/* FKTI - Clean White Theme with Colorful Accents */

:root {
  /* Base Colors - Clean White */
  --bg: #ffffff;
  --bg-subtle: #fafafa;
  --white: #fff;
  --gray-50: #fafafa;
  --gray-100: #f5f5f7;
  --gray-200: #e5e5e5;
  --gray-300: #d1d5db;
  --gray-500: #86868b;
  --gray-600: #6e6e73;
  --gray-900: #1d1d1f;
  
  /* Vibrant Color Palette */
  --blue: #3b82f6;
  --blue-dark: #2563eb;
  --blue-darker: #1d4ed8;
  --green: #22c55e;
  --green-dark: #16a34a;
  --purple: #8b5cf6;
  --purple-dark: #7c3aed;
  --pink: #ec4899;
  --pink-dark: #db2777;
  --orange: #f97316;
  --orange-dark: #ea580c;
  --cyan: #06b6d4;
  --cyan-dark: #0891b2;
  --amber: #f59e0b;
  --red: #ef4444;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
}

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

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--gray-900);
  font-size: 14px;
  line-height: 1.5;
}

/* Hide header completely */
header { display: none !important; }

/* ═══════════════════════════════════════════════════════════════
   3D BUTTONS - Global Style
   ═══════════════════════════════════════════════════════════════ */

.btn, button.btn, a.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
  border: none;
  position: relative;
}

/* Primary Button - Blue 3D */
.btn-primary {
  background: linear-gradient(180deg, #3b82f6 0%, #2563eb 100%);
  color: white;
  box-shadow: 
    0 4px 0 #1d4ed8,
    0 6px 12px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #1d4ed8,
    0 10px 20px rgba(37, 99, 235, 0.4);
}

.btn-primary:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #1d4ed8,
    0 3px 8px rgba(37, 99, 235, 0.3);
}

/* Secondary Button - White 3D */
.btn-secondary {
  background: linear-gradient(180deg, #ffffff 0%, #f5f5f7 100%);
  color: #1d1d1f;
  border: 1px solid #d1d5db;
  box-shadow: 
    0 4px 0 #d1d5db,
    0 6px 12px rgba(0, 0, 0, 0.1);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #d1d5db,
    0 10px 20px rgba(0, 0, 0, 0.12);
}

.btn-secondary:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #d1d5db,
    0 3px 8px rgba(0, 0, 0, 0.08);
}

/* Success Button - Green 3D */
.btn-success {
  background: linear-gradient(180deg, #22c55e 0%, #16a34a 100%);
  color: white;
  box-shadow: 
    0 4px 0 #15803d,
    0 6px 12px rgba(22, 163, 74, 0.35);
}

.btn-success:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #15803d,
    0 10px 20px rgba(22, 163, 74, 0.4);
}

.btn-success:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #15803d,
    0 3px 8px rgba(22, 163, 74, 0.3);
}

/* Purple Button - 3D */
.btn-purple {
  background: linear-gradient(180deg, #8b5cf6 0%, #7c3aed 100%);
  color: white;
  box-shadow: 
    0 4px 0 #6d28d9,
    0 6px 12px rgba(139, 92, 246, 0.35);
}

.btn-purple:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #6d28d9,
    0 10px 20px rgba(139, 92, 246, 0.4);
}

.btn-purple:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #6d28d9,
    0 3px 8px rgba(139, 92, 246, 0.3);
}

/* Orange Button - 3D */
.btn-orange {
  background: linear-gradient(180deg, #f97316 0%, #ea580c 100%);
  color: white;
  box-shadow: 
    0 4px 0 #c2410c,
    0 6px 12px rgba(249, 115, 22, 0.35);
}

.btn-orange:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #c2410c,
    0 10px 20px rgba(249, 115, 22, 0.4);
}

.btn-orange:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #c2410c,
    0 3px 8px rgba(249, 115, 22, 0.3);
}

/* Pink Button - 3D */
.btn-pink {
  background: linear-gradient(180deg, #ec4899 0%, #db2777 100%);
  color: white;
  box-shadow: 
    0 4px 0 #be185d,
    0 6px 12px rgba(236, 72, 153, 0.35);
}

