/* ==========================================================================
   YouTube Comment History Finder Stylesheet
   Design Paradigm: Ultra-Premium Minimalist Glassmorphism (Dark Mode)
   ========================================================================== */

/* 1. Global Setup & Design Tokens */
:root {
  /* Color System (Monochrome & Premium Gray Palette) */
  --bg-dark: hsl(0, 0%, 4%);
  --bg-dark-accent: hsl(0, 0%, 8%);
  
  --glass-bg: hsla(0, 0%, 10%, 0.65);
  --glass-border: hsla(0, 0%, 25%, 0.3);
  --glass-border-hover: hsla(0, 0%, 50%, 0.4);
  
  --primary-accent: hsl(0, 0%, 98%);       /* Premium Silver/White */
  --primary-accent-glow: hsla(0, 0%, 100%, 0.04);
  --secondary-accent: hsl(0, 0%, 80%);    /* Elegant Medium Gray */
  --secondary-accent-glow: hsla(0, 0%, 100%, 0.04);
  
  --text-primary: hsl(0, 0%, 98%);
  --text-muted: hsl(0, 0%, 75%);
  --text-dark: hsl(0, 0%, 50%);

  /* Layout Variables */
  --container-width: 1040px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 8px;
  
  /* Fonts */
  --font-headers: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Timing Functions */
  --transition-bezier: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: all 0.4s var(--transition-bezier);
}

/* 2. Base Resets & Document Configuration */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  position: relative;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 3. Typography & Utility Classes */
h1, h2, h3, h4 {
  font-family: var(--font-headers);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

p {
  color: var(--text-muted);
}

a {
  color: var(--primary-accent);
  text-decoration: none;
  transition: var(--transition-smooth);
}

a:hover {
  filter: brightness(0.85);
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* 4. Decorative Background Glow Orbs */
.glow-orb {
  position: absolute;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  z-index: -1;
  pointer-events: none;
  opacity: 0.6;
}

.orb-primary {
  background: radial-gradient(circle, var(--primary-accent-glow) 0%, transparent 70%);
  top: -200px;
  right: -100px;
}

.orb-secondary {
  background: radial-gradient(circle, var(--secondary-accent-glow) 0%, transparent 70%);
  bottom: 200px;
  left: -200px;
}

/* 5. Header Component */
.app-header {
  padding: 24px 0;
  border-bottom: 1px solid var(--glass-border);
  backdrop-filter: blur(20px);
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: hsla(0, 0%, 4%, 0.8);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  color: var(--primary-accent);
  filter: drop-shadow(0 0 8px var(--primary-accent-glow));
}

.brand-name {
  font-family: var(--font-headers);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

.github-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background-color: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 50px;
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.github-badge:hover {
  border-color: var(--text-muted);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.github-icon {
  width: 18px;
  height: 18px;
}

/* 6. Hero Section & Fast-Track Utility Card */
.hero-section {
  padding: 80px 0 60px 0;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.gradient-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
  background: linear-gradient(135deg, var(--text-primary) 30%, hsl(0, 0%, 60%) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-title .highlight {
  position: relative;
  background: linear-gradient(135deg, hsl(0, 0%, 100%) 0%, hsl(0, 0%, 70%) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 1.2rem;
  max-width: 680px;
  margin-bottom: 48px;
  line-height: 1.7;
}

/* Universal Glassmorphism Card Style */
.glass-card {
  background-color: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-radius: var(--radius-lg);
  transition: var(--transition-smooth);
}

.glass-card:hover {
  border-color: var(--glass-border-hover);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5), 0 0 20px rgba(255, 255, 255, 0.03);
  transform: translateY(-2px);
}

/* Fast-Track Card Specifics */
.fast-track-card {
  max-width: 720px;
  padding: 48px;
  text-align: center;
  position: relative;
  margin-top: 12px;
  margin-bottom: 50px;
}

.card-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, hsl(0, 0%, 20%) 0%, hsl(0, 0%, 10%) 100%);
  border: 1px solid hsla(0, 0%, 100%, 0.15);
  color: hsl(0, 0%, 90%);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  padding: 6px 16px;
  border-radius: 50px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.fast-track-card h2 {
  font-size: 1.75rem;
  margin-bottom: 16px;
}

.fast-track-card p {
  font-size: 1rem;
  margin-bottom: 36px;
  line-height: 1.6;
}

/* Hero Embedded Brand Image Section */
.hero-image-container {
  margin-top: 50px;
  width: 100%;
  max-width: 640px;
  padding: 8px;
  background-color: hsla(0, 0%, 10%, 0.45);
  border: 1px solid hsla(0, 0%, 25%, 0.3);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), 0 0 30px rgba(255, 255, 255, 0.02);
  display: flex;
  justify-content: center;
  align-items: center;
  transition: var(--transition-smooth);
}

.hero-image-container:hover {
  border-color: hsla(0, 0%, 50%, 0.4);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.6), 0 0 40px rgba(255, 255, 255, 0.04);
  transform: translateY(-2px);
}

.hero-brand-image {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: calc(var(--radius-lg) - 8px);
  border: 1px solid hsla(0, 0%, 100%, 0.05);
  display: block;
}

/* Premium Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 16px 36px;
  border-radius: var(--radius-md);
  font-family: var(--font-headers);
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  transition: var(--transition-smooth);
  border: none;
  position: relative;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
}

.btn-primary {
  background: linear-gradient(135deg, hsl(0, 0%, 96%) 0%, hsl(0, 0%, 80%) 100%);
  color: hsl(0, 0%, 4%);
  border: 1px solid hsla(0, 0%, 100%, 0.8);
}

