/**
 * STUDYHUBEXPERTS DESIGN SYSTEM
 * A complete visual identity following "Academic calm + tech precision"
 * Version: 2.0
 */

/* ============================================
   1. CSS CUSTOM PROPERTIES (DESIGN TOKENS)
   ============================================ */

:root {
  /* === COLOR PALETTE === */
  /* Primary Colors */
  --color-midnight-blue: #1A2A42;
  --color-sky-mint: #56E0C5;
  --color-clean-white: #F9FAFB;
  --color-slate-graphite: #6C7A91;

  /* Semantic Colors */
  --color-success-green: #0BB783;
  --color-warning-amber: #FFC94A;
  --color-trust-red: #E55454;

  /* Extended Palette for UI states */
  --color-midnight-blue-dark: #0F1823;
  --color-midnight-blue-light: #2A3F5F;
  --color-sky-mint-light: #7AEBD7;
  --color-sky-mint-dark: #3BC4AC;

  /* Neutral Grays */
  --color-gray-50: #F9FAFB;
  --color-gray-100: #F3F4F6;
  --color-gray-200: #E5E7EB;
  --color-gray-300: #D1D5DB;
  --color-gray-400: #9CA3AF;
  --color-gray-500: #6C7A91;
  --color-gray-600: #4B5563;
  --color-gray-700: #374151;
  --color-gray-800: #1F2937;
  --color-gray-900: #111827;

  /* === TYPOGRAPHY === */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-accent: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Font Sizes (Responsive Scale) */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg: 1.125rem;     /* 18px */
  --text-xl: 1.25rem;      /* 20px */
  --text-2xl: 1.5rem;      /* 24px */
  --text-3xl: 1.875rem;    /* 30px */
  --text-4xl: 2.25rem;     /* 36px */
  --text-5xl: 3rem;        /* 48px */

  /* Font Weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Line Heights */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.75;

  /* === SPACING === */
  --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 */

  /* === LAYOUT === */
  --radius-sm: 4px;
  --radius-base: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows (Soft, Academic-appropriate) */
  --shadow-xs: 0 1px 2px 0 rgba(26, 42, 66, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(26, 42, 66, 0.1), 0 1px 2px 0 rgba(26, 42, 66, 0.06);
  --shadow-base: 0 4px 6px -1px rgba(26, 42, 66, 0.1), 0 2px 4px -1px rgba(26, 42, 66, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(26, 42, 66, 0.1), 0 4px 6px -2px rgba(26, 42, 66, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(26, 42, 66, 0.1), 0 10px 10px -5px rgba(26, 42, 66, 0.04);

  /* === TRANSITIONS === */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms 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;
}

/* ============================================
   2. BASE STYLES & RESET
   ============================================ */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--color-gray-800);
  background-color: var(--color-clean-white);
  min-height: 100vh;
}

/* ============================================
   3. TYPOGRAPHY SYSTEM
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-accent);
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  color: var(--color-midnight-blue);
  margin-bottom: var(--space-4);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

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

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

a:hover {
  color: var(--color-sky-mint);
}

strong, b {
  font-weight: var(--font-bold);
  color: var(--color-midnight-blue);
}

/* ============================================
   4. BUTTON SYSTEM
   ============================================ */

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

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

/* Primary Button */
.btn-primary {
  background-color: var(--color-midnight-blue);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-midnight-blue-dark);
  box-shadow: var(--shadow-base);
  transform: translateY(-1px);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: var(--shadow-xs);
}

/* Secondary Button */
.btn-secondary {
  background-color: white;
  color: var(--color-midnight-blue);
  border: 1.5px solid var(--color-gray-300);
  box-shadow: var(--shadow-xs);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--color-midnight-blue);
  background-color: var(--color-gray-50);
  box-shadow: var(--shadow-sm);
}

/* Accent Button */
.btn-accent {
  background-color: var(--color-sky-mint);
  color: var(--color-midnight-blue);
  box-shadow: var(--shadow-sm);
}