.btn-pink:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #be185d,
    0 10px 20px rgba(236, 72, 153, 0.4);
}

.btn-pink:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #be185d,
    0 3px 8px rgba(236, 72, 153, 0.3);
}

/* Cyan Button - 3D */
.btn-cyan {
  background: linear-gradient(180deg, #06b6d4 0%, #0891b2 100%);
  color: white;
  box-shadow: 
    0 4px 0 #0e7490,
    0 6px 12px rgba(6, 182, 212, 0.35);
}

.btn-cyan:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 6px 0 #0e7490,
    0 10px 20px rgba(6, 182, 212, 0.4);
}

.btn-cyan:active {
  transform: translateY(2px);
  box-shadow: 
    0 2px 0 #0e7490,
    0 3px 8px rgba(6, 182, 212, 0.3);
}

/* Small Buttons */
.btn-sm {
  padding: 8px 16px;
  font-size: 12px;
  border-radius: 10px;
}

.btn-sm.btn-primary,
.btn-sm.btn-success,
.btn-sm.btn-purple,
.btn-sm.btn-orange,
.btn-sm.btn-pink,
.btn-sm.btn-cyan {
  box-shadow: 
    0 3px 0 currentColor,
    0 4px 8px rgba(0, 0, 0, 0.2);
}

.btn-sm.btn-primary { box-shadow: 0 3px 0 #1d4ed8, 0 4px 8px rgba(37, 99, 235, 0.3); }
.btn-sm.btn-success { box-shadow: 0 3px 0 #15803d, 0 4px 8px rgba(22, 163, 74, 0.3); }
.btn-sm.btn-secondary { box-shadow: 0 3px 0 #d1d5db, 0 4px 8px rgba(0, 0, 0, 0.08); }

/* Large Buttons */
.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
  border-radius: 14px;
}

.btn-lg.btn-primary { box-shadow: 0 5px 0 #1d4ed8, 0 8px 16px rgba(37, 99, 235, 0.35); }
.btn-lg.btn-success { box-shadow: 0 5px 0 #15803d, 0 8px 16px rgba(22, 163, 74, 0.35); }
.btn-lg.btn-secondary { box-shadow: 0 5px 0 #d1d5db, 0 8px 16px rgba(0, 0, 0, 0.1); }

/* ═══════════════════════════════════════════════════════════════
   COLORFUL ACCENTS - Decorative Elements
   ═══════════════════════════════════════════════════════════════ */

/* Colorful Cards */
.card-blue { border-left: 4px solid var(--blue); }
.card-green { border-left: 4px solid var(--green); }
.card-purple { border-left: 4px solid var(--purple); }
.card-orange { border-left: 4px solid var(--orange); }
.card-pink { border-left: 4px solid var(--pink); }
.card-cyan { border-left: 4px solid var(--cyan); }

/* Gradient text */
.text-gradient {
  background: linear-gradient(135deg, var(--blue) 0%, var(--purple) 50%, var(--pink) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Colorful badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
}

.badge-blue { background: #dbeafe; color: #1d4ed8; }
.badge-green { background: #dcfce7; color: #15803d; }
.badge-purple { background: #f3e8ff; color: #7c3aed; }
.badge-orange { background: #ffedd5; color: #c2410c; }
.badge-pink { background: #fce7f3; color: #be185d; }
.badge-cyan { background: #cffafe; color: #0e7490; }
.badge-amber { background: #fef3c7; color: #b45309; }

/* ═══ NAVIGATION - Subtle Aurora ═══ */
#navbar {
  background: linear-gradient(90deg, 
    rgba(252,231,243,0.5) 0%,
    rgba(254,243,199,0.5) 25%,
    rgba(220,252,231,0.5) 50%,
    rgba(224,242,254,0.5) 75%,
    rgba(243,232,255,0.5) 100%
  );
  backdrop-filter: saturate(120%) blur(20px);
  -webkit-backdrop-filter: saturate(120%) blur(20px);
  position: sticky;
  top: 0;
  z-index: 9999;
  border-bottom: 1px solid rgba(0,0,0,0.05);
  animation: aurora 15s ease infinite;
  background-size: 300% 100%;
}

