/* ========================================
   CSS VARIABLES
   ======================================== */
:root {
  /* Colors */
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-secondary: #10b981;
  --color-accent: #f59e0b;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-border: #e5e7eb;
  --color-error: #ef4444;
  --color-success: #10b981;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  
  /* Typography */
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Breakpoints */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
}

/* ========================================
   CSS RESET
   ======================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-base);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

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

input, button, textarea, select {
  font: inherit;
}

p, h1, h2, h3, h4, h5, h6 {
  overflow-wrap: break-word;
}

ul, ol {
  list-style: none;
}

a {
  text-decoration: none;
  color: inherit;
}

button {
  background: none;
  border: none;
  cursor: pointer;
}

/* ========================================
   BASE TYPOGRAPHY
   ======================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

h1 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-lg);
}

h2 {
  font-size: var(--font-size-2xl);
}

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

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

p {
  margin-bottom: var(--space-md);
  line-height: 1.6;
}

a {
  color: var(--color-primary);
  transition: color var(--transition-fast);
}

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

/* Responsive typography */
@media (min-width: 768px) {
  h1 {
    font-size: var(--font-size-4xl);
  }
  
  h2 {
    font-size: var(--font-size-3xl);
  }
  
  h3 {
    font-size: var(--font-size-2xl);
  }
}

/* ========================================
   LAYOUT UTILITIES
   ======================================== */
.container {
  width: 100%;
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--space-lg);
    padding-right: var(--space-lg);
  }
}

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

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

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

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

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

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

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

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

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

/* Grid utilities */
.grid {
  display: grid;
  gap: var(--space-md);
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* Section spacing */
.section {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}

@media (min-width: 768px) {
  .section {
    padding-top: var(--space-3xl);
    padding-bottom: var(--space-3xl);
  }
}

/* ========================================
   NAVBAR COMPONENT
   ======================================== */
.navbar {
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

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

.navbar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.navbar .logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
}

.navbar .logo:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
  border-radius: var(--radius-sm);
}

.navbar-burger {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: var(--space-sm);
  background: transparent;
  border: none;
  cursor: pointer;
}

.navbar-burger span {
  display: block;
  width: 1.5rem;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition-fast);
}

.navbar-burger:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
  border-radius: var(--radius-sm);
}

.navbar-burger:hover span {
  background-color: var(--color-primary);
}

/* Hamburger animation when active */
.navbar-burger.is-active span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.navbar-burger.is-active span:nth-child(2) {
  opacity: 0;
}

.navbar-burger.is-active span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.navbar-menu {
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  right: 0;
  width: 80%;
  max-width: 300px;
  height: 100vh;
  background-color: var(--color-bg);
  box-shadow: var(--shadow-lg);
  padding: var(--space-xl);
  gap: var(--space-md);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  z-index: 1001;
}

.navbar-menu.is-active {
  transform: translateX(0);
}

.navbar-menu a {
  padding: var(--space-md);
  color: var(--color-text);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.navbar-menu a:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-primary);
}

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

/* Desktop navigation */
@media (min-width: 768px) {
  .navbar-burger {
    display: none;
  }
  
  .navbar-menu {
    display: flex;
    position: static;
    flex-direction: row;
    width: auto;
    height: auto;
    max-width: none;
    padding: 0;
    box-shadow: none;
    transform: none;
    background-color: transparent;
  }
  
  .navbar-menu.is-active {
    transform: none;
  }
}

/* ========================================
   BUTTON COMPONENT
   ======================================== */
.btn {
  display: inline-block;
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-align: center;
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 2px solid transparent;
  line-height: 1;
}

.btn:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
}

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

.btn-primary {
  background-color: var(--color-primary);
  color: white;
}

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

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

.btn-secondary:hover:not(:disabled) {
  background-color: #059669;
}

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

.btn-outline:hover:not(:disabled) {
  background-color: var(--color-primary);
  color: white;
}

.btn-lg {
  padding: var(--space-lg) var(--space-2xl);
  font-size: var(--font-size-lg);
}

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

.cta-button {
  background-color: var(--color-accent);
  color: white;
  padding: var(--space-md) var(--space-xl);
  border-radius: var(--radius-lg);
  font-weight: 600;
  transition: all var(--transition-fast);
}

.cta-button:hover {
  background-color: #d97706;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.cta-button:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
}

/* ========================================
   FORM COMPONENT
   ======================================== */
.contact-form {
  max-width: 600px;
  margin: 0 auto;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  background-color: var(--color-bg);
}

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

.contact-form input:invalid:not(:placeholder-shown),
.contact-form select:invalid:not(:placeholder-shown) {
  border-color: var(--color-error);
}

.contact-form label {
  display: block;
  margin-bottom: var(--space-sm);
  font-weight: 500;
  color: var(--color-text);
}

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

.contact-form button[type="submit"] {
  width: 100%;
  margin-top: var(--space-md);
}

.form-message {
  margin-top: var(--space-md);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  font-weight: 500;
}

.form-message.success {
  background-color: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
  border: 1px solid var(--color-success);
}

.form-message.error {
  background-color: rgba(239, 68, 68, 0.1);
  color: var(--color-error);
  border: 1px solid var(--color-error);
}

/* ========================================
   MODAL COMPONENT
   ======================================== */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2000;
}

.modal[aria-hidden="false"] {
  display: block;
}

.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.modal-content {
  position: relative;
  background-color: var(--color-bg);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  margin: var(--space-xl);
  max-width: 600px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  z-index: 2001;
}

@media (min-width: 768px) {
  .modal-content {
    margin: calc(5vh) auto;
    padding: var(--space-2xl);
  }
}

.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  font-size: var(--font-size-2xl);
  color: var(--color-text-light);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
  line-height: 1;
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--color-text);
}

.modal-close:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.modal h2 {
  margin-bottom: var(--space-lg);
  padding-right: var(--space-xl);
}

/* Prevent body scroll when modal is open */
body.modal-open {
  overflow: hidden;
}

/* ========================================
   TABLE COMPONENT
   ======================================== */
table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-lg) 0;
  background-color: var(--color-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

thead {
  background-color: var(--color-primary);
  color: white;
}

th, td {
  padding: var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

th {
  font-weight: 600;
  text-transform: uppercase;
  font-size: var(--font-size-sm);
  letter-spacing: 0.05em;
}

tbody tr {
  transition: background-color var(--transition-fast);
}

tbody tr:hover {
  background-color: var(--color-bg-alt);
}

tbody tr:last-child td {
  border-bottom: none;
}

/* Responsive table */
@media (max-width: 767px) {
  table {
    font-size: var(--font-size-sm);
  }
  
  th, td {
    padding: var(--space-sm);
  }
}

/* ========================================
   FOCUS INDICATORS (Accessibility)
   ======================================== */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Enhanced focus for interactive elements */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ========================================
   UTILITY CLASSES
   ======================================== */
.text-center {
  text-align: center;
}

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

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

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.pt-0 { padding-top: 0; }
.pt-sm { padding-top: var(--space-sm); }
.pt-md { padding-top: var(--space-md); }
.pt-lg { padding-top: var(--space-lg); }
.pt-xl { padding-top: var(--space-xl); }

.pb-0 { padding-bottom: 0; }
.pb-sm { padding-bottom: var(--space-sm); }
.pb-md { padding-bottom: var(--space-md); }
.pb-lg { padding-bottom: var(--space-lg); }
.pb-xl { padding-bottom: var(--space-xl); }

.hidden {
  display: none;
}

.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;
}