.btn-accent:hover:not(:disabled) {
  background-color: var(--color-sky-mint-dark);
  box-shadow: var(--shadow-base);
  transform: translateY(-1px);
}

/* Success Button */
.btn-success {
  background-color: var(--color-success-green);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-success:hover:not(:disabled) {
  background-color: #099966;
  transform: translateY(-1px);
}

/* Warning Button */
.btn-warning {
  background-color: var(--color-warning-amber);
  color: var(--color-midnight-blue);
  box-shadow: var(--shadow-sm);
}

/* Danger Button */
.btn-danger {
  background-color: var(--color-trust-red);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-danger:hover:not(:disabled) {
  background-color: #D43F3F;
  transform: translateY(-1px);
}

/* Ghost Button (Tertiary) */
.btn-ghost {
  background-color: transparent;
  color: var(--color-slate-graphite);
  border: none;
  box-shadow: none;
}

.btn-ghost:hover:not(:disabled) {
  background-color: var(--color-gray-100);
  color: var(--color-midnight-blue);
}

/* Button Sizes */
.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

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

/* Button Full Width */
.btn-block {
  width: 100%;
}

/* ============================================
   5. CARD SYSTEM
   ============================================ */

.card {
  background-color: white;
  border-radius: var(--radius-base);
  box-shadow: var(--shadow-sm);
  padding: var(--space-6);
  transition: all var(--transition-base);
  border: 1px solid var(--color-gray-100);
}

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

.card-title {
  font-family: var(--font-accent);
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--color-midnight-blue);
  margin-bottom: var(--space-3);
}

.card-body {
  color: var(--color-slate-graphite);
  font-size: var(--text-base);
}

.card-footer {
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-gray-200);
  display: flex;
  gap: var(--space-3);
  align-items: center;
}

/* Card Variants */
.card-flat {
  box-shadow: none;
  border: 1px solid var(--color-gray-200);
}

.card-elevated {
  box-shadow: var(--shadow-lg);
}

.card-interactive {
  cursor: pointer;
}

.card-interactive:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--color-sky-mint);
}

/* ============================================
   6. BADGE SYSTEM
   ============================================ */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  line-height: 1;
  white-space: nowrap;
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

/* Badge Status Colors */
.badge-pending {
  background-color: #FEF3C7;
  color: #92400E;
}

.badge-accepted, .badge-in-progress {
  background-color: #D1FAE5;
  color: #065F46;
}

.badge-completed {
  background-color: #DBEAFE;
  color: #1E40AF;
}

.badge-cancelled, .badge-rejected {
  background-color: #FEE2E2;
  color: #991B1B;
}

.badge-open {
  background-color: #E0F2FE;
  color: #075985;
}

.badge-success {
  background-color: #D1FAE5;
  color: var(--color-success-green);
}

.badge-warning {
  background-color: #FEF3C7;
  color: #B45309;
}

.badge-info {
  background-color: #E0F2FE;
  color: #0369A1;
}

/* Badge with Dot Indicator */
.badge-dot::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: currentColor;
}

/* ============================================
   7. FORM SYSTEM
   ============================================ */

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

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

.form-label-required::after {
  content: '*';
  color: var(--color-trust-red);
  margin-left: var(--space-1);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-primary);
  font-size: var(--text-base);
  color: var(--color-gray-800);
  background-color: white;
  border: 1.5px solid var(--color-gray-300);
  border-radius: var(--radius-base);
  transition: all var(--transition-fast);
  outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-sky-mint);
  box-shadow: 0 0 0 3px rgba(86, 224, 197, 0.1);
}

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

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

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

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

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

.form-input.error:focus,
.form-textarea.error:focus,
.form-select.error:focus {
  box-shadow: 0 0 0 3px rgba(229, 84, 84, 0.1);
}

/* Checkbox & Radio */
.form-checkbox,
.form-radio {
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--color-gray-300);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.form-checkbox:checked,
.form-radio:checked {
  background-color: var(--color-midnight-blue);
  border-color: var(--color-midnight-blue);
}

/* ============================================
   8. NAVIGATION & LAYOUT
   ============================================ */