@keyframes aurora {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

#navbar .container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.nav-section { display: contents; }
.nav-section.main-nav { display: contents; }

.nav-btn {
  background: transparent;
  border: none;
  border-radius: 6px;
  color: #1d1d1f;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  padding: 6px 12px;
  font-family: inherit;
  transition: all 0.15s ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.nav-btn:hover {
  background: rgba(0,0,0,0.05);
}

/* Home/Hub button */
.hub-btn, .nav-btn[onclick*="Hub"] {
  color: #6e6e73;
}

/* Python course button */
.python-btn, .nav-btn[onclick*="Python"] {
  color: #6e6e73;
}

/* Active/current page */
.nav-btn.active, .nav-btn[style*="opacity: 1"] {
  background: rgba(0,0,0,0.06);
  font-weight: 600;
}

/* ═══ Progress - barely visible ═══ */
.progress-container {
  padding: 6px 16px;
  background: var(--white);
}

.progress-bar {
  height: 1px;
  background: var(--blue);
  width: 0%;
}

.progress-text {
  font-size: 10px;
  color: var(--gray-500);
  text-align: center;
  margin-top: 2px;
}

/* ═══ Content ═══ */
main, main.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 32px 20px 60px;
  padding-top: 80px; /* Space for sticky nav */
}

/* Offset for sticky header on all pages */
body {
  padding-top: 0;
}

/* Section scroll offset */
section[id], div[id] {
  scroll-margin-top: 60px;
}

.content-section { display: none; }
.content-section.active { display: block; }

/* ═══ Typography ═══ */
.content-section h2 {
  font-size: 28px;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: 16px;
}

.content-section h3 {
  font-size: 19px;
  font-weight: 600;
  margin: 24px 0 10px;
}

.content-section h4 {
  font-size: 16px;
  font-weight: 600;
  margin: 20px 0 8px;
}

p {
  font-size: 14px;
  color: var(--gray-600);
  margin-bottom: 12px;
  line-height: 1.6;
}

/* ═══ Cards ═══ */
.welcome-card, .lesson-card {
  background: var(--white);
  padding: 20px;
  margin: 16px 0;
  border-radius: 12px;
  border: 1px solid rgba(0,0,0,0.06);
}

.lesson-card h3 { margin-top: 0; font-size: 17px; }

.feature-list { list-style: none; }
.feature-list li {
  padding: 8px 0;
  font-size: 13px;
  color: var(--gray-600);
  border-bottom: 1px solid var(--gray-100);
}
.feature-list li:last-child { border: none; }

/* ═══ Code ═══ */
pre {
  background: var(--gray-100) !important;
  padding: 16px;
  border-radius: 8px;
  margin: 16px 0;
  overflow-x: auto;
}

pre code {
  font-family: 'SF Mono', Menlo, monospace !important;
  font-size: 13px !important;
  color: var(--gray-900) !important;
  background: none !important;
  line-height: 1.5;
}

code {
  font-family: 'SF Mono', Menlo, monospace !important;
  background: var(--gray-100) !important;
  padding: 2px 5px;
  border-radius: 4px;
  font-size: 13px;
  color: var(--gray-900) !important;
}

pre code { padding: 0 !important; }

/* ═══ Code & terminal blocks: always high-contrast readable (site-wide) ═══ */
.code-block,
.terminal-mock {
  background: #0f172a !important;
  color: #f8fafc !important;
  padding: 16px 20px !important;
  border-radius: 12px !important;
  font-family: 'Fira Code', 'SF Mono', Menlo, monospace !important;
  font-size: 0.95em !important;
  font-weight: 500 !important;
  border: 1px solid #334155 !important;
}
.code-block pre,
.code-block code,
.terminal-mock pre,
.terminal-mock code,
.code-block *,
.terminal-mock * {
  background: transparent !important;
  color: #f8fafc !important;
  margin: 0 !important;
  border: none !important;
}
.terminal-mock .prompt { color: #22c55e !important; font-weight: 600 !important; }
.terminal-mock .output { color: #e2e8f0 !important; }

