/* ==========================================================================
   ROOT VARIABLES
   ========================================================================== */

:root {
  /* Colors - Professional Blue & Gray Palette */
  --color-primary: #2563eb;
  --color-primary-light: #3b82f6;
  --color-primary-dark: #1e40af;
  --color-primary-50: #eff6ff;
  --color-primary-100: #dbeafe;
  
  --color-secondary: #475569;
  --color-secondary-light: #64748b;
  --color-secondary-dark: #334155;
  
  --color-background: #ffffff;
  --color-background-alt: #f8fafc;
  --color-background-muted: #f1f5f9;
  
  --color-text: #1e293b;
  --color-text-light: #475569;
  --color-text-muted: #64748b;
  
  --color-success: #10b981;
  --color-success-light: #34d399;
  --color-success-dark: #059669;
  
  --color-warning: #f59e0b;
  --color-warning-light: #fbbf24;
  --color-warning-dark: #d97706;
  
  --color-danger: #ef4444;
  --color-danger-light: #f87171;
  --color-danger-dark: #dc2626;
  
  --color-neutral-50: #f8fafc;
  --color-neutral-100: #f1f5f9;
  --color-neutral-200: #e2e8f0;
  --color-neutral-300: #cbd5e1;
  --color-neutral-400: #94a3b8;
  --color-neutral-500: #64748b;
  --color-neutral-600: #475569;
  --color-neutral-700: #334155;
  --color-neutral-800: #1e293b;
  --color-neutral-900: #0f172a;
  
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-border-dark: #cbd5e1;
  
  /* Typography */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-family-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-family-mono: 'Courier New', Courier, 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;
  
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  --line-height-loose: 2;
  
  /* Spacing Scale */
  --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 */
  
  /* Border Radius */
  --radius-sm: 0.25rem;   /* 4px */
  --radius-base: 0.5rem;  /* 8px */
  --radius-md: 0.75rem;   /* 12px */
  --radius-lg: 1rem;      /* 16px */
  --radius-xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Transitions */
  --transition-fast: 150ms;
  --transition-base: 250ms;
  --transition-slow: 350ms;
  --transition-timing: cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* ==========================================================================
   RESET & NORMALIZE
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  width: 100%;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

iframe {
  border: 0;
}

ul,
ol {
  list-style: none;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

/* ==========================================================================
   BASE TYPOGRAPHY
   ========================================================================== */

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

h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-6);
}

h2 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-5);
}

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);
}

@media (min-width: 768px) {
  h1 {
    font-size: var(--font-size-5xl);
  }
  
  h2 {
    font-size: var(--font-size-4xl);
  }
  
  h3 {
    font-size: var(--font-size-3xl);
  }
}

p {
  margin-bottom: var(--space-4);
  }

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-base) var(--transition-timing);
}

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

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

strong,
b {
  font-weight: var(--font-weight-semibold);
}

em,
i {
  font-style: italic;
}

small {
  font-size: var(--font-size-sm);
}

code,
kbd,
samp,
pre {
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
}

code {
  padding: 0.125rem 0.25rem;
  background-color: var(--color-neutral-100);
  border-radius: var(--radius-sm);
  color: var(--color-text);
}

pre {
  padding: var(--space-4);
  background-color: var(--color-neutral-900);
  color: var(--color-neutral-50);
  border-radius: var(--radius-base);
  overflow-x: auto;
  margin-bottom: var(--space-4);
}

pre code {
  padding: 0;
  background-color: transparent;
  color: inherit;
}

blockquote {
  padding-left: var(--space-6);
  border-left: 4px solid var(--color-primary);
  font-style: italic;
  color: var(--color-text-light);
  margin-bottom: var(--space-4);
}

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: var(--space-8) 0;
}

/* ==========================================================================
   UTILITY CLASSES
   ========================================================================== */

/* Container */
.container {
  width: 100%;
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  overflow-x: hidden;
}

@media (max-width: 625px) {
  .container {
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }
}

@media (min-width: 640px) {
  .container {
    padding-left: var(--space-6);
    padding-right: var(--space-6);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-left: var(--space-8);
    padding-right: var(--space-8);
  }
}

.container-narrow {
  max-width: 960px;
}

.container-wide {
  max-width: 1536px;
}

/* Flexbox Utilities */
.flex {
  display: flex;
}

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

.flex-row {
  flex-direction: row;
}

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

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

.items-start {
  align-items: flex-start;
}

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

.items-end {
  align-items: flex-end;
}

.justify-start {
  justify-content: flex-start;
}

.justify-center {
  justify-content: center;
}

.justify-end {
  justify-content: flex-end;
}

.justify-between {
  justify-content: space-between;
}

.gap-2 {
  gap: var(--space-2);
}

.gap-4 {
  gap: var(--space-4);
}

.gap-6 {
  gap: var(--space-6);
}

.gap-8 {
  gap: var(--space-8);
}

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

.grid-cols-1 {
  grid-template-columns: repeat(1, minmax(0, 1fr));
}

.grid-cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-cols-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