.navbar {
  background-color: white;
  border-bottom: 1px solid var(--color-gray-200);
  box-shadow: var(--shadow-xs);
  padding: var(--space-4) 0;
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
}

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

.navbar-logo {
  font-family: var(--font-accent);
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--color-midnight-blue);
  text-decoration: none;
}

.navbar-menu {
  display: flex;
  gap: var(--space-6);
  align-items: center;
}

.navbar-link {
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  color: var(--color-slate-graphite);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
}

.navbar-link:hover,
.navbar-link.active {
  color: var(--color-midnight-blue);
}

/* Subtle underline animation on navigation */
.navbar-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-sky-mint);
  transition: width var(--transition-base);
}

.navbar-link:hover::after,
.navbar-link.active::after {
  width: 100%;
}

/* Main Content Container */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

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

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

/* Page Layout */
.page-header {
  padding: var(--space-8) 0;
  border-bottom: 1px solid var(--color-gray-200);
  margin-bottom: var(--space-8);
}

.page-title {
  font-family: var(--font-accent);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-midnight-blue);
  margin-bottom: var(--space-2);
}

.page-subtitle {
  font-size: var(--text-lg);
  color: var(--color-slate-graphite);
}

/* ============================================
   9. NOTIFICATION & TOAST SYSTEM
   ============================================ */

.toast {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  min-width: 300px;
  max-width: 400px;
  padding: var(--space-4);
  background-color: white;
  border-radius: var(--radius-base);
  box-shadow: var(--shadow-lg);
  border-left: 4px solid var(--color-midnight-blue);
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
  animation: slideInRight var(--transition-base);
  z-index: var(--z-tooltip);
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.toast-success {
  border-left-color: var(--color-success-green);
}

.toast-warning {
  border-left-color: var(--color-warning-amber);
}

.toast-error {
  border-left-color: var(--color-trust-red);
}

.toast-info {
  border-left-color: var(--color-sky-mint);
}

/* Notification Badge */
.notification-badge {
  position: relative;
}

.notification-badge::after {
  content: attr(data-count);
  position: absolute;
  top: -8px;
  right: -8px;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  background-color: var(--color-trust-red);
  color: white;
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ============================================
   10. LOADING & SKELETON STATES
   ============================================ */

.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-loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-base);
}

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

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

.skeleton-title {
  height: 1.5em;
  width: 60%;
  margin-bottom: var(--space-3);
}

.skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
}

.skeleton-card {
  height: 200px;
  border-radius: var(--radius-base);
}

/* Spinner */
.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-gray-200);
  border-top-color: var(--color-midnight-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ============================================
   11. GEOMETRIC PATTERNS & BRANDING
   ============================================ */

/* Hexagon Pattern Background (subtle) */
.pattern-hexagon {
  background-image:
    linear-gradient(30deg, transparent 45%, rgba(86, 224, 197, 0.03) 45%, rgba(86, 224, 197, 0.03) 55%, transparent 55%),
    linear-gradient(-30deg, transparent 45%, rgba(86, 224, 197, 0.03) 45%, rgba(86, 224, 197, 0.03) 55%, transparent 55%);
  background-size: 40px 70px;
}

/* Triangle Pattern */
.pattern-triangle {
  background-image:
    linear-gradient(45deg, rgba(26, 42, 66, 0.02) 25%, transparent 25%),
    linear-gradient(-45deg, rgba(26, 42, 66, 0.02) 25%, transparent 25%);
  background-size: 30px 30px;
}

/* Accent Stroke (decorative element) */
.accent-stroke {
  position: relative;
}

.accent-stroke::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--color-sky-mint), var(--color-midnight-blue));
  border-radius: var(--radius-full);
}

/* ============================================
   12. MODAL & OVERLAY SYSTEM
   ============================================ */

.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(26, 42, 66, 0.4);
  backdrop-filter: blur(4px);
  z-index: var(--z-modal-backdrop);
  animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 600px;
  width: 90%;
  max-height: 90vh;
  background-color: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: var(--z-modal);
  animation: modalSlideUp var(--transition-base);
  overflow: hidden;
}