.btn:hover {
  transform: scale(1.03);
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.08), 0 0 15px rgba(255, 255, 255, 0.03);
  filter: brightness(1.05);
}

.btn-arrow {
  width: 18px;
  height: 18px;
  transition: var(--transition-smooth);
}

.btn:hover .btn-arrow {
  transform: translateX(5px);
}

.safe-note {
  display: block;
  font-size: 0.75rem;
  color: var(--text-dark);
  margin-top: 18px;
}

/* 7. Interactive Guide / Tab Section */
.guide-section {
  padding: 60px 0;
  border-top: 1px solid var(--glass-border);
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 2.25rem;
  margin-bottom: 12px;
}

.section-header p {
  max-width: 580px;
  margin: 0 auto;
}

/* Platform Switch Tabs */
.tabs-container {
  display: flex;
  justify-content: center;
  margin-bottom: 32px;
}

.tabs-list {
  background-color: var(--bg-dark-accent);
  padding: 6px;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
  display: flex;
  gap: 4px;
}

.tab-button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-headers);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.tab-button.active {
  background-color: hsl(0, 0%, 96%);
  color: hsl(0, 0%, 4%);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  border: 1px solid hsla(0, 0%, 100%, 0.15);
}

.tab-button:not(.active):hover {
  color: var(--text-primary);
  background-color: rgba(255, 255, 255, 0.05);
}

.tab-icon {
  width: 18px;
  height: 18px;
}

/* Custom Step List inside Glass Card */
.guide-card {
  padding: 48px;
  max-width: 860px;
  margin: 0 auto;
}

.guide-panel {
  display: none;
  animation: fadeIn 0.4s var(--transition-bezier) forwards;
}

.guide-panel.active {
  display: block;
}

.guide-panel h3 {
  font-size: 1.5rem;
  margin-bottom: 32px;
  position: relative;
  display: inline-block;
}

.guide-panel h3::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 40px;
  height: 3px;
  background-color: hsl(0, 0%, 75%);
  border-radius: 5px;
}

.step-list {
  list-style: none;
  display: grid;
  gap: 32px;
}

.step-item {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.step-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-dark-accent);
  border: 1px solid var(--glass-border);
  color: var(--primary-accent);
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: 800;
  font-family: var(--font-headers);
  flex-shrink: 0;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.step-content h4 {
  font-size: 1.15rem;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.step-content p {
  font-size: 0.95rem;
  line-height: 1.6;
}

.step-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* Image Placeholder styling */
.step-placeholder-box {
  margin-top: 40px;
  padding: 36px;
  border: 1.5px dashed var(--glass-border);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
  background-color: rgba(255, 255, 255, 0.01);
  color: var(--text-dark);
}

.box-icon {
  width: 40px;
  height: 40px;
}

.step-placeholder-box span {
  font-size: 0.875rem;
  max-width: 320px;
}

/* 8. FAQ Components */
.faq-section {
  padding: 60px 0 100px 0;
  border-top: 1px solid var(--glass-border);
}

.faq-container {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  border-radius: var(--radius-md) !important;
}

.faq-trigger {
  width: 100%;
  padding: 24px;
  background: transparent;
  border: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  text-align: left;
  color: var(--text-primary);
  font-family: var(--font-headers);
  font-weight: 600;
  font-size: 1.1rem;
}

.faq-trigger span {
  padding-right: 24px;
}

.faq-arrow {
  width: 18px;
  height: 18px;
  color: var(--text-muted);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  flex-shrink: 0;
}

.faq-item.active {
  border-color: var(--glass-border-hover);
}

.faq-item.active .faq-arrow {
  transform: rotate(180deg);
  color: var(--primary-accent);
}

.faq-answer {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  padding: 0 24px;
  transition: all 0.4s var(--transition-bezier);
}

.faq-answer p {
  padding-bottom: 24px;
  font-size: 0.95rem;
  line-height: 1.6;
  border-top: 1px solid rgba(255, 255, 255, 0.03);
  padding-top: 16px;
}

/* 9. Footer Component */
.app-footer {
  margin-top: auto;
  padding: 40px 0;
  border-top: 1px solid var(--glass-border);
  background-color: var(--bg-dark-accent);
  font-size: 0.875rem;
  color: var(--text-dark);
}

.footer-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-muted);
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--primary-accent);
}

/* 10. Keyframes & Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 11. Responsive Layout & Media Queries */
@media (max-width: 768px) {
  .gradient-title {
    font-size: 2.5rem;
  }
  
  .hero-lead {
    font-size: 1.05rem;
    margin-bottom: 36px;
  }
  
  .fast-track-card {
    padding: 32px 24px;
  }
  
  .fast-track-card h2 {
    font-size: 1.4rem;
  }
  
  .btn {
    padding: 14px 28px;
    font-size: 0.95rem;
    width: 100%;
    justify-content: center;
  }
  
  .hero-image-container {
    margin-top: 50px;
    padding: 6px;
  }
  
  .guide-card {
    padding: 24px;
  }
  
  .tab-button {
    padding: 10px 16px;
    font-size: 0.875rem;
  }
  
  .faq-trigger {
    padding: 18px;
    font-size: 1rem;
  }
  
  .faq-answer {
    padding: 0 18px;
  }
  
  .faq-answer p {
    padding-bottom: 18px;
  }
  
  .footer-container {
    flex-direction: column;
    gap: 20px;
  }
}