/* ===== SHARED UI/UX IMPROVEMENTS ===== */

:root {
  --success:      #10b981;
  --warning:      #f59e0b;
  --danger:       #ef4444;
}

[data-theme="dark"] {
  --header-bg:    linear-gradient(135deg, #1e40af 0%, #4c1d95 100%);
}

.site-header .back-link {
  display: inline-block;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.88rem;
  font-weight: 500;
  margin-bottom: 16px;
  text-decoration: none;
  transition: opacity var(--transition, 0.3s ease), color var(--transition, 0.3s ease);
}

.site-header .back-link:hover {
  opacity: 1;
  color: #fff;
}

/* Main */
main {
  flex: 1;
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 48px 24px;
}

/* Section Title */
.section-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 24px;
}

section + section {
  margin-top: 48px;
}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
  margin-bottom: 24px;
  transition: box-shadow var(--transition);
}

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

.card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
}

/* Forms */
.form-group {
  margin-bottom: 24px;
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  background: var(--surface);
  font-family: inherit;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  font-size: 1rem;
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  color: white;
}

.btn-secondary {
  background: var(--surface);
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

/* Alerts */
.alert {
  padding: 16px 20px;
  border-radius: var(--radius);
  margin: 16px 0;
  border-left: 4px solid;
}

.alert-success {
  background: rgba(16, 185, 129, 0.08);
  border-color: var(--success);
  color: #065f46;
}

.alert-warning {
  background: rgba(245, 158, 11, 0.08);
  border-color: var(--warning);
  color: #92400e;
}

.alert-danger {
  background: rgba(239, 68, 68, 0.08);
  border-color: var(--danger);
  color: #991b1b;
}

/* Tabs */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--border);
  margin-bottom: 24px;
  gap: 8px;
  flex-wrap: wrap;
}

.tab {
  padding: 12px 20px;
  border-radius: 10px 10px 0 0;
  cursor: pointer;
  transition: all var(--transition);
  font-weight: 500;
  color: var(--muted);
  background: transparent;
  border: none;
  font-size: 0.95rem;
  font-family: inherit;
}

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

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* Navigation Menu (for SPAs) */
.nav-menu {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 24px;
}

.nav-item {
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--transition);
  font-weight: 500;
  color: rgba(255,255,255,0.8);
  background: rgba(255,255,255,0.1);
  font-size: 0.9rem;
  border: none;
}

.nav-item:hover, .nav-item.active {
  background: rgba(255,255,255,0.25);
  color: white;
}

/* Sections */
.section {
  display: none;
  animation: fadeIn 0.4s ease;
}

.section.active {
  display: block;
}

/* Hero */
.hero {
  text-align: center;
  margin-bottom: 48px;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto;
}

/* Progress Bar */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin: 20px 0;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  transition: width 0.4s ease;
}

/* Result Card */
.result-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  margin-top: 24px;
  box-shadow: var(--shadow);
  text-align: center;
}

.result-score {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Levels Grid */
.levels-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}

.level-card {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all var(--transition);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.level-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  transform: scaleX(0);
  transition: transform var(--transition);
}

.level-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.level-card:hover::before {
  transform: scaleX(1);
}

.level-number {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin-bottom: 16px;
}

.level-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.level-description {
  color: var(--muted);
  margin-bottom: 12px;
  font-size: 0.95rem;
}

.level-example {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  padding: 12px;
  border-radius: 8px;
  font-size: 0.85rem;
}

.level-example strong {
  display: block;
  margin-bottom: 4px;
  opacity: 0.9;
}

/* Simulator */
.simulator {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  margin: 24px 0;
  box-shadow: var(--shadow);
}

/* Quiz */
.quiz-question {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.quiz-options {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.quiz-option {
  padding: 14px 18px;
  border: 2px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  transition: all var(--transition);
  background: var(--surface);
  font-size: 0.95rem;
}

.quiz-option:hover {
  border-color: var(--primary);
  background: rgba(102, 126, 234, 0.05);
}

.quiz-option.selected {
  border-color: var(--primary);
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
}

/* Guidelines Output */
.guidelines-output {
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.08) 0%, rgba(118, 75, 162, 0.08) 100%);
  padding: 24px;
  border-radius: var(--radius);
  margin-top: 20px;
  border-left: 4px solid var(--primary);
}

.copy-btn {
  margin-top: 16px;
  font-size: 0.9rem;
  padding: 10px 20px;
}

/* Theme Toggle */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  width: 44px;
  height: 44px;
  border-radius: 50% !important;
  border: none;
  background: var(--surface, #ffffff);
  box-shadow: var(--shadow, 0 4px 24px rgba(102, 126, 234, 0.10));
  cursor: pointer;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition, 0.3s ease);
  z-index: 200;
  padding: 0;
  margin: 0;
}

.theme-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-hover);
}

.theme-toggle:focus {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: #fff;
  padding: 8px 16px;
  z-index: 1000;
  transition: top 0.3s ease;
}

.skip-link:focus {
  top: 0;
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  box-shadow: var(--shadow);
  cursor: pointer;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition);
  z-index: 150;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

/* Header scroll effect */
.site-header.scrolled,
.header.scrolled {
  padding: 16px 24px !important;
  backdrop-filter: blur(12px);
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.95) 0%, rgba(118, 75, 162, 0.95) 100%) !important;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  position: sticky;
  top: 0;
  z-index: 100;
}

[data-theme="dark"] .site-header.scrolled,
[data-theme="dark"] .header.scrolled {
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.95) 0%, rgba(76, 29, 149, 0.95) 100%) !important;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-fade-in {
  animation: fadeInUp 0.6s ease forwards;
}

/* Card hover glow */
.card:hover,
.level-card:hover,
.app-card:hover {
  box-shadow: var(--shadow-hover), 0 0 30px rgba(102, 126, 234, 0.15);
}

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

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Mobile menu button */
.mobile-menu-btn {
  display: none;
  position: absolute;
  top: 20px;
  right: 20px;
  width: 44px;
  height: 44px;
  border: none;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.mobile-menu-btn:hover {
  background: rgba(255, 255, 255, 0.25);
}

.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: all 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Responsive */
@media (max-width: 768px) {
  .mobile-menu-btn {
    display: flex;
  }
  
  .theme-toggle {
    top: 12px;
    right: 12px;
    width: 36px;
    height: 36px;
    font-size: 1rem;
  }

  main {
    padding: 32px 16px;
  }

  .site-header {
    padding: 32px 20px 28px;
  }

  .site-header .logo {
    font-size: 1.6rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }
  
  .levels-grid {
    grid-template-columns: 1fr;
  }

  .nav-menu {
    gap: 6px;
  }

  .nav-item {
    padding: 8px 14px;
    font-size: 0.8rem;
  }

  .card {
    padding: 20px;
  }
}