@keyframes modalSlideUp {
  from {
    opacity: 0;
    transform: translate(-50%, -45%);
  }
  to {
    opacity: 1;
    transform: translate(-50%, -50%);
  }
}

.modal-header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--color-gray-200);
}

.modal-title {
  font-family: var(--font-accent);
  font-size: var(--text-2xl);
  font-weight: var(--font-semibold);
  color: var(--color-midnight-blue);
}

.modal-body {
  padding: var(--space-6);
  overflow-y: auto;
  max-height: calc(90vh - 180px);
}

.modal-footer {
  padding: var(--space-6);
  border-top: 1px solid var(--color-gray-200);
  display: flex;
  gap: var(--space-3);
  justify-content: flex-end;
}

/* ============================================
   13. AVATAR & USER PROFILE ELEMENTS
   ============================================ */

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid white;
  box-shadow: var(--shadow-sm);
}

.avatar-sm {
  width: 32px;
  height: 32px;
}

.avatar-lg {
  width: 64px;
  height: 64px;
}

.avatar-xl {
  width: 96px;
  height: 96px;
}

.avatar-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-midnight-blue), var(--color-sky-mint));
  color: white;
  font-weight: var(--font-semibold);
  font-size: var(--text-lg);
}

/* Online Status Indicator */
.avatar-online {
  position: relative;
}

.avatar-online::after {
  content: '';
  position: absolute;
  bottom: 2px;
  right: 2px;
  width: 12px;
  height: 12px;
  background-color: var(--color-success-green);
  border: 2px solid white;
  border-radius: 50%;
}

/* ============================================
   14. UTILITY CLASSES
   ============================================ */

/* Spacing Utilities */
.mt-0 { margin-top: 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); }

.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); }

.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

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

.text-primary { color: var(--color-midnight-blue); }
.text-accent { color: var(--color-sky-mint); }
.text-muted { color: var(--color-slate-graphite); }
.text-success { color: var(--color-success-green); }
.text-warning { color: var(--color-warning-amber); }
.text-danger { color: var(--color-trust-red); }

/* Display Utilities */
.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }

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

/* Width Utilities */
.w-full { width: 100%; }
.w-auto { width: auto; }

/* Height Utilities */
.h-full { height: 100%; }

/* Border Utilities */
.border { border: 1px solid var(--color-gray-200); }
.border-t { border-top: 1px solid var(--color-gray-200); }
.border-b { border-bottom: 1px solid var(--color-gray-200); }
.border-l { border-left: 1px solid var(--color-gray-200); }
.border-r { border-right: 1px solid var(--color-gray-200); }

/* Rounded Utilities */
.rounded { border-radius: var(--radius-base); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

/* Shadow Utilities */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-base); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-none { box-shadow: none; }

/* Cursor Utilities */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

/* Overflow Utilities */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-y-auto { overflow-y: auto; }

/* Position Utilities */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* ============================================
   15. RESPONSIVE DESIGN (MOBILE-FIRST)
   ============================================ */

@media (max-width: 768px) {
  :root {
    --text-4xl: 2rem;
    --text-3xl: 1.5rem;
    --text-2xl: 1.25rem;
  }

  .container {
    padding: 0 var(--space-4);
  }

  .card {
    padding: var(--space-4);
  }

  .navbar-container {
    padding: 0 var(--space-4);
  }

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

  .btn {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
  }

  .modal {
    width: 95%;
  }
}

/* ============================================
   16. DARK MODE SUPPORT (FUTURE)
   ============================================ */

@media (prefers-color-scheme: dark) {
  /* Dark mode variables would go here */
  /* Currently designed for light mode only */
}

/* ============================================
   17. PRINT STYLES
   ============================================ */

@media print {
  body {
    background-color: white;
  }

  .navbar,
  .btn,
  .modal-backdrop {
    display: none;
  }

  .card {
    box-shadow: none;
    border: 1px solid var(--color-gray-300);
  }
}