/* Copy button on code blocks (top right) */
.code-block, .terminal-mock, .fkti-pre-wrap { position: relative !important; }
.fkti-copy-btn {
  position: absolute !important;
  top: 10px !important;
  right: 10px !important;
  width: 36px !important;
  height: 36px !important;
  padding: 0 !important;
  border: none !important;
  border-radius: 8px !important;
  background: rgba(255,255,255,0.15) !important;
  color: #f8fafc !important;
  cursor: pointer !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  font-size: 14px !important;
  z-index: 5 !important;
  transition: background 0.2s, color 0.2s !important;
}
.fkti-copy-btn:hover { background: rgba(255,255,255,0.3) !important; color: #fff !important; }
.fkti-copy-btn.fkti-copy-done { background: #22c55e !important; color: #fff !important; }
.fkti-pre-wrap { background: #0f172a !important; padding: 16px 20px !important; border-radius: 12px !important; margin: 16px 0 !important; }
.fkti-pre-wrap pre { background: transparent !important; margin: 0 !important; color: #f8fafc !important; }

.hljs-comment { color: var(--gray-500) !important; }
.hljs-keyword { color: #a626a4 !important; }
.hljs-string { color: #50a14f !important; }
.hljs-number { color: #986801 !important; }
.hljs-function, .hljs-title { color: #4078f2 !important; }

/* ═══ Info boxes ═══ */
.explanation, .tip-box, .warning-box, .insight-box {
  padding: 14px 16px;
  margin: 16px 0;
  border-radius: 8px;
  font-size: 13px;
}

.explanation { background: #f0f7ff; }
.tip-box { background: #f0fff4; }
.warning-box { background: #fff5f5; }
.insight-box { background: #fffaf0; }

/* ═══ Buttons ═══ */
.start-btn, .next-btn, .section-quiz-btn, .final-quiz-btn, .check-quiz-btn, .download-btn {
  background: var(--blue);
  color: white;
  border: none;
  padding: 8px 16px;
  font-size: 14px;
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
}

.next-section { text-align: center; margin: 32px 0; }
.section-quiz-btn, .final-quiz-btn { margin: 16px auto; display: block; }
.check-quiz-btn { font-size: 12px; padding: 6px 12px; margin-top: 10px; }

.interactive-box {
  background: var(--gray-100);
  padding: 24px;
  margin: 24px 0;
  border-radius: 12px;
  text-align: center;
}

/* ═══ Quiz ═══ */
.subsection-quiz {
  background: var(--gray-100);
  padding: 20px;
  margin: 20px 0;
  border-radius: 12px;
}

.subsection-quiz h4 { margin: 0 0 12px; font-size: 16px; }

.quiz-option {
  display: block;
  padding: 10px 12px;
  margin: 6px 0;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
}

.quiz-option:hover { border-color: var(--blue); }
.quiz-option input { margin-right: 8px; }

.quiz-feedback { margin-top: 12px; padding: 10px; border-radius: 6px; font-size: 13px; }
.quiz-feedback-correct { background: #f0fff4; }
.quiz-feedback-incorrect { background: #fff5f5; }

/* ═══ Exercises ═══ */
.exercise-card {
  padding: 20px;
  margin: 16px 0;
  border-radius: 12px;
  background: var(--white);
  border: 1px solid rgba(0,0,0,0.06);
}

.exercise-card.beginner { border-left: 3px solid #34c759; }
.exercise-card.intermediate { border-left: 3px solid #ff9500; }
.exercise-card.advanced { border-left: 3px solid #ff3b30; }

.exercise-card h3 { font-size: 16px; margin: 0 0 10px; }

.exercise {
  background: var(--gray-100);
  padding: 16px;
  margin: 10px 0;
  border-radius: 8px;
}

.exercise h4 { margin: 0 0 6px; font-size: 14px; }

details { margin-top: 12px; }
summary {
  background: var(--gray-900);
  color: white;
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
  display: inline-block;
}

/* ═══ Completion ═══ */
.completion-box {
  background: var(--gray-900);
  color: white;
  padding: 32px;
  margin: 24px 0;
  border-radius: 12px;
  text-align: center;
}

.completion-box h3 { font-size: 22px; margin-bottom: 8px; color: white; }
.completion-box p { color: rgba(255,255,255,0.7); }