@media (min-width: 768px) {
  .md\:grid-cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  
  .md\:grid-cols-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 625px) {
  .grid-cols-2,
  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (min-width: 1024px) {
  .lg\:grid-cols-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  
  .lg\:grid-cols-4 {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* Spacing Utilities */
.mt-0 { margin-top: var(--space-0); }
.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); }
.mt-12 { margin-top: var(--space-12); }
.mt-16 { margin-top: var(--space-16); }

.mb-0 { margin-bottom: var(--space-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); }
.mb-12 { margin-bottom: var(--space-12); }
.mb-16 { margin-bottom: var(--space-16); }

.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); }
.py-12 { padding-top: var(--space-12); padding-bottom: var(--space-12); }
.py-16 { padding-top: var(--space-16); padding-bottom: var(--space-16); }

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

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

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

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

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

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

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

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

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

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

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

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

/* ==========================================================================
   COMPONENT: BUTTONS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: var(--radius-base);
  cursor: pointer;
  transition: all var(--transition-base) var(--transition-timing);
  user-select: none;
}

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  color: #ffffff;
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
}

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

.btn-secondary:hover {
  background-color: var(--color-background-muted);
  border-color: var(--color-border-dark);
  color: var(--color-text);
}

.btn-outline {
  color: var(--color-primary);
  background-color: transparent;
  border-color: var(--color-primary);
}

.btn-outline:hover {
  color: #ffffff;
  background-color: var(--color-primary);
}

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

.btn-ghost:hover {
  background-color: var(--color-background-muted);
  color: var(--color-text);
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-lg);
}

/* ==========================================================================
   COMPONENT: FORMS
   ========================================================================== */

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

.input,
.textarea,
.select {
  display: block;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-base);
  transition: all var(--transition-base) var(--transition-timing);
}

.input:focus,
.textarea:focus,
.select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.input:disabled,
.textarea:disabled,
.select:disabled {
  background-color: var(--color-background-muted);
  cursor: not-allowed;
  opacity: 0.6;
}

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

.textarea {
  min-height: 120px;
  resize: vertical;
}

.select {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3E%3Cpath stroke='%2364748b' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3E%3C/svg%3E");
  background-position: right var(--space-3) center;
  background-repeat: no-repeat;
  background-size: 1.5em 1.5em;
  padding-right: var(--space-10);
  appearance: none;
}

.form-group {
  margin-bottom: var(--space-6);
}

.form-help {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.form-error {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-danger);
}

.input-error,
.textarea-error,
.select-error {
  border-color: var(--color-danger);
}

.input-error:focus,
.textarea-error:focus,
.select-error:focus {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

/* ==========================================================================
   COMPONENT: CARD
   ========================================================================== */

.card {
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base) var(--transition-timing);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-header {
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border-light);
}

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

.card-body {
  color: var(--color-text-light);
}

.card-footer {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border-light);
}

/* ==========================================================================
   ACCESSIBILITY
   ========================================================================== */

/* Focus Visible Outline */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Skip to main content link */
.skip-to-main {
  position: absolute;
  left: -9999px;
  z-index: 999;
  padding: var(--space-4) var(--space-6);
  background-color: var(--color-primary);
  color: #ffffff;
  text-decoration: none;
  border-radius: var(--radius-base);
}

.skip-to-main:focus {
  left: var(--space-4);
  top: var(--space-4);
}

/* Respect user motion preferences */
@media (prefers-reduced-motion: reduce) {
  .card:hover {
    transform: none;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .btn {
    border-width: 2px;
  }
  
  .card {
    border-width: 2px;
  }
}

/* ==========================================================================
   SECTION SPACING
   ========================================================================== */

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

@media (min-width: 768px) {
  .section {
    padding: var(--space-16) 0;
  }
}

@media (min-width: 1024px) {
  .section {
    padding: var(--space-20) 0;
  }
}

.section-lg {
  padding: var(--space-16) 0;
}

@media (min-width: 768px) {
  .section-lg {
    padding: var(--space-20) 0;
  }
}

@media (min-width: 1024px) {
  .section-lg {
    padding: var(--space-24) 0;
  }
}

/* ==========================================================================
   MOBILE OVERFLOW PREVENTION (625px and below)
   ========================================================================== */

@media (max-width: 625px) {
  /* Prevent all elements from causing horizontal scroll */
  * {
    max-width: 100%;
  }
  
  /* Allow specific elements to use full width */
  html,
  body,
  .container,
  .container-narrow,
  .container-wide {
    max-width: 100%;
  }
  
  /* Ensure images and media respect container */
  img,
  picture,
  video,
  canvas,
  svg,
  iframe {
    max-width: 100%;
    height: auto;
  }
  
  /* Ensure pre and code blocks don't overflow */
  pre {
    overflow-x: auto;
    word-wrap: break-word;
    white-space: pre-wrap;
  }
  
  /* Force flex and grid containers to respect boundaries */
  .flex,
  .grid {
    max-width: 100%;
  }
}