);
  --focus-ring-offset: 2px;
  --focus-ring-width: 2px;
  --focus-ring: 0 0 0 var(--focus-ring-offset) var(--color-bg-surface), 0 0 0 calc(var(--focus-ring-offset) + var(--focus-ring-width)) var(--focus-ring-color);
  
  /* ---- Z-index ---- */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 1200;
  --z-modal: 1300;
  --z-toast: 1400;
  --z-tooltip: 1500;
  --z-navbar: 1100;
}


/* ==========================================================================
   2. CSS Reset & Base Styles
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--navbar-height) + var(--space-4));
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family-sans);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-body);
  min-height: 100vh;
}

/* Skip link for keyboard users */
.skip-link {
  position: absolute;
  top: var(--space-3);
  left: var(--space-3);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg-surface);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  transform: translateY(-200%);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  z-index: var(--z-navbar);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  box-shadow: var(--shadow-lg);
}

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

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

/* Focus styles for accessibility */
:focus {
  outline: none;
}

:focus-visible {
  box-shadow: var(--focus-ring);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

/* Headings */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-4);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-tight);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
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: 0 0 var(--space-4);
  color: var(--color-text-secondary);
}

/* Remove default button styles */
button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}


/* ==========================================================================
   3. Layout Utilities
   ========================================================================== */

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

.container-narrow {
  max-width: 768px;
}

.container-wide {
  max-width: 1440px;
}

/* Main content wrapper (accounts for sticky navbar) */
.main-wrapper {
  padding-top: var(--space-8);
  padding-bottom: var(--section-spacing);
}

/* Section spacing */
.section {
  padding-top: var(--section-spacing);
  padding-bottom: var(--section-spacing);
}

.section-sm {
  padding-top: var(--section-spacing-sm);
  padding-bottom: var(--section-spacing-sm);
}

.section-lg {
  padding-top: var(--section-spacing-lg);
  padding-bottom: var(--section-spacing-lg);
}

/* Stack (vertical spacing) */
.stack > * + * {
  margin-top: var(--space-4);
}

.stack-sm > * + * {
  margin-top: var(--space-2);
}

.stack-lg > * + * {
  margin-top: var(--space-6);
}

.stack-xl > * + * {
  margin-top: var(--space-8);
}


/* ==========================================================================
   4. Typography Utilities
   ========================================================================== */

/* Display headings (hero, etc.) */
.heading-display {
  font-size: clamp(var(--font-size-4xl), 5vw, var(--font-size-6xl));
  font-weight: var(--font-weight-extrabold);
  line-height: 1.1;
  letter-spacing: var(--letter-spacing-tight);
}

.heading-1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
}

.heading-2 {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-semibold);
}

.heading-3 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
}

.heading-4 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-medium);
}

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

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

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

/* Text colors */
.text-primary {
  color: var(--color-text-primary);
}

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

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

/* Lead paragraph */
.lead {
  font-size: var(--font-size-xl);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  max-width: 42rem;
}

/* Caption / small text */
.caption {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* Overline */
.overline {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wide);
  color: var(--color-text-muted);
}


/* ==========================================================================
   5. Button Components
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  border: var(--border-width) solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  -webkit-user-select: none;
  user-select: none;
}

.btn:focus-visible {
  box-shadow: var(--focus-ring);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Primary */
.btn-primary {
  background-color: var(--color-primary-600);
  color: var(--color-white);
  border-color: var(--color-primary-600);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-700);
  border-color: var(--color-primary-700);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Secondary */
.btn-secondary {
  background-color: var(--color-white);
  color: var(--color-text-primary);
  border-color: var(--color-border-strong);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-gray-50);
  border-color: var(--color-gray-400);
}

/* Ghost */
.btn-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
}

.btn-ghost:hover:not(:disabled) {
  background-color: var(--color-bg-muted);
  color: var(--color-text-primary);
}

/* Danger */
.btn-danger {
  background-color: var(--color-danger-500);
  color: var(--color-white);
  border-color: var(--color-danger-500);
}

.btn-danger:hover:not(:disabled) {
  background-color: var(--color-danger-600);
  border-color: var(--color-danger-600);
}

/* Sizes */
.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--font-size-base);
}

.btn-full {
  width: 100%;
}

/* Icon button */
.btn-icon {
  padding: var(--space-2);
}

.btn-icon svg {
  width: 1.25rem;
  height: 1.25rem;
}


/* ==========================================================================
   6. Card Components
   ========================================================================== */

.card {
  background-color: var(--color-bg-surface);
  border: var(--border-width) solid var(--color-border-muted);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
}

.card-elevated {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.card-body {
  padding: var(--space-6);
}