/* ═══ Timeline ═══ */
.learning-path {
  margin: 24px 0;
  padding: 20px;
  background: var(--white);
  border-radius: 12px;
  border: 1px solid rgba(0,0,0,0.06);
}

.learning-path h3 { text-align: center; margin-bottom: 16px; font-size: 17px; }

.timeline { display: grid; gap: 8px; }

.timeline-item {
  background: var(--gray-100);
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 13px;
}

/* ═══ Checkbox ═══ */
.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 16px 0;
  font-size: 13px;
  cursor: pointer;
  padding: 10px;
  background: var(--gray-100);
  border-radius: 6px;
}

.checkbox-label input { width: 16px; height: 16px; }

/* ═══ Modal ═══ */
.modal {
  display: none;
  position: fixed;
  z-index: 10000;
  left: 0; top: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.3);
  backdrop-filter: blur(4px);
}

.modal-content {
  background: var(--white);
  margin: 5% auto;
  width: 90%;
  max-width: 560px;
  border-radius: 12px;
  max-height: 85vh;
  overflow-y: auto;
}

.close { float: right; font-size: 20px; padding: 12px 16px; cursor: pointer; color: var(--gray-500); }

/* ═══ Certificate ═══ */
.certificate { text-align: center; padding: 32px; }
.certificate h1 { font-size: 24px; margin-bottom: 6px; }
.certificate h2 { font-size: 18px; color: var(--gray-600); font-weight: 400; }
.cert-text { font-size: 14px; color: var(--gray-600); }
.cert-input {
  font-size: 18px;
  padding: 10px 16px;
  margin: 16px 0;
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  text-align: center;
  width: 80%;
  font-family: inherit;
}

/* ═══ Footer ═══ */
footer {
  background: var(--gray-100);
  padding: 16px;
  text-align: center;
  font-size: 11px;
  color: var(--gray-500);
}

.footer-content { display: flex; align-items: center; justify-content: center; gap: 8px; }
.footer-logo { width: 20px; height: 20px; opacity: 0.5; }
.footer-text h3 { font-size: 11px; color: var(--gray-600); }
.footer-text p { font-size: 10px; margin: 0; }

/* ═══ Stats ═══ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 20px 0;
}

.stat-item {
  text-align: center;
  padding: 16px;
  background: var(--white);
  border-radius: 8px;
  border: 1px solid rgba(0,0,0,0.06);
}

.stat-item h5 { font-size: 24px; margin-bottom: 2px; }
.stat-item p { font-size: 11px; color: var(--gray-500); margin: 0; }

.case-study {
  background: var(--gray-100);
  padding: 16px;
  margin: 12px 0;
  border-radius: 8px;
  font-size: 13px;
}

.case-study h5 { font-size: 14px; margin-bottom: 6px; }

/* ═══ Mobile ═══ */
@media (max-width: 600px) {
  #navbar .container { height: 40px; gap: 12px; padding: 0 12px; }
  .nav-btn { font-size: 10px; }
  main.container { padding: 20px 16px 40px; }
  .content-section h2 { font-size: 22px; }
  .welcome-card, .lesson-card { padding: 16px; }
  .stats-grid { grid-template-columns: 1fr; }
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-thumb { background: var(--gray-200); border-radius: 3px; }

@media print {
  #navbar, .progress-container, footer { display: none !important; }
  .content-section { display: block !important; }
}

/* Back to Top Button - Global */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(180deg, var(--primary-blue, #3b82f6) 0%, var(--primary-dark, #2563eb) 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    z-index: 1000;
    box-shadow: 0 4px 0 #1d4ed8, 0 6px 12px rgba(37, 99, 235, 0.35);
    transition: all 0.3s ease;
    opacity: 0;
    transform: translateY(20px);
}

.back-to-top.show {
    display: flex;
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 0 #1d4ed8, 0 10px 20px rgba(37, 99, 235, 0.4);
}

.back-to-top:active {
    transform: translateY(2px);
    box-shadow: 0 2px 0 #1d4ed8, 0 3px 8px rgba(37, 99, 235, 0.3);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 18px;
    }
}