/* BCA 8th Sem Exam Preparation Engine - Modern Professional Dark Theme */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700&family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Outfit:wght@500;600;700;800&display=swap');

:root {
  --bg-dark: #090d16;
  --bg-surface: #0f172a;
  --bg-card: rgba(30, 41, 59, 0.7);
  --bg-card-hover: rgba(51, 65, 85, 0.8);
  --border-slate: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(56, 189, 248, 0.3);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  
  --or-primary: #f43f5e;
  --or-glow: rgba(244, 63, 94, 0.2);
  
  --da-primary: #38bdf8;
  --da-glow: rgba(56, 189, 248, 0.2);
  
  --iot-primary: #10b981;
  --iot-glow: rgba(16, 185, 129, 0.2);

  --accent-indigo: #6366f1;
  --accent-violet: #8b5cf6;
}

body {
  font-family: 'Plus Jakarta Sans', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  min-height: 100vh;
  overflow-x: hidden;
  background-image: 
    radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.08) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(56, 189, 248, 0.06) 0px, transparent 50%);
}

h1, h2, h3, h4, .font-heading {
  font-family: 'Outfit', sans-serif;
}

code, pre, .font-code {
  font-family: 'JetBrains Mono', monospace;
}

/* Glassmorphism components */
.glass-panel {
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-slate);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.glass-nav {
  background: rgba(9, 13, 22, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

/* Course Theme Cards & Glows */
.course-card-active {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.9), rgba(15, 23, 42, 0.95)) !important;
  border-color: rgba(99, 102, 241, 0.5) !important;
  box-shadow: 0 4px 25px -2px rgba(99, 102, 241, 0.25) !important;
}

.course-or {
  border-color: rgba(244, 63, 94, 0.4);
  box-shadow: 0 4px 20px -2px var(--or-glow);
}

.course-da {
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: 0 4px 20px -2px var(--da-glow);
}

.course-iot {
  border-color: rgba(16, 185, 129, 0.4);
  box-shadow: 0 4px 20px -2px var(--iot-glow);
}

/* Formula Pop-out Cards */
.formula-card {
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  background: linear-gradient(145deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.9));
  position: relative;
  overflow: hidden;
}

.formula-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(to bottom, #6366f1, #38bdf8);
}

.formula-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px -5px rgba(99, 102, 241, 0.25);
  border-color: rgba(99, 102, 241, 0.5);
}

/* KaTeX custom sizing & color override */
.katex-display {
  margin: 0.6em 0 !important;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.5rem 0;
}

.katex {
  font-size: 1.08em;
  color: #f1f5f9 !important;
}

/* Step-by-Step Solver Animations */
.step-card {
  transition: all 0.4s ease-in-out;
  opacity: 0;
  transform: translateY(12px);
}

.step-card.active {
  opacity: 1;
  transform: translateY(0);
}

/* Custom Scrollbars */
::-webkit-scrollbar {
  width: 7px;
  height: 7px;
}

::-webkit-scrollbar-track {
  background: #090d16;
}

::-webkit-scrollbar-thumb {
  background: #334155;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #475569;
}

/* Quiz Engine Styling */
.quiz-option {
  transition: all 0.2s ease;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.quiz-option:hover:not(.disabled) {
  border-color: #38bdf8;
  background-color: rgba(56, 189, 248, 0.1);
}

.quiz-option.correct {
  border-color: #10b981 !important;
  background-color: rgba(16, 185, 129, 0.2) !important;
  color: #a7f3d0 !important;
}

.quiz-option.incorrect {
  border-color: #f43f5e !important;
  background-color: rgba(244, 63, 94, 0.2) !important;
  color: #fecdd3 !important;
}

/* Audio Player Bar */
.audio-bar {
  background: rgba(15, 23, 42, 0.95);
  border-top: 1px solid rgba(99, 102, 241, 0.3);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.5);
}

/* Code Sandbox Highlight */
.code-wrapper {
  position: relative;
  background: #030712;
  border-radius: 0.75rem;
  border: 1px solid #1e293b;
}

.code-wrapper pre {
  padding: 1.25rem;
  overflow-x: auto;
}

/* Chatbot Floating Drawer & Widget Styles */
#chatbot-drawer {
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
}

#chatbot-drawer.hidden-drawer {
  transform: translateY(100%) scale(0.95);
  opacity: 0;
  pointer-events: none;
}

.chat-bubble-user {
  background: linear-gradient(135deg, #4f46e5, #6366f1);
  color: #ffffff;
  border-radius: 1rem 1rem 0.2rem 1rem;
}

.chat-bubble-bot {
  background: rgba(30, 41, 59, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: #f1f5f9;
  border-radius: 1rem 1rem 1rem 0.2rem;
}

.chip-btn {
  background: rgba(30, 41, 59, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.2s ease;
}

.chip-btn:hover {
  background: rgba(99, 102, 241, 0.25);
  border-color: rgba(99, 102, 241, 0.6);
  color: #38bdf8;
}

/* High-frequency TU Badge */
.tu-hot-badge {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.2), rgba(217, 119, 6, 0.3));
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.5);
}

/* Responsive tweaks */
@media (max-width: 640px) {
  .katex {
    font-size: 0.92em;
  }
}