/* styles.css - Modern Industrial Design System for Zirconia vs Glass Beads Comparison */

:root {
  /* Colors - Modern Industrial Palette (Navy, Slate, Crisp Accents) */
  --primary-deep: #0B192C;      /* Very Dark Blue / Industrial Dark */
  --primary-mid: #1E3E62;       /* Slate Steel Blue */
  --primary-accent: #008DDA;    /* High-contrast Electric Blue */
  --primary-light: #41C9E2;     /* Ice Blue Accent */
  
  --neutral-dark: #000000;
  --neutral-charcoal: #1E293B;  /* Slate Charcoal */
  --neutral-slate: #475569;     /* Gray Label Text */
  --neutral-light: #F8FAFC;     /* Background Off-white */
  --neutral-white: #FFFFFF;
  --border-color: #E2E8F0;      /* Light border */
  --border-focus: #008DDA;
  
  /* Status Colors */
  --zirconia-color: #008DDA;    /* Representing premium high performance */
  --glass-color: #64748B;       /* Representing economical standard */
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* Layout Spacing & Borders */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.02);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -1px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.03);
}

/* Base Reset & Typography */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--neutral-light);
}

body {
  font-family: var(--font-family);
  color: var(--neutral-charcoal);
  line-height: 1.65;
  background-color: var(--neutral-light);
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--primary-deep);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: 2.25rem;
  letter-spacing: -0.025em;
}

h2 {
  font-size: 1.75rem;
  margin-top: 2rem;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
}

h3 {
  font-size: 1.35rem;
  margin-top: 1.5rem;
}

p {
  margin-bottom: 1.25rem;
  color: var(--neutral-slate);
}

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

a:hover {
  color: var(--primary-mid);
}

ul, ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

/* App Header & Navigation */
.app-header {
  background-color: var(--primary-deep);
  color: var(--neutral-white);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: var(--shadow-md);
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--neutral-white);
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: -0.02em;
}

.logo-badge {
  background-color: var(--primary-accent);
  color: var(--neutral-white);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 900;
  text-transform: uppercase;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 1.25rem;
  margin-bottom: 0;
  padding-left: 0;
}

.nav-menu a {
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
  font-size: 0.925rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
}

.nav-menu a:hover, .nav-menu a.active {
  color: var(--neutral-white);
  background-color: rgba(255, 255, 255, 0.1);
}

.rfq-btn {
  background-color: var(--primary-accent);
  color: var(--neutral-white) !important;
  font-weight: 600;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-sm);
  transition: var(--transition-smooth);
}

.rfq-btn:hover {
  background-color: var(--primary-light);
  transform: translateY(-1px);
}

/* Master Layout Structure */
.layout-wrapper {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 2rem;
  padding: 2rem;
}

/* Sidebar Styling */
.sidebar-nav {
  background-color: var(--neutral-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.25rem;
  height: calc(100vh - 120px);
  position: sticky;
  top: 100px;
  overflow-y: auto;
  box-shadow: var(--shadow-sm);
}

.sidebar-title {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--neutral-slate);
  font-weight: 700;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-title:first-child {
  margin-top: 0;
}

.sidebar-links {
  list-style: none;
  padding-left: 0;
  margin-bottom: 0;
}

.sidebar-links a {
  display: block;
  color: var(--neutral-charcoal);
  font-size: 0.875rem;
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  font-weight: 500;
  transition: var(--transition-smooth);
}

.sidebar-links a:hover, .sidebar-links a.active {
  background-color: var(--neutral-light);
  color: var(--primary-accent);
  padding-left: 1rem;
}

/* Main Content Panel */
.content-main {
  background-color: var(--neutral-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  min-height: 80vh;
}

/* Homepage Hero Section */
.hero-block {
  background: linear-gradient(135deg, var(--primary-deep) 0%, var(--primary-mid) 100%);
  color: var(--neutral-white);
  padding: 3rem;
  border-radius: var(--radius-lg);
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.hero-block::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(0, 141, 218, 0.15) 0%, transparent 70%);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero-block h1 {
  color: var(--neutral-white);
  font-size: 2.75rem;
  line-height: 1.15;
  margin-bottom: 1rem;
}

.hero-block p {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1.15rem;
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition-smooth);
  border: none;
}

.btn-primary {
  background-color: var(--primary-accent);
  color: var(--neutral-white);
}

.btn-primary:hover {
  background-color: var(--primary-light);
  color: var(--primary-deep);
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: rgba(255, 255, 255, 0.15);
  color: var(--neutral-white);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
}

/* Card & Grids */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.card {
  background-color: var(--neutral-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-accent);
}

.card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.card-icon {
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background-color: rgba(0, 141, 218, 0.1);
  color: var(--primary-accent);
}

/* Comparison Tables */
.table-container {
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-sm);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.925rem;
}

th {
  background-color: var(--primary-deep);
  color: var(--neutral-white);
  font-weight: 600;
  padding: 1rem 1.25rem;
}

td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--neutral-charcoal);
}

tr:last-child td {
  border-bottom: none;
}

tr:nth-child(even) td {
  background-color: var(--neutral-light);
}

/* Comparison specific table classes */
.highlight-zirconia {
  font-weight: 700;
  color: var(--primary-mid);
  background-color: rgba(0, 141, 218, 0.04) !important;
}