.card-header {
  padding: var(--space-4) var(--space-6);
  border-bottom: var(--border-width) solid var(--color-border-muted);
}

.card-footer {
  padding: var(--space-4) var(--space-6);
  border-top: var(--border-width) solid var(--color-border-muted);
  background-color: var(--color-bg-muted);
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin: 0;
}


/* ==========================================================================
   7. Form Components
   ========================================================================== */

.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
}

.form-hint {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  font-weight: var(--font-weight-normal);
  margin-left: var(--space-1);
}

.form-input,
.form-select,
.form-textarea {
  display: block;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-base);
  font-family: inherit;
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-surface);
  border: var(--border-width) solid var(--color-border);
  box-shadow: var(--shadow-xs);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
}

.form-input:hover,
.form-select:hover,
.form-textarea:hover {
  border-color: var(--color-gray-400);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-primary-500);
  box-shadow: 0 0 0 3px var(--color-primary-100);
  outline: none;
}

.form-input.is-invalid,
.form-select.is-invalid {
  border-color: var(--color-danger-500);
}

.form-input.is-invalid:focus {
  box-shadow: 0 0 0 3px var(--color-danger-100);
}

/* Checkbox & Radio */
.form-checkbox {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.checkbox-input {
  width: 1rem;
  height: 1rem;
  accent-color: var(--color-primary-600);
  cursor: pointer;
}

.checkbox-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
}

/* Form actions */
.form-actions {
  margin-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-3);
}

.form-error {
  font-size: var(--font-size-sm);
  color: var(--color-danger-600);
  margin-top: var(--space-1);
}


/* ==========================================================================
   8. Notice / Alert Components
   ========================================================================== */

/* Flash container - holds all notices */
.flash-container {
  position: fixed;
  top: var(--space-4);
  left: 50%;
  transform: translateX(-50%);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 480px;
  width: calc(100% - var(--space-8));
}

.notice {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-4);
  border-radius: var(--radius-lg);
  font-weight: var(--font-weight-medium);
  box-shadow: var(--shadow-lg);
  animation: notice-slide-in 0.3s ease-out;
}

.notice-content {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  flex: 1;
  min-width: 0;
}

.notice-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 1px;
}

.notice-text {
  flex: 1;
  min-width: 0;
}

.notice-message {
  margin: 0;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1.4;
}

.notice-details {
  margin: var(--space-1) 0 0;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-normal);
  opacity: 0.85;
  line-height: 1.4;
}

.notice-dismiss {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  opacity: 0.6;
  transition: opacity 0.15s ease, background-color 0.15s ease;
}

.notice-dismiss:hover {
  opacity: 1;
  background-color: rgba(0, 0, 0, 0.05);
}

.notice-dismiss svg {
  width: 16px;
  height: 16px;
}

@keyframes notice-slide-in {
  from {
    opacity: 0;
    transform: translateY(-1rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.notice-success {
  background-color: var(--color-success-50);
  border: var(--border-width) solid var(--color-success-500);
  color: var(--color-success-700);
}

.notice-success .notice-dismiss {
  color: var(--color-success-700);
}

.notice-error {
  background-color: var(--color-danger-50);
  border: var(--border-width) solid var(--color-danger-500);
  color: var(--color-danger-700);
}

.notice-error .notice-dismiss {
  color: var(--color-danger-700);
}

.notice-warning {
  background-color: var(--color-warning-50);
  border: var(--border-width) solid var(--color-warning-500);
  color: var(--color-warning-700);
}

.notice-warning .notice-dismiss {
  color: var(--color-warning-700);
}

.notice-info {
  background-color: var(--color-primary-50);
  border: var(--border-width) solid var(--color-primary-500);
  color: var(--color-primary-700);
}

.notice-info .notice-dismiss {
  color: var(--color-primary-700);
}

/* Fade out animation */
.notice.fade-out {
  animation: notice-fade-out 0.3s ease-out forwards;
}

@keyframes notice-fade-out {
  to {
    opacity: 0;
    transform: translateY(-0.5rem);
  }
}


/* ==========================================================================
   9. Badge / Pill Components
   ========================================================================== */

.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.badge-primary {
  background-color: var(--color-primary-100);
  color: var(--color-primary-700);
}

.badge-success {
  background-color: var(--color-success-100);
  color: var(--color-success-700);
}

.badge-warning {
  background-color: var(--color-warning-100);
  color: var(--color-warning-700);
}

.badge-danger {
  background-color: var(--color-danger-100);
  color: var(--color-danger-700);
}

.badge-neutral {
  background-color: var(--color-gray-100);
  color: var(--color-gray-700);
}

/* Pills (rounded badges) */
.pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  background-color: var(--color-bg-muted);
  color: var(--color-text-secondary);
  border-radius: var(--radius-full);
  border: var(--border-width) solid var(--color-border);
}

.pill-primary {
  background-color: var(--color-primary-50);
  color: var(--color-primary-700);
  border-color: var(--color-primary-200);
}


/* ==========================================================================
   10. Utility Classes
   ========================================================================== */

/* Spacing utilities */
.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.py-6 { padding-top: var(--space-6); padding-bottom: var(--space-6); }
.py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }

.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.px-6 { padding-left: var(--space-6); padding-right: var(--space-6); }

/* Flexbox utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* Grid utilities */
.grid { display: grid; }

/* Text utilities */
.text-center { text-align: center; }
.text-right { text-align: right; }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

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

/* Responsive visibility */
@media (max-width: 768px) {
  .hide-mobile { display: none !important; }
}

@media (min-width: 769px) {
  .hide-desktop { display: none !important; }
}


/* ==========================================================================
   12. Takeoff Search Component
   ========================================================================== */

.takeoff-search {
  position: relative;
  width: 100%;
}

.takeoff-search__input {
  width: 100%;
}

.takeoff-search__results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--color-bg-surface);
  border: var(--border-width) solid var(--color-border-strong);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  box-shadow: var(--shadow-md);
  max-height: 300px;
  overflow-y: auto;
  z-index: 100;
}

.takeoff-search-result {
  padding: var(--space-3) var(--space-4);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: background-color var(--transition-fast);
}

.takeoff-search-result:last-child {
  border-bottom: none;
}

.takeoff-search-result:hover {
  background-color: var(--color-primary-50);
}

.takeoff-search-result--disabled {
  cursor: default;
  color: var(--color-text-muted);
  font-style: italic;
}

.takeoff-search-result--disabled:hover {
  background-color: transparent;
}

.takeoff-search-result__name {
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
}

.takeoff-search-result__country {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.takeoff-search-result__count {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* Selected takeoff display */
.takeoff-selected {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-bg-surface);
  border: var(--border-width) solid var(--color-border-strong);
  border-radius: var(--radius-md);
  gap: var(--space-2);
}

.takeoff-selected__name {
  flex: 1;
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.takeoff-selected__clear {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: var(--color-gray-200);
  color: var(--color-text-secondary);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: var(--font-size-lg);
  line-height: 1;
  transition: all var(--transition-fast);
}

.takeoff-selected__clear:hover {
  background: var(--color-danger-100);
  color: var(--color-danger-600);
}


/* ==========================================================================
   13. Error States & Loading Components
   ========================================================================== */

/* Inline form field errors */
.field-error {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--font-size-sm);
  color: var(--color-danger-600);
  line-height: 1.4;
}

/* Form input error state */
.form-input.has-error,
.form-input:invalid:not(:placeholder-shown),
input.has-error,
select.has-error,
textarea.has-error {
  border-color: var(--color-danger-500);
  box-shadow: 0 0 0 3px var(--color-danger-100);
}

.form-input.has-error:focus,
input.has-error:focus,
select.has-error:focus,
textarea.has-error:focus {
  border-color: var(--color-danger-500);
  box-shadow: 0 0 0 3px var(--color-danger-100);
}

/* Error summary box (for form validation) */
.error-summary {
  padding: var(--space-4);
  margin-bottom: var(--space-5);
  background-color: var(--color-danger-50);
  border: var(--border-width) solid var(--color-danger-200);
  border-left: 4px solid var(--color-danger-500);
  border-radius: var(--radius-md);
}

.error-summary__title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin: 0 0 var(--space-3);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-danger-700);
}

.error-summary__title svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.error-summary__list {
  margin: 0;
  padding-left: var(--space-5);
  font-size: var(--font-size-sm);
  color: var(--color-danger-700);
}

.error-summary__list li {
  margin-bottom: var(--space-1);
  line-height: 1.5;
}

.error-summary__list li:last-child {
  margin-bottom: 0;
}

/* Loading spinner */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
}

.spinner-sm {
  width: 14px;
  height: 14px;
  border-width: 2px;
}

.spinner-lg {
  width: 32px;
  height: 32px;
  border-width: 3px;
}

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

/* Loading overlay for sections */
.loading-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(255, 255, 255, 0.8);
  border-radius: inherit;
  z-index: 10;
}

/* Loading skeleton (placeholder while content loads) */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-gray-200) 25%,
    var(--color-gray-100) 50%,
    var(--color-gray-200) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

.skeleton-text {
  height: 1em;
  margin-bottom: var(--space-2);
}

.skeleton-text:last-child {
  width: 60%;
}

.skeleton-heading {
  height: 1.5em;
  width: 40%;
  margin-bottom: var(--space-3);
}