.highlight-glass {
  font-weight: 700;
  color: var(--neutral-slate);
  background-color: rgba(100, 116, 139, 0.04) !important;
}

/* Engineering Tools Layout */
.tool-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 3rem;
  background-color: var(--neutral-light);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

@media (max-width: 992px) {
  .tool-grid {
    grid-template-columns: 1fr;
  }
}

.tool-controls {
  background-color: var(--neutral-white);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.tool-outputs {
  background-color: var(--primary-deep);
  color: var(--neutral-white);
  padding: 2rem;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.tool-outputs h3 {
  color: var(--neutral-white);
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  padding-bottom: 0.5rem;
  margin-top: 0;
}

.tool-outputs p {
  color: rgba(255, 255, 255, 0.8);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--neutral-charcoal);
}

.form-control {
  width: 100%;
  padding: 0.65rem 0.85rem;
  font-size: 0.95rem;
  font-family: inherit;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--neutral-white);
  transition: var(--transition-smooth);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(0, 141, 218, 0.15);
}

.output-value {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--primary-light);
  line-height: 1.2;
  margin: 1rem 0;
}

/* Call To Action Banner */
.cta-banner {
  background: radial-gradient(circle at top right, var(--primary-mid), var(--primary-deep));
  color: var(--neutral-white);
  padding: 3rem;
  border-radius: var(--radius-lg);
  text-align: center;
  margin: 3rem 0;
  box-shadow: var(--shadow-lg);
}

.cta-banner h2 {
  color: var(--neutral-white);
  border-bottom: none;
  margin-top: 0;
  font-size: 2rem;
}

.cta-banner p {
  color: rgba(255, 255, 255, 0.85);
  max-width: 600px;
  margin: 0 auto 2rem auto;
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* FAQ Accordion Styling */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: var(--neutral-white);
  overflow: hidden;
  transition: var(--transition-smooth);
}

.faq-question {
  padding: 1.25rem 1.5rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--neutral-white);
  user-select: none;
}

.faq-question:hover {
  background-color: var(--neutral-light);
}

.faq-question::after {
  content: '+';
  font-size: 1.25rem;
  color: var(--primary-accent);
  transition: var(--transition-smooth);
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  padding: 0 1.5rem;
  transition: max-height 0.25s ease-out;
  background-color: var(--neutral-white);
}

.faq-item.active .faq-answer {
  max-height: 500px; /* high value to permit expansion */
  padding: 0 1.5rem 1.5rem 1.5rem;
  border-top: 1px solid var(--border-color);
}

/* Decision Flowchart Interaction */
.flowchart-svg-container {
  background-color: var(--neutral-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 2.5rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.flowchart-step-btn {
  background-color: var(--neutral-light);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.5rem 1rem;
  margin: 0.25rem;
  cursor: pointer;
  font-weight: 600;
  transition: var(--transition-smooth);
}

.flowchart-step-btn.selected {
  background-color: var(--primary-accent);
  color: var(--neutral-white);
  border-color: var(--primary-accent);
}

/* Footer styling */
.app-footer {
  background-color: var(--primary-deep);
  color: var(--neutral-white);
  padding: 4rem 2rem 2rem 2rem;
  margin-top: 4rem;
  border-top: 4rem solid var(--primary-mid);
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
}

@media (max-width: 768px) {
  .footer-container {
    grid-template-columns: 1fr;
  }
}

.footer-logo {
  font-weight: 800;
  font-size: 1.4rem;
  margin-bottom: 1rem;
  display: block;
}

.footer-links-col h4 {
  color: var(--neutral-white);
  font-size: 1rem;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links-col ul {
  list-style: none;
  padding-left: 0;
}

.footer-links-col a {
  color: rgba(255, 255, 255, 0.75);
  display: block;
  padding: 0.25rem 0;
  font-size: 0.875rem;
}

.footer-links-col a:hover {
  color: var(--neutral-white);
  padding-left: 0.25rem;
}

.footer-bottom {
  max-width: 1400px;
  margin: 3rem auto 0 auto;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.5);
}

/* Router Routing & SPA Section Visibility */
.route-section {
  display: none;
}

.route-section.active {
  display: block;
}

/* Responsive Overrides */
@media (max-width: 1200px) {
  .layout-wrapper {
    grid-template-columns: 1fr;
  }
  .sidebar-nav {
    height: auto;
    position: static;
    margin-bottom: 2rem;
  }
}

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    gap: 1rem;
    align-items: stretch;
  }
  .main-nav {
    flex-direction: column;
    gap: 1rem;
  }
  .nav-menu {
    flex-direction: column;
    width: 100%;
    text-align: center;
  }
  .hero-block {
    padding: 2rem;
  }
  .hero-block h1 {
    font-size: 2rem;
  }
  .content-main {
    padding: 1.5rem;
  }
}