.skeleton-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
}

.skeleton-card {
  height: 120px;
}

@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Empty state (no data) */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-12) var(--space-6);
  text-align: center;
}

.empty-state__icon {
  width: 64px;
  height: 64px;
  margin-bottom: var(--space-4);
  color: var(--color-gray-400);
}

.empty-state__title {
  margin: 0 0 var(--space-2);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

.empty-state__description {
  margin: 0 0 var(--space-5);
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  max-width: 400px;
}

/* Disabled state for interactive elements */
.disabled,
[disabled],
:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

/* Retry action */
.retry-action {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-primary-600);
  background-color: var(--color-primary-50);
  border: var(--border-width) solid var(--color-primary-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.retry-action:hover {
  background-color: var(--color-primary-100);
  border-color: var(--color-primary-300);
}

.retry-action svg {
  width: 16px;
  height: 16px;
}

/* Service unavailable banner */
.service-banner {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-warning-50);
  border: var(--border-width) solid var(--color-warning-200);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--color-warning-800);
}

.service-banner > svg {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  color: var(--color-warning-500);
}

.service-banner__content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

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

.service-banner__content span {
  opacity: 0.85;
}

.service-banner .retry-action {
  flex-shrink: 0;
  margin-left: auto;
}

.service-banner--error {
  background-color: var(--color-danger-50);
  border-color: var(--color-danger-200);
  color: var(--color-danger-800);
}

.service-banner--error > svg {
  color: var(--color-danger-500);
}

/* ==========================================================================
   14. Progressive Loading & Lazy Tab Styles
   ========================================================================== */

/* Tab loading container */
.tab-loading-container {
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-8);
}

/* Skeleton grid for stats */
.skeleton-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-4);
  width: 100%;
}

.skeleton-stat-card {
  background: var(--color-bg-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  border: 1px solid var(--color-border);
}

/* Error state for lazy loading */
.tab-error-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 150px;
  padding: var(--space-8);
}

.tab-error-content {
  text-align: center;
  color: var(--color-text-secondary);
}

.tab-error-icon {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-3);
}

.tab-error-message {
  margin-bottom: var(--space-4);
  font-size: var(--font-size-base);
}

/* Loading placeholder with spinner */
.loading-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-8);
  color: var(--color-text-secondary);
  gap: var(--space-3);
}

.loading-placeholder p {
  font-size: var(--font-size-sm);
  margin: 0;
}

/* Hidden utility class */
.hidden {
  display: none !important;
}

/* Inline spinner for buttons */
.btn-spinner {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.btn-spinner .spinner {
  width: 16px;
  height: 16px;
  border-width: 2px;
}

/* ==========================================================================
   15. Expandable/Collapsible Sections
   ========================================================================== */

/* Expandable content area */
.expandable-content {
  transition: height 0.3s ease;
}

.expandable-content.collapsed {
  display: none;
}

.expandable-content.expanded {
  display: block;
}

/* Expand/collapse trigger button */
.expand-trigger {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.expand-trigger:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text-primary);
}

.expand-trigger svg {
  transition: transform 0.3s ease;
}

.expand-trigger[aria-expanded="true"] svg {
  transform: rotate(180deg);
}

/* Summary card (compact view before expansion) */
.summary-card {
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.summary-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
}

.summary-card-title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin: 0;
}

.summary-card-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-100);
  color: var(--color-primary-700);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
}

/* Key metrics row - horizontal scrollable on mobile */
.key-metrics-row {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--color-border-muted);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.key-metric {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 80px;
  text-align: center;
}

.key-metric-value {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  line-height: 1.2;
}

.key-metric-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Performance grade indicator */
.grade-indicator {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-lg);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
}

.grade-indicator.grade-a { background: var(--color-success-100); color: var(--color-success-700); }
.grade-indicator.grade-b { background: #dbeafe; color: #1d4ed8; }
.grade-indicator.grade-c { background: var(--color-warning-100); color: var(--color-warning-700); }
.grade-indicator.grade-d { background: #fed7aa; color: #c2410c; }
.grade-indicator.grade-f { background: var(--color-danger-100); color: var(--color-danger-700); }

/* Analysis insight banner */
.insight-banner {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-primary-50);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--color-primary-500);
  margin-bottom: var(--space-4);
}

.insight-banner-icon {
  font-size: var(--font-size-xl);
  flex-shrink: 0;
}

.insight-banner-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ==========================================================================
   16. Responsive Breakpoints Reference
   ========================================================================== */

/*
   Mobile:  < 640px
   Tablet:  640px - 1023px
   Desktop: >= 1024px
   Wide:    >= 1280